Commit | Line | Data |
---|---|---|
f2cac67d | 1 | /* |
ca632f55 | 2 | * TXx9 SPI controller driver. |
f2cac67d AN |
3 | * |
4 | * Based on linux/arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c | |
5 | * Copyright (C) 2000-2001 Toshiba Corporation | |
6 | * | |
7 | * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the | |
8 | * terms of the GNU General Public License version 2. This program is | |
9 | * licensed "as is" without any warranty of any kind, whether express | |
10 | * or implied. | |
11 | * | |
12 | * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com) | |
13 | * | |
14 | * Convert to generic SPI framework - Atsushi Nemoto (anemo@mba.ocn.ne.jp) | |
15 | */ | |
16 | #include <linux/init.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/interrupt.h> | |
20 | #include <linux/platform_device.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/spi/spi.h> | |
25 | #include <linux/err.h> | |
26 | #include <linux/clk.h> | |
ba0a7f39 | 27 | #include <linux/io.h> |
f2cac67d AN |
28 | #include <asm/gpio.h> |
29 | ||
30 | ||
31 | #define SPI_FIFO_SIZE 4 | |
dbf763a2 AN |
32 | #define SPI_MAX_DIVIDER 0xff /* Max. value for SPCR1.SER */ |
33 | #define SPI_MIN_DIVIDER 1 /* Min. value for SPCR1.SER */ | |
f2cac67d AN |
34 | |
35 | #define TXx9_SPMCR 0x00 | |
36 | #define TXx9_SPCR0 0x04 | |
37 | #define TXx9_SPCR1 0x08 | |
38 | #define TXx9_SPFS 0x0c | |
39 | #define TXx9_SPSR 0x14 | |
40 | #define TXx9_SPDR 0x18 | |
41 | ||
42 | /* SPMCR : SPI Master Control */ | |
43 | #define TXx9_SPMCR_OPMODE 0xc0 | |
44 | #define TXx9_SPMCR_CONFIG 0x40 | |
45 | #define TXx9_SPMCR_ACTIVE 0x80 | |
46 | #define TXx9_SPMCR_SPSTP 0x02 | |
47 | #define TXx9_SPMCR_BCLR 0x01 | |
48 | ||
49 | /* SPCR0 : SPI Control 0 */ | |
50 | #define TXx9_SPCR0_TXIFL_MASK 0xc000 | |
51 | #define TXx9_SPCR0_RXIFL_MASK 0x3000 | |
52 | #define TXx9_SPCR0_SIDIE 0x0800 | |
53 | #define TXx9_SPCR0_SOEIE 0x0400 | |
54 | #define TXx9_SPCR0_RBSIE 0x0200 | |
55 | #define TXx9_SPCR0_TBSIE 0x0100 | |
56 | #define TXx9_SPCR0_IFSPSE 0x0010 | |
57 | #define TXx9_SPCR0_SBOS 0x0004 | |
58 | #define TXx9_SPCR0_SPHA 0x0002 | |
59 | #define TXx9_SPCR0_SPOL 0x0001 | |
60 | ||
61 | /* SPSR : SPI Status */ | |
62 | #define TXx9_SPSR_TBSI 0x8000 | |
63 | #define TXx9_SPSR_RBSI 0x4000 | |
64 | #define TXx9_SPSR_TBS_MASK 0x3800 | |
65 | #define TXx9_SPSR_RBS_MASK 0x0700 | |
66 | #define TXx9_SPSR_SPOE 0x0080 | |
67 | #define TXx9_SPSR_IFSD 0x0008 | |
68 | #define TXx9_SPSR_SIDLE 0x0004 | |
69 | #define TXx9_SPSR_STRDY 0x0002 | |
70 | #define TXx9_SPSR_SRRDY 0x0001 | |
71 | ||
72 | ||
73 | struct txx9spi { | |
74 | struct workqueue_struct *workqueue; | |
75 | struct work_struct work; | |
76 | spinlock_t lock; /* protect 'queue' */ | |
77 | struct list_head queue; | |
78 | wait_queue_head_t waitq; | |
79 | void __iomem *membase; | |
f2cac67d AN |
80 | int baseclk; |
81 | struct clk *clk; | |
82 | u32 max_speed_hz, min_speed_hz; | |
83 | int last_chipselect; | |
84 | int last_chipselect_val; | |
85 | }; | |
86 | ||
87 | static u32 txx9spi_rd(struct txx9spi *c, int reg) | |
88 | { | |
89 | return __raw_readl(c->membase + reg); | |
90 | } | |
91 | static void txx9spi_wr(struct txx9spi *c, u32 val, int reg) | |
92 | { | |
93 | __raw_writel(val, c->membase + reg); | |
94 | } | |
95 | ||
96 | static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c, | |
97 | int on, unsigned int cs_delay) | |
98 | { | |
99 | int val = (spi->mode & SPI_CS_HIGH) ? on : !on; | |
100 | if (on) { | |
101 | /* deselect the chip with cs_change hint in last transfer */ | |
102 | if (c->last_chipselect >= 0) | |
103 | gpio_set_value(c->last_chipselect, | |
104 | !c->last_chipselect_val); | |
105 | c->last_chipselect = spi->chip_select; | |
106 | c->last_chipselect_val = val; | |
107 | } else { | |
108 | c->last_chipselect = -1; | |
109 | ndelay(cs_delay); /* CS Hold Time */ | |
110 | } | |
111 | gpio_set_value(spi->chip_select, val); | |
112 | ndelay(cs_delay); /* CS Setup Time / CS Recovery Time */ | |
113 | } | |
114 | ||
f2cac67d AN |
115 | static int txx9spi_setup(struct spi_device *spi) |
116 | { | |
117 | struct txx9spi *c = spi_master_get_devdata(spi->master); | |
118 | u8 bits_per_word; | |
119 | ||
f2cac67d AN |
120 | if (!spi->max_speed_hz |
121 | || spi->max_speed_hz > c->max_speed_hz | |
122 | || spi->max_speed_hz < c->min_speed_hz) | |
123 | return -EINVAL; | |
124 | ||
7d077197 | 125 | bits_per_word = spi->bits_per_word; |
f2cac67d AN |
126 | if (bits_per_word != 8 && bits_per_word != 16) |
127 | return -EINVAL; | |
128 | ||
129 | if (gpio_direction_output(spi->chip_select, | |
130 | !(spi->mode & SPI_CS_HIGH))) { | |
131 | dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n"); | |
132 | return -EINVAL; | |
133 | } | |
134 | ||
135 | /* deselect chip */ | |
136 | spin_lock(&c->lock); | |
137 | txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz); | |
138 | spin_unlock(&c->lock); | |
139 | ||
140 | return 0; | |
141 | } | |
142 | ||
143 | static irqreturn_t txx9spi_interrupt(int irq, void *dev_id) | |
144 | { | |
145 | struct txx9spi *c = dev_id; | |
146 | ||
147 | /* disable rx intr */ | |
148 | txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE, | |
149 | TXx9_SPCR0); | |
150 | wake_up(&c->waitq); | |
151 | return IRQ_HANDLED; | |
152 | } | |
153 | ||
154 | static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m) | |
155 | { | |
156 | struct spi_device *spi = m->spi; | |
157 | struct spi_transfer *t; | |
158 | unsigned int cs_delay; | |
159 | unsigned int cs_change = 1; | |
160 | int status = 0; | |
161 | u32 mcr; | |
162 | u32 prev_speed_hz = 0; | |
163 | u8 prev_bits_per_word = 0; | |
164 | ||
165 | /* CS setup/hold/recovery time in nsec */ | |
166 | cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz; | |
167 | ||
168 | mcr = txx9spi_rd(c, TXx9_SPMCR); | |
169 | if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) { | |
170 | dev_err(&spi->dev, "Bad mode.\n"); | |
171 | status = -EIO; | |
172 | goto exit; | |
173 | } | |
174 | mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR); | |
175 | ||
176 | /* enter config mode */ | |
177 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
178 | txx9spi_wr(c, TXx9_SPCR0_SBOS | |
179 | | ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0) | |
180 | | ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0) | |
181 | | 0x08, | |
182 | TXx9_SPCR0); | |
183 | ||
184 | list_for_each_entry (t, &m->transfers, transfer_list) { | |
185 | const void *txbuf = t->tx_buf; | |
186 | void *rxbuf = t->rx_buf; | |
187 | u32 data; | |
188 | unsigned int len = t->len; | |
189 | unsigned int wsize; | |
190 | u32 speed_hz = t->speed_hz ? : spi->max_speed_hz; | |
191 | u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word; | |
192 | ||
193 | bits_per_word = bits_per_word ? : 8; | |
194 | wsize = bits_per_word >> 3; /* in bytes */ | |
195 | ||
196 | if (prev_speed_hz != speed_hz | |
197 | || prev_bits_per_word != bits_per_word) { | |
dbf763a2 AN |
198 | int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1; |
199 | n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER); | |
f2cac67d AN |
200 | /* enter config mode */ |
201 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, | |
202 | TXx9_SPMCR); | |
203 | txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1); | |
204 | /* enter active mode */ | |
205 | txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR); | |
206 | ||
207 | prev_speed_hz = speed_hz; | |
208 | prev_bits_per_word = bits_per_word; | |
209 | } | |
210 | ||
211 | if (cs_change) | |
212 | txx9spi_cs_func(spi, c, 1, cs_delay); | |
213 | cs_change = t->cs_change; | |
214 | while (len) { | |
215 | unsigned int count = SPI_FIFO_SIZE; | |
216 | int i; | |
217 | u32 cr0; | |
218 | ||
219 | if (len < count * wsize) | |
220 | count = len / wsize; | |
221 | /* now tx must be idle... */ | |
222 | while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE)) | |
223 | cpu_relax(); | |
224 | cr0 = txx9spi_rd(c, TXx9_SPCR0); | |
225 | cr0 &= ~TXx9_SPCR0_RXIFL_MASK; | |
226 | cr0 |= (count - 1) << 12; | |
227 | /* enable rx intr */ | |
228 | cr0 |= TXx9_SPCR0_RBSIE; | |
229 | txx9spi_wr(c, cr0, TXx9_SPCR0); | |
230 | /* send */ | |
231 | for (i = 0; i < count; i++) { | |
232 | if (txbuf) { | |
233 | data = (wsize == 1) | |
234 | ? *(const u8 *)txbuf | |
235 | : *(const u16 *)txbuf; | |
236 | txx9spi_wr(c, data, TXx9_SPDR); | |
237 | txbuf += wsize; | |
238 | } else | |
239 | txx9spi_wr(c, 0, TXx9_SPDR); | |
240 | } | |
241 | /* wait all rx data */ | |
242 | wait_event(c->waitq, | |
243 | txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI); | |
244 | /* receive */ | |
245 | for (i = 0; i < count; i++) { | |
246 | data = txx9spi_rd(c, TXx9_SPDR); | |
247 | if (rxbuf) { | |
248 | if (wsize == 1) | |
249 | *(u8 *)rxbuf = data; | |
250 | else | |
251 | *(u16 *)rxbuf = data; | |
252 | rxbuf += wsize; | |
253 | } | |
254 | } | |
255 | len -= count * wsize; | |
256 | } | |
257 | m->actual_length += t->len; | |
258 | if (t->delay_usecs) | |
259 | udelay(t->delay_usecs); | |
260 | ||
261 | if (!cs_change) | |
262 | continue; | |
263 | if (t->transfer_list.next == &m->transfers) | |
264 | break; | |
265 | /* sometimes a short mid-message deselect of the chip | |
266 | * may be needed to terminate a mode or command | |
267 | */ | |
268 | txx9spi_cs_func(spi, c, 0, cs_delay); | |
269 | } | |
270 | ||
271 | exit: | |
272 | m->status = status; | |
273 | m->complete(m->context); | |
274 | ||
275 | /* normally deactivate chipselect ... unless no error and | |
276 | * cs_change has hinted that the next message will probably | |
277 | * be for this chip too. | |
278 | */ | |
279 | if (!(status == 0 && cs_change)) | |
280 | txx9spi_cs_func(spi, c, 0, cs_delay); | |
281 | ||
282 | /* enter config mode */ | |
283 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
284 | } | |
285 | ||
286 | static void txx9spi_work(struct work_struct *work) | |
287 | { | |
288 | struct txx9spi *c = container_of(work, struct txx9spi, work); | |
289 | unsigned long flags; | |
290 | ||
291 | spin_lock_irqsave(&c->lock, flags); | |
292 | while (!list_empty(&c->queue)) { | |
293 | struct spi_message *m; | |
294 | ||
295 | m = container_of(c->queue.next, struct spi_message, queue); | |
296 | list_del_init(&m->queue); | |
297 | spin_unlock_irqrestore(&c->lock, flags); | |
298 | ||
299 | txx9spi_work_one(c, m); | |
300 | ||
301 | spin_lock_irqsave(&c->lock, flags); | |
302 | } | |
303 | spin_unlock_irqrestore(&c->lock, flags); | |
304 | } | |
305 | ||
306 | static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m) | |
307 | { | |
308 | struct spi_master *master = spi->master; | |
309 | struct txx9spi *c = spi_master_get_devdata(master); | |
310 | struct spi_transfer *t; | |
311 | unsigned long flags; | |
312 | ||
313 | m->actual_length = 0; | |
314 | ||
315 | /* check each transfer's parameters */ | |
316 | list_for_each_entry (t, &m->transfers, transfer_list) { | |
317 | u32 speed_hz = t->speed_hz ? : spi->max_speed_hz; | |
318 | u8 bits_per_word = t->bits_per_word ? : spi->bits_per_word; | |
319 | ||
320 | bits_per_word = bits_per_word ? : 8; | |
321 | if (!t->tx_buf && !t->rx_buf && t->len) | |
322 | return -EINVAL; | |
323 | if (bits_per_word != 8 && bits_per_word != 16) | |
324 | return -EINVAL; | |
325 | if (t->len & ((bits_per_word >> 3) - 1)) | |
326 | return -EINVAL; | |
327 | if (speed_hz < c->min_speed_hz || speed_hz > c->max_speed_hz) | |
328 | return -EINVAL; | |
329 | } | |
330 | ||
331 | spin_lock_irqsave(&c->lock, flags); | |
332 | list_add_tail(&m->queue, &c->queue); | |
333 | queue_work(c->workqueue, &c->work); | |
334 | spin_unlock_irqrestore(&c->lock, flags); | |
335 | ||
336 | return 0; | |
337 | } | |
338 | ||
339 | static int __init txx9spi_probe(struct platform_device *dev) | |
340 | { | |
341 | struct spi_master *master; | |
342 | struct txx9spi *c; | |
343 | struct resource *res; | |
344 | int ret = -ENODEV; | |
345 | u32 mcr; | |
ba0a7f39 | 346 | int irq; |
f2cac67d AN |
347 | |
348 | master = spi_alloc_master(&dev->dev, sizeof(*c)); | |
349 | if (!master) | |
350 | return ret; | |
351 | c = spi_master_get_devdata(master); | |
f2cac67d AN |
352 | platform_set_drvdata(dev, master); |
353 | ||
354 | INIT_WORK(&c->work, txx9spi_work); | |
355 | spin_lock_init(&c->lock); | |
356 | INIT_LIST_HEAD(&c->queue); | |
357 | init_waitqueue_head(&c->waitq); | |
358 | ||
359 | c->clk = clk_get(&dev->dev, "spi-baseclk"); | |
360 | if (IS_ERR(c->clk)) { | |
361 | ret = PTR_ERR(c->clk); | |
362 | c->clk = NULL; | |
363 | goto exit; | |
364 | } | |
365 | ret = clk_enable(c->clk); | |
366 | if (ret) { | |
367 | clk_put(c->clk); | |
368 | c->clk = NULL; | |
369 | goto exit; | |
370 | } | |
371 | c->baseclk = clk_get_rate(c->clk); | |
dbf763a2 AN |
372 | c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1); |
373 | c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1); | |
f2cac67d AN |
374 | |
375 | res = platform_get_resource(dev, IORESOURCE_MEM, 0); | |
376 | if (!res) | |
ba0a7f39 | 377 | goto exit_busy; |
d53342bf | 378 | if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res), |
ba0a7f39 AN |
379 | "spi_txx9")) |
380 | goto exit_busy; | |
d53342bf | 381 | c->membase = devm_ioremap(&dev->dev, res->start, resource_size(res)); |
f2cac67d | 382 | if (!c->membase) |
ba0a7f39 | 383 | goto exit_busy; |
f2cac67d AN |
384 | |
385 | /* enter config mode */ | |
386 | mcr = txx9spi_rd(c, TXx9_SPMCR); | |
387 | mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR); | |
388 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
389 | ||
ba0a7f39 AN |
390 | irq = platform_get_irq(dev, 0); |
391 | if (irq < 0) | |
392 | goto exit_busy; | |
393 | ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0, | |
394 | "spi_txx9", c); | |
395 | if (ret) | |
f2cac67d | 396 | goto exit; |
f2cac67d | 397 | |
6c7377ab KS |
398 | c->workqueue = create_singlethread_workqueue( |
399 | dev_name(master->dev.parent)); | |
f2cac67d | 400 | if (!c->workqueue) |
ba0a7f39 | 401 | goto exit_busy; |
f2cac67d AN |
402 | c->last_chipselect = -1; |
403 | ||
404 | dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n", | |
ba0a7f39 | 405 | (unsigned long long)res->start, irq, |
f2cac67d AN |
406 | (c->baseclk + 500000) / 1000000); |
407 | ||
e7db06b5 DB |
408 | /* the spi->mode bits understood by this driver: */ |
409 | master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA; | |
410 | ||
f2cac67d AN |
411 | master->bus_num = dev->id; |
412 | master->setup = txx9spi_setup; | |
413 | master->transfer = txx9spi_transfer; | |
414 | master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */ | |
415 | ||
416 | ret = spi_register_master(master); | |
417 | if (ret) | |
418 | goto exit; | |
419 | return 0; | |
ba0a7f39 AN |
420 | exit_busy: |
421 | ret = -EBUSY; | |
f2cac67d AN |
422 | exit: |
423 | if (c->workqueue) | |
424 | destroy_workqueue(c->workqueue); | |
f2cac67d AN |
425 | if (c->clk) { |
426 | clk_disable(c->clk); | |
427 | clk_put(c->clk); | |
428 | } | |
429 | platform_set_drvdata(dev, NULL); | |
430 | spi_master_put(master); | |
431 | return ret; | |
432 | } | |
433 | ||
434 | static int __exit txx9spi_remove(struct platform_device *dev) | |
435 | { | |
436 | struct spi_master *master = spi_master_get(platform_get_drvdata(dev)); | |
437 | struct txx9spi *c = spi_master_get_devdata(master); | |
438 | ||
439 | spi_unregister_master(master); | |
440 | platform_set_drvdata(dev, NULL); | |
441 | destroy_workqueue(c->workqueue); | |
f2cac67d AN |
442 | clk_disable(c->clk); |
443 | clk_put(c->clk); | |
444 | spi_master_put(master); | |
445 | return 0; | |
446 | } | |
447 | ||
7e38c3c4 KS |
448 | /* work with hotplug and coldplug */ |
449 | MODULE_ALIAS("platform:spi_txx9"); | |
450 | ||
f2cac67d AN |
451 | static struct platform_driver txx9spi_driver = { |
452 | .remove = __exit_p(txx9spi_remove), | |
453 | .driver = { | |
4ccdb4c8 | 454 | .name = "spi_txx9", |
f2cac67d AN |
455 | .owner = THIS_MODULE, |
456 | }, | |
457 | }; | |
458 | ||
459 | static int __init txx9spi_init(void) | |
460 | { | |
461 | return platform_driver_probe(&txx9spi_driver, txx9spi_probe); | |
462 | } | |
463 | subsys_initcall(txx9spi_init); | |
464 | ||
465 | static void __exit txx9spi_exit(void) | |
466 | { | |
467 | platform_driver_unregister(&txx9spi_driver); | |
468 | } | |
469 | module_exit(txx9spi_exit); | |
470 | ||
471 | MODULE_DESCRIPTION("TXx9 SPI Driver"); | |
472 | MODULE_LICENSE("GPL"); |