2 * MPC512x PSC in SPI mode driver.
4 * Copyright (C) 2007,2008 Freescale Semiconductor Inc.
5 * Original port from 52xx driver:
6 * Hongjun Chen <hong-jun.chen@freescale.com>
8 * Fork of mpc52xx_psc_spi.c:
9 * Copyright (C) 2006 TOPTICA Photonics AG., Dragos Carp
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/interrupt.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_platform.h>
24 #include <linux/completion.h>
26 #include <linux/delay.h>
27 #include <linux/clk.h>
28 #include <linux/spi/spi.h>
29 #include <linux/fsl_devices.h>
30 #include <linux/gpio.h>
31 #include <asm/mpc52xx_psc.h>
39 * This macro abstracts the differences in the PSC register layout between
40 * MPC5121 (which uses a struct mpc52xx_psc) and MPC5125 (using mpc5125_psc).
42 #define psc_addr(mps, regname) ({ \
44 switch (mps->type) { \
45 case TYPE_MPC5121: { \
46 struct mpc52xx_psc __iomem *psc = mps->psc; \
47 __ret = &psc->regname; \
50 case TYPE_MPC5125: { \
51 struct mpc5125_psc __iomem *psc = mps->psc; \
52 __ret = &psc->regname; \
58 struct mpc512x_psc_spi
{
59 void (*cs_control
)(struct spi_device
*spi
, bool on
);
61 /* driver internal data */
64 struct mpc512x_psc_fifo __iomem
*fifo
;
71 struct completion txisrdone
;
74 /* controller state */
75 struct mpc512x_psc_spi_cs
{
80 /* set clock freq, clock ramp, bits per work
81 * if t is NULL then reset the values to the default values
83 static int mpc512x_psc_spi_transfer_setup(struct spi_device
*spi
,
84 struct spi_transfer
*t
)
86 struct mpc512x_psc_spi_cs
*cs
= spi
->controller_state
;
88 cs
->speed_hz
= (t
&& t
->speed_hz
)
89 ? t
->speed_hz
: spi
->max_speed_hz
;
90 cs
->bits_per_word
= (t
&& t
->bits_per_word
)
91 ? t
->bits_per_word
: spi
->bits_per_word
;
92 cs
->bits_per_word
= ((cs
->bits_per_word
+ 7) / 8) * 8;
96 static void mpc512x_psc_spi_activate_cs(struct spi_device
*spi
)
98 struct mpc512x_psc_spi_cs
*cs
= spi
->controller_state
;
99 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(spi
->master
);
105 sicr
= in_be32(psc_addr(mps
, sicr
));
107 /* Set clock phase and polarity */
108 if (spi
->mode
& SPI_CPHA
)
113 if (spi
->mode
& SPI_CPOL
)
118 if (spi
->mode
& SPI_LSB_FIRST
)
122 out_be32(psc_addr(mps
, sicr
), sicr
);
124 ccr
= in_be32(psc_addr(mps
, ccr
));
126 speed
= cs
->speed_hz
;
128 speed
= 1000000; /* default 1MHz */
129 bclkdiv
= (mps
->mclk_rate
/ speed
) - 1;
131 ccr
|= (((bclkdiv
& 0xff) << 16) | (((bclkdiv
>> 8) & 0xff) << 8));
132 out_be32(psc_addr(mps
, ccr
), ccr
);
133 mps
->bits_per_word
= cs
->bits_per_word
;
135 if (mps
->cs_control
&& gpio_is_valid(spi
->cs_gpio
))
136 mps
->cs_control(spi
, (spi
->mode
& SPI_CS_HIGH
) ? 1 : 0);
139 static void mpc512x_psc_spi_deactivate_cs(struct spi_device
*spi
)
141 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(spi
->master
);
143 if (mps
->cs_control
&& gpio_is_valid(spi
->cs_gpio
))
144 mps
->cs_control(spi
, (spi
->mode
& SPI_CS_HIGH
) ? 0 : 1);
148 /* extract and scale size field in txsz or rxsz */
149 #define MPC512x_PSC_FIFO_SZ(sz) ((sz & 0x7ff) << 2);
153 static int mpc512x_psc_spi_transfer_rxtx(struct spi_device
*spi
,
154 struct spi_transfer
*t
)
156 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(spi
->master
);
157 struct mpc512x_psc_fifo __iomem
*fifo
= mps
->fifo
;
158 size_t tx_len
= t
->len
;
159 size_t rx_len
= t
->len
;
160 u8
*tx_buf
= (u8
*)t
->tx_buf
;
161 u8
*rx_buf
= (u8
*)t
->rx_buf
;
163 if (!tx_buf
&& !rx_buf
&& t
->len
)
166 while (rx_len
|| tx_len
) {
174 * send the TX bytes in as large a chunk as possible
175 * but neither exceed the TX nor the RX FIFOs
177 fifosz
= MPC512x_PSC_FIFO_SZ(in_be32(&fifo
->txsz
));
178 txcount
= min(fifosz
, tx_len
);
179 fifosz
= MPC512x_PSC_FIFO_SZ(in_be32(&fifo
->rxsz
));
180 fifosz
-= in_be32(&fifo
->rxcnt
) + 1;
181 txcount
= min(fifosz
, txcount
);
184 /* fill the TX FIFO */
185 while (txcount
-- > 0) {
186 data
= tx_buf
? *tx_buf
++ : 0;
187 if (tx_len
== EOFBYTE
&& t
->cs_change
)
188 setbits32(&fifo
->txcmd
,
189 MPC512x_PSC_FIFO_EOF
);
190 out_8(&fifo
->txdata_8
, data
);
194 /* have the ISR trigger when the TX FIFO is empty */
195 reinit_completion(&mps
->txisrdone
);
196 out_be32(&fifo
->txisr
, MPC512x_PSC_FIFO_EMPTY
);
197 out_be32(&fifo
->tximr
, MPC512x_PSC_FIFO_EMPTY
);
198 wait_for_completion(&mps
->txisrdone
);
202 * consume as much RX data as the FIFO holds, while we
203 * iterate over the transfer's TX data length
205 * only insist in draining all the remaining RX bytes
206 * when the TX bytes were exhausted (that's at the very
207 * end of this transfer, not when still iterating over
208 * the transfer's chunks)
214 * grab whatever was in the FIFO when we started
215 * looking, don't bother fetching what was added to
216 * the FIFO while we read from it -- we'll return
217 * here eventually and prefer sending out remaining
220 fifosz
= in_be32(&fifo
->rxcnt
);
221 rxcount
= min(fifosz
, rx_len
);
222 while (rxcount
-- > 0) {
223 data
= in_8(&fifo
->rxdata_8
);
230 * come back later if there still is TX data to send,
231 * bail out of the RX drain loop if all of the TX data
232 * was sent and all of the RX data was received (i.e.
233 * when the transmission has completed)
241 * TX data transmission has completed while RX data
242 * is still pending -- that's a transient situation
243 * which depends on wire speed and specific
244 * hardware implementation details (buffering) yet
245 * should resolve very quickly
247 * just yield for a moment to not hog the CPU for
248 * too long when running SPI at low speed
250 * the timeout range is rather arbitrary and tries
251 * to balance throughput against system load; the
252 * chosen values result in a minimal timeout of 50
253 * times 10us and thus work at speeds as low as
254 * some 20kbps, while the maximum timeout at the
255 * transfer's end could be 5ms _if_ nothing else
256 * ticks in the system _and_ RX data still wasn't
257 * received, which only occurs in situations that
258 * are exceptional; removing the unpredictability
259 * of the timeout either decreases throughput
260 * (longer timeouts), or puts more load on the
261 * system (fixed short timeouts) or requires the
262 * use of a timeout API instead of a counter and an
263 * unknown inner delay
265 usleep_range(10, 100);
267 } while (--rxtries
> 0);
268 if (!tx_len
&& rx_len
&& !rxtries
) {
270 * not enough RX bytes even after several retries
271 * and the resulting rather long timeout?
273 rxcount
= in_be32(&fifo
->rxcnt
);
275 "short xfer, missing %zd RX bytes, FIFO level %zd\n",
280 * drain and drop RX data which "should not be there" in
281 * the first place, for undisturbed transmission this turns
282 * into a NOP (except for the FIFO level fetch)
284 if (!tx_len
&& !rx_len
) {
285 while (in_be32(&fifo
->rxcnt
))
286 in_8(&fifo
->rxdata_8
);
293 static int mpc512x_psc_spi_msg_xfer(struct spi_master
*master
,
294 struct spi_message
*m
)
296 struct spi_device
*spi
;
299 struct spi_transfer
*t
;
304 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
305 status
= mpc512x_psc_spi_transfer_setup(spi
, t
);
310 mpc512x_psc_spi_activate_cs(spi
);
311 cs_change
= t
->cs_change
;
313 status
= mpc512x_psc_spi_transfer_rxtx(spi
, t
);
316 m
->actual_length
+= t
->len
;
319 udelay(t
->delay_usecs
);
322 mpc512x_psc_spi_deactivate_cs(spi
);
327 m
->complete(m
->context
);
329 if (status
|| !cs_change
)
330 mpc512x_psc_spi_deactivate_cs(spi
);
332 mpc512x_psc_spi_transfer_setup(spi
, NULL
);
334 spi_finalize_current_message(master
);
338 static int mpc512x_psc_spi_prep_xfer_hw(struct spi_master
*master
)
340 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(master
);
342 dev_dbg(&master
->dev
, "%s()\n", __func__
);
345 in_8(psc_addr(mps
, mr2
));
346 out_8(psc_addr(mps
, mr2
), 0x0);
348 /* enable transmitter/receiver */
349 out_8(psc_addr(mps
, command
), MPC52xx_PSC_TX_ENABLE
| MPC52xx_PSC_RX_ENABLE
);
354 static int mpc512x_psc_spi_unprep_xfer_hw(struct spi_master
*master
)
356 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(master
);
357 struct mpc512x_psc_fifo __iomem
*fifo
= mps
->fifo
;
359 dev_dbg(&master
->dev
, "%s()\n", __func__
);
361 /* disable transmitter/receiver and fifo interrupt */
362 out_8(psc_addr(mps
, command
), MPC52xx_PSC_TX_DISABLE
| MPC52xx_PSC_RX_DISABLE
);
363 out_be32(&fifo
->tximr
, 0);
368 static int mpc512x_psc_spi_setup(struct spi_device
*spi
)
370 struct mpc512x_psc_spi_cs
*cs
= spi
->controller_state
;
373 if (spi
->bits_per_word
% 8)
377 cs
= kzalloc(sizeof *cs
, GFP_KERNEL
);
381 if (gpio_is_valid(spi
->cs_gpio
)) {
382 ret
= gpio_request(spi
->cs_gpio
, dev_name(&spi
->dev
));
384 dev_err(&spi
->dev
, "can't get CS gpio: %d\n",
389 gpio_direction_output(spi
->cs_gpio
,
390 spi
->mode
& SPI_CS_HIGH
? 0 : 1);
393 spi
->controller_state
= cs
;
396 cs
->bits_per_word
= spi
->bits_per_word
;
397 cs
->speed_hz
= spi
->max_speed_hz
;
402 static void mpc512x_psc_spi_cleanup(struct spi_device
*spi
)
404 if (gpio_is_valid(spi
->cs_gpio
))
405 gpio_free(spi
->cs_gpio
);
406 kfree(spi
->controller_state
);
409 static int mpc512x_psc_spi_port_config(struct spi_master
*master
,
410 struct mpc512x_psc_spi
*mps
)
412 struct mpc512x_psc_fifo __iomem
*fifo
= mps
->fifo
;
418 /* Reset the PSC into a known state */
419 out_8(psc_addr(mps
, command
), MPC52xx_PSC_RST_RX
);
420 out_8(psc_addr(mps
, command
), MPC52xx_PSC_RST_TX
);
421 out_8(psc_addr(mps
, command
), MPC52xx_PSC_TX_DISABLE
| MPC52xx_PSC_RX_DISABLE
);
423 /* Disable psc interrupts all useful interrupts are in fifo */
424 out_be16(psc_addr(mps
, isr_imr
.imr
), 0);
426 /* Disable fifo interrupts, will be enabled later */
427 out_be32(&fifo
->tximr
, 0);
428 out_be32(&fifo
->rximr
, 0);
430 /* Setup fifo slice address and size */
431 /*out_be32(&fifo->txsz, 0x0fe00004);*/
432 /*out_be32(&fifo->rxsz, 0x0ff00004);*/
434 sicr
= 0x01000000 | /* SIM = 0001 -- 8 bit */
435 0x00800000 | /* GenClk = 1 -- internal clk */
436 0x00008000 | /* SPI = 1 */
437 0x00004000 | /* MSTR = 1 -- SPI master */
438 0x00000800; /* UseEOF = 1 -- SS low until EOF */
440 out_be32(psc_addr(mps
, sicr
), sicr
);
442 ccr
= in_be32(psc_addr(mps
, ccr
));
444 speed
= 1000000; /* default 1MHz */
445 bclkdiv
= (mps
->mclk_rate
/ speed
) - 1;
446 ccr
|= (((bclkdiv
& 0xff) << 16) | (((bclkdiv
>> 8) & 0xff) << 8));
447 out_be32(psc_addr(mps
, ccr
), ccr
);
449 /* Set 2ms DTL delay */
450 out_8(psc_addr(mps
, ctur
), 0x00);
451 out_8(psc_addr(mps
, ctlr
), 0x82);
453 /* we don't use the alarms */
454 out_be32(&fifo
->rxalarm
, 0xfff);
455 out_be32(&fifo
->txalarm
, 0);
457 /* Enable FIFO slices for Rx/Tx */
458 out_be32(&fifo
->rxcmd
,
459 MPC512x_PSC_FIFO_ENABLE_SLICE
| MPC512x_PSC_FIFO_ENABLE_DMA
);
460 out_be32(&fifo
->txcmd
,
461 MPC512x_PSC_FIFO_ENABLE_SLICE
| MPC512x_PSC_FIFO_ENABLE_DMA
);
463 mps
->bits_per_word
= 8;
468 static irqreturn_t
mpc512x_psc_spi_isr(int irq
, void *dev_id
)
470 struct mpc512x_psc_spi
*mps
= (struct mpc512x_psc_spi
*)dev_id
;
471 struct mpc512x_psc_fifo __iomem
*fifo
= mps
->fifo
;
473 /* clear interrupt and wake up the rx/tx routine */
474 if (in_be32(&fifo
->txisr
) &
475 in_be32(&fifo
->tximr
) & MPC512x_PSC_FIFO_EMPTY
) {
476 out_be32(&fifo
->txisr
, MPC512x_PSC_FIFO_EMPTY
);
477 out_be32(&fifo
->tximr
, 0);
478 complete(&mps
->txisrdone
);
484 static void mpc512x_spi_cs_control(struct spi_device
*spi
, bool onoff
)
486 gpio_set_value(spi
->cs_gpio
, onoff
);
489 static int mpc512x_psc_spi_do_probe(struct device
*dev
, u32 regaddr
,
490 u32 size
, unsigned int irq
)
492 struct fsl_spi_platform_data
*pdata
= dev_get_platdata(dev
);
493 struct mpc512x_psc_spi
*mps
;
494 struct spi_master
*master
;
499 master
= spi_alloc_master(dev
, sizeof *mps
);
503 dev_set_drvdata(dev
, master
);
504 mps
= spi_master_get_devdata(master
);
505 mps
->type
= (int)of_device_get_match_data(dev
);
509 mps
->cs_control
= mpc512x_spi_cs_control
;
511 mps
->cs_control
= pdata
->cs_control
;
512 master
->bus_num
= pdata
->bus_num
;
513 master
->num_chipselect
= pdata
->max_chipselect
;
516 master
->mode_bits
= SPI_CPOL
| SPI_CPHA
| SPI_CS_HIGH
| SPI_LSB_FIRST
;
517 master
->setup
= mpc512x_psc_spi_setup
;
518 master
->prepare_transfer_hardware
= mpc512x_psc_spi_prep_xfer_hw
;
519 master
->transfer_one_message
= mpc512x_psc_spi_msg_xfer
;
520 master
->unprepare_transfer_hardware
= mpc512x_psc_spi_unprep_xfer_hw
;
521 master
->cleanup
= mpc512x_psc_spi_cleanup
;
522 master
->dev
.of_node
= dev
->of_node
;
524 tempp
= devm_ioremap(dev
, regaddr
, size
);
526 dev_err(dev
, "could not ioremap I/O port range\n");
532 (struct mpc512x_psc_fifo
*)(tempp
+ sizeof(struct mpc52xx_psc
));
533 ret
= devm_request_irq(dev
, mps
->irq
, mpc512x_psc_spi_isr
, IRQF_SHARED
,
534 "mpc512x-psc-spi", mps
);
537 init_completion(&mps
->txisrdone
);
539 clk
= devm_clk_get(dev
, "mclk");
544 ret
= clk_prepare_enable(clk
);
548 mps
->mclk_rate
= clk_get_rate(clk
);
550 clk
= devm_clk_get(dev
, "ipg");
553 goto free_mclk_clock
;
555 ret
= clk_prepare_enable(clk
);
557 goto free_mclk_clock
;
560 ret
= mpc512x_psc_spi_port_config(master
, mps
);
564 ret
= devm_spi_register_master(dev
, master
);
571 clk_disable_unprepare(mps
->clk_ipg
);
573 clk_disable_unprepare(mps
->clk_mclk
);
575 spi_master_put(master
);
580 static int mpc512x_psc_spi_do_remove(struct device
*dev
)
582 struct spi_master
*master
= dev_get_drvdata(dev
);
583 struct mpc512x_psc_spi
*mps
= spi_master_get_devdata(master
);
585 clk_disable_unprepare(mps
->clk_mclk
);
586 clk_disable_unprepare(mps
->clk_ipg
);
591 static int mpc512x_psc_spi_of_probe(struct platform_device
*op
)
593 const u32
*regaddr_p
;
594 u64 regaddr64
, size64
;
596 regaddr_p
= of_get_address(op
->dev
.of_node
, 0, &size64
, NULL
);
598 dev_err(&op
->dev
, "Invalid PSC address\n");
601 regaddr64
= of_translate_address(op
->dev
.of_node
, regaddr_p
);
603 return mpc512x_psc_spi_do_probe(&op
->dev
, (u32
) regaddr64
, (u32
) size64
,
604 irq_of_parse_and_map(op
->dev
.of_node
, 0));
607 static int mpc512x_psc_spi_of_remove(struct platform_device
*op
)
609 return mpc512x_psc_spi_do_remove(&op
->dev
);
612 static const struct of_device_id mpc512x_psc_spi_of_match
[] = {
613 { .compatible
= "fsl,mpc5121-psc-spi", .data
= (void *)TYPE_MPC5121
},
614 { .compatible
= "fsl,mpc5125-psc-spi", .data
= (void *)TYPE_MPC5125
},
618 MODULE_DEVICE_TABLE(of
, mpc512x_psc_spi_of_match
);
620 static struct platform_driver mpc512x_psc_spi_of_driver
= {
621 .probe
= mpc512x_psc_spi_of_probe
,
622 .remove
= mpc512x_psc_spi_of_remove
,
624 .name
= "mpc512x-psc-spi",
625 .of_match_table
= mpc512x_psc_spi_of_match
,
628 module_platform_driver(mpc512x_psc_spi_of_driver
);
630 MODULE_AUTHOR("John Rigby");
631 MODULE_DESCRIPTION("MPC512x PSC SPI Driver");
632 MODULE_LICENSE("GPL");