Avoid beyond bounds copy while caching ACL
[zen-stable.git] / drivers / spi / spi-s3c64xx.c
blobdcf7e1006426d2fef19c8c62a38dac5b5a8b55b2
1 /*
2 * Copyright (C) 2009 Samsung Electronics Ltd.
3 * Jaswinder Singh <jassi.brar@samsung.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/workqueue.h>
23 #include <linux/delay.h>
24 #include <linux/clk.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/platform_device.h>
27 #include <linux/spi/spi.h>
29 #include <mach/dma.h>
30 #include <plat/s3c64xx-spi.h>
32 /* Registers and bit-fields */
34 #define S3C64XX_SPI_CH_CFG 0x00
35 #define S3C64XX_SPI_CLK_CFG 0x04
36 #define S3C64XX_SPI_MODE_CFG 0x08
37 #define S3C64XX_SPI_SLAVE_SEL 0x0C
38 #define S3C64XX_SPI_INT_EN 0x10
39 #define S3C64XX_SPI_STATUS 0x14
40 #define S3C64XX_SPI_TX_DATA 0x18
41 #define S3C64XX_SPI_RX_DATA 0x1C
42 #define S3C64XX_SPI_PACKET_CNT 0x20
43 #define S3C64XX_SPI_PENDING_CLR 0x24
44 #define S3C64XX_SPI_SWAP_CFG 0x28
45 #define S3C64XX_SPI_FB_CLK 0x2C
47 #define S3C64XX_SPI_CH_HS_EN (1<<6) /* High Speed Enable */
48 #define S3C64XX_SPI_CH_SW_RST (1<<5)
49 #define S3C64XX_SPI_CH_SLAVE (1<<4)
50 #define S3C64XX_SPI_CPOL_L (1<<3)
51 #define S3C64XX_SPI_CPHA_B (1<<2)
52 #define S3C64XX_SPI_CH_RXCH_ON (1<<1)
53 #define S3C64XX_SPI_CH_TXCH_ON (1<<0)
55 #define S3C64XX_SPI_CLKSEL_SRCMSK (3<<9)
56 #define S3C64XX_SPI_CLKSEL_SRCSHFT 9
57 #define S3C64XX_SPI_ENCLK_ENABLE (1<<8)
58 #define S3C64XX_SPI_PSR_MASK 0xff
60 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE (0<<29)
61 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD (1<<29)
62 #define S3C64XX_SPI_MODE_CH_TSZ_WORD (2<<29)
63 #define S3C64XX_SPI_MODE_CH_TSZ_MASK (3<<29)
64 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE (0<<17)
65 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17)
66 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17)
67 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17)
68 #define S3C64XX_SPI_MODE_RXDMA_ON (1<<2)
69 #define S3C64XX_SPI_MODE_TXDMA_ON (1<<1)
70 #define S3C64XX_SPI_MODE_4BURST (1<<0)
72 #define S3C64XX_SPI_SLAVE_AUTO (1<<1)
73 #define S3C64XX_SPI_SLAVE_SIG_INACT (1<<0)
75 #define S3C64XX_SPI_ACT(c) writel(0, (c)->regs + S3C64XX_SPI_SLAVE_SEL)
77 #define S3C64XX_SPI_DEACT(c) writel(S3C64XX_SPI_SLAVE_SIG_INACT, \
78 (c)->regs + S3C64XX_SPI_SLAVE_SEL)
80 #define S3C64XX_SPI_INT_TRAILING_EN (1<<6)
81 #define S3C64XX_SPI_INT_RX_OVERRUN_EN (1<<5)
82 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN (1<<4)
83 #define S3C64XX_SPI_INT_TX_OVERRUN_EN (1<<3)
84 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN (1<<2)
85 #define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1)
86 #define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0)
88 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5)
89 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4)
90 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR (1<<3)
91 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR (1<<2)
92 #define S3C64XX_SPI_ST_RX_FIFORDY (1<<1)
93 #define S3C64XX_SPI_ST_TX_FIFORDY (1<<0)
95 #define S3C64XX_SPI_PACKET_CNT_EN (1<<16)
97 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4)
98 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3)
99 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR (1<<2)
100 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR (1<<1)
101 #define S3C64XX_SPI_PND_TRAILING_CLR (1<<0)
103 #define S3C64XX_SPI_SWAP_RX_HALF_WORD (1<<7)
104 #define S3C64XX_SPI_SWAP_RX_BYTE (1<<6)
105 #define S3C64XX_SPI_SWAP_RX_BIT (1<<5)
106 #define S3C64XX_SPI_SWAP_RX_EN (1<<4)
107 #define S3C64XX_SPI_SWAP_TX_HALF_WORD (1<<3)
108 #define S3C64XX_SPI_SWAP_TX_BYTE (1<<2)
109 #define S3C64XX_SPI_SWAP_TX_BIT (1<<1)
110 #define S3C64XX_SPI_SWAP_TX_EN (1<<0)
112 #define S3C64XX_SPI_FBCLK_MSK (3<<0)
114 #define S3C64XX_SPI_ST_TRLCNTZ(v, i) ((((v) >> (i)->rx_lvl_offset) & \
115 (((i)->fifo_lvl_mask + 1))) \
116 ? 1 : 0)
118 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & (1 << (i)->tx_st_done)) ? 1 : 0)
119 #define TX_FIFO_LVL(v, i) (((v) >> 6) & (i)->fifo_lvl_mask)
120 #define RX_FIFO_LVL(v, i) (((v) >> (i)->rx_lvl_offset) & (i)->fifo_lvl_mask)
122 #define S3C64XX_SPI_MAX_TRAILCNT 0x3ff
123 #define S3C64XX_SPI_TRAILCNT_OFF 19
125 #define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT
127 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
129 #define SUSPND (1<<0)
130 #define SPIBUSY (1<<1)
131 #define RXBUSY (1<<2)
132 #define TXBUSY (1<<3)
134 struct s3c64xx_spi_dma_data {
135 unsigned ch;
136 enum dma_data_direction direction;
137 enum dma_ch dmach;
141 * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
142 * @clk: Pointer to the spi clock.
143 * @src_clk: Pointer to the clock used to generate SPI signals.
144 * @master: Pointer to the SPI Protocol master.
145 * @workqueue: Work queue for the SPI xfer requests.
146 * @cntrlr_info: Platform specific data for the controller this driver manages.
147 * @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
148 * @work: Work
149 * @queue: To log SPI xfer requests.
150 * @lock: Controller specific lock.
151 * @state: Set of FLAGS to indicate status.
152 * @rx_dmach: Controller's DMA channel for Rx.
153 * @tx_dmach: Controller's DMA channel for Tx.
154 * @sfr_start: BUS address of SPI controller regs.
155 * @regs: Pointer to ioremap'ed controller registers.
156 * @xfer_completion: To indicate completion of xfer task.
157 * @cur_mode: Stores the active configuration of the controller.
158 * @cur_bpw: Stores the active bits per word settings.
159 * @cur_speed: Stores the active xfer clock speed.
161 struct s3c64xx_spi_driver_data {
162 void __iomem *regs;
163 struct clk *clk;
164 struct clk *src_clk;
165 struct platform_device *pdev;
166 struct spi_master *master;
167 struct workqueue_struct *workqueue;
168 struct s3c64xx_spi_info *cntrlr_info;
169 struct spi_device *tgl_spi;
170 struct work_struct work;
171 struct list_head queue;
172 spinlock_t lock;
173 unsigned long sfr_start;
174 struct completion xfer_completion;
175 unsigned state;
176 unsigned cur_mode, cur_bpw;
177 unsigned cur_speed;
178 struct s3c64xx_spi_dma_data rx_dma;
179 struct s3c64xx_spi_dma_data tx_dma;
180 struct samsung_dma_ops *ops;
183 static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
184 .name = "samsung-spi-dma",
187 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
189 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
190 void __iomem *regs = sdd->regs;
191 unsigned long loops;
192 u32 val;
194 writel(0, regs + S3C64XX_SPI_PACKET_CNT);
196 val = readl(regs + S3C64XX_SPI_CH_CFG);
197 val |= S3C64XX_SPI_CH_SW_RST;
198 val &= ~S3C64XX_SPI_CH_HS_EN;
199 writel(val, regs + S3C64XX_SPI_CH_CFG);
201 /* Flush TxFIFO*/
202 loops = msecs_to_loops(1);
203 do {
204 val = readl(regs + S3C64XX_SPI_STATUS);
205 } while (TX_FIFO_LVL(val, sci) && loops--);
207 if (loops == 0)
208 dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
210 /* Flush RxFIFO*/
211 loops = msecs_to_loops(1);
212 do {
213 val = readl(regs + S3C64XX_SPI_STATUS);
214 if (RX_FIFO_LVL(val, sci))
215 readl(regs + S3C64XX_SPI_RX_DATA);
216 else
217 break;
218 } while (loops--);
220 if (loops == 0)
221 dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
223 val = readl(regs + S3C64XX_SPI_CH_CFG);
224 val &= ~S3C64XX_SPI_CH_SW_RST;
225 writel(val, regs + S3C64XX_SPI_CH_CFG);
227 val = readl(regs + S3C64XX_SPI_MODE_CFG);
228 val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
229 writel(val, regs + S3C64XX_SPI_MODE_CFG);
231 val = readl(regs + S3C64XX_SPI_CH_CFG);
232 val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
233 writel(val, regs + S3C64XX_SPI_CH_CFG);
236 static void s3c64xx_spi_dmacb(void *data)
238 struct s3c64xx_spi_driver_data *sdd;
239 struct s3c64xx_spi_dma_data *dma = data;
240 unsigned long flags;
242 if (dma->direction == DMA_FROM_DEVICE)
243 sdd = container_of(data,
244 struct s3c64xx_spi_driver_data, rx_dma);
245 else
246 sdd = container_of(data,
247 struct s3c64xx_spi_driver_data, tx_dma);
249 spin_lock_irqsave(&sdd->lock, flags);
251 if (dma->direction == DMA_FROM_DEVICE) {
252 sdd->state &= ~RXBUSY;
253 if (!(sdd->state & TXBUSY))
254 complete(&sdd->xfer_completion);
255 } else {
256 sdd->state &= ~TXBUSY;
257 if (!(sdd->state & RXBUSY))
258 complete(&sdd->xfer_completion);
261 spin_unlock_irqrestore(&sdd->lock, flags);
264 static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
265 unsigned len, dma_addr_t buf)
267 struct s3c64xx_spi_driver_data *sdd;
268 struct samsung_dma_prep_info info;
270 if (dma->direction == DMA_FROM_DEVICE)
271 sdd = container_of((void *)dma,
272 struct s3c64xx_spi_driver_data, rx_dma);
273 else
274 sdd = container_of((void *)dma,
275 struct s3c64xx_spi_driver_data, tx_dma);
277 info.cap = DMA_SLAVE;
278 info.len = len;
279 info.fp = s3c64xx_spi_dmacb;
280 info.fp_param = dma;
281 info.direction = dma->direction;
282 info.buf = buf;
284 sdd->ops->prepare(dma->ch, &info);
285 sdd->ops->trigger(dma->ch);
288 static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
290 struct samsung_dma_info info;
292 sdd->ops = samsung_dma_get_ops();
294 info.cap = DMA_SLAVE;
295 info.client = &s3c64xx_spi_dma_client;
296 info.width = sdd->cur_bpw / 8;
298 info.direction = sdd->rx_dma.direction;
299 info.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
300 sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &info);
301 info.direction = sdd->tx_dma.direction;
302 info.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
303 sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &info);
305 return 1;
308 static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
309 struct spi_device *spi,
310 struct spi_transfer *xfer, int dma_mode)
312 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
313 void __iomem *regs = sdd->regs;
314 u32 modecfg, chcfg;
316 modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
317 modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
319 chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
320 chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
322 if (dma_mode) {
323 chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
324 } else {
325 /* Always shift in data in FIFO, even if xfer is Tx only,
326 * this helps setting PCKT_CNT value for generating clocks
327 * as exactly needed.
329 chcfg |= S3C64XX_SPI_CH_RXCH_ON;
330 writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
331 | S3C64XX_SPI_PACKET_CNT_EN,
332 regs + S3C64XX_SPI_PACKET_CNT);
335 if (xfer->tx_buf != NULL) {
336 sdd->state |= TXBUSY;
337 chcfg |= S3C64XX_SPI_CH_TXCH_ON;
338 if (dma_mode) {
339 modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
340 prepare_dma(&sdd->tx_dma, xfer->len, xfer->tx_dma);
341 } else {
342 switch (sdd->cur_bpw) {
343 case 32:
344 iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
345 xfer->tx_buf, xfer->len / 4);
346 break;
347 case 16:
348 iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
349 xfer->tx_buf, xfer->len / 2);
350 break;
351 default:
352 iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
353 xfer->tx_buf, xfer->len);
354 break;
359 if (xfer->rx_buf != NULL) {
360 sdd->state |= RXBUSY;
362 if (sci->high_speed && sdd->cur_speed >= 30000000UL
363 && !(sdd->cur_mode & SPI_CPHA))
364 chcfg |= S3C64XX_SPI_CH_HS_EN;
366 if (dma_mode) {
367 modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
368 chcfg |= S3C64XX_SPI_CH_RXCH_ON;
369 writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
370 | S3C64XX_SPI_PACKET_CNT_EN,
371 regs + S3C64XX_SPI_PACKET_CNT);
372 prepare_dma(&sdd->rx_dma, xfer->len, xfer->rx_dma);
376 writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
377 writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
380 static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
381 struct spi_device *spi)
383 struct s3c64xx_spi_csinfo *cs;
385 if (sdd->tgl_spi != NULL) { /* If last device toggled after mssg */
386 if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
387 /* Deselect the last toggled device */
388 cs = sdd->tgl_spi->controller_data;
389 cs->set_level(cs->line,
390 spi->mode & SPI_CS_HIGH ? 0 : 1);
392 sdd->tgl_spi = NULL;
395 cs = spi->controller_data;
396 cs->set_level(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
399 static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
400 struct spi_transfer *xfer, int dma_mode)
402 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
403 void __iomem *regs = sdd->regs;
404 unsigned long val;
405 int ms;
407 /* millisecs to xfer 'len' bytes @ 'cur_speed' */
408 ms = xfer->len * 8 * 1000 / sdd->cur_speed;
409 ms += 10; /* some tolerance */
411 if (dma_mode) {
412 val = msecs_to_jiffies(ms) + 10;
413 val = wait_for_completion_timeout(&sdd->xfer_completion, val);
414 } else {
415 u32 status;
416 val = msecs_to_loops(ms);
417 do {
418 status = readl(regs + S3C64XX_SPI_STATUS);
419 } while (RX_FIFO_LVL(status, sci) < xfer->len && --val);
422 if (!val)
423 return -EIO;
425 if (dma_mode) {
426 u32 status;
429 * DmaTx returns after simply writing data in the FIFO,
430 * w/o waiting for real transmission on the bus to finish.
431 * DmaRx returns only after Dma read data from FIFO which
432 * needs bus transmission to finish, so we don't worry if
433 * Xfer involved Rx(with or without Tx).
435 if (xfer->rx_buf == NULL) {
436 val = msecs_to_loops(10);
437 status = readl(regs + S3C64XX_SPI_STATUS);
438 while ((TX_FIFO_LVL(status, sci)
439 || !S3C64XX_SPI_ST_TX_DONE(status, sci))
440 && --val) {
441 cpu_relax();
442 status = readl(regs + S3C64XX_SPI_STATUS);
445 if (!val)
446 return -EIO;
448 } else {
449 /* If it was only Tx */
450 if (xfer->rx_buf == NULL) {
451 sdd->state &= ~TXBUSY;
452 return 0;
455 switch (sdd->cur_bpw) {
456 case 32:
457 ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
458 xfer->rx_buf, xfer->len / 4);
459 break;
460 case 16:
461 ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
462 xfer->rx_buf, xfer->len / 2);
463 break;
464 default:
465 ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
466 xfer->rx_buf, xfer->len);
467 break;
469 sdd->state &= ~RXBUSY;
472 return 0;
475 static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
476 struct spi_device *spi)
478 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
480 if (sdd->tgl_spi == spi)
481 sdd->tgl_spi = NULL;
483 cs->set_level(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
486 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
488 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
489 void __iomem *regs = sdd->regs;
490 u32 val;
492 /* Disable Clock */
493 if (sci->clk_from_cmu) {
494 clk_disable(sdd->src_clk);
495 } else {
496 val = readl(regs + S3C64XX_SPI_CLK_CFG);
497 val &= ~S3C64XX_SPI_ENCLK_ENABLE;
498 writel(val, regs + S3C64XX_SPI_CLK_CFG);
501 /* Set Polarity and Phase */
502 val = readl(regs + S3C64XX_SPI_CH_CFG);
503 val &= ~(S3C64XX_SPI_CH_SLAVE |
504 S3C64XX_SPI_CPOL_L |
505 S3C64XX_SPI_CPHA_B);
507 if (sdd->cur_mode & SPI_CPOL)
508 val |= S3C64XX_SPI_CPOL_L;
510 if (sdd->cur_mode & SPI_CPHA)
511 val |= S3C64XX_SPI_CPHA_B;
513 writel(val, regs + S3C64XX_SPI_CH_CFG);
515 /* Set Channel & DMA Mode */
516 val = readl(regs + S3C64XX_SPI_MODE_CFG);
517 val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
518 | S3C64XX_SPI_MODE_CH_TSZ_MASK);
520 switch (sdd->cur_bpw) {
521 case 32:
522 val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
523 val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
524 break;
525 case 16:
526 val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
527 val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
528 break;
529 default:
530 val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
531 val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
532 break;
535 writel(val, regs + S3C64XX_SPI_MODE_CFG);
537 if (sci->clk_from_cmu) {
538 /* Configure Clock */
539 /* There is half-multiplier before the SPI */
540 clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
541 /* Enable Clock */
542 clk_enable(sdd->src_clk);
543 } else {
544 /* Configure Clock */
545 val = readl(regs + S3C64XX_SPI_CLK_CFG);
546 val &= ~S3C64XX_SPI_PSR_MASK;
547 val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
548 & S3C64XX_SPI_PSR_MASK);
549 writel(val, regs + S3C64XX_SPI_CLK_CFG);
551 /* Enable Clock */
552 val = readl(regs + S3C64XX_SPI_CLK_CFG);
553 val |= S3C64XX_SPI_ENCLK_ENABLE;
554 writel(val, regs + S3C64XX_SPI_CLK_CFG);
558 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
560 static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
561 struct spi_message *msg)
563 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
564 struct device *dev = &sdd->pdev->dev;
565 struct spi_transfer *xfer;
567 if (msg->is_dma_mapped)
568 return 0;
570 /* First mark all xfer unmapped */
571 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
572 xfer->rx_dma = XFER_DMAADDR_INVALID;
573 xfer->tx_dma = XFER_DMAADDR_INVALID;
576 /* Map until end or first fail */
577 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
579 if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1))
580 continue;
582 if (xfer->tx_buf != NULL) {
583 xfer->tx_dma = dma_map_single(dev,
584 (void *)xfer->tx_buf, xfer->len,
585 DMA_TO_DEVICE);
586 if (dma_mapping_error(dev, xfer->tx_dma)) {
587 dev_err(dev, "dma_map_single Tx failed\n");
588 xfer->tx_dma = XFER_DMAADDR_INVALID;
589 return -ENOMEM;
593 if (xfer->rx_buf != NULL) {
594 xfer->rx_dma = dma_map_single(dev, xfer->rx_buf,
595 xfer->len, DMA_FROM_DEVICE);
596 if (dma_mapping_error(dev, xfer->rx_dma)) {
597 dev_err(dev, "dma_map_single Rx failed\n");
598 dma_unmap_single(dev, xfer->tx_dma,
599 xfer->len, DMA_TO_DEVICE);
600 xfer->tx_dma = XFER_DMAADDR_INVALID;
601 xfer->rx_dma = XFER_DMAADDR_INVALID;
602 return -ENOMEM;
607 return 0;
610 static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
611 struct spi_message *msg)
613 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
614 struct device *dev = &sdd->pdev->dev;
615 struct spi_transfer *xfer;
617 if (msg->is_dma_mapped)
618 return;
620 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
622 if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1))
623 continue;
625 if (xfer->rx_buf != NULL
626 && xfer->rx_dma != XFER_DMAADDR_INVALID)
627 dma_unmap_single(dev, xfer->rx_dma,
628 xfer->len, DMA_FROM_DEVICE);
630 if (xfer->tx_buf != NULL
631 && xfer->tx_dma != XFER_DMAADDR_INVALID)
632 dma_unmap_single(dev, xfer->tx_dma,
633 xfer->len, DMA_TO_DEVICE);
637 static void handle_msg(struct s3c64xx_spi_driver_data *sdd,
638 struct spi_message *msg)
640 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
641 struct spi_device *spi = msg->spi;
642 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
643 struct spi_transfer *xfer;
644 int status = 0, cs_toggle = 0;
645 u32 speed;
646 u8 bpw;
648 /* If Master's(controller) state differs from that needed by Slave */
649 if (sdd->cur_speed != spi->max_speed_hz
650 || sdd->cur_mode != spi->mode
651 || sdd->cur_bpw != spi->bits_per_word) {
652 sdd->cur_bpw = spi->bits_per_word;
653 sdd->cur_speed = spi->max_speed_hz;
654 sdd->cur_mode = spi->mode;
655 s3c64xx_spi_config(sdd);
658 /* Map all the transfers if needed */
659 if (s3c64xx_spi_map_mssg(sdd, msg)) {
660 dev_err(&spi->dev,
661 "Xfer: Unable to map message buffers!\n");
662 status = -ENOMEM;
663 goto out;
666 /* Configure feedback delay */
667 writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
669 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
671 unsigned long flags;
672 int use_dma;
674 INIT_COMPLETION(sdd->xfer_completion);
676 /* Only BPW and Speed may change across transfers */
677 bpw = xfer->bits_per_word ? : spi->bits_per_word;
678 speed = xfer->speed_hz ? : spi->max_speed_hz;
680 if (xfer->len % (bpw / 8)) {
681 dev_err(&spi->dev,
682 "Xfer length(%u) not a multiple of word size(%u)\n",
683 xfer->len, bpw / 8);
684 status = -EIO;
685 goto out;
688 if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
689 sdd->cur_bpw = bpw;
690 sdd->cur_speed = speed;
691 s3c64xx_spi_config(sdd);
694 /* Polling method for xfers not bigger than FIFO capacity */
695 if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1))
696 use_dma = 0;
697 else
698 use_dma = 1;
700 spin_lock_irqsave(&sdd->lock, flags);
702 /* Pending only which is to be done */
703 sdd->state &= ~RXBUSY;
704 sdd->state &= ~TXBUSY;
706 enable_datapath(sdd, spi, xfer, use_dma);
708 /* Slave Select */
709 enable_cs(sdd, spi);
711 /* Start the signals */
712 S3C64XX_SPI_ACT(sdd);
714 spin_unlock_irqrestore(&sdd->lock, flags);
716 status = wait_for_xfer(sdd, xfer, use_dma);
718 /* Quiese the signals */
719 S3C64XX_SPI_DEACT(sdd);
721 if (status) {
722 dev_err(&spi->dev, "I/O Error: "
723 "rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
724 xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
725 (sdd->state & RXBUSY) ? 'f' : 'p',
726 (sdd->state & TXBUSY) ? 'f' : 'p',
727 xfer->len);
729 if (use_dma) {
730 if (xfer->tx_buf != NULL
731 && (sdd->state & TXBUSY))
732 sdd->ops->stop(sdd->tx_dma.ch);
733 if (xfer->rx_buf != NULL
734 && (sdd->state & RXBUSY))
735 sdd->ops->stop(sdd->rx_dma.ch);
738 goto out;
741 if (xfer->delay_usecs)
742 udelay(xfer->delay_usecs);
744 if (xfer->cs_change) {
745 /* Hint that the next mssg is gonna be
746 for the same device */
747 if (list_is_last(&xfer->transfer_list,
748 &msg->transfers))
749 cs_toggle = 1;
750 else
751 disable_cs(sdd, spi);
754 msg->actual_length += xfer->len;
756 flush_fifo(sdd);
759 out:
760 if (!cs_toggle || status)
761 disable_cs(sdd, spi);
762 else
763 sdd->tgl_spi = spi;
765 s3c64xx_spi_unmap_mssg(sdd, msg);
767 msg->status = status;
769 if (msg->complete)
770 msg->complete(msg->context);
773 static void s3c64xx_spi_work(struct work_struct *work)
775 struct s3c64xx_spi_driver_data *sdd = container_of(work,
776 struct s3c64xx_spi_driver_data, work);
777 unsigned long flags;
779 /* Acquire DMA channels */
780 while (!acquire_dma(sdd))
781 msleep(10);
783 spin_lock_irqsave(&sdd->lock, flags);
785 while (!list_empty(&sdd->queue)
786 && !(sdd->state & SUSPND)) {
788 struct spi_message *msg;
790 msg = container_of(sdd->queue.next, struct spi_message, queue);
792 list_del_init(&msg->queue);
794 /* Set Xfer busy flag */
795 sdd->state |= SPIBUSY;
797 spin_unlock_irqrestore(&sdd->lock, flags);
799 handle_msg(sdd, msg);
801 spin_lock_irqsave(&sdd->lock, flags);
803 sdd->state &= ~SPIBUSY;
806 spin_unlock_irqrestore(&sdd->lock, flags);
808 /* Free DMA channels */
809 sdd->ops->release(sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
810 sdd->ops->release(sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
813 static int s3c64xx_spi_transfer(struct spi_device *spi,
814 struct spi_message *msg)
816 struct s3c64xx_spi_driver_data *sdd;
817 unsigned long flags;
819 sdd = spi_master_get_devdata(spi->master);
821 spin_lock_irqsave(&sdd->lock, flags);
823 if (sdd->state & SUSPND) {
824 spin_unlock_irqrestore(&sdd->lock, flags);
825 return -ESHUTDOWN;
828 msg->status = -EINPROGRESS;
829 msg->actual_length = 0;
831 list_add_tail(&msg->queue, &sdd->queue);
833 queue_work(sdd->workqueue, &sdd->work);
835 spin_unlock_irqrestore(&sdd->lock, flags);
837 return 0;
841 * Here we only check the validity of requested configuration
842 * and save the configuration in a local data-structure.
843 * The controller is actually configured only just before we
844 * get a message to transfer.
846 static int s3c64xx_spi_setup(struct spi_device *spi)
848 struct s3c64xx_spi_csinfo *cs = spi->controller_data;
849 struct s3c64xx_spi_driver_data *sdd;
850 struct s3c64xx_spi_info *sci;
851 struct spi_message *msg;
852 unsigned long flags;
853 int err = 0;
855 if (cs == NULL || cs->set_level == NULL) {
856 dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
857 return -ENODEV;
860 sdd = spi_master_get_devdata(spi->master);
861 sci = sdd->cntrlr_info;
863 spin_lock_irqsave(&sdd->lock, flags);
865 list_for_each_entry(msg, &sdd->queue, queue) {
866 /* Is some mssg is already queued for this device */
867 if (msg->spi == spi) {
868 dev_err(&spi->dev,
869 "setup: attempt while mssg in queue!\n");
870 spin_unlock_irqrestore(&sdd->lock, flags);
871 return -EBUSY;
875 if (sdd->state & SUSPND) {
876 spin_unlock_irqrestore(&sdd->lock, flags);
877 dev_err(&spi->dev,
878 "setup: SPI-%d not active!\n", spi->master->bus_num);
879 return -ESHUTDOWN;
882 spin_unlock_irqrestore(&sdd->lock, flags);
884 if (spi->bits_per_word != 8
885 && spi->bits_per_word != 16
886 && spi->bits_per_word != 32) {
887 dev_err(&spi->dev, "setup: %dbits/wrd not supported!\n",
888 spi->bits_per_word);
889 err = -EINVAL;
890 goto setup_exit;
893 /* Check if we can provide the requested rate */
894 if (!sci->clk_from_cmu) {
895 u32 psr, speed;
897 /* Max possible */
898 speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
900 if (spi->max_speed_hz > speed)
901 spi->max_speed_hz = speed;
903 psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
904 psr &= S3C64XX_SPI_PSR_MASK;
905 if (psr == S3C64XX_SPI_PSR_MASK)
906 psr--;
908 speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
909 if (spi->max_speed_hz < speed) {
910 if (psr+1 < S3C64XX_SPI_PSR_MASK) {
911 psr++;
912 } else {
913 err = -EINVAL;
914 goto setup_exit;
918 speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
919 if (spi->max_speed_hz >= speed)
920 spi->max_speed_hz = speed;
921 else
922 err = -EINVAL;
925 setup_exit:
927 /* setup() returns with device de-selected */
928 disable_cs(sdd, spi);
930 return err;
933 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
935 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
936 void __iomem *regs = sdd->regs;
937 unsigned int val;
939 sdd->cur_speed = 0;
941 S3C64XX_SPI_DEACT(sdd);
943 /* Disable Interrupts - we use Polling if not DMA mode */
944 writel(0, regs + S3C64XX_SPI_INT_EN);
946 if (!sci->clk_from_cmu)
947 writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
948 regs + S3C64XX_SPI_CLK_CFG);
949 writel(0, regs + S3C64XX_SPI_MODE_CFG);
950 writel(0, regs + S3C64XX_SPI_PACKET_CNT);
952 /* Clear any irq pending bits */
953 writel(readl(regs + S3C64XX_SPI_PENDING_CLR),
954 regs + S3C64XX_SPI_PENDING_CLR);
956 writel(0, regs + S3C64XX_SPI_SWAP_CFG);
958 val = readl(regs + S3C64XX_SPI_MODE_CFG);
959 val &= ~S3C64XX_SPI_MODE_4BURST;
960 val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
961 val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
962 writel(val, regs + S3C64XX_SPI_MODE_CFG);
964 flush_fifo(sdd);
967 static int __init s3c64xx_spi_probe(struct platform_device *pdev)
969 struct resource *mem_res, *dmatx_res, *dmarx_res;
970 struct s3c64xx_spi_driver_data *sdd;
971 struct s3c64xx_spi_info *sci;
972 struct spi_master *master;
973 int ret;
974 char clk_name[16];
976 if (pdev->id < 0) {
977 dev_err(&pdev->dev,
978 "Invalid platform device id-%d\n", pdev->id);
979 return -ENODEV;
982 if (pdev->dev.platform_data == NULL) {
983 dev_err(&pdev->dev, "platform_data missing!\n");
984 return -ENODEV;
987 sci = pdev->dev.platform_data;
989 /* Check for availability of necessary resource */
991 dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
992 if (dmatx_res == NULL) {
993 dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n");
994 return -ENXIO;
997 dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
998 if (dmarx_res == NULL) {
999 dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n");
1000 return -ENXIO;
1003 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1004 if (mem_res == NULL) {
1005 dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1006 return -ENXIO;
1009 master = spi_alloc_master(&pdev->dev,
1010 sizeof(struct s3c64xx_spi_driver_data));
1011 if (master == NULL) {
1012 dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1013 return -ENOMEM;
1016 platform_set_drvdata(pdev, master);
1018 sdd = spi_master_get_devdata(master);
1019 sdd->master = master;
1020 sdd->cntrlr_info = sci;
1021 sdd->pdev = pdev;
1022 sdd->sfr_start = mem_res->start;
1023 sdd->tx_dma.dmach = dmatx_res->start;
1024 sdd->tx_dma.direction = DMA_TO_DEVICE;
1025 sdd->rx_dma.dmach = dmarx_res->start;
1026 sdd->rx_dma.direction = DMA_FROM_DEVICE;
1028 sdd->cur_bpw = 8;
1030 master->bus_num = pdev->id;
1031 master->setup = s3c64xx_spi_setup;
1032 master->transfer = s3c64xx_spi_transfer;
1033 master->num_chipselect = sci->num_cs;
1034 master->dma_alignment = 8;
1035 /* the spi->mode bits understood by this driver: */
1036 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1038 if (request_mem_region(mem_res->start,
1039 resource_size(mem_res), pdev->name) == NULL) {
1040 dev_err(&pdev->dev, "Req mem region failed\n");
1041 ret = -ENXIO;
1042 goto err0;
1045 sdd->regs = ioremap(mem_res->start, resource_size(mem_res));
1046 if (sdd->regs == NULL) {
1047 dev_err(&pdev->dev, "Unable to remap IO\n");
1048 ret = -ENXIO;
1049 goto err1;
1052 if (sci->cfg_gpio == NULL || sci->cfg_gpio(pdev)) {
1053 dev_err(&pdev->dev, "Unable to config gpio\n");
1054 ret = -EBUSY;
1055 goto err2;
1058 /* Setup clocks */
1059 sdd->clk = clk_get(&pdev->dev, "spi");
1060 if (IS_ERR(sdd->clk)) {
1061 dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1062 ret = PTR_ERR(sdd->clk);
1063 goto err3;
1066 if (clk_enable(sdd->clk)) {
1067 dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1068 ret = -EBUSY;
1069 goto err4;
1072 sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1073 sdd->src_clk = clk_get(&pdev->dev, clk_name);
1074 if (IS_ERR(sdd->src_clk)) {
1075 dev_err(&pdev->dev,
1076 "Unable to acquire clock '%s'\n", clk_name);
1077 ret = PTR_ERR(sdd->src_clk);
1078 goto err5;
1081 if (clk_enable(sdd->src_clk)) {
1082 dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1083 ret = -EBUSY;
1084 goto err6;
1087 sdd->workqueue = create_singlethread_workqueue(
1088 dev_name(master->dev.parent));
1089 if (sdd->workqueue == NULL) {
1090 dev_err(&pdev->dev, "Unable to create workqueue\n");
1091 ret = -ENOMEM;
1092 goto err7;
1095 /* Setup Deufult Mode */
1096 s3c64xx_spi_hwinit(sdd, pdev->id);
1098 spin_lock_init(&sdd->lock);
1099 init_completion(&sdd->xfer_completion);
1100 INIT_WORK(&sdd->work, s3c64xx_spi_work);
1101 INIT_LIST_HEAD(&sdd->queue);
1103 if (spi_register_master(master)) {
1104 dev_err(&pdev->dev, "cannot register SPI master\n");
1105 ret = -EBUSY;
1106 goto err8;
1109 dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d "
1110 "with %d Slaves attached\n",
1111 pdev->id, master->num_chipselect);
1112 dev_dbg(&pdev->dev, "\tIOmem=[0x%x-0x%x]\tDMA=[Rx-%d, Tx-%d]\n",
1113 mem_res->end, mem_res->start,
1114 sdd->rx_dma.dmach, sdd->tx_dma.dmach);
1116 return 0;
1118 err8:
1119 destroy_workqueue(sdd->workqueue);
1120 err7:
1121 clk_disable(sdd->src_clk);
1122 err6:
1123 clk_put(sdd->src_clk);
1124 err5:
1125 clk_disable(sdd->clk);
1126 err4:
1127 clk_put(sdd->clk);
1128 err3:
1129 err2:
1130 iounmap((void *) sdd->regs);
1131 err1:
1132 release_mem_region(mem_res->start, resource_size(mem_res));
1133 err0:
1134 platform_set_drvdata(pdev, NULL);
1135 spi_master_put(master);
1137 return ret;
1140 static int s3c64xx_spi_remove(struct platform_device *pdev)
1142 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1143 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1144 struct resource *mem_res;
1145 unsigned long flags;
1147 spin_lock_irqsave(&sdd->lock, flags);
1148 sdd->state |= SUSPND;
1149 spin_unlock_irqrestore(&sdd->lock, flags);
1151 while (sdd->state & SPIBUSY)
1152 msleep(10);
1154 spi_unregister_master(master);
1156 destroy_workqueue(sdd->workqueue);
1158 clk_disable(sdd->src_clk);
1159 clk_put(sdd->src_clk);
1161 clk_disable(sdd->clk);
1162 clk_put(sdd->clk);
1164 iounmap((void *) sdd->regs);
1166 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1167 if (mem_res != NULL)
1168 release_mem_region(mem_res->start, resource_size(mem_res));
1170 platform_set_drvdata(pdev, NULL);
1171 spi_master_put(master);
1173 return 0;
1176 #ifdef CONFIG_PM
1177 static int s3c64xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1179 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1180 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1181 unsigned long flags;
1183 spin_lock_irqsave(&sdd->lock, flags);
1184 sdd->state |= SUSPND;
1185 spin_unlock_irqrestore(&sdd->lock, flags);
1187 while (sdd->state & SPIBUSY)
1188 msleep(10);
1190 /* Disable the clock */
1191 clk_disable(sdd->src_clk);
1192 clk_disable(sdd->clk);
1194 sdd->cur_speed = 0; /* Output Clock is stopped */
1196 return 0;
1199 static int s3c64xx_spi_resume(struct platform_device *pdev)
1201 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
1202 struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1203 struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1204 unsigned long flags;
1206 sci->cfg_gpio(pdev);
1208 /* Enable the clock */
1209 clk_enable(sdd->src_clk);
1210 clk_enable(sdd->clk);
1212 s3c64xx_spi_hwinit(sdd, pdev->id);
1214 spin_lock_irqsave(&sdd->lock, flags);
1215 sdd->state &= ~SUSPND;
1216 spin_unlock_irqrestore(&sdd->lock, flags);
1218 return 0;
1220 #else
1221 #define s3c64xx_spi_suspend NULL
1222 #define s3c64xx_spi_resume NULL
1223 #endif /* CONFIG_PM */
1225 static struct platform_driver s3c64xx_spi_driver = {
1226 .driver = {
1227 .name = "s3c64xx-spi",
1228 .owner = THIS_MODULE,
1230 .remove = s3c64xx_spi_remove,
1231 .suspend = s3c64xx_spi_suspend,
1232 .resume = s3c64xx_spi_resume,
1234 MODULE_ALIAS("platform:s3c64xx-spi");
1236 static int __init s3c64xx_spi_init(void)
1238 return platform_driver_probe(&s3c64xx_spi_driver, s3c64xx_spi_probe);
1240 subsys_initcall(s3c64xx_spi_init);
1242 static void __exit s3c64xx_spi_exit(void)
1244 platform_driver_unregister(&s3c64xx_spi_driver);
1246 module_exit(s3c64xx_spi_exit);
1248 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1249 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1250 MODULE_LICENSE("GPL");