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> |
d7614de4 | 28 | #include <linux/module.h> |
e221fa40 | 29 | #include <linux/gpio.h> |
f2cac67d AN |
30 | |
31 | ||
32 | #define SPI_FIFO_SIZE 4 | |
dbf763a2 AN |
33 | #define SPI_MAX_DIVIDER 0xff /* Max. value for SPCR1.SER */ |
34 | #define SPI_MIN_DIVIDER 1 /* Min. value for SPCR1.SER */ | |
f2cac67d AN |
35 | |
36 | #define TXx9_SPMCR 0x00 | |
37 | #define TXx9_SPCR0 0x04 | |
38 | #define TXx9_SPCR1 0x08 | |
39 | #define TXx9_SPFS 0x0c | |
40 | #define TXx9_SPSR 0x14 | |
41 | #define TXx9_SPDR 0x18 | |
42 | ||
43 | /* SPMCR : SPI Master Control */ | |
44 | #define TXx9_SPMCR_OPMODE 0xc0 | |
45 | #define TXx9_SPMCR_CONFIG 0x40 | |
46 | #define TXx9_SPMCR_ACTIVE 0x80 | |
47 | #define TXx9_SPMCR_SPSTP 0x02 | |
48 | #define TXx9_SPMCR_BCLR 0x01 | |
49 | ||
50 | /* SPCR0 : SPI Control 0 */ | |
51 | #define TXx9_SPCR0_TXIFL_MASK 0xc000 | |
52 | #define TXx9_SPCR0_RXIFL_MASK 0x3000 | |
53 | #define TXx9_SPCR0_SIDIE 0x0800 | |
54 | #define TXx9_SPCR0_SOEIE 0x0400 | |
55 | #define TXx9_SPCR0_RBSIE 0x0200 | |
56 | #define TXx9_SPCR0_TBSIE 0x0100 | |
57 | #define TXx9_SPCR0_IFSPSE 0x0010 | |
58 | #define TXx9_SPCR0_SBOS 0x0004 | |
59 | #define TXx9_SPCR0_SPHA 0x0002 | |
60 | #define TXx9_SPCR0_SPOL 0x0001 | |
61 | ||
62 | /* SPSR : SPI Status */ | |
63 | #define TXx9_SPSR_TBSI 0x8000 | |
64 | #define TXx9_SPSR_RBSI 0x4000 | |
65 | #define TXx9_SPSR_TBS_MASK 0x3800 | |
66 | #define TXx9_SPSR_RBS_MASK 0x0700 | |
67 | #define TXx9_SPSR_SPOE 0x0080 | |
68 | #define TXx9_SPSR_IFSD 0x0008 | |
69 | #define TXx9_SPSR_SIDLE 0x0004 | |
70 | #define TXx9_SPSR_STRDY 0x0002 | |
71 | #define TXx9_SPSR_SRRDY 0x0001 | |
72 | ||
73 | ||
74 | struct txx9spi { | |
f2cac67d AN |
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; | |
f2cac67d AN |
82 | int last_chipselect; |
83 | int last_chipselect_val; | |
84 | }; | |
85 | ||
86 | static u32 txx9spi_rd(struct txx9spi *c, int reg) | |
87 | { | |
88 | return __raw_readl(c->membase + reg); | |
89 | } | |
90 | static void txx9spi_wr(struct txx9spi *c, u32 val, int reg) | |
91 | { | |
92 | __raw_writel(val, c->membase + reg); | |
93 | } | |
94 | ||
95 | static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c, | |
96 | int on, unsigned int cs_delay) | |
97 | { | |
98 | int val = (spi->mode & SPI_CS_HIGH) ? on : !on; | |
a2cea983 | 99 | |
f2cac67d AN |
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); | |
f2cac67d | 118 | |
425f96d2 | 119 | if (!spi->max_speed_hz) |
f2cac67d AN |
120 | return -EINVAL; |
121 | ||
f2cac67d AN |
122 | if (gpio_direction_output(spi->chip_select, |
123 | !(spi->mode & SPI_CS_HIGH))) { | |
124 | dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n"); | |
125 | return -EINVAL; | |
126 | } | |
127 | ||
128 | /* deselect chip */ | |
129 | spin_lock(&c->lock); | |
130 | txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz); | |
131 | spin_unlock(&c->lock); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static irqreturn_t txx9spi_interrupt(int irq, void *dev_id) | |
137 | { | |
138 | struct txx9spi *c = dev_id; | |
139 | ||
140 | /* disable rx intr */ | |
141 | txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE, | |
142 | TXx9_SPCR0); | |
143 | wake_up(&c->waitq); | |
144 | return IRQ_HANDLED; | |
145 | } | |
146 | ||
147 | static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m) | |
148 | { | |
149 | struct spi_device *spi = m->spi; | |
150 | struct spi_transfer *t; | |
151 | unsigned int cs_delay; | |
152 | unsigned int cs_change = 1; | |
153 | int status = 0; | |
154 | u32 mcr; | |
155 | u32 prev_speed_hz = 0; | |
156 | u8 prev_bits_per_word = 0; | |
157 | ||
158 | /* CS setup/hold/recovery time in nsec */ | |
159 | cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz; | |
160 | ||
161 | mcr = txx9spi_rd(c, TXx9_SPMCR); | |
162 | if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) { | |
163 | dev_err(&spi->dev, "Bad mode.\n"); | |
164 | status = -EIO; | |
165 | goto exit; | |
166 | } | |
167 | mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR); | |
168 | ||
169 | /* enter config mode */ | |
170 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
171 | txx9spi_wr(c, TXx9_SPCR0_SBOS | |
172 | | ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0) | |
173 | | ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0) | |
174 | | 0x08, | |
175 | TXx9_SPCR0); | |
176 | ||
256fbf36 | 177 | list_for_each_entry(t, &m->transfers, transfer_list) { |
f2cac67d AN |
178 | const void *txbuf = t->tx_buf; |
179 | void *rxbuf = t->rx_buf; | |
180 | u32 data; | |
181 | unsigned int len = t->len; | |
182 | unsigned int wsize; | |
fc306de9 | 183 | u32 speed_hz = t->speed_hz; |
766ed704 | 184 | u8 bits_per_word = t->bits_per_word; |
f2cac67d | 185 | |
f2cac67d AN |
186 | wsize = bits_per_word >> 3; /* in bytes */ |
187 | ||
188 | if (prev_speed_hz != speed_hz | |
189 | || prev_bits_per_word != bits_per_word) { | |
dbf763a2 | 190 | int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1; |
a2cea983 | 191 | |
dbf763a2 | 192 | n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER); |
f2cac67d AN |
193 | /* enter config mode */ |
194 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, | |
195 | TXx9_SPMCR); | |
196 | txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1); | |
197 | /* enter active mode */ | |
198 | txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR); | |
199 | ||
200 | prev_speed_hz = speed_hz; | |
201 | prev_bits_per_word = bits_per_word; | |
202 | } | |
203 | ||
204 | if (cs_change) | |
205 | txx9spi_cs_func(spi, c, 1, cs_delay); | |
206 | cs_change = t->cs_change; | |
207 | while (len) { | |
208 | unsigned int count = SPI_FIFO_SIZE; | |
209 | int i; | |
210 | u32 cr0; | |
211 | ||
212 | if (len < count * wsize) | |
213 | count = len / wsize; | |
214 | /* now tx must be idle... */ | |
215 | while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE)) | |
216 | cpu_relax(); | |
217 | cr0 = txx9spi_rd(c, TXx9_SPCR0); | |
218 | cr0 &= ~TXx9_SPCR0_RXIFL_MASK; | |
219 | cr0 |= (count - 1) << 12; | |
220 | /* enable rx intr */ | |
221 | cr0 |= TXx9_SPCR0_RBSIE; | |
222 | txx9spi_wr(c, cr0, TXx9_SPCR0); | |
223 | /* send */ | |
224 | for (i = 0; i < count; i++) { | |
225 | if (txbuf) { | |
226 | data = (wsize == 1) | |
227 | ? *(const u8 *)txbuf | |
228 | : *(const u16 *)txbuf; | |
229 | txx9spi_wr(c, data, TXx9_SPDR); | |
230 | txbuf += wsize; | |
231 | } else | |
232 | txx9spi_wr(c, 0, TXx9_SPDR); | |
233 | } | |
234 | /* wait all rx data */ | |
235 | wait_event(c->waitq, | |
236 | txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI); | |
237 | /* receive */ | |
238 | for (i = 0; i < count; i++) { | |
239 | data = txx9spi_rd(c, TXx9_SPDR); | |
240 | if (rxbuf) { | |
241 | if (wsize == 1) | |
242 | *(u8 *)rxbuf = data; | |
243 | else | |
244 | *(u16 *)rxbuf = data; | |
245 | rxbuf += wsize; | |
246 | } | |
247 | } | |
248 | len -= count * wsize; | |
249 | } | |
250 | m->actual_length += t->len; | |
251 | if (t->delay_usecs) | |
252 | udelay(t->delay_usecs); | |
253 | ||
254 | if (!cs_change) | |
255 | continue; | |
256 | if (t->transfer_list.next == &m->transfers) | |
257 | break; | |
258 | /* sometimes a short mid-message deselect of the chip | |
259 | * may be needed to terminate a mode or command | |
260 | */ | |
261 | txx9spi_cs_func(spi, c, 0, cs_delay); | |
262 | } | |
263 | ||
264 | exit: | |
265 | m->status = status; | |
0a6d3879 AL |
266 | if (m->complete) |
267 | m->complete(m->context); | |
f2cac67d AN |
268 | |
269 | /* normally deactivate chipselect ... unless no error and | |
270 | * cs_change has hinted that the next message will probably | |
271 | * be for this chip too. | |
272 | */ | |
273 | if (!(status == 0 && cs_change)) | |
274 | txx9spi_cs_func(spi, c, 0, cs_delay); | |
275 | ||
276 | /* enter config mode */ | |
277 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
278 | } | |
279 | ||
280 | static void txx9spi_work(struct work_struct *work) | |
281 | { | |
282 | struct txx9spi *c = container_of(work, struct txx9spi, work); | |
283 | unsigned long flags; | |
284 | ||
285 | spin_lock_irqsave(&c->lock, flags); | |
286 | while (!list_empty(&c->queue)) { | |
287 | struct spi_message *m; | |
288 | ||
289 | m = container_of(c->queue.next, struct spi_message, queue); | |
290 | list_del_init(&m->queue); | |
291 | spin_unlock_irqrestore(&c->lock, flags); | |
292 | ||
293 | txx9spi_work_one(c, m); | |
294 | ||
295 | spin_lock_irqsave(&c->lock, flags); | |
296 | } | |
297 | spin_unlock_irqrestore(&c->lock, flags); | |
298 | } | |
299 | ||
300 | static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m) | |
301 | { | |
302 | struct spi_master *master = spi->master; | |
303 | struct txx9spi *c = spi_master_get_devdata(master); | |
304 | struct spi_transfer *t; | |
305 | unsigned long flags; | |
306 | ||
307 | m->actual_length = 0; | |
308 | ||
309 | /* check each transfer's parameters */ | |
256fbf36 | 310 | list_for_each_entry(t, &m->transfers, transfer_list) { |
f2cac67d AN |
311 | if (!t->tx_buf && !t->rx_buf && t->len) |
312 | return -EINVAL; | |
f2cac67d AN |
313 | } |
314 | ||
315 | spin_lock_irqsave(&c->lock, flags); | |
316 | list_add_tail(&m->queue, &c->queue); | |
b43afff7 | 317 | schedule_work(&c->work); |
f2cac67d AN |
318 | spin_unlock_irqrestore(&c->lock, flags); |
319 | ||
320 | return 0; | |
321 | } | |
322 | ||
2deff8d6 | 323 | static int txx9spi_probe(struct platform_device *dev) |
f2cac67d AN |
324 | { |
325 | struct spi_master *master; | |
326 | struct txx9spi *c; | |
327 | struct resource *res; | |
328 | int ret = -ENODEV; | |
329 | u32 mcr; | |
ba0a7f39 | 330 | int irq; |
f2cac67d AN |
331 | |
332 | master = spi_alloc_master(&dev->dev, sizeof(*c)); | |
333 | if (!master) | |
334 | return ret; | |
335 | c = spi_master_get_devdata(master); | |
f2cac67d AN |
336 | platform_set_drvdata(dev, master); |
337 | ||
338 | INIT_WORK(&c->work, txx9spi_work); | |
339 | spin_lock_init(&c->lock); | |
340 | INIT_LIST_HEAD(&c->queue); | |
341 | init_waitqueue_head(&c->waitq); | |
342 | ||
18e34d56 | 343 | c->clk = devm_clk_get(&dev->dev, "spi-baseclk"); |
f2cac67d AN |
344 | if (IS_ERR(c->clk)) { |
345 | ret = PTR_ERR(c->clk); | |
346 | c->clk = NULL; | |
347 | goto exit; | |
348 | } | |
1ae4ec14 | 349 | ret = clk_prepare_enable(c->clk); |
f2cac67d | 350 | if (ret) { |
f2cac67d AN |
351 | c->clk = NULL; |
352 | goto exit; | |
353 | } | |
354 | c->baseclk = clk_get_rate(c->clk); | |
425f96d2 AL |
355 | master->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1); |
356 | master->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1); | |
f2cac67d AN |
357 | |
358 | res = platform_get_resource(dev, IORESOURCE_MEM, 0); | |
7bdadd8d JH |
359 | c->membase = devm_ioremap_resource(&dev->dev, res); |
360 | if (IS_ERR(c->membase)) | |
ba0a7f39 | 361 | goto exit_busy; |
f2cac67d AN |
362 | |
363 | /* enter config mode */ | |
364 | mcr = txx9spi_rd(c, TXx9_SPMCR); | |
365 | mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR); | |
366 | txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR); | |
367 | ||
ba0a7f39 AN |
368 | irq = platform_get_irq(dev, 0); |
369 | if (irq < 0) | |
370 | goto exit_busy; | |
371 | ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0, | |
372 | "spi_txx9", c); | |
373 | if (ret) | |
f2cac67d | 374 | goto exit; |
f2cac67d | 375 | |
f2cac67d AN |
376 | c->last_chipselect = -1; |
377 | ||
378 | dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n", | |
ba0a7f39 | 379 | (unsigned long long)res->start, irq, |
f2cac67d AN |
380 | (c->baseclk + 500000) / 1000000); |
381 | ||
e7db06b5 DB |
382 | /* the spi->mode bits understood by this driver: */ |
383 | master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA; | |
384 | ||
f2cac67d AN |
385 | master->bus_num = dev->id; |
386 | master->setup = txx9spi_setup; | |
387 | master->transfer = txx9spi_transfer; | |
388 | master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */ | |
24778be2 | 389 | master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16); |
f2cac67d | 390 | |
2fe7e4ad | 391 | ret = devm_spi_register_master(&dev->dev, master); |
f2cac67d AN |
392 | if (ret) |
393 | goto exit; | |
394 | return 0; | |
ba0a7f39 AN |
395 | exit_busy: |
396 | ret = -EBUSY; | |
f2cac67d | 397 | exit: |
1ae4ec14 | 398 | clk_disable_unprepare(c->clk); |
f2cac67d AN |
399 | spi_master_put(master); |
400 | return ret; | |
401 | } | |
402 | ||
2deff8d6 | 403 | static int txx9spi_remove(struct platform_device *dev) |
f2cac67d | 404 | { |
b38f87ec | 405 | struct spi_master *master = platform_get_drvdata(dev); |
f2cac67d AN |
406 | struct txx9spi *c = spi_master_get_devdata(master); |
407 | ||
b43afff7 | 408 | flush_work(&c->work); |
1ae4ec14 | 409 | clk_disable_unprepare(c->clk); |
f2cac67d AN |
410 | return 0; |
411 | } | |
412 | ||
7e38c3c4 KS |
413 | /* work with hotplug and coldplug */ |
414 | MODULE_ALIAS("platform:spi_txx9"); | |
415 | ||
f2cac67d | 416 | static struct platform_driver txx9spi_driver = { |
1d82d0c2 | 417 | .probe = txx9spi_probe, |
2deff8d6 | 418 | .remove = txx9spi_remove, |
f2cac67d | 419 | .driver = { |
4ccdb4c8 | 420 | .name = "spi_txx9", |
f2cac67d AN |
421 | }, |
422 | }; | |
423 | ||
424 | static int __init txx9spi_init(void) | |
425 | { | |
1d82d0c2 | 426 | return platform_driver_register(&txx9spi_driver); |
f2cac67d AN |
427 | } |
428 | subsys_initcall(txx9spi_init); | |
429 | ||
430 | static void __exit txx9spi_exit(void) | |
431 | { | |
432 | platform_driver_unregister(&txx9spi_driver); | |
433 | } | |
434 | module_exit(txx9spi_exit); | |
435 | ||
436 | MODULE_DESCRIPTION("TXx9 SPI Driver"); | |
437 | MODULE_LICENSE("GPL"); |