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bug: introduce BUILD_BUG_ON_INVALID() macro
[linux/fpc-iii.git] / drivers / spi / spi-pl022.c
blob400ae2121a2a48cd1c78469f0c727972b180a777
1 /*
2 * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
3 *
4 * Copyright (C) 2008-2009 ST-Ericsson AB
5 * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
6 *
7 * Author: Linus Walleij <linus.walleij@stericsson.com>
8 *
9 * Initial version inspired by:
10 * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
11 * Initial adoption to PL022 by:
12 * Sachin Verma <sachin.verma@st.com>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 */
24
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/ioport.h>
29 #include <linux/errno.h>
30 #include <linux/interrupt.h>
31 #include <linux/spi/spi.h>
32 #include <linux/delay.h>
33 #include <linux/clk.h>
34 #include <linux/err.h>
35 #include <linux/amba/bus.h>
36 #include <linux/amba/pl022.h>
37 #include <linux/io.h>
38 #include <linux/slab.h>
39 #include <linux/dmaengine.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/scatterlist.h>
42 #include <linux/pm_runtime.h>
43
44 /*
45 * This macro is used to define some register default values.
46 * reg is masked with mask, the OR:ed with an (again masked)
47 * val shifted sb steps to the left.
48 */
49 #define SSP_WRITE_BITS(reg, val, mask, sb) \
50 ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
51
52 /*
53 * This macro is also used to define some default values.
54 * It will just shift val by sb steps to the left and mask
55 * the result with mask.
56 */
57 #define GEN_MASK_BITS(val, mask, sb) \
58 (((val)<<(sb)) & (mask))
59
60 #define DRIVE_TX 0
61 #define DO_NOT_DRIVE_TX 1
62
63 #define DO_NOT_QUEUE_DMA 0
64 #define QUEUE_DMA 1
65
66 #define RX_TRANSFER 1
67 #define TX_TRANSFER 2
68
69 /*
70 * Macros to access SSP Registers with their offsets
71 */
72 #define SSP_CR0(r) (r + 0x000)
73 #define SSP_CR1(r) (r + 0x004)
74 #define SSP_DR(r) (r + 0x008)
75 #define SSP_SR(r) (r + 0x00C)
76 #define SSP_CPSR(r) (r + 0x010)
77 #define SSP_IMSC(r) (r + 0x014)
78 #define SSP_RIS(r) (r + 0x018)
79 #define SSP_MIS(r) (r + 0x01C)
80 #define SSP_ICR(r) (r + 0x020)
81 #define SSP_DMACR(r) (r + 0x024)
82 #define SSP_ITCR(r) (r + 0x080)
83 #define SSP_ITIP(r) (r + 0x084)
84 #define SSP_ITOP(r) (r + 0x088)
85 #define SSP_TDR(r) (r + 0x08C)
86
87 #define SSP_PID0(r) (r + 0xFE0)
88 #define SSP_PID1(r) (r + 0xFE4)
89 #define SSP_PID2(r) (r + 0xFE8)
90 #define SSP_PID3(r) (r + 0xFEC)
91
92 #define SSP_CID0(r) (r + 0xFF0)
93 #define SSP_CID1(r) (r + 0xFF4)
94 #define SSP_CID2(r) (r + 0xFF8)
95 #define SSP_CID3(r) (r + 0xFFC)
96
97 /*
98 * SSP Control Register 0 - SSP_CR0
99 */
100 #define SSP_CR0_MASK_DSS (0x0FUL << 0)
101 #define SSP_CR0_MASK_FRF (0x3UL << 4)
102 #define SSP_CR0_MASK_SPO (0x1UL << 6)
103 #define SSP_CR0_MASK_SPH (0x1UL << 7)
104 #define SSP_CR0_MASK_SCR (0xFFUL << 8)
105
106 /*
107 * The ST version of this block moves som bits
108 * in SSP_CR0 and extends it to 32 bits
109 */
110 #define SSP_CR0_MASK_DSS_ST (0x1FUL << 0)
111 #define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5)
112 #define SSP_CR0_MASK_CSS_ST (0x1FUL << 16)
113 #define SSP_CR0_MASK_FRF_ST (0x3UL << 21)
114
115 /*
116 * SSP Control Register 0 - SSP_CR1
117 */
118 #define SSP_CR1_MASK_LBM (0x1UL << 0)
119 #define SSP_CR1_MASK_SSE (0x1UL << 1)
120 #define SSP_CR1_MASK_MS (0x1UL << 2)
121 #define SSP_CR1_MASK_SOD (0x1UL << 3)
122
123 /*
124 * The ST version of this block adds some bits
125 * in SSP_CR1
126 */
127 #define SSP_CR1_MASK_RENDN_ST (0x1UL << 4)
128 #define SSP_CR1_MASK_TENDN_ST (0x1UL << 5)
129 #define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6)
130 #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
131 #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
132 /* This one is only in the PL023 variant */
133 #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
134
135 /*
136 * SSP Status Register - SSP_SR
137 */
138 #define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */
139 #define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */
140 #define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */
141 #define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */
142 #define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */
143
144 /*
145 * SSP Clock Prescale Register - SSP_CPSR
146 */
147 #define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0)
148
149 /*
150 * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
151 */
152 #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
153 #define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */
154 #define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */
155 #define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */
156
157 /*
158 * SSP Raw Interrupt Status Register - SSP_RIS
159 */
160 /* Receive Overrun Raw Interrupt status */
161 #define SSP_RIS_MASK_RORRIS (0x1UL << 0)
162 /* Receive Timeout Raw Interrupt status */
163 #define SSP_RIS_MASK_RTRIS (0x1UL << 1)
164 /* Receive FIFO Raw Interrupt status */
165 #define SSP_RIS_MASK_RXRIS (0x1UL << 2)
166 /* Transmit FIFO Raw Interrupt status */
167 #define SSP_RIS_MASK_TXRIS (0x1UL << 3)
168
169 /*
170 * SSP Masked Interrupt Status Register - SSP_MIS
171 */
172 /* Receive Overrun Masked Interrupt status */
173 #define SSP_MIS_MASK_RORMIS (0x1UL << 0)
174 /* Receive Timeout Masked Interrupt status */
175 #define SSP_MIS_MASK_RTMIS (0x1UL << 1)
176 /* Receive FIFO Masked Interrupt status */
177 #define SSP_MIS_MASK_RXMIS (0x1UL << 2)
178 /* Transmit FIFO Masked Interrupt status */
179 #define SSP_MIS_MASK_TXMIS (0x1UL << 3)
180
181 /*
182 * SSP Interrupt Clear Register - SSP_ICR
183 */
184 /* Receive Overrun Raw Clear Interrupt bit */
185 #define SSP_ICR_MASK_RORIC (0x1UL << 0)
186 /* Receive Timeout Clear Interrupt bit */
187 #define SSP_ICR_MASK_RTIC (0x1UL << 1)
188
189 /*
190 * SSP DMA Control Register - SSP_DMACR
191 */
192 /* Receive DMA Enable bit */
193 #define SSP_DMACR_MASK_RXDMAE (0x1UL << 0)
194 /* Transmit DMA Enable bit */
195 #define SSP_DMACR_MASK_TXDMAE (0x1UL << 1)
196
197 /*
198 * SSP Integration Test control Register - SSP_ITCR
199 */
200 #define SSP_ITCR_MASK_ITEN (0x1UL << 0)
201 #define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1)
202
203 /*
204 * SSP Integration Test Input Register - SSP_ITIP
205 */
206 #define ITIP_MASK_SSPRXD (0x1UL << 0)
207 #define ITIP_MASK_SSPFSSIN (0x1UL << 1)
208 #define ITIP_MASK_SSPCLKIN (0x1UL << 2)
209 #define ITIP_MASK_RXDMAC (0x1UL << 3)
210 #define ITIP_MASK_TXDMAC (0x1UL << 4)
211 #define ITIP_MASK_SSPTXDIN (0x1UL << 5)
212
213 /*
214 * SSP Integration Test output Register - SSP_ITOP
215 */
216 #define ITOP_MASK_SSPTXD (0x1UL << 0)
217 #define ITOP_MASK_SSPFSSOUT (0x1UL << 1)
218 #define ITOP_MASK_SSPCLKOUT (0x1UL << 2)
219 #define ITOP_MASK_SSPOEn (0x1UL << 3)
220 #define ITOP_MASK_SSPCTLOEn (0x1UL << 4)
221 #define ITOP_MASK_RORINTR (0x1UL << 5)
222 #define ITOP_MASK_RTINTR (0x1UL << 6)
223 #define ITOP_MASK_RXINTR (0x1UL << 7)
224 #define ITOP_MASK_TXINTR (0x1UL << 8)
225 #define ITOP_MASK_INTR (0x1UL << 9)
226 #define ITOP_MASK_RXDMABREQ (0x1UL << 10)
227 #define ITOP_MASK_RXDMASREQ (0x1UL << 11)
228 #define ITOP_MASK_TXDMABREQ (0x1UL << 12)
229 #define ITOP_MASK_TXDMASREQ (0x1UL << 13)
230
231 /*
232 * SSP Test Data Register - SSP_TDR
233 */
234 #define TDR_MASK_TESTDATA (0xFFFFFFFF)
235
236 /*
237 * Message State
238 * we use the spi_message.state (void *) pointer to
239 * hold a single state value, that's why all this
240 * (void *) casting is done here.
241 */
242 #define STATE_START ((void *) 0)
243 #define STATE_RUNNING ((void *) 1)
244 #define STATE_DONE ((void *) 2)
245 #define STATE_ERROR ((void *) -1)
246
247 /*
248 * SSP State - Whether Enabled or Disabled
249 */
250 #define SSP_DISABLED (0)
251 #define SSP_ENABLED (1)
252
253 /*
254 * SSP DMA State - Whether DMA Enabled or Disabled
255 */
256 #define SSP_DMA_DISABLED (0)
257 #define SSP_DMA_ENABLED (1)
258
259 /*
260 * SSP Clock Defaults
261 */
262 #define SSP_DEFAULT_CLKRATE 0x2
263 #define SSP_DEFAULT_PRESCALE 0x40
264
265 /*
266 * SSP Clock Parameter ranges
267 */
268 #define CPSDVR_MIN 0x02
269 #define CPSDVR_MAX 0xFE
270 #define SCR_MIN 0x00
271 #define SCR_MAX 0xFF
272
273 /*
274 * SSP Interrupt related Macros
275 */
276 #define DEFAULT_SSP_REG_IMSC 0x0UL
277 #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
278 #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
279
280 #define CLEAR_ALL_INTERRUPTS 0x3
281
282 #define SPI_POLLING_TIMEOUT 1000
283
284 /*
285 * The type of reading going on on this chip
286 */
287 enum ssp_reading {
288 READING_NULL,
289 READING_U8,
290 READING_U16,
291 READING_U32
292 };
293
294 /**
295 * The type of writing going on on this chip
296 */
297 enum ssp_writing {
298 WRITING_NULL,
299 WRITING_U8,
300 WRITING_U16,
301 WRITING_U32
302 };
303
304 /**
305 * struct vendor_data - vendor-specific config parameters
306 * for PL022 derivates
307 * @fifodepth: depth of FIFOs (both)
308 * @max_bpw: maximum number of bits per word
309 * @unidir: supports unidirection transfers
310 * @extended_cr: 32 bit wide control register 0 with extra
311 * features and extra features in CR1 as found in the ST variants
312 * @pl023: supports a subset of the ST extensions called "PL023"
313 */
314 struct vendor_data {
315 int fifodepth;
316 int max_bpw;
317 bool unidir;
318 bool extended_cr;
319 bool pl023;
320 bool loopback;
321 };
322
323 /**
324 * struct pl022 - This is the private SSP driver data structure
325 * @adev: AMBA device model hookup
326 * @vendor: vendor data for the IP block
327 * @phybase: the physical memory where the SSP device resides
328 * @virtbase: the virtual memory where the SSP is mapped
329 * @clk: outgoing clock "SPICLK" for the SPI bus
330 * @master: SPI framework hookup
331 * @master_info: controller-specific data from machine setup
332 * @kworker: thread struct for message pump
333 * @kworker_task: pointer to task for message pump kworker thread
334 * @pump_messages: work struct for scheduling work to the message pump
335 * @queue_lock: spinlock to syncronise access to message queue
336 * @queue: message queue
337 * @busy: message pump is busy
338 * @running: message pump is running
339 * @pump_transfers: Tasklet used in Interrupt Transfer mode
340 * @cur_msg: Pointer to current spi_message being processed
341 * @cur_transfer: Pointer to current spi_transfer
342 * @cur_chip: pointer to current clients chip(assigned from controller_state)
343 * @next_msg_cs_active: the next message in the queue has been examined
344 * and it was found that it uses the same chip select as the previous
345 * message, so we left it active after the previous transfer, and it's
346 * active already.
347 * @tx: current position in TX buffer to be read
348 * @tx_end: end position in TX buffer to be read
349 * @rx: current position in RX buffer to be written
350 * @rx_end: end position in RX buffer to be written
351 * @read: the type of read currently going on
352 * @write: the type of write currently going on
353 * @exp_fifo_level: expected FIFO level
354 * @dma_rx_channel: optional channel for RX DMA
355 * @dma_tx_channel: optional channel for TX DMA
356 * @sgt_rx: scattertable for the RX transfer
357 * @sgt_tx: scattertable for the TX transfer
358 * @dummypage: a dummy page used for driving data on the bus with DMA
359 */
360 struct pl022 {
361 struct amba_device *adev;
362 struct vendor_data *vendor;
363 resource_size_t phybase;
364 void __iomem *virtbase;
365 struct clk *clk;
366 struct spi_master *master;
367 struct pl022_ssp_controller *master_info;
368 /* Message per-transfer pump */
369 struct tasklet_struct pump_transfers;
370 struct spi_message *cur_msg;
371 struct spi_transfer *cur_transfer;
372 struct chip_data *cur_chip;
373 bool next_msg_cs_active;
374 void *tx;
375 void *tx_end;
376 void *rx;
377 void *rx_end;
378 enum ssp_reading read;
379 enum ssp_writing write;
380 u32 exp_fifo_level;
381 enum ssp_rx_level_trig rx_lev_trig;
382 enum ssp_tx_level_trig tx_lev_trig;
383 /* DMA settings */
384 #ifdef CONFIG_DMA_ENGINE
385 struct dma_chan *dma_rx_channel;
386 struct dma_chan *dma_tx_channel;
387 struct sg_table sgt_rx;
388 struct sg_table sgt_tx;
389 char *dummypage;
390 bool dma_running;
391 #endif
392 };
393
394 /**
395 * struct chip_data - To maintain runtime state of SSP for each client chip
396 * @cr0: Value of control register CR0 of SSP - on later ST variants this
397 * register is 32 bits wide rather than just 16
398 * @cr1: Value of control register CR1 of SSP
399 * @dmacr: Value of DMA control Register of SSP
400 * @cpsr: Value of Clock prescale register
401 * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
402 * @enable_dma: Whether to enable DMA or not
403 * @read: function ptr to be used to read when doing xfer for this chip
404 * @write: function ptr to be used to write when doing xfer for this chip
405 * @cs_control: chip select callback provided by chip
406 * @xfer_type: polling/interrupt/DMA
407 *
408 * Runtime state of the SSP controller, maintained per chip,
409 * This would be set according to the current message that would be served
410 */
411 struct chip_data {
412 u32 cr0;
413 u16 cr1;
414 u16 dmacr;
415 u16 cpsr;
416 u8 n_bytes;
417 bool enable_dma;
418 enum ssp_reading read;
419 enum ssp_writing write;
420 void (*cs_control) (u32 command);
421 int xfer_type;
422 };
423
424 /**
425 * null_cs_control - Dummy chip select function
426 * @command: select/delect the chip
427 *
428 * If no chip select function is provided by client this is used as dummy
429 * chip select
430 */
431 static void null_cs_control(u32 command)
432 {
433 pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
434 }
435
436 /**
437 * giveback - current spi_message is over, schedule next message and call
438 * callback of this message. Assumes that caller already
439 * set message->status; dma and pio irqs are blocked
440 * @pl022: SSP driver private data structure
441 */
442 static void giveback(struct pl022 *pl022)
443 {
444 struct spi_transfer *last_transfer;
445 pl022->next_msg_cs_active = false;
446
447 last_transfer = list_entry(pl022->cur_msg->transfers.prev,
448 struct spi_transfer,
449 transfer_list);
450
451 /* Delay if requested before any change in chip select */
452 if (last_transfer->delay_usecs)
453 /*
454 * FIXME: This runs in interrupt context.
455 * Is this really smart?
456 */
457 udelay(last_transfer->delay_usecs);
458
459 if (!last_transfer->cs_change) {
460 struct spi_message *next_msg;
461
462 /*
463 * cs_change was not set. We can keep the chip select
464 * enabled if there is message in the queue and it is
465 * for the same spi device.
466 *
467 * We cannot postpone this until pump_messages, because
468 * after calling msg->complete (below) the driver that
469 * sent the current message could be unloaded, which
470 * could invalidate the cs_control() callback...
471 */
472 /* get a pointer to the next message, if any */
473 next_msg = spi_get_next_queued_message(pl022->master);
474
475 /*
476 * see if the next and current messages point
477 * to the same spi device.
478 */
479 if (next_msg && next_msg->spi != pl022->cur_msg->spi)
480 next_msg = NULL;
481 if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
482 pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
483 else
484 pl022->next_msg_cs_active = true;
485
486 }
487
488 pl022->cur_msg = NULL;
489 pl022->cur_transfer = NULL;
490 pl022->cur_chip = NULL;
491 spi_finalize_current_message(pl022->master);
492 }
493
494 /**
495 * flush - flush the FIFO to reach a clean state
496 * @pl022: SSP driver private data structure
497 */
498 static int flush(struct pl022 *pl022)
499 {
500 unsigned long limit = loops_per_jiffy << 1;
501
502 dev_dbg(&pl022->adev->dev, "flush\n");
503 do {
504 while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
505 readw(SSP_DR(pl022->virtbase));
506 } while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
507
508 pl022->exp_fifo_level = 0;
509
510 return limit;
511 }
512
513 /**
514 * restore_state - Load configuration of current chip
515 * @pl022: SSP driver private data structure
516 */
517 static void restore_state(struct pl022 *pl022)
518 {
519 struct chip_data *chip = pl022->cur_chip;
520
521 if (pl022->vendor->extended_cr)
522 writel(chip->cr0, SSP_CR0(pl022->virtbase));
523 else
524 writew(chip->cr0, SSP_CR0(pl022->virtbase));
525 writew(chip->cr1, SSP_CR1(pl022->virtbase));
526 writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
527 writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
528 writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
529 writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
530 }
531
532 /*
533 * Default SSP Register Values
534 */
535 #define DEFAULT_SSP_REG_CR0 ( \
536 GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
537 GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
538 GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
539 GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
540 GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
541 )
542
543 /* ST versions have slightly different bit layout */
544 #define DEFAULT_SSP_REG_CR0_ST ( \
545 GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
546 GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
547 GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
548 GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
549 GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
550 GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \
551 GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
552 )
553
554 /* The PL023 version is slightly different again */
555 #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
556 GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
557 GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
558 GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
559 GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
560 )
561
562 #define DEFAULT_SSP_REG_CR1 ( \
563 GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
564 GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
565 GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
566 GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
567 )
568
569 /* ST versions extend this register to use all 16 bits */
570 #define DEFAULT_SSP_REG_CR1_ST ( \
571 DEFAULT_SSP_REG_CR1 | \
572 GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
573 GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
574 GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
575 GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
576 GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
577 )
578
579 /*
580 * The PL023 variant has further differences: no loopback mode, no microwire
581 * support, and a new clock feedback delay setting.
582 */
583 #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
584 GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
585 GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
586 GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
587 GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
588 GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
589 GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
590 GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
591 GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
592 )
593
594 #define DEFAULT_SSP_REG_CPSR ( \
595 GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
596 )
597
598 #define DEFAULT_SSP_REG_DMACR (\
599 GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
600 GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
601 )
602
603 /**
604 * load_ssp_default_config - Load default configuration for SSP
605 * @pl022: SSP driver private data structure
606 */
607 static void load_ssp_default_config(struct pl022 *pl022)
608 {
609 if (pl022->vendor->pl023) {
610 writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
611 writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
612 } else if (pl022->vendor->extended_cr) {
613 writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
614 writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
615 } else {
616 writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
617 writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
618 }
619 writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
620 writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
621 writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
622 writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
623 }
624
625 /**
626 * This will write to TX and read from RX according to the parameters
627 * set in pl022.
628 */
629 static void readwriter(struct pl022 *pl022)
630 {
631
632 /*
633 * The FIFO depth is different between primecell variants.
634 * I believe filling in too much in the FIFO might cause
635 * errons in 8bit wide transfers on ARM variants (just 8 words
636 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
637 *
638 * To prevent this issue, the TX FIFO is only filled to the
639 * unused RX FIFO fill length, regardless of what the TX
640 * FIFO status flag indicates.
641 */
642 dev_dbg(&pl022->adev->dev,
643 "%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
644 __func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
645
646 /* Read as much as you can */
647 while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
648 && (pl022->rx < pl022->rx_end)) {
649 switch (pl022->read) {
650 case READING_NULL:
651 readw(SSP_DR(pl022->virtbase));
652 break;
653 case READING_U8:
654 *(u8 *) (pl022->rx) =
655 readw(SSP_DR(pl022->virtbase)) & 0xFFU;
656 break;
657 case READING_U16:
658 *(u16 *) (pl022->rx) =
659 (u16) readw(SSP_DR(pl022->virtbase));
660 break;
661 case READING_U32:
662 *(u32 *) (pl022->rx) =
663 readl(SSP_DR(pl022->virtbase));
664 break;
665 }
666 pl022->rx += (pl022->cur_chip->n_bytes);
667 pl022->exp_fifo_level--;
668 }
669 /*
670 * Write as much as possible up to the RX FIFO size
671 */
672 while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
673 && (pl022->tx < pl022->tx_end)) {
674 switch (pl022->write) {
675 case WRITING_NULL:
676 writew(0x0, SSP_DR(pl022->virtbase));
677 break;
678 case WRITING_U8:
679 writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
680 break;
681 case WRITING_U16:
682 writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
683 break;
684 case WRITING_U32:
685 writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
686 break;
687 }
688 pl022->tx += (pl022->cur_chip->n_bytes);
689 pl022->exp_fifo_level++;
690 /*
691 * This inner reader takes care of things appearing in the RX
692 * FIFO as we're transmitting. This will happen a lot since the
693 * clock starts running when you put things into the TX FIFO,
694 * and then things are continuously clocked into the RX FIFO.
695 */
696 while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
697 && (pl022->rx < pl022->rx_end)) {
698 switch (pl022->read) {
699 case READING_NULL:
700 readw(SSP_DR(pl022->virtbase));
701 break;
702 case READING_U8:
703 *(u8 *) (pl022->rx) =
704 readw(SSP_DR(pl022->virtbase)) & 0xFFU;
705 break;
706 case READING_U16:
707 *(u16 *) (pl022->rx) =
708 (u16) readw(SSP_DR(pl022->virtbase));
709 break;
710 case READING_U32:
711 *(u32 *) (pl022->rx) =
712 readl(SSP_DR(pl022->virtbase));
713 break;
714 }
715 pl022->rx += (pl022->cur_chip->n_bytes);
716 pl022->exp_fifo_level--;
717 }
718 }
719 /*
720 * When we exit here the TX FIFO should be full and the RX FIFO
721 * should be empty
722 */
723 }
724
725 /**
726 * next_transfer - Move to the Next transfer in the current spi message
727 * @pl022: SSP driver private data structure
728 *
729 * This function moves though the linked list of spi transfers in the
730 * current spi message and returns with the state of current spi
731 * message i.e whether its last transfer is done(STATE_DONE) or
732 * Next transfer is ready(STATE_RUNNING)
733 */
734 static void *next_transfer(struct pl022 *pl022)
735 {
736 struct spi_message *msg = pl022->cur_msg;
737 struct spi_transfer *trans = pl022->cur_transfer;
738
739 /* Move to next transfer */
740 if (trans->transfer_list.next != &msg->transfers) {
741 pl022->cur_transfer =
742 list_entry(trans->transfer_list.next,
743 struct spi_transfer, transfer_list);
744 return STATE_RUNNING;
745 }
746 return STATE_DONE;
747 }
748
749 /*
750 * This DMA functionality is only compiled in if we have
751 * access to the generic DMA devices/DMA engine.
752 */
753 #ifdef CONFIG_DMA_ENGINE
754 static void unmap_free_dma_scatter(struct pl022 *pl022)
755 {
756 /* Unmap and free the SG tables */
757 dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
758 pl022->sgt_tx.nents, DMA_TO_DEVICE);
759 dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
760 pl022->sgt_rx.nents, DMA_FROM_DEVICE);
761 sg_free_table(&pl022->sgt_rx);
762 sg_free_table(&pl022->sgt_tx);
763 }
764
765 static void dma_callback(void *data)
766 {
767 struct pl022 *pl022 = data;
768 struct spi_message *msg = pl022->cur_msg;
769
770 BUG_ON(!pl022->sgt_rx.sgl);
771
772 #ifdef VERBOSE_DEBUG
773 /*
774 * Optionally dump out buffers to inspect contents, this is
775 * good if you want to convince yourself that the loopback
776 * read/write contents are the same, when adopting to a new
777 * DMA engine.
778 */
779 {
780 struct scatterlist *sg;
781 unsigned int i;
782
783 dma_sync_sg_for_cpu(&pl022->adev->dev,
784 pl022->sgt_rx.sgl,
785 pl022->sgt_rx.nents,
786 DMA_FROM_DEVICE);
787
788 for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
789 dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
790 print_hex_dump(KERN_ERR, "SPI RX: ",
791 DUMP_PREFIX_OFFSET,
792 16,
793 1,
794 sg_virt(sg),
795 sg_dma_len(sg),
796 1);
797 }
798 for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
799 dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
800 print_hex_dump(KERN_ERR, "SPI TX: ",
801 DUMP_PREFIX_OFFSET,
802 16,
803 1,
804 sg_virt(sg),
805 sg_dma_len(sg),
806 1);
807 }
808 }
809 #endif
810
811 unmap_free_dma_scatter(pl022);
812
813 /* Update total bytes transferred */
814 msg->actual_length += pl022->cur_transfer->len;
815 if (pl022->cur_transfer->cs_change)
816 pl022->cur_chip->
817 cs_control(SSP_CHIP_DESELECT);
818
819 /* Move to next transfer */
820 msg->state = next_transfer(pl022);
821 tasklet_schedule(&pl022->pump_transfers);
822 }
823
824 static void setup_dma_scatter(struct pl022 *pl022,
825 void *buffer,
826 unsigned int length,
827 struct sg_table *sgtab)
828 {
829 struct scatterlist *sg;
830 int bytesleft = length;
831 void *bufp = buffer;
832 int mapbytes;
833 int i;
834
835 if (buffer) {
836 for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
837 /*
838 * If there are less bytes left than what fits
839 * in the current page (plus page alignment offset)
840 * we just feed in this, else we stuff in as much
841 * as we can.
842 */
843 if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
844 mapbytes = bytesleft;
845 else
846 mapbytes = PAGE_SIZE - offset_in_page(bufp);
847 sg_set_page(sg, virt_to_page(bufp),
848 mapbytes, offset_in_page(bufp));
849 bufp += mapbytes;
850 bytesleft -= mapbytes;
851 dev_dbg(&pl022->adev->dev,
852 "set RX/TX target page @ %p, %d bytes, %d left\n",
853 bufp, mapbytes, bytesleft);
854 }
855 } else {
856 /* Map the dummy buffer on every page */
857 for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
858 if (bytesleft < PAGE_SIZE)
859 mapbytes = bytesleft;
860 else
861 mapbytes = PAGE_SIZE;
862 sg_set_page(sg, virt_to_page(pl022->dummypage),
863 mapbytes, 0);
864 bytesleft -= mapbytes;
865 dev_dbg(&pl022->adev->dev,
866 "set RX/TX to dummy page %d bytes, %d left\n",
867 mapbytes, bytesleft);
868
869 }
870 }
871 BUG_ON(bytesleft);
872 }
873
874 /**
875 * configure_dma - configures the channels for the next transfer
876 * @pl022: SSP driver's private data structure
877 */
878 static int configure_dma(struct pl022 *pl022)
879 {
880 struct dma_slave_config rx_conf = {
881 .src_addr = SSP_DR(pl022->phybase),
882 .direction = DMA_DEV_TO_MEM,
883 .device_fc = false,
884 };
885 struct dma_slave_config tx_conf = {
886 .dst_addr = SSP_DR(pl022->phybase),
887 .direction = DMA_MEM_TO_DEV,
888 .device_fc = false,
889 };
890 unsigned int pages;
891 int ret;
892 int rx_sglen, tx_sglen;
893 struct dma_chan *rxchan = pl022->dma_rx_channel;
894 struct dma_chan *txchan = pl022->dma_tx_channel;
895 struct dma_async_tx_descriptor *rxdesc;
896 struct dma_async_tx_descriptor *txdesc;
897
898 /* Check that the channels are available */
899 if (!rxchan || !txchan)
900 return -ENODEV;
901
902 /*
903 * If supplied, the DMA burstsize should equal the FIFO trigger level.
904 * Notice that the DMA engine uses one-to-one mapping. Since we can
905 * not trigger on 2 elements this needs explicit mapping rather than
906 * calculation.
907 */
908 switch (pl022->rx_lev_trig) {
909 case SSP_RX_1_OR_MORE_ELEM:
910 rx_conf.src_maxburst = 1;
911 break;
912 case SSP_RX_4_OR_MORE_ELEM:
913 rx_conf.src_maxburst = 4;
914 break;
915 case SSP_RX_8_OR_MORE_ELEM:
916 rx_conf.src_maxburst = 8;
917 break;
918 case SSP_RX_16_OR_MORE_ELEM:
919 rx_conf.src_maxburst = 16;
920 break;
921 case SSP_RX_32_OR_MORE_ELEM:
922 rx_conf.src_maxburst = 32;
923 break;
924 default:
925 rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
926 break;
927 }
928
929 switch (pl022->tx_lev_trig) {
930 case SSP_TX_1_OR_MORE_EMPTY_LOC:
931 tx_conf.dst_maxburst = 1;
932 break;
933 case SSP_TX_4_OR_MORE_EMPTY_LOC:
934 tx_conf.dst_maxburst = 4;
935 break;
936 case SSP_TX_8_OR_MORE_EMPTY_LOC:
937 tx_conf.dst_maxburst = 8;
938 break;
939 case SSP_TX_16_OR_MORE_EMPTY_LOC:
940 tx_conf.dst_maxburst = 16;
941 break;
942 case SSP_TX_32_OR_MORE_EMPTY_LOC:
943 tx_conf.dst_maxburst = 32;
944 break;
945 default:
946 tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
947 break;
948 }
949
950 switch (pl022->read) {
951 case READING_NULL:
952 /* Use the same as for writing */
953 rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
954 break;
955 case READING_U8:
956 rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
957 break;
958 case READING_U16:
959 rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
960 break;
961 case READING_U32:
962 rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
963 break;
964 }
965
966 switch (pl022->write) {
967 case WRITING_NULL:
968 /* Use the same as for reading */
969 tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
970 break;
971 case WRITING_U8:
972 tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
973 break;
974 case WRITING_U16:
975 tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
976 break;
977 case WRITING_U32:
978 tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
979 break;
980 }
981
982 /* SPI pecularity: we need to read and write the same width */
983 if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
984 rx_conf.src_addr_width = tx_conf.dst_addr_width;
985 if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
986 tx_conf.dst_addr_width = rx_conf.src_addr_width;
987 BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
988
989 dmaengine_slave_config(rxchan, &rx_conf);
990 dmaengine_slave_config(txchan, &tx_conf);
991
992 /* Create sglists for the transfers */
993 pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
994 dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
995
996 ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
997 if (ret)
998 goto err_alloc_rx_sg;
999
1000 ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1001 if (ret)
1002 goto err_alloc_tx_sg;
1003
1004 /* Fill in the scatterlists for the RX+TX buffers */
1005 setup_dma_scatter(pl022, pl022->rx,
1006 pl022->cur_transfer->len, &pl022->sgt_rx);
1007 setup_dma_scatter(pl022, pl022->tx,
1008 pl022->cur_transfer->len, &pl022->sgt_tx);
1009
1010 /* Map DMA buffers */
1011 rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1012 pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1013 if (!rx_sglen)
1014 goto err_rx_sgmap;
1015
1016 tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1017 pl022->sgt_tx.nents, DMA_TO_DEVICE);
1018 if (!tx_sglen)
1019 goto err_tx_sgmap;
1020
1021 /* Send both scatterlists */
1022 rxdesc = dmaengine_prep_slave_sg(rxchan,
1023 pl022->sgt_rx.sgl,
1024 rx_sglen,
1025 DMA_DEV_TO_MEM,
1026 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1027 if (!rxdesc)
1028 goto err_rxdesc;
1029
1030 txdesc = dmaengine_prep_slave_sg(txchan,
1031 pl022->sgt_tx.sgl,
1032 tx_sglen,
1033 DMA_MEM_TO_DEV,
1034 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1035 if (!txdesc)
1036 goto err_txdesc;
1037
1038 /* Put the callback on the RX transfer only, that should finish last */
1039 rxdesc->callback = dma_callback;
1040 rxdesc->callback_param = pl022;
1041
1042 /* Submit and fire RX and TX with TX last so we're ready to read! */
1043 dmaengine_submit(rxdesc);
1044 dmaengine_submit(txdesc);
1045 dma_async_issue_pending(rxchan);
1046 dma_async_issue_pending(txchan);
1047 pl022->dma_running = true;
1048
1049 return 0;
1050
1051 err_txdesc:
1052 dmaengine_terminate_all(txchan);
1053 err_rxdesc:
1054 dmaengine_terminate_all(rxchan);
1055 dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1056 pl022->sgt_tx.nents, DMA_TO_DEVICE);
1057 err_tx_sgmap:
1058 dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1059 pl022->sgt_tx.nents, DMA_FROM_DEVICE);
1060 err_rx_sgmap:
1061 sg_free_table(&pl022->sgt_tx);
1062 err_alloc_tx_sg:
1063 sg_free_table(&pl022->sgt_rx);
1064 err_alloc_rx_sg:
1065 return -ENOMEM;
1066 }
1067
1068 static int __devinit pl022_dma_probe(struct pl022 *pl022)
1069 {
1070 dma_cap_mask_t mask;
1071
1072 /* Try to acquire a generic DMA engine slave channel */
1073 dma_cap_zero(mask);
1074 dma_cap_set(DMA_SLAVE, mask);
1075 /*
1076 * We need both RX and TX channels to do DMA, else do none
1077 * of them.
1078 */
1079 pl022->dma_rx_channel = dma_request_channel(mask,
1080 pl022->master_info->dma_filter,
1081 pl022->master_info->dma_rx_param);
1082 if (!pl022->dma_rx_channel) {
1083 dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1084 goto err_no_rxchan;
1085 }
1086
1087 pl022->dma_tx_channel = dma_request_channel(mask,
1088 pl022->master_info->dma_filter,
1089 pl022->master_info->dma_tx_param);
1090 if (!pl022->dma_tx_channel) {
1091 dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1092 goto err_no_txchan;
1093 }
1094
1095 pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1096 if (!pl022->dummypage) {
1097 dev_dbg(&pl022->adev->dev, "no DMA dummypage!\n");
1098 goto err_no_dummypage;
1099 }
1100
1101 dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1102 dma_chan_name(pl022->dma_rx_channel),
1103 dma_chan_name(pl022->dma_tx_channel));
1104
1105 return 0;
1106
1107 err_no_dummypage:
1108 dma_release_channel(pl022->dma_tx_channel);
1109 err_no_txchan:
1110 dma_release_channel(pl022->dma_rx_channel);
1111 pl022->dma_rx_channel = NULL;
1112 err_no_rxchan:
1113 dev_err(&pl022->adev->dev,
1114 "Failed to work in dma mode, work without dma!\n");
1115 return -ENODEV;
1116 }
1117
1118 static void terminate_dma(struct pl022 *pl022)
1119 {
1120 struct dma_chan *rxchan = pl022->dma_rx_channel;
1121 struct dma_chan *txchan = pl022->dma_tx_channel;
1122
1123 dmaengine_terminate_all(rxchan);
1124 dmaengine_terminate_all(txchan);
1125 unmap_free_dma_scatter(pl022);
1126 pl022->dma_running = false;
1127 }
1128
1129 static void pl022_dma_remove(struct pl022 *pl022)
1130 {
1131 if (pl022->dma_running)
1132 terminate_dma(pl022);
1133 if (pl022->dma_tx_channel)
1134 dma_release_channel(pl022->dma_tx_channel);
1135 if (pl022->dma_rx_channel)
1136 dma_release_channel(pl022->dma_rx_channel);
1137 kfree(pl022->dummypage);
1138 }
1139
1140 #else
1141 static inline int configure_dma(struct pl022 *pl022)
1142 {
1143 return -ENODEV;
1144 }
1145
1146 static inline int pl022_dma_probe(struct pl022 *pl022)
1147 {
1148 return 0;
1149 }
1150
1151 static inline void pl022_dma_remove(struct pl022 *pl022)
1152 {
1153 }
1154 #endif
1155
1156 /**
1157 * pl022_interrupt_handler - Interrupt handler for SSP controller
1158 *
1159 * This function handles interrupts generated for an interrupt based transfer.
1160 * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1161 * current message's state as STATE_ERROR and schedule the tasklet
1162 * pump_transfers which will do the postprocessing of the current message by
1163 * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1164 * more data, and writes data in TX FIFO till it is not full. If we complete
1165 * the transfer we move to the next transfer and schedule the tasklet.
1166 */
1167 static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1168 {
1169 struct pl022 *pl022 = dev_id;
1170 struct spi_message *msg = pl022->cur_msg;
1171 u16 irq_status = 0;
1172 u16 flag = 0;
1173
1174 if (unlikely(!msg)) {
1175 dev_err(&pl022->adev->dev,
1176 "bad message state in interrupt handler");
1177 /* Never fail */
1178 return IRQ_HANDLED;
1179 }
1180
1181 /* Read the Interrupt Status Register */
1182 irq_status = readw(SSP_MIS(pl022->virtbase));
1183
1184 if (unlikely(!irq_status))
1185 return IRQ_NONE;
1186
1187 /*
1188 * This handles the FIFO interrupts, the timeout
1189 * interrupts are flatly ignored, they cannot be
1190 * trusted.
1191 */
1192 if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1193 /*
1194 * Overrun interrupt - bail out since our Data has been
1195 * corrupted
1196 */
1197 dev_err(&pl022->adev->dev, "FIFO overrun\n");
1198 if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1199 dev_err(&pl022->adev->dev,
1200 "RXFIFO is full\n");
1201 if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
1202 dev_err(&pl022->adev->dev,
1203 "TXFIFO is full\n");
1204
1205 /*
1206 * Disable and clear interrupts, disable SSP,
1207 * mark message with bad status so it can be
1208 * retried.
1209 */
1210 writew(DISABLE_ALL_INTERRUPTS,
1211 SSP_IMSC(pl022->virtbase));
1212 writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1213 writew((readw(SSP_CR1(pl022->virtbase)) &
1214 (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1215 msg->state = STATE_ERROR;
1216
1217 /* Schedule message queue handler */
1218 tasklet_schedule(&pl022->pump_transfers);
1219 return IRQ_HANDLED;
1220 }
1221
1222 readwriter(pl022);
1223
1224 if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
1225 flag = 1;
1226 /* Disable Transmit interrupt, enable receive interrupt */
1227 writew((readw(SSP_IMSC(pl022->virtbase)) &
1228 ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1229 SSP_IMSC(pl022->virtbase));
1230 }
1231
1232 /*
1233 * Since all transactions must write as much as shall be read,
1234 * we can conclude the entire transaction once RX is complete.
1235 * At this point, all TX will always be finished.
1236 */
1237 if (pl022->rx >= pl022->rx_end) {
1238 writew(DISABLE_ALL_INTERRUPTS,
1239 SSP_IMSC(pl022->virtbase));
1240 writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1241 if (unlikely(pl022->rx > pl022->rx_end)) {
1242 dev_warn(&pl022->adev->dev, "read %u surplus "
1243 "bytes (did you request an odd "
1244 "number of bytes on a 16bit bus?)\n",
1245 (u32) (pl022->rx - pl022->rx_end));
1246 }
1247 /* Update total bytes transferred */
1248 msg->actual_length += pl022->cur_transfer->len;
1249 if (pl022->cur_transfer->cs_change)
1250 pl022->cur_chip->
1251 cs_control(SSP_CHIP_DESELECT);
1252 /* Move to next transfer */
1253 msg->state = next_transfer(pl022);
1254 tasklet_schedule(&pl022->pump_transfers);
1255 return IRQ_HANDLED;
1256 }
1257
1258 return IRQ_HANDLED;
1259 }
1260
1261 /**
1262 * This sets up the pointers to memory for the next message to
1263 * send out on the SPI bus.
1264 */
1265 static int set_up_next_transfer(struct pl022 *pl022,
1266 struct spi_transfer *transfer)
1267 {
1268 int residue;
1269
1270 /* Sanity check the message for this bus width */
1271 residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1272 if (unlikely(residue != 0)) {
1273 dev_err(&pl022->adev->dev,
1274 "message of %u bytes to transmit but the current "
1275 "chip bus has a data width of %u bytes!\n",
1276 pl022->cur_transfer->len,
1277 pl022->cur_chip->n_bytes);
1278 dev_err(&pl022->adev->dev, "skipping this message\n");
1279 return -EIO;
1280 }
1281 pl022->tx = (void *)transfer->tx_buf;
1282 pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1283 pl022->rx = (void *)transfer->rx_buf;
1284 pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1285 pl022->write =
1286 pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1287 pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1288 return 0;
1289 }
1290
1291 /**
1292 * pump_transfers - Tasklet function which schedules next transfer
1293 * when running in interrupt or DMA transfer mode.
1294 * @data: SSP driver private data structure
1295 *
1296 */
1297 static void pump_transfers(unsigned long data)
1298 {
1299 struct pl022 *pl022 = (struct pl022 *) data;
1300 struct spi_message *message = NULL;
1301 struct spi_transfer *transfer = NULL;
1302 struct spi_transfer *previous = NULL;
1303
1304 /* Get current state information */
1305 message = pl022->cur_msg;
1306 transfer = pl022->cur_transfer;
1307
1308 /* Handle for abort */
1309 if (message->state == STATE_ERROR) {
1310 message->status = -EIO;
1311 giveback(pl022);
1312 return;
1313 }
1314
1315 /* Handle end of message */
1316 if (message->state == STATE_DONE) {
1317 message->status = 0;
1318 giveback(pl022);
1319 return;
1320 }
1321
1322 /* Delay if requested at end of transfer before CS change */
1323 if (message->state == STATE_RUNNING) {
1324 previous = list_entry(transfer->transfer_list.prev,
1325 struct spi_transfer,
1326 transfer_list);
1327 if (previous->delay_usecs)
1328 /*
1329 * FIXME: This runs in interrupt context.
1330 * Is this really smart?
1331 */
1332 udelay(previous->delay_usecs);
1333
1334 /* Reselect chip select only if cs_change was requested */
1335 if (previous->cs_change)
1336 pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
1337 } else {
1338 /* STATE_START */
1339 message->state = STATE_RUNNING;
1340 }
1341
1342 if (set_up_next_transfer(pl022, transfer)) {
1343 message->state = STATE_ERROR;
1344 message->status = -EIO;
1345 giveback(pl022);
1346 return;
1347 }
1348 /* Flush the FIFOs and let's go! */
1349 flush(pl022);
1350
1351 if (pl022->cur_chip->enable_dma) {
1352 if (configure_dma(pl022)) {
1353 dev_dbg(&pl022->adev->dev,
1354 "configuration of DMA failed, fall back to interrupt mode\n");
1355 goto err_config_dma;
1356 }
1357 return;
1358 }
1359
1360 err_config_dma:
1361 /* enable all interrupts except RX */
1362 writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1363 }
1364
1365 static void do_interrupt_dma_transfer(struct pl022 *pl022)
1366 {
1367 /*
1368 * Default is to enable all interrupts except RX -
1369 * this will be enabled once TX is complete
1370 */
1371 u32 irqflags = ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM;
1372
1373 /* Enable target chip, if not already active */
1374 if (!pl022->next_msg_cs_active)
1375 pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
1376
1377 if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1378 /* Error path */
1379 pl022->cur_msg->state = STATE_ERROR;
1380 pl022->cur_msg->status = -EIO;
1381 giveback(pl022);
1382 return;
1383 }
1384 /* If we're using DMA, set up DMA here */
1385 if (pl022->cur_chip->enable_dma) {
1386 /* Configure DMA transfer */
1387 if (configure_dma(pl022)) {
1388 dev_dbg(&pl022->adev->dev,
1389 "configuration of DMA failed, fall back to interrupt mode\n");
1390 goto err_config_dma;
1391 }
1392 /* Disable interrupts in DMA mode, IRQ from DMA controller */
1393 irqflags = DISABLE_ALL_INTERRUPTS;
1394 }
1395 err_config_dma:
1396 /* Enable SSP, turn on interrupts */
1397 writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1398 SSP_CR1(pl022->virtbase));
1399 writew(irqflags, SSP_IMSC(pl022->virtbase));
1400 }
1401
1402 static void do_polling_transfer(struct pl022 *pl022)
1403 {
1404 struct spi_message *message = NULL;
1405 struct spi_transfer *transfer = NULL;
1406 struct spi_transfer *previous = NULL;
1407 struct chip_data *chip;
1408 unsigned long time, timeout;
1409
1410 chip = pl022->cur_chip;
1411 message = pl022->cur_msg;
1412
1413 while (message->state != STATE_DONE) {
1414 /* Handle for abort */
1415 if (message->state == STATE_ERROR)
1416 break;
1417 transfer = pl022->cur_transfer;
1418
1419 /* Delay if requested at end of transfer */
1420 if (message->state == STATE_RUNNING) {
1421 previous =
1422 list_entry(transfer->transfer_list.prev,
1423 struct spi_transfer, transfer_list);
1424 if (previous->delay_usecs)
1425 udelay(previous->delay_usecs);
1426 if (previous->cs_change)
1427 pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
1428 } else {
1429 /* STATE_START */
1430 message->state = STATE_RUNNING;
1431 if (!pl022->next_msg_cs_active)
1432 pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
1433 }
1434
1435 /* Configuration Changing Per Transfer */
1436 if (set_up_next_transfer(pl022, transfer)) {
1437 /* Error path */
1438 message->state = STATE_ERROR;
1439 break;
1440 }
1441 /* Flush FIFOs and enable SSP */
1442 flush(pl022);
1443 writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1444 SSP_CR1(pl022->virtbase));
1445
1446 dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1447
1448 timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1449 while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1450 time = jiffies;
1451 readwriter(pl022);
1452 if (time_after(time, timeout)) {
1453 dev_warn(&pl022->adev->dev,
1454 "%s: timeout!\n", __func__);
1455 message->state = STATE_ERROR;
1456 goto out;
1457 }
1458 cpu_relax();
1459 }
1460
1461 /* Update total byte transferred */
1462 message->actual_length += pl022->cur_transfer->len;
1463 if (pl022->cur_transfer->cs_change)
1464 pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
1465 /* Move to next transfer */
1466 message->state = next_transfer(pl022);
1467 }
1468 out:
1469 /* Handle end of message */
1470 if (message->state == STATE_DONE)
1471 message->status = 0;
1472 else
1473 message->status = -EIO;
1474
1475 giveback(pl022);
1476 return;
1477 }
1478
1479 static int pl022_transfer_one_message(struct spi_master *master,
1480 struct spi_message *msg)
1481 {
1482 struct pl022 *pl022 = spi_master_get_devdata(master);
1483
1484 /* Initial message state */
1485 pl022->cur_msg = msg;
1486 msg->state = STATE_START;
1487
1488 pl022->cur_transfer = list_entry(msg->transfers.next,
1489 struct spi_transfer, transfer_list);
1490
1491 /* Setup the SPI using the per chip configuration */
1492 pl022->cur_chip = spi_get_ctldata(msg->spi);
1493
1494 restore_state(pl022);
1495 flush(pl022);
1496
1497 if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1498 do_polling_transfer(pl022);
1499 else
1500 do_interrupt_dma_transfer(pl022);
1501
1502 return 0;
1503 }
1504
1505 static int pl022_prepare_transfer_hardware(struct spi_master *master)
1506 {
1507 struct pl022 *pl022 = spi_master_get_devdata(master);
1508
1509 /*
1510 * Just make sure we have all we need to run the transfer by syncing
1511 * with the runtime PM framework.
1512 */
1513 pm_runtime_get_sync(&pl022->adev->dev);
1514 return 0;
1515 }
1516
1517 static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1518 {
1519 struct pl022 *pl022 = spi_master_get_devdata(master);
1520
1521 /* nothing more to do - disable spi/ssp and power off */
1522 writew((readw(SSP_CR1(pl022->virtbase)) &
1523 (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1524
1525 if (pl022->master_info->autosuspend_delay > 0) {
1526 pm_runtime_mark_last_busy(&pl022->adev->dev);
1527 pm_runtime_put_autosuspend(&pl022->adev->dev);
1528 } else {
1529 pm_runtime_put(&pl022->adev->dev);
1530 }
1531
1532 return 0;
1533 }
1534
1535 static int verify_controller_parameters(struct pl022 *pl022,
1536 struct pl022_config_chip const *chip_info)
1537 {
1538 if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1539 || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1540 dev_err(&pl022->adev->dev,
1541 "interface is configured incorrectly\n");
1542 return -EINVAL;
1543 }
1544 if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1545 (!pl022->vendor->unidir)) {
1546 dev_err(&pl022->adev->dev,
1547 "unidirectional mode not supported in this "
1548 "hardware version\n");
1549 return -EINVAL;
1550 }
1551 if ((chip_info->hierarchy != SSP_MASTER)
1552 && (chip_info->hierarchy != SSP_SLAVE)) {
1553 dev_err(&pl022->adev->dev,
1554 "hierarchy is configured incorrectly\n");
1555 return -EINVAL;
1556 }
1557 if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1558 && (chip_info->com_mode != DMA_TRANSFER)
1559 && (chip_info->com_mode != POLLING_TRANSFER)) {
1560 dev_err(&pl022->adev->dev,
1561 "Communication mode is configured incorrectly\n");
1562 return -EINVAL;
1563 }
1564 switch (chip_info->rx_lev_trig) {
1565 case SSP_RX_1_OR_MORE_ELEM:
1566 case SSP_RX_4_OR_MORE_ELEM:
1567 case SSP_RX_8_OR_MORE_ELEM:
1568 /* These are always OK, all variants can handle this */
1569 break;
1570 case SSP_RX_16_OR_MORE_ELEM:
1571 if (pl022->vendor->fifodepth < 16) {
1572 dev_err(&pl022->adev->dev,
1573 "RX FIFO Trigger Level is configured incorrectly\n");
1574 return -EINVAL;
1575 }
1576 break;
1577 case SSP_RX_32_OR_MORE_ELEM:
1578 if (pl022->vendor->fifodepth < 32) {
1579 dev_err(&pl022->adev->dev,
1580 "RX FIFO Trigger Level is configured incorrectly\n");
1581 return -EINVAL;
1582 }
1583 break;
1584 default:
1585 dev_err(&pl022->adev->dev,
1586 "RX FIFO Trigger Level is configured incorrectly\n");
1587 return -EINVAL;
1588 break;
1589 }
1590 switch (chip_info->tx_lev_trig) {
1591 case SSP_TX_1_OR_MORE_EMPTY_LOC:
1592 case SSP_TX_4_OR_MORE_EMPTY_LOC:
1593 case SSP_TX_8_OR_MORE_EMPTY_LOC:
1594 /* These are always OK, all variants can handle this */
1595 break;
1596 case SSP_TX_16_OR_MORE_EMPTY_LOC:
1597 if (pl022->vendor->fifodepth < 16) {
1598 dev_err(&pl022->adev->dev,
1599 "TX FIFO Trigger Level is configured incorrectly\n");
1600 return -EINVAL;
1601 }
1602 break;
1603 case SSP_TX_32_OR_MORE_EMPTY_LOC:
1604 if (pl022->vendor->fifodepth < 32) {
1605 dev_err(&pl022->adev->dev,
1606 "TX FIFO Trigger Level is configured incorrectly\n");
1607 return -EINVAL;
1608 }
1609 break;
1610 default:
1611 dev_err(&pl022->adev->dev,
1612 "TX FIFO Trigger Level is configured incorrectly\n");
1613 return -EINVAL;
1614 break;
1615 }
1616 if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1617 if ((chip_info->ctrl_len < SSP_BITS_4)
1618 || (chip_info->ctrl_len > SSP_BITS_32)) {
1619 dev_err(&pl022->adev->dev,
1620 "CTRL LEN is configured incorrectly\n");
1621 return -EINVAL;
1622 }
1623 if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1624 && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1625 dev_err(&pl022->adev->dev,
1626 "Wait State is configured incorrectly\n");
1627 return -EINVAL;
1628 }
1629 /* Half duplex is only available in the ST Micro version */
1630 if (pl022->vendor->extended_cr) {
1631 if ((chip_info->duplex !=
1632 SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1633 && (chip_info->duplex !=
1634 SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1635 dev_err(&pl022->adev->dev,
1636 "Microwire duplex mode is configured incorrectly\n");
1637 return -EINVAL;
1638 }
1639 } else {
1640 if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1641 dev_err(&pl022->adev->dev,
1642 "Microwire half duplex mode requested,"
1643 " but this is only available in the"
1644 " ST version of PL022\n");
1645 return -EINVAL;
1646 }
1647 }
1648 return 0;
1649 }
1650
1651 static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1652 {
1653 return rate / (cpsdvsr * (1 + scr));
1654 }
1655
1656 static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1657 ssp_clock_params * clk_freq)
1658 {
1659 /* Lets calculate the frequency parameters */
1660 u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1661 u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1662 best_scr = 0, tmp, found = 0;
1663
1664 rate = clk_get_rate(pl022->clk);
1665 /* cpsdvscr = 2 & scr 0 */
1666 max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1667 /* cpsdvsr = 254 & scr = 255 */
1668 min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1669
1670 if (freq > max_tclk)
1671 dev_warn(&pl022->adev->dev,
1672 "Max speed that can be programmed is %d Hz, you requested %d\n",
1673 max_tclk, freq);
1674
1675 if (freq < min_tclk) {
1676 dev_err(&pl022->adev->dev,
1677 "Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1678 freq, min_tclk);
1679 return -EINVAL;
1680 }
1681
1682 /*
1683 * best_freq will give closest possible available rate (<= requested
1684 * freq) for all values of scr & cpsdvsr.
1685 */
1686 while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1687 while (scr <= SCR_MAX) {
1688 tmp = spi_rate(rate, cpsdvsr, scr);
1689
1690 if (tmp > freq) {
1691 /* we need lower freq */
1692 scr++;
1693 continue;
1694 }
1695
1696 /*
1697 * If found exact value, mark found and break.
1698 * If found more closer value, update and break.
1699 */
1700 if (tmp > best_freq) {
1701 best_freq = tmp;
1702 best_cpsdvsr = cpsdvsr;
1703 best_scr = scr;
1704
1705 if (tmp == freq)
1706 found = 1;
1707 }
1708 /*
1709 * increased scr will give lower rates, which are not
1710 * required
1711 */
1712 break;
1713 }
1714 cpsdvsr += 2;
1715 scr = SCR_MIN;
1716 }
1717
1718 WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1719 freq);
1720
1721 clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1722 clk_freq->scr = (u8) (best_scr & 0xFF);
1723 dev_dbg(&pl022->adev->dev,
1724 "SSP Target Frequency is: %u, Effective Frequency is %u\n",
1725 freq, best_freq);
1726 dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1727 clk_freq->cpsdvsr, clk_freq->scr);
1728
1729 return 0;
1730 }
1731
1732 /*
1733 * A piece of default chip info unless the platform
1734 * supplies it.
1735 */
1736 static const struct pl022_config_chip pl022_default_chip_info = {
1737 .com_mode = POLLING_TRANSFER,
1738 .iface = SSP_INTERFACE_MOTOROLA_SPI,
1739 .hierarchy = SSP_SLAVE,
1740 .slave_tx_disable = DO_NOT_DRIVE_TX,
1741 .rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1742 .tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1743 .ctrl_len = SSP_BITS_8,
1744 .wait_state = SSP_MWIRE_WAIT_ZERO,
1745 .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1746 .cs_control = null_cs_control,
1747 };
1748
1749 /**
1750 * pl022_setup - setup function registered to SPI master framework
1751 * @spi: spi device which is requesting setup
1752 *
1753 * This function is registered to the SPI framework for this SPI master
1754 * controller. If it is the first time when setup is called by this device,
1755 * this function will initialize the runtime state for this chip and save
1756 * the same in the device structure. Else it will update the runtime info
1757 * with the updated chip info. Nothing is really being written to the
1758 * controller hardware here, that is not done until the actual transfer
1759 * commence.
1760 */
1761 static int pl022_setup(struct spi_device *spi)
1762 {
1763 struct pl022_config_chip const *chip_info;
1764 struct chip_data *chip;
1765 struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1766 int status = 0;
1767 struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1768 unsigned int bits = spi->bits_per_word;
1769 u32 tmp;
1770
1771 if (!spi->max_speed_hz)
1772 return -EINVAL;
1773
1774 /* Get controller_state if one is supplied */
1775 chip = spi_get_ctldata(spi);
1776
1777 if (chip == NULL) {
1778 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1779 if (!chip) {
1780 dev_err(&spi->dev,
1781 "cannot allocate controller state\n");
1782 return -ENOMEM;
1783 }
1784 dev_dbg(&spi->dev,
1785 "allocated memory for controller's runtime state\n");
1786 }
1787
1788 /* Get controller data if one is supplied */
1789 chip_info = spi->controller_data;
1790
1791 if (chip_info == NULL) {
1792 chip_info = &pl022_default_chip_info;
1793 /* spi_board_info.controller_data not is supplied */
1794 dev_dbg(&spi->dev,
1795 "using default controller_data settings\n");
1796 } else
1797 dev_dbg(&spi->dev,
1798 "using user supplied controller_data settings\n");
1799
1800 /*
1801 * We can override with custom divisors, else we use the board
1802 * frequency setting
1803 */
1804 if ((0 == chip_info->clk_freq.cpsdvsr)
1805 && (0 == chip_info->clk_freq.scr)) {
1806 status = calculate_effective_freq(pl022,
1807 spi->max_speed_hz,
1808 &clk_freq);
1809 if (status < 0)
1810 goto err_config_params;
1811 } else {
1812 memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1813 if ((clk_freq.cpsdvsr % 2) != 0)
1814 clk_freq.cpsdvsr =
1815 clk_freq.cpsdvsr - 1;
1816 }
1817 if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1818 || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1819 status = -EINVAL;
1820 dev_err(&spi->dev,
1821 "cpsdvsr is configured incorrectly\n");
1822 goto err_config_params;
1823 }
1824
1825 status = verify_controller_parameters(pl022, chip_info);
1826 if (status) {
1827 dev_err(&spi->dev, "controller data is incorrect");
1828 goto err_config_params;
1829 }
1830
1831 pl022->rx_lev_trig = chip_info->rx_lev_trig;
1832 pl022->tx_lev_trig = chip_info->tx_lev_trig;
1833
1834 /* Now set controller state based on controller data */
1835 chip->xfer_type = chip_info->com_mode;
1836 if (!chip_info->cs_control) {
1837 chip->cs_control = null_cs_control;
1838 dev_warn(&spi->dev,
1839 "chip select function is NULL for this chip\n");
1840 } else
1841 chip->cs_control = chip_info->cs_control;
1842
1843 /* Check bits per word with vendor specific range */
1844 if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1845 status = -ENOTSUPP;
1846 dev_err(&spi->dev, "illegal data size for this controller!\n");
1847 dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1848 pl022->vendor->max_bpw);
1849 goto err_config_params;
1850 } else if (bits <= 8) {
1851 dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1852 chip->n_bytes = 1;
1853 chip->read = READING_U8;
1854 chip->write = WRITING_U8;
1855 } else if (bits <= 16) {
1856 dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1857 chip->n_bytes = 2;
1858 chip->read = READING_U16;
1859 chip->write = WRITING_U16;
1860 } else {
1861 dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1862 chip->n_bytes = 4;
1863 chip->read = READING_U32;
1864 chip->write = WRITING_U32;
1865 }
1866
1867 /* Now Initialize all register settings required for this chip */
1868 chip->cr0 = 0;
1869 chip->cr1 = 0;
1870 chip->dmacr = 0;
1871 chip->cpsr = 0;
1872 if ((chip_info->com_mode == DMA_TRANSFER)
1873 && ((pl022->master_info)->enable_dma)) {
1874 chip->enable_dma = true;
1875 dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1876 SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1877 SSP_DMACR_MASK_RXDMAE, 0);
1878 SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1879 SSP_DMACR_MASK_TXDMAE, 1);
1880 } else {
1881 chip->enable_dma = false;
1882 dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1883 SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1884 SSP_DMACR_MASK_RXDMAE, 0);
1885 SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1886 SSP_DMACR_MASK_TXDMAE, 1);
1887 }
1888
1889 chip->cpsr = clk_freq.cpsdvsr;
1890
1891 /* Special setup for the ST micro extended control registers */
1892 if (pl022->vendor->extended_cr) {
1893 u32 etx;
1894
1895 if (pl022->vendor->pl023) {
1896 /* These bits are only in the PL023 */
1897 SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
1898 SSP_CR1_MASK_FBCLKDEL_ST, 13);
1899 } else {
1900 /* These bits are in the PL022 but not PL023 */
1901 SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
1902 SSP_CR0_MASK_HALFDUP_ST, 5);
1903 SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
1904 SSP_CR0_MASK_CSS_ST, 16);
1905 SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1906 SSP_CR0_MASK_FRF_ST, 21);
1907 SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
1908 SSP_CR1_MASK_MWAIT_ST, 6);
1909 }
1910 SSP_WRITE_BITS(chip->cr0, bits - 1,
1911 SSP_CR0_MASK_DSS_ST, 0);
1912
1913 if (spi->mode & SPI_LSB_FIRST) {
1914 tmp = SSP_RX_LSB;
1915 etx = SSP_TX_LSB;
1916 } else {
1917 tmp = SSP_RX_MSB;
1918 etx = SSP_TX_MSB;
1919 }
1920 SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
1921 SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
1922 SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
1923 SSP_CR1_MASK_RXIFLSEL_ST, 7);
1924 SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
1925 SSP_CR1_MASK_TXIFLSEL_ST, 10);
1926 } else {
1927 SSP_WRITE_BITS(chip->cr0, bits - 1,
1928 SSP_CR0_MASK_DSS, 0);
1929 SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1930 SSP_CR0_MASK_FRF, 4);
1931 }
1932
1933 /* Stuff that is common for all versions */
1934 if (spi->mode & SPI_CPOL)
1935 tmp = SSP_CLK_POL_IDLE_HIGH;
1936 else
1937 tmp = SSP_CLK_POL_IDLE_LOW;
1938 SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
1939
1940 if (spi->mode & SPI_CPHA)
1941 tmp = SSP_CLK_SECOND_EDGE;
1942 else
1943 tmp = SSP_CLK_FIRST_EDGE;
1944 SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
1945
1946 SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
1947 /* Loopback is available on all versions except PL023 */
1948 if (pl022->vendor->loopback) {
1949 if (spi->mode & SPI_LOOP)
1950 tmp = LOOPBACK_ENABLED;
1951 else
1952 tmp = LOOPBACK_DISABLED;
1953 SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
1954 }
1955 SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
1956 SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
1957 SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
1958 3);
1959
1960 /* Save controller_state */
1961 spi_set_ctldata(spi, chip);
1962 return status;
1963 err_config_params:
1964 spi_set_ctldata(spi, NULL);
1965 kfree(chip);
1966 return status;
1967 }
1968
1969 /**
1970 * pl022_cleanup - cleanup function registered to SPI master framework
1971 * @spi: spi device which is requesting cleanup
1972 *
1973 * This function is registered to the SPI framework for this SPI master
1974 * controller. It will free the runtime state of chip.
1975 */
1976 static void pl022_cleanup(struct spi_device *spi)
1977 {
1978 struct chip_data *chip = spi_get_ctldata(spi);
1979
1980 spi_set_ctldata(spi, NULL);
1981 kfree(chip);
1982 }
1983
1984 static int __devinit
1985 pl022_probe(struct amba_device *adev, const struct amba_id *id)
1986 {
1987 struct device *dev = &adev->dev;
1988 struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
1989 struct spi_master *master;
1990 struct pl022 *pl022 = NULL; /*Data for this driver */
1991 int status = 0;
1992
1993 dev_info(&adev->dev,
1994 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
1995 if (platform_info == NULL) {
1996 dev_err(&adev->dev, "probe - no platform data supplied\n");
1997 status = -ENODEV;
1998 goto err_no_pdata;
1999 }
2000
2001 /* Allocate master with space for data */
2002 master = spi_alloc_master(dev, sizeof(struct pl022));
2003 if (master == NULL) {
2004 dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2005 status = -ENOMEM;
2006 goto err_no_master;
2007 }
2008
2009 pl022 = spi_master_get_devdata(master);
2010 pl022->master = master;
2011 pl022->master_info = platform_info;
2012 pl022->adev = adev;
2013 pl022->vendor = id->data;
2014
2015 /*
2016 * Bus Number Which has been Assigned to this SSP controller
2017 * on this board
2018 */
2019 master->bus_num = platform_info->bus_id;
2020 master->num_chipselect = platform_info->num_chipselect;
2021 master->cleanup = pl022_cleanup;
2022 master->setup = pl022_setup;
2023 master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
2024 master->transfer_one_message = pl022_transfer_one_message;
2025 master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2026 master->rt = platform_info->rt;
2027
2028 /*
2029 * Supports mode 0-3, loopback, and active low CS. Transfers are
2030 * always MS bit first on the original pl022.
2031 */
2032 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2033 if (pl022->vendor->extended_cr)
2034 master->mode_bits |= SPI_LSB_FIRST;
2035
2036 dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2037
2038 status = amba_request_regions(adev, NULL);
2039 if (status)
2040 goto err_no_ioregion;
2041
2042 pl022->phybase = adev->res.start;
2043 pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
2044 if (pl022->virtbase == NULL) {
2045 status = -ENOMEM;
2046 goto err_no_ioremap;
2047 }
2048 printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n",
2049 adev->res.start, pl022->virtbase);
2050
2051 pl022->clk = clk_get(&adev->dev, NULL);
2052 if (IS_ERR(pl022->clk)) {
2053 status = PTR_ERR(pl022->clk);
2054 dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2055 goto err_no_clk;
2056 }
2057
2058 status = clk_prepare(pl022->clk);
2059 if (status) {
2060 dev_err(&adev->dev, "could not prepare SSP/SPI bus clock\n");
2061 goto err_clk_prep;
2062 }
2063
2064 status = clk_enable(pl022->clk);
2065 if (status) {
2066 dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2067 goto err_no_clk_en;
2068 }
2069
2070 /* Initialize transfer pump */
2071 tasklet_init(&pl022->pump_transfers, pump_transfers,
2072 (unsigned long)pl022);
2073
2074 /* Disable SSP */
2075 writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2076 SSP_CR1(pl022->virtbase));
2077 load_ssp_default_config(pl022);
2078
2079 status = request_irq(adev->irq[0], pl022_interrupt_handler, 0, "pl022",
2080 pl022);
2081 if (status < 0) {
2082 dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2083 goto err_no_irq;
2084 }
2085
2086 /* Get DMA channels */
2087 if (platform_info->enable_dma) {
2088 status = pl022_dma_probe(pl022);
2089 if (status != 0)
2090 platform_info->enable_dma = 0;
2091 }
2092
2093 /* Register with the SPI framework */
2094 amba_set_drvdata(adev, pl022);
2095 status = spi_register_master(master);
2096 if (status != 0) {
2097 dev_err(&adev->dev,
2098 "probe - problem registering spi master\n");
2099 goto err_spi_register;
2100 }
2101 dev_dbg(dev, "probe succeeded\n");
2102
2103 /* let runtime pm put suspend */
2104 if (platform_info->autosuspend_delay > 0) {
2105 dev_info(&adev->dev,
2106 "will use autosuspend for runtime pm, delay %dms\n",
2107 platform_info->autosuspend_delay);
2108 pm_runtime_set_autosuspend_delay(dev,
2109 platform_info->autosuspend_delay);
2110 pm_runtime_use_autosuspend(dev);
2111 pm_runtime_put_autosuspend(dev);
2112 } else {
2113 pm_runtime_put(dev);
2114 }
2115 return 0;
2116
2117 err_spi_register:
2118 if (platform_info->enable_dma)
2119 pl022_dma_remove(pl022);
2120
2121 free_irq(adev->irq[0], pl022);
2122 err_no_irq:
2123 clk_disable(pl022->clk);
2124 err_no_clk_en:
2125 clk_unprepare(pl022->clk);
2126 err_clk_prep:
2127 clk_put(pl022->clk);
2128 err_no_clk:
2129 iounmap(pl022->virtbase);
2130 err_no_ioremap:
2131 amba_release_regions(adev);
2132 err_no_ioregion:
2133 spi_master_put(master);
2134 err_no_master:
2135 err_no_pdata:
2136 return status;
2137 }
2138
2139 static int __devexit
2140 pl022_remove(struct amba_device *adev)
2141 {
2142 struct pl022 *pl022 = amba_get_drvdata(adev);
2143
2144 if (!pl022)
2145 return 0;
2146
2147 /*
2148 * undo pm_runtime_put() in probe. I assume that we're not
2149 * accessing the primecell here.
2150 */
2151 pm_runtime_get_noresume(&adev->dev);
2152
2153 load_ssp_default_config(pl022);
2154 if (pl022->master_info->enable_dma)
2155 pl022_dma_remove(pl022);
2156
2157 free_irq(adev->irq[0], pl022);
2158 clk_disable(pl022->clk);
2159 clk_unprepare(pl022->clk);
2160 clk_put(pl022->clk);
2161 iounmap(pl022->virtbase);
2162 amba_release_regions(adev);
2163 tasklet_disable(&pl022->pump_transfers);
2164 spi_unregister_master(pl022->master);
2165 spi_master_put(pl022->master);
2166 amba_set_drvdata(adev, NULL);
2167 return 0;
2168 }
2169
2170 #ifdef CONFIG_SUSPEND
2171 static int pl022_suspend(struct device *dev)
2172 {
2173 struct pl022 *pl022 = dev_get_drvdata(dev);
2174 int ret;
2175
2176 ret = spi_master_suspend(pl022->master);
2177 if (ret) {
2178 dev_warn(dev, "cannot suspend master\n");
2179 return ret;
2180 }
2181
2182 dev_dbg(dev, "suspended\n");
2183 return 0;
2184 }
2185
2186 static int pl022_resume(struct device *dev)
2187 {
2188 struct pl022 *pl022 = dev_get_drvdata(dev);
2189 int ret;
2190
2191 /* Start the queue running */
2192 ret = spi_master_resume(pl022->master);
2193 if (ret)
2194 dev_err(dev, "problem starting queue (%d)\n", ret);
2195 else
2196 dev_dbg(dev, "resumed\n");
2197
2198 return ret;
2199 }
2200 #endif /* CONFIG_PM */
2201
2202 #ifdef CONFIG_PM_RUNTIME
2203 static int pl022_runtime_suspend(struct device *dev)
2204 {
2205 struct pl022 *pl022 = dev_get_drvdata(dev);
2206
2207 clk_disable(pl022->clk);
2208
2209 return 0;
2210 }
2211
2212 static int pl022_runtime_resume(struct device *dev)
2213 {
2214 struct pl022 *pl022 = dev_get_drvdata(dev);
2215
2216 clk_enable(pl022->clk);
2217
2218 return 0;
2219 }
2220 #endif
2221
2222 static const struct dev_pm_ops pl022_dev_pm_ops = {
2223 SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2224 SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2225 };
2226
2227 static struct vendor_data vendor_arm = {
2228 .fifodepth = 8,
2229 .max_bpw = 16,
2230 .unidir = false,
2231 .extended_cr = false,
2232 .pl023 = false,
2233 .loopback = true,
2234 };
2235
2236 static struct vendor_data vendor_st = {
2237 .fifodepth = 32,
2238 .max_bpw = 32,
2239 .unidir = false,
2240 .extended_cr = true,
2241 .pl023 = false,
2242 .loopback = true,
2243 };
2244
2245 static struct vendor_data vendor_st_pl023 = {
2246 .fifodepth = 32,
2247 .max_bpw = 32,
2248 .unidir = false,
2249 .extended_cr = true,
2250 .pl023 = true,
2251 .loopback = false,
2252 };
2253
2254 static struct vendor_data vendor_db5500_pl023 = {
2255 .fifodepth = 32,
2256 .max_bpw = 32,
2257 .unidir = false,
2258 .extended_cr = true,
2259 .pl023 = true,
2260 .loopback = true,
2261 };
2262
2263 static struct amba_id pl022_ids[] = {
2264 {
2265 /*
2266 * ARM PL022 variant, this has a 16bit wide
2267 * and 8 locations deep TX/RX FIFO
2268 */
2269 .id = 0x00041022,
2270 .mask = 0x000fffff,
2271 .data = &vendor_arm,
2272 },
2273 {
2274 /*
2275 * ST Micro derivative, this has 32bit wide
2276 * and 32 locations deep TX/RX FIFO
2277 */
2278 .id = 0x01080022,
2279 .mask = 0xffffffff,
2280 .data = &vendor_st,
2281 },
2282 {
2283 /*
2284 * ST-Ericsson derivative "PL023" (this is not
2285 * an official ARM number), this is a PL022 SSP block
2286 * stripped to SPI mode only, it has 32bit wide
2287 * and 32 locations deep TX/RX FIFO but no extended
2288 * CR0/CR1 register
2289 */
2290 .id = 0x00080023,
2291 .mask = 0xffffffff,
2292 .data = &vendor_st_pl023,
2293 },
2294 {
2295 .id = 0x10080023,
2296 .mask = 0xffffffff,
2297 .data = &vendor_db5500_pl023,
2298 },
2299 { 0, 0 },
2300 };
2301
2302 MODULE_DEVICE_TABLE(amba, pl022_ids);
2303
2304 static struct amba_driver pl022_driver = {
2305 .drv = {
2306 .name = "ssp-pl022",
2307 .pm = &pl022_dev_pm_ops,
2308 },
2309 .id_table = pl022_ids,
2310 .probe = pl022_probe,
2311 .remove = __devexit_p(pl022_remove),
2312 };
2313
2314 static int __init pl022_init(void)
2315 {
2316 return amba_driver_register(&pl022_driver);
2317 }
2318 subsys_initcall(pl022_init);
2319
2320 static void __exit pl022_exit(void)
2321 {
2322 amba_driver_unregister(&pl022_driver);
2323 }
2324 module_exit(pl022_exit);
2325
2326 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2327 MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2328 MODULE_LICENSE("GPL");
Linux with added FPC-III support