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b42dfed8 FF |
1 | /* |
2 | * Broadcom BCM63xx SPI controller support | |
3 | * | |
cde4384e | 4 | * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org> |
b42dfed8 FF |
5 | * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version 2 | |
10 | * of the License, or (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the | |
19 | * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | |
20 | */ | |
21 | ||
22 | #include <linux/kernel.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/clk.h> | |
25 | #include <linux/io.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/platform_device.h> | |
28 | #include <linux/delay.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <linux/spi/spi.h> | |
31 | #include <linux/completion.h> | |
32 | #include <linux/err.h> | |
cde4384e FF |
33 | #include <linux/workqueue.h> |
34 | #include <linux/pm_runtime.h> | |
b42dfed8 FF |
35 | |
36 | #include <bcm63xx_dev_spi.h> | |
37 | ||
38 | #define PFX KBUILD_MODNAME | |
b42dfed8 | 39 | |
b17de076 JG |
40 | #define BCM63XX_SPI_MAX_PREPEND 15 |
41 | ||
b42dfed8 | 42 | struct bcm63xx_spi { |
b42dfed8 FF |
43 | struct completion done; |
44 | ||
45 | void __iomem *regs; | |
46 | int irq; | |
47 | ||
48 | /* Platform data */ | |
b42dfed8 | 49 | unsigned fifo_size; |
5a670445 FF |
50 | unsigned int msg_type_shift; |
51 | unsigned int msg_ctl_width; | |
b42dfed8 | 52 | |
b42dfed8 FF |
53 | /* data iomem */ |
54 | u8 __iomem *tx_io; | |
55 | const u8 __iomem *rx_io; | |
56 | ||
b42dfed8 FF |
57 | struct clk *clk; |
58 | struct platform_device *pdev; | |
59 | }; | |
60 | ||
61 | static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs, | |
62 | unsigned int offset) | |
63 | { | |
64 | return bcm_readb(bs->regs + bcm63xx_spireg(offset)); | |
65 | } | |
66 | ||
67 | static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs, | |
68 | unsigned int offset) | |
69 | { | |
70 | return bcm_readw(bs->regs + bcm63xx_spireg(offset)); | |
71 | } | |
72 | ||
73 | static inline void bcm_spi_writeb(struct bcm63xx_spi *bs, | |
74 | u8 value, unsigned int offset) | |
75 | { | |
76 | bcm_writeb(value, bs->regs + bcm63xx_spireg(offset)); | |
77 | } | |
78 | ||
79 | static inline void bcm_spi_writew(struct bcm63xx_spi *bs, | |
80 | u16 value, unsigned int offset) | |
81 | { | |
82 | bcm_writew(value, bs->regs + bcm63xx_spireg(offset)); | |
83 | } | |
84 | ||
85 | static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = { | |
86 | { 20000000, SPI_CLK_20MHZ }, | |
87 | { 12500000, SPI_CLK_12_50MHZ }, | |
88 | { 6250000, SPI_CLK_6_250MHZ }, | |
89 | { 3125000, SPI_CLK_3_125MHZ }, | |
90 | { 1563000, SPI_CLK_1_563MHZ }, | |
91 | { 781000, SPI_CLK_0_781MHZ }, | |
92 | { 391000, SPI_CLK_0_391MHZ } | |
93 | }; | |
94 | ||
cde4384e FF |
95 | static void bcm63xx_spi_setup_transfer(struct spi_device *spi, |
96 | struct spi_transfer *t) | |
97 | { | |
98 | struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); | |
cde4384e FF |
99 | u8 clk_cfg, reg; |
100 | int i; | |
101 | ||
b42dfed8 FF |
102 | /* Find the closest clock configuration */ |
103 | for (i = 0; i < SPI_CLK_MASK; i++) { | |
68792e2a | 104 | if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) { |
b42dfed8 FF |
105 | clk_cfg = bcm63xx_spi_freq_table[i][1]; |
106 | break; | |
107 | } | |
108 | } | |
109 | ||
110 | /* No matching configuration found, default to lowest */ | |
111 | if (i == SPI_CLK_MASK) | |
112 | clk_cfg = SPI_CLK_0_391MHZ; | |
113 | ||
114 | /* clear existing clock configuration bits of the register */ | |
115 | reg = bcm_spi_readb(bs, SPI_CLK_CFG); | |
116 | reg &= ~SPI_CLK_MASK; | |
117 | reg |= clk_cfg; | |
118 | ||
119 | bcm_spi_writeb(bs, reg, SPI_CLK_CFG); | |
120 | dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n", | |
68792e2a | 121 | clk_cfg, t->speed_hz); |
b42dfed8 FF |
122 | } |
123 | ||
124 | /* the spi->mode bits understood by this driver: */ | |
125 | #define MODEBITS (SPI_CPOL | SPI_CPHA) | |
126 | ||
b17de076 JG |
127 | static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first, |
128 | unsigned int num_transfers) | |
b42dfed8 FF |
129 | { |
130 | struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); | |
131 | u16 msg_ctl; | |
132 | u16 cmd; | |
c0fde3ba | 133 | u8 rx_tail; |
b17de076 JG |
134 | unsigned int i, timeout = 0, prepend_len = 0, len = 0; |
135 | struct spi_transfer *t = first; | |
136 | bool do_rx = false; | |
137 | bool do_tx = false; | |
b42dfed8 | 138 | |
cde4384e FF |
139 | /* Disable the CMD_DONE interrupt */ |
140 | bcm_spi_writeb(bs, 0, SPI_INT_MASK); | |
141 | ||
b42dfed8 FF |
142 | dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", |
143 | t->tx_buf, t->rx_buf, t->len); | |
144 | ||
b17de076 JG |
145 | if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND) |
146 | prepend_len = t->len; | |
147 | ||
148 | /* prepare the buffer */ | |
149 | for (i = 0; i < num_transfers; i++) { | |
150 | if (t->tx_buf) { | |
151 | do_tx = true; | |
152 | memcpy_toio(bs->tx_io + len, t->tx_buf, t->len); | |
153 | ||
154 | /* don't prepend more than one tx */ | |
155 | if (t != first) | |
156 | prepend_len = 0; | |
157 | } | |
158 | ||
159 | if (t->rx_buf) { | |
160 | do_rx = true; | |
161 | /* prepend is half-duplex write only */ | |
162 | if (t == first) | |
163 | prepend_len = 0; | |
164 | } | |
165 | ||
166 | len += t->len; | |
167 | ||
168 | t = list_entry(t->transfer_list.next, struct spi_transfer, | |
169 | transfer_list); | |
170 | } | |
171 | ||
cde4384e | 172 | init_completion(&bs->done); |
b42dfed8 FF |
173 | |
174 | /* Fill in the Message control register */ | |
b17de076 | 175 | msg_ctl = (len << SPI_BYTE_CNT_SHIFT); |
b42dfed8 | 176 | |
b17de076 | 177 | if (do_rx && do_tx && prepend_len == 0) |
5a670445 | 178 | msg_ctl |= (SPI_FD_RW << bs->msg_type_shift); |
b17de076 | 179 | else if (do_rx) |
5a670445 | 180 | msg_ctl |= (SPI_HD_R << bs->msg_type_shift); |
b17de076 | 181 | else if (do_tx) |
5a670445 FF |
182 | msg_ctl |= (SPI_HD_W << bs->msg_type_shift); |
183 | ||
184 | switch (bs->msg_ctl_width) { | |
185 | case 8: | |
186 | bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL); | |
187 | break; | |
188 | case 16: | |
189 | bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL); | |
190 | break; | |
191 | } | |
b42dfed8 FF |
192 | |
193 | /* Issue the transfer */ | |
194 | cmd = SPI_CMD_START_IMMEDIATE; | |
b17de076 | 195 | cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); |
b42dfed8 FF |
196 | cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT); |
197 | bcm_spi_writew(bs, cmd, SPI_CMD); | |
b42dfed8 | 198 | |
cde4384e FF |
199 | /* Enable the CMD_DONE interrupt */ |
200 | bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); | |
b42dfed8 | 201 | |
c0fde3ba JG |
202 | timeout = wait_for_completion_timeout(&bs->done, HZ); |
203 | if (!timeout) | |
204 | return -ETIMEDOUT; | |
205 | ||
20e9e78f | 206 | if (!do_rx) |
b17de076 JG |
207 | return 0; |
208 | ||
209 | len = 0; | |
210 | t = first; | |
c0fde3ba | 211 | /* Read out all the data */ |
b17de076 JG |
212 | for (i = 0; i < num_transfers; i++) { |
213 | if (t->rx_buf) | |
214 | memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len); | |
215 | ||
216 | if (t != first || prepend_len == 0) | |
217 | len += t->len; | |
218 | ||
219 | t = list_entry(t->transfer_list.next, struct spi_transfer, | |
220 | transfer_list); | |
221 | } | |
c0fde3ba JG |
222 | |
223 | return 0; | |
b42dfed8 FF |
224 | } |
225 | ||
cde4384e FF |
226 | static int bcm63xx_spi_transfer_one(struct spi_master *master, |
227 | struct spi_message *m) | |
228 | { | |
229 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); | |
b17de076 | 230 | struct spi_transfer *t, *first = NULL; |
cde4384e FF |
231 | struct spi_device *spi = m->spi; |
232 | int status = 0; | |
b17de076 JG |
233 | unsigned int n_transfers = 0, total_len = 0; |
234 | bool can_use_prepend = false; | |
235 | ||
236 | /* | |
237 | * This SPI controller does not support keeping CS active after a | |
238 | * transfer. | |
239 | * Work around this by merging as many transfers we can into one big | |
240 | * full-duplex transfers. | |
241 | */ | |
b42dfed8 | 242 | list_for_each_entry(t, &m->transfers, transfer_list) { |
b17de076 JG |
243 | if (!first) |
244 | first = t; | |
245 | ||
246 | n_transfers++; | |
247 | total_len += t->len; | |
248 | ||
249 | if (n_transfers == 2 && !first->rx_buf && !t->tx_buf && | |
250 | first->len <= BCM63XX_SPI_MAX_PREPEND) | |
251 | can_use_prepend = true; | |
252 | else if (can_use_prepend && t->tx_buf) | |
253 | can_use_prepend = false; | |
254 | ||
c0fde3ba | 255 | /* we can only transfer one fifo worth of data */ |
b17de076 JG |
256 | if ((can_use_prepend && |
257 | total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) || | |
258 | (!can_use_prepend && total_len > bs->fifo_size)) { | |
c0fde3ba | 259 | dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n", |
b17de076 | 260 | total_len, bs->fifo_size); |
c0fde3ba JG |
261 | status = -EINVAL; |
262 | goto exit; | |
263 | } | |
cde4384e | 264 | |
b17de076 JG |
265 | /* all combined transfers have to have the same speed */ |
266 | if (t->speed_hz != first->speed_hz) { | |
267 | dev_err(&spi->dev, "unable to change speed between transfers\n"); | |
c0fde3ba JG |
268 | status = -EINVAL; |
269 | goto exit; | |
270 | } | |
cde4384e | 271 | |
b17de076 JG |
272 | /* CS will be deasserted directly after transfer */ |
273 | if (t->delay_usecs) { | |
274 | dev_err(&spi->dev, "unable to keep CS asserted after transfer\n"); | |
c0fde3ba JG |
275 | status = -EINVAL; |
276 | goto exit; | |
277 | } | |
cde4384e | 278 | |
b17de076 JG |
279 | if (t->cs_change || |
280 | list_is_last(&t->transfer_list, &m->transfers)) { | |
281 | /* configure adapter for a new transfer */ | |
282 | bcm63xx_spi_setup_transfer(spi, first); | |
cde4384e | 283 | |
b17de076 JG |
284 | /* send the data */ |
285 | status = bcm63xx_txrx_bufs(spi, first, n_transfers); | |
286 | if (status) | |
287 | goto exit; | |
288 | ||
289 | m->actual_length += total_len; | |
b42dfed8 | 290 | |
b17de076 JG |
291 | first = NULL; |
292 | n_transfers = 0; | |
293 | total_len = 0; | |
294 | can_use_prepend = false; | |
295 | } | |
cde4384e FF |
296 | } |
297 | exit: | |
298 | m->status = status; | |
299 | spi_finalize_current_message(master); | |
b42dfed8 | 300 | |
cde4384e | 301 | return 0; |
b42dfed8 FF |
302 | } |
303 | ||
304 | /* This driver supports single master mode only. Hence | |
305 | * CMD_DONE is the only interrupt we care about | |
306 | */ | |
307 | static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id) | |
308 | { | |
309 | struct spi_master *master = (struct spi_master *)dev_id; | |
310 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); | |
311 | u8 intr; | |
b42dfed8 FF |
312 | |
313 | /* Read interupts and clear them immediately */ | |
314 | intr = bcm_spi_readb(bs, SPI_INT_STATUS); | |
315 | bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); | |
316 | bcm_spi_writeb(bs, 0, SPI_INT_MASK); | |
317 | ||
cde4384e FF |
318 | /* A transfer completed */ |
319 | if (intr & SPI_INTR_CMD_DONE) | |
320 | complete(&bs->done); | |
b42dfed8 FF |
321 | |
322 | return IRQ_HANDLED; | |
323 | } | |
324 | ||
325 | ||
fd4a319b | 326 | static int bcm63xx_spi_probe(struct platform_device *pdev) |
b42dfed8 FF |
327 | { |
328 | struct resource *r; | |
329 | struct device *dev = &pdev->dev; | |
8074cf06 | 330 | struct bcm63xx_spi_pdata *pdata = dev_get_platdata(&pdev->dev); |
b42dfed8 FF |
331 | int irq; |
332 | struct spi_master *master; | |
333 | struct clk *clk; | |
334 | struct bcm63xx_spi *bs; | |
335 | int ret; | |
336 | ||
b42dfed8 FF |
337 | irq = platform_get_irq(pdev, 0); |
338 | if (irq < 0) { | |
339 | dev_err(dev, "no irq\n"); | |
acf4fc6f | 340 | return -ENXIO; |
b42dfed8 FF |
341 | } |
342 | ||
acf4fc6f | 343 | clk = devm_clk_get(dev, "spi"); |
b42dfed8 FF |
344 | if (IS_ERR(clk)) { |
345 | dev_err(dev, "no clock for device\n"); | |
acf4fc6f | 346 | return PTR_ERR(clk); |
b42dfed8 FF |
347 | } |
348 | ||
349 | master = spi_alloc_master(dev, sizeof(*bs)); | |
350 | if (!master) { | |
351 | dev_err(dev, "out of memory\n"); | |
acf4fc6f | 352 | return -ENOMEM; |
b42dfed8 FF |
353 | } |
354 | ||
355 | bs = spi_master_get_devdata(master); | |
b42dfed8 FF |
356 | |
357 | platform_set_drvdata(pdev, master); | |
358 | bs->pdev = pdev; | |
359 | ||
de0fa83c | 360 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
b66c7730 JG |
361 | bs->regs = devm_ioremap_resource(&pdev->dev, r); |
362 | if (IS_ERR(bs->regs)) { | |
363 | ret = PTR_ERR(bs->regs); | |
b42dfed8 FF |
364 | goto out_err; |
365 | } | |
366 | ||
367 | bs->irq = irq; | |
368 | bs->clk = clk; | |
369 | bs->fifo_size = pdata->fifo_size; | |
370 | ||
371 | ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0, | |
372 | pdev->name, master); | |
373 | if (ret) { | |
374 | dev_err(dev, "unable to request irq\n"); | |
375 | goto out_err; | |
376 | } | |
377 | ||
378 | master->bus_num = pdata->bus_num; | |
379 | master->num_chipselect = pdata->num_chipselect; | |
cde4384e | 380 | master->transfer_one_message = bcm63xx_spi_transfer_one; |
88a3a255 | 381 | master->mode_bits = MODEBITS; |
24778be2 | 382 | master->bits_per_word_mask = SPI_BPW_MASK(8); |
5355d96d | 383 | master->auto_runtime_pm = true; |
5a670445 FF |
384 | bs->msg_type_shift = pdata->msg_type_shift; |
385 | bs->msg_ctl_width = pdata->msg_ctl_width; | |
b42dfed8 FF |
386 | bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA)); |
387 | bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA)); | |
b42dfed8 | 388 | |
5a670445 FF |
389 | switch (bs->msg_ctl_width) { |
390 | case 8: | |
391 | case 16: | |
392 | break; | |
393 | default: | |
394 | dev_err(dev, "unsupported MSG_CTL width: %d\n", | |
395 | bs->msg_ctl_width); | |
b435ff21 | 396 | goto out_err; |
5a670445 FF |
397 | } |
398 | ||
b42dfed8 | 399 | /* Initialize hardware */ |
ea01e8a4 JG |
400 | ret = clk_prepare_enable(bs->clk); |
401 | if (ret) | |
402 | goto out_err; | |
403 | ||
b42dfed8 FF |
404 | bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); |
405 | ||
406 | /* register and we are done */ | |
bca76931 | 407 | ret = devm_spi_register_master(dev, master); |
b42dfed8 FF |
408 | if (ret) { |
409 | dev_err(dev, "spi register failed\n"); | |
410 | goto out_clk_disable; | |
411 | } | |
412 | ||
61d15963 FF |
413 | dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d)\n", |
414 | r->start, irq, bs->fifo_size); | |
b42dfed8 FF |
415 | |
416 | return 0; | |
417 | ||
418 | out_clk_disable: | |
4fbb82a7 | 419 | clk_disable_unprepare(clk); |
b42dfed8 | 420 | out_err: |
b42dfed8 | 421 | spi_master_put(master); |
b42dfed8 FF |
422 | return ret; |
423 | } | |
424 | ||
fd4a319b | 425 | static int bcm63xx_spi_remove(struct platform_device *pdev) |
b42dfed8 | 426 | { |
9637b86f | 427 | struct spi_master *master = platform_get_drvdata(pdev); |
b42dfed8 FF |
428 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
429 | ||
430 | /* reset spi block */ | |
431 | bcm_spi_writeb(bs, 0, SPI_INT_MASK); | |
b42dfed8 FF |
432 | |
433 | /* HW shutdown */ | |
4fbb82a7 | 434 | clk_disable_unprepare(bs->clk); |
b42dfed8 | 435 | |
b42dfed8 FF |
436 | return 0; |
437 | } | |
438 | ||
1bae2028 | 439 | #ifdef CONFIG_PM_SLEEP |
b42dfed8 FF |
440 | static int bcm63xx_spi_suspend(struct device *dev) |
441 | { | |
a1216394 | 442 | struct spi_master *master = dev_get_drvdata(dev); |
b42dfed8 FF |
443 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
444 | ||
96519957 FF |
445 | spi_master_suspend(master); |
446 | ||
4fbb82a7 | 447 | clk_disable_unprepare(bs->clk); |
b42dfed8 FF |
448 | |
449 | return 0; | |
450 | } | |
451 | ||
452 | static int bcm63xx_spi_resume(struct device *dev) | |
453 | { | |
a1216394 | 454 | struct spi_master *master = dev_get_drvdata(dev); |
b42dfed8 | 455 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
ea01e8a4 | 456 | int ret; |
b42dfed8 | 457 | |
ea01e8a4 JG |
458 | ret = clk_prepare_enable(bs->clk); |
459 | if (ret) | |
460 | return ret; | |
b42dfed8 | 461 | |
96519957 FF |
462 | spi_master_resume(master); |
463 | ||
b42dfed8 FF |
464 | return 0; |
465 | } | |
1bae2028 | 466 | #endif |
b42dfed8 FF |
467 | |
468 | static const struct dev_pm_ops bcm63xx_spi_pm_ops = { | |
1bae2028 | 469 | SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume) |
b42dfed8 FF |
470 | }; |
471 | ||
b42dfed8 FF |
472 | static struct platform_driver bcm63xx_spi_driver = { |
473 | .driver = { | |
474 | .name = "bcm63xx-spi", | |
475 | .owner = THIS_MODULE, | |
1bae2028 | 476 | .pm = &bcm63xx_spi_pm_ops, |
b42dfed8 FF |
477 | }, |
478 | .probe = bcm63xx_spi_probe, | |
fd4a319b | 479 | .remove = bcm63xx_spi_remove, |
b42dfed8 FF |
480 | }; |
481 | ||
482 | module_platform_driver(bcm63xx_spi_driver); | |
483 | ||
484 | MODULE_ALIAS("platform:bcm63xx_spi"); | |
485 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); | |
486 | MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>"); | |
487 | MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver"); | |
488 | MODULE_LICENSE("GPL"); |