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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>
27#include <linux/io.h>
28#include <linux/module.h>
29#include <linux/gpio.h>
30
31
32#define SPI_FIFO_SIZE 4
33#define SPI_MAX_DIVIDER 0xff
34#define SPI_MIN_DIVIDER 1
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
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
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
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
74struct txx9spi {
75 struct workqueue_struct *workqueue;
76 struct work_struct work;
77 spinlock_t lock;
78 struct list_head queue;
79 wait_queue_head_t waitq;
80 void __iomem *membase;
81 int baseclk;
82 struct clk *clk;
83 u32 max_speed_hz, min_speed_hz;
84 int last_chipselect;
85 int last_chipselect_val;
86};
87
88static u32 txx9spi_rd(struct txx9spi *c, int reg)
89{
90 return __raw_readl(c->membase + reg);
91}
92static void txx9spi_wr(struct txx9spi *c, u32 val, int reg)
93{
94 __raw_writel(val, c->membase + reg);
95}
96
97static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
98 int on, unsigned int cs_delay)
99{
100 int val = (spi->mode & SPI_CS_HIGH) ? on : !on;
101 if (on) {
102
103 if (c->last_chipselect >= 0)
104 gpio_set_value(c->last_chipselect,
105 !c->last_chipselect_val);
106 c->last_chipselect = spi->chip_select;
107 c->last_chipselect_val = val;
108 } else {
109 c->last_chipselect = -1;
110 ndelay(cs_delay);
111 }
112 gpio_set_value(spi->chip_select, val);
113 ndelay(cs_delay);
114}
115
116static int txx9spi_setup(struct spi_device *spi)
117{
118 struct txx9spi *c = spi_master_get_devdata(spi->master);
119
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
125 if (gpio_direction_output(spi->chip_select,
126 !(spi->mode & SPI_CS_HIGH))) {
127 dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
128 return -EINVAL;
129 }
130
131
132 spin_lock(&c->lock);
133 txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz);
134 spin_unlock(&c->lock);
135
136 return 0;
137}
138
139static irqreturn_t txx9spi_interrupt(int irq, void *dev_id)
140{
141 struct txx9spi *c = dev_id;
142
143
144 txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE,
145 TXx9_SPCR0);
146 wake_up(&c->waitq);
147 return IRQ_HANDLED;
148}
149
150static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m)
151{
152 struct spi_device *spi = m->spi;
153 struct spi_transfer *t;
154 unsigned int cs_delay;
155 unsigned int cs_change = 1;
156 int status = 0;
157 u32 mcr;
158 u32 prev_speed_hz = 0;
159 u8 prev_bits_per_word = 0;
160
161
162 cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz;
163
164 mcr = txx9spi_rd(c, TXx9_SPMCR);
165 if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) {
166 dev_err(&spi->dev, "Bad mode.\n");
167 status = -EIO;
168 goto exit;
169 }
170 mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
171
172
173 txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
174 txx9spi_wr(c, TXx9_SPCR0_SBOS
175 | ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0)
176 | ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0)
177 | 0x08,
178 TXx9_SPCR0);
179
180 list_for_each_entry (t, &m->transfers, transfer_list) {
181 const void *txbuf = t->tx_buf;
182 void *rxbuf = t->rx_buf;
183 u32 data;
184 unsigned int len = t->len;
185 unsigned int wsize;
186 u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
187 u8 bits_per_word = t->bits_per_word;
188
189 wsize = bits_per_word >> 3;
190
191 if (prev_speed_hz != speed_hz
192 || prev_bits_per_word != bits_per_word) {
193 int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1;
194 n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER);
195
196 txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR,
197 TXx9_SPMCR);
198 txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1);
199
200 txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR);
201
202 prev_speed_hz = speed_hz;
203 prev_bits_per_word = bits_per_word;
204 }
205
206 if (cs_change)
207 txx9spi_cs_func(spi, c, 1, cs_delay);
208 cs_change = t->cs_change;
209 while (len) {
210 unsigned int count = SPI_FIFO_SIZE;
211 int i;
212 u32 cr0;
213
214 if (len < count * wsize)
215 count = len / wsize;
216
217 while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE))
218 cpu_relax();
219 cr0 = txx9spi_rd(c, TXx9_SPCR0);
220 cr0 &= ~TXx9_SPCR0_RXIFL_MASK;
221 cr0 |= (count - 1) << 12;
222
223 cr0 |= TXx9_SPCR0_RBSIE;
224 txx9spi_wr(c, cr0, TXx9_SPCR0);
225
226 for (i = 0; i < count; i++) {
227 if (txbuf) {
228 data = (wsize == 1)
229 ? *(const u8 *)txbuf
230 : *(const u16 *)txbuf;
231 txx9spi_wr(c, data, TXx9_SPDR);
232 txbuf += wsize;
233 } else
234 txx9spi_wr(c, 0, TXx9_SPDR);
235 }
236
237 wait_event(c->waitq,
238 txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI);
239
240 for (i = 0; i < count; i++) {
241 data = txx9spi_rd(c, TXx9_SPDR);
242 if (rxbuf) {
243 if (wsize == 1)
244 *(u8 *)rxbuf = data;
245 else
246 *(u16 *)rxbuf = data;
247 rxbuf += wsize;
248 }
249 }
250 len -= count * wsize;
251 }
252 m->actual_length += t->len;
253 if (t->delay_usecs)
254 udelay(t->delay_usecs);
255
256 if (!cs_change)
257 continue;
258 if (t->transfer_list.next == &m->transfers)
259 break;
260
261
262
263 txx9spi_cs_func(spi, c, 0, cs_delay);
264 }
265
266exit:
267 m->status = status;
268 m->complete(m->context);
269
270
271
272
273
274 if (!(status == 0 && cs_change))
275 txx9spi_cs_func(spi, c, 0, cs_delay);
276
277
278 txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
279}
280
281static void txx9spi_work(struct work_struct *work)
282{
283 struct txx9spi *c = container_of(work, struct txx9spi, work);
284 unsigned long flags;
285
286 spin_lock_irqsave(&c->lock, flags);
287 while (!list_empty(&c->queue)) {
288 struct spi_message *m;
289
290 m = container_of(c->queue.next, struct spi_message, queue);
291 list_del_init(&m->queue);
292 spin_unlock_irqrestore(&c->lock, flags);
293
294 txx9spi_work_one(c, m);
295
296 spin_lock_irqsave(&c->lock, flags);
297 }
298 spin_unlock_irqrestore(&c->lock, flags);
299}
300
301static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m)
302{
303 struct spi_master *master = spi->master;
304 struct txx9spi *c = spi_master_get_devdata(master);
305 struct spi_transfer *t;
306 unsigned long flags;
307
308 m->actual_length = 0;
309
310
311 list_for_each_entry (t, &m->transfers, transfer_list) {
312 u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
313 u8 bits_per_word = t->bits_per_word;
314
315 if (!t->tx_buf && !t->rx_buf && t->len)
316 return -EINVAL;
317 if (t->len & ((bits_per_word >> 3) - 1))
318 return -EINVAL;
319 if (speed_hz < c->min_speed_hz || speed_hz > c->max_speed_hz)
320 return -EINVAL;
321 }
322
323 spin_lock_irqsave(&c->lock, flags);
324 list_add_tail(&m->queue, &c->queue);
325 queue_work(c->workqueue, &c->work);
326 spin_unlock_irqrestore(&c->lock, flags);
327
328 return 0;
329}
330
331static int txx9spi_probe(struct platform_device *dev)
332{
333 struct spi_master *master;
334 struct txx9spi *c;
335 struct resource *res;
336 int ret = -ENODEV;
337 u32 mcr;
338 int irq;
339
340 master = spi_alloc_master(&dev->dev, sizeof(*c));
341 if (!master)
342 return ret;
343 c = spi_master_get_devdata(master);
344 platform_set_drvdata(dev, master);
345
346 INIT_WORK(&c->work, txx9spi_work);
347 spin_lock_init(&c->lock);
348 INIT_LIST_HEAD(&c->queue);
349 init_waitqueue_head(&c->waitq);
350
351 c->clk = clk_get(&dev->dev, "spi-baseclk");
352 if (IS_ERR(c->clk)) {
353 ret = PTR_ERR(c->clk);
354 c->clk = NULL;
355 goto exit;
356 }
357 ret = clk_enable(c->clk);
358 if (ret) {
359 clk_put(c->clk);
360 c->clk = NULL;
361 goto exit;
362 }
363 c->baseclk = clk_get_rate(c->clk);
364 c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
365 c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
366
367 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
368 if (!res)
369 goto exit_busy;
370 if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
371 "spi_txx9"))
372 goto exit_busy;
373 c->membase = devm_ioremap(&dev->dev, res->start, resource_size(res));
374 if (!c->membase)
375 goto exit_busy;
376
377
378 mcr = txx9spi_rd(c, TXx9_SPMCR);
379 mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
380 txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
381
382 irq = platform_get_irq(dev, 0);
383 if (irq < 0)
384 goto exit_busy;
385 ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0,
386 "spi_txx9", c);
387 if (ret)
388 goto exit;
389
390 c->workqueue = create_singlethread_workqueue(
391 dev_name(master->dev.parent));
392 if (!c->workqueue)
393 goto exit_busy;
394 c->last_chipselect = -1;
395
396 dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
397 (unsigned long long)res->start, irq,
398 (c->baseclk + 500000) / 1000000);
399
400
401 master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
402
403 master->bus_num = dev->id;
404 master->setup = txx9spi_setup;
405 master->transfer = txx9spi_transfer;
406 master->num_chipselect = (u16)UINT_MAX;
407 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
408
409 ret = spi_register_master(master);
410 if (ret)
411 goto exit;
412 return 0;
413exit_busy:
414 ret = -EBUSY;
415exit:
416 if (c->workqueue)
417 destroy_workqueue(c->workqueue);
418 if (c->clk) {
419 clk_disable(c->clk);
420 clk_put(c->clk);
421 }
422 spi_master_put(master);
423 return ret;
424}
425
426static int txx9spi_remove(struct platform_device *dev)
427{
428 struct spi_master *master = spi_master_get(platform_get_drvdata(dev));
429 struct txx9spi *c = spi_master_get_devdata(master);
430
431 spi_unregister_master(master);
432 destroy_workqueue(c->workqueue);
433 clk_disable(c->clk);
434 clk_put(c->clk);
435 spi_master_put(master);
436 return 0;
437}
438
439
440MODULE_ALIAS("platform:spi_txx9");
441
442static struct platform_driver txx9spi_driver = {
443 .remove = txx9spi_remove,
444 .driver = {
445 .name = "spi_txx9",
446 .owner = THIS_MODULE,
447 },
448};
449
450static int __init txx9spi_init(void)
451{
452 return platform_driver_probe(&txx9spi_driver, txx9spi_probe);
453}
454subsys_initcall(txx9spi_init);
455
456static void __exit txx9spi_exit(void)
457{
458 platform_driver_unregister(&txx9spi_driver);
459}
460module_exit(txx9spi_exit);
461
462MODULE_DESCRIPTION("TXx9 SPI Driver");
463MODULE_LICENSE("GPL");
464
