ramips: clean up rt2880 spi probe/remove
[openwrt/openwrt.git] / target / linux / ramips / patches-3.18 / 0050-SPI-ralink-add-Ralink-SoC-spi-driver.patch
1 From fc006d0622ab8c43086b2c9018c03012db332033 Mon Sep 17 00:00:00 2001
2 From: John Crispin <blogic@openwrt.org>
3 Date: Sun, 27 Jul 2014 11:15:12 +0100
4 Subject: [PATCH 50/57] SPI: ralink: add Ralink SoC spi driver
5
6 Add the driver needed to make SPI work on Ralink SoC.
7
8 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
9 Acked-by: John Crispin <blogic@openwrt.org>
10 ---
11 drivers/spi/Kconfig | 6 +
12 drivers/spi/Makefile | 1 +
13 drivers/spi/spi-rt2880.c | 432 ++++++++++++++++++++++++++++++++++++++++++++++
14 3 files changed, 439 insertions(+)
15 create mode 100644 drivers/spi/spi-rt2880.c
16
17 --- a/drivers/spi/Kconfig
18 +++ b/drivers/spi/Kconfig
19 @@ -433,6 +433,12 @@ config SPI_QUP
20 This driver can also be built as a module. If so, the module
21 will be called spi_qup.
22
23 +config SPI_RT2880
24 + tristate "Ralink RT288x SPI Controller"
25 + depends on RALINK
26 + help
27 + This selects a driver for the Ralink RT288x/RT305x SPI Controller.
28 +
29 config SPI_S3C24XX
30 tristate "Samsung S3C24XX series SPI"
31 depends on ARCH_S3C24XX
32 --- a/drivers/spi/Makefile
33 +++ b/drivers/spi/Makefile
34 @@ -65,6 +65,7 @@ obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa
35 obj-$(CONFIG_SPI_QUP) += spi-qup.o
36 obj-$(CONFIG_SPI_ROCKCHIP) += spi-rockchip.o
37 obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
38 +obj-$(CONFIG_SPI_RT2880) += spi-rt2880.o
39 obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o
40 spi-s3c24xx-hw-y := spi-s3c24xx.o
41 spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
42 --- /dev/null
43 +++ b/drivers/spi/spi-rt2880.c
44 @@ -0,0 +1,488 @@
45 +/*
46 + * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver
47 + *
48 + * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
49 + * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
50 + *
51 + * Some parts are based on spi-orion.c:
52 + * Author: Shadi Ammouri <shadi@marvell.com>
53 + * Copyright (C) 2007-2008 Marvell Ltd.
54 + *
55 + * This program is free software; you can redistribute it and/or modify
56 + * it under the terms of the GNU General Public License version 2 as
57 + * published by the Free Software Foundation.
58 + */
59 +
60 +#include <linux/init.h>
61 +#include <linux/module.h>
62 +#include <linux/clk.h>
63 +#include <linux/err.h>
64 +#include <linux/delay.h>
65 +#include <linux/io.h>
66 +#include <linux/reset.h>
67 +#include <linux/spi/spi.h>
68 +#include <linux/platform_device.h>
69 +
70 +#define DRIVER_NAME "spi-rt2880"
71 +/* only one slave is supported*/
72 +#define RALINK_NUM_CHIPSELECTS 1
73 +
74 +#define RAMIPS_SPI_STAT 0x00
75 +#define RAMIPS_SPI_CFG 0x10
76 +#define RAMIPS_SPI_CTL 0x14
77 +#define RAMIPS_SPI_DATA 0x20
78 +#define RAMIPS_SPI_ADDR 0x24
79 +#define RAMIPS_SPI_BS 0x28
80 +#define RAMIPS_SPI_USER 0x2C
81 +#define RAMIPS_SPI_TXFIFO 0x30
82 +#define RAMIPS_SPI_RXFIFO 0x34
83 +#define RAMIPS_SPI_FIFO_STAT 0x38
84 +#define RAMIPS_SPI_MODE 0x3C
85 +#define RAMIPS_SPI_DEV_OFFSET 0x40
86 +#define RAMIPS_SPI_DMA 0x80
87 +#define RAMIPS_SPI_DMASTAT 0x84
88 +#define RAMIPS_SPI_ARBITER 0xF0
89 +
90 +/* SPISTAT register bit field */
91 +#define SPISTAT_BUSY BIT(0)
92 +
93 +/* SPICFG register bit field */
94 +#define SPICFG_ADDRMODE BIT(12)
95 +#define SPICFG_RXENVDIS BIT(11)
96 +#define SPICFG_RXCAP BIT(10)
97 +#define SPICFG_SPIENMODE BIT(9)
98 +#define SPICFG_MSBFIRST BIT(8)
99 +#define SPICFG_SPICLKPOL BIT(6)
100 +#define SPICFG_RXCLKEDGE_FALLING BIT(5)
101 +#define SPICFG_TXCLKEDGE_FALLING BIT(4)
102 +#define SPICFG_HIZSPI BIT(3)
103 +#define SPICFG_SPICLK_PRESCALE_MASK 0x7
104 +#define SPICFG_SPICLK_DIV2 0
105 +#define SPICFG_SPICLK_DIV4 1
106 +#define SPICFG_SPICLK_DIV8 2
107 +#define SPICFG_SPICLK_DIV16 3
108 +#define SPICFG_SPICLK_DIV32 4
109 +#define SPICFG_SPICLK_DIV64 5
110 +#define SPICFG_SPICLK_DIV128 6
111 +#define SPICFG_SPICLK_DISABLE 7
112 +
113 +/* SPICTL register bit field */
114 +#define SPICTL_START BIT(4)
115 +#define SPICTL_HIZSDO BIT(3)
116 +#define SPICTL_STARTWR BIT(2)
117 +#define SPICTL_STARTRD BIT(1)
118 +#define SPICTL_SPIENA BIT(0)
119 +
120 +/* SPIUSER register bit field */
121 +#define SPIUSER_USERMODE BIT(21)
122 +#define SPIUSER_INSTR_PHASE BIT(20)
123 +#define SPIUSER_ADDR_PHASE_MASK 0x7
124 +#define SPIUSER_ADDR_PHASE_OFFSET 17
125 +#define SPIUSER_MODE_PHASE BIT(16)
126 +#define SPIUSER_DUMMY_PHASE_MASK 0x3
127 +#define SPIUSER_DUMMY_PHASE_OFFSET 14
128 +#define SPIUSER_DATA_PHASE_MASK 0x3
129 +#define SPIUSER_DATA_PHASE_OFFSET 12
130 +#define SPIUSER_DATA_READ (BIT(0) << SPIUSER_DATA_PHASE_OFFSET)
131 +#define SPIUSER_DATA_WRITE (BIT(1) << SPIUSER_DATA_PHASE_OFFSET)
132 +#define SPIUSER_ADDR_TYPE_OFFSET 9
133 +#define SPIUSER_MODE_TYPE_OFFSET 6
134 +#define SPIUSER_DUMMY_TYPE_OFFSET 3
135 +#define SPIUSER_DATA_TYPE_OFFSET 0
136 +#define SPIUSER_TRANSFER_MASK 0x7
137 +#define SPIUSER_TRANSFER_SINGLE BIT(0)
138 +#define SPIUSER_TRANSFER_DUAL BIT(1)
139 +#define SPIUSER_TRANSFER_QUAD BIT(2)
140 +
141 +#define SPIUSER_TRANSFER_TYPE(type) ( \
142 + (type << SPIUSER_ADDR_TYPE_OFFSET) | \
143 + (type << SPIUSER_MODE_TYPE_OFFSET) | \
144 + (type << SPIUSER_DUMMY_TYPE_OFFSET) | \
145 + (type << SPIUSER_DATA_TYPE_OFFSET) \
146 +)
147 +
148 +/* SPIFIFOSTAT register bit field */
149 +#define SPIFIFOSTAT_TXEMPTY BIT(19)
150 +#define SPIFIFOSTAT_RXEMPTY BIT(18)
151 +#define SPIFIFOSTAT_TXFULL BIT(17)
152 +#define SPIFIFOSTAT_RXFULL BIT(16)
153 +#define SPIFIFOSTAT_FIFO_MASK 0xff
154 +#define SPIFIFOSTAT_TX_OFFSET 8
155 +#define SPIFIFOSTAT_RX_OFFSET 0
156 +
157 +#define SPI_FIFO_DEPTH 16
158 +
159 +/* SPIMODE register bit field */
160 +#define SPIMODE_MODE_OFFSET 24
161 +#define SPIMODE_DUMMY_OFFSET 0
162 +
163 +/* SPIARB register bit field */
164 +#define SPICTL_ARB_EN BIT(31)
165 +#define SPICTL_CSCTL1 BIT(16)
166 +#define SPI1_POR BIT(1)
167 +#define SPI0_POR BIT(0)
168 +
169 +#define RT2880_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | \
170 + SPI_CS_HIGH)
171 +
172 +struct rt2880_spi {
173 + struct spi_master *master;
174 + void __iomem *base;
175 + unsigned int sys_freq;
176 + unsigned int speed;
177 + u16 wait_loops;
178 + struct clk *clk;
179 +};
180 +
181 +static inline struct rt2880_spi *spidev_to_rt2880_spi(struct spi_device *spi)
182 +{
183 + return spi_master_get_devdata(spi->master);
184 +}
185 +
186 +static inline u32 rt2880_spi_read(struct rt2880_spi *rs, u32 reg)
187 +{
188 + return ioread32(rs->base + reg);
189 +}
190 +
191 +static inline void rt2880_spi_write(struct rt2880_spi *rs, u32 reg,
192 + const u32 val)
193 +{
194 + iowrite32(val, rs->base + reg);
195 +}
196 +
197 +static inline void rt2880_spi_setbits(struct rt2880_spi *rs, u32 reg, u32 mask)
198 +{
199 + void __iomem *addr = rs->base + reg;
200 +
201 + iowrite32((ioread32(addr) | mask), addr);
202 +}
203 +
204 +static inline void rt2880_spi_clrbits(struct rt2880_spi *rs, u32 reg, u32 mask)
205 +{
206 + void __iomem *addr = rs->base + reg;
207 +
208 + iowrite32((ioread32(addr) & ~mask), addr);
209 +}
210 +
211 +static int rt2880_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
212 +{
213 + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
214 + u32 rate;
215 + u32 prescale;
216 + u32 reg;
217 +
218 + dev_dbg(&spi->dev, "speed:%u\n", speed);
219 +
220 + /*
221 + * the supported rates are: 2, 4, 8, ... 128
222 + * round up as we look for equal or less speed
223 + */
224 + rate = DIV_ROUND_UP(rs->sys_freq, speed);
225 + dev_dbg(&spi->dev, "rate-1:%u\n", rate);
226 + rate = roundup_pow_of_two(rate);
227 + dev_dbg(&spi->dev, "rate-2:%u\n", rate);
228 +
229 + /* Convert the rate to SPI clock divisor value. */
230 + prescale = ilog2(rate / 2);
231 + dev_dbg(&spi->dev, "prescale:%u\n", prescale);
232 +
233 + reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG);
234 + reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale);
235 + rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg);
236 +
237 + /* some tolerance. double and add 100 */
238 + rs->wait_loops = (8 * HZ * loops_per_jiffy) /
239 + (clk_get_rate(rs->clk) / rate);
240 + rs->wait_loops = (rs->wait_loops << 1) + 100;
241 + rs->speed = speed;
242 + return 0;
243 +}
244 +
245 +/*
246 + * called only when no transfer is active on the bus
247 + */
248 +static int
249 +rt2880_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
250 +{
251 + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
252 + unsigned int speed = spi->max_speed_hz;
253 + int rc;
254 +
255 + if ((t != NULL) && t->speed_hz)
256 + speed = t->speed_hz;
257 +
258 + if (rs->speed != speed) {
259 + dev_dbg(&spi->dev, "speed_hz:%u\n", speed);
260 + rc = rt2880_spi_baudrate_set(spi, speed);
261 + if (rc)
262 + return rc;
263 + }
264 +
265 + return 0;
266 +}
267 +
268 +static void rt2880_spi_set_cs(struct rt2880_spi *rs, int enable)
269 +{
270 + if (enable)
271 + rt2880_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
272 + else
273 + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
274 +}
275 +
276 +static int rt2880_spi_wait_ready(struct rt2880_spi *rs, int len)
277 +{
278 + int loop = rs->wait_loops * len;
279 +
280 + while ((rt2880_spi_read(rs, RAMIPS_SPI_STAT) & SPISTAT_BUSY) && --loop)
281 + cpu_relax();
282 +
283 + if (loop)
284 + return 0;
285 +
286 + return -ETIMEDOUT;
287 +}
288 +
289 +static unsigned int
290 +rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
291 +{
292 + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
293 + unsigned count = 0;
294 + u8 *rx = xfer->rx_buf;
295 + const u8 *tx = xfer->tx_buf;
296 + int err;
297 +
298 + dev_dbg(&spi->dev, "read (%d): %s %s\n", xfer->len,
299 + (tx != NULL) ? "tx" : " ",
300 + (rx != NULL) ? "rx" : " ");
301 +
302 + if (tx) {
303 + for (count = 0; count < xfer->len; count++) {
304 + rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
305 + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
306 + err = rt2880_spi_wait_ready(rs, 1);
307 + if (err) {
308 + dev_err(&spi->dev, "TX failed, err=%d\n", err);
309 + goto out;
310 + }
311 + }
312 + }
313 +
314 + if (rx) {
315 + for (count = 0; count < xfer->len; count++) {
316 + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD);
317 + err = rt2880_spi_wait_ready(rs, 1);
318 + if (err) {
319 + dev_err(&spi->dev, "RX failed, err=%d\n", err);
320 + goto out;
321 + }
322 + rx[count] = (u8) rt2880_spi_read(rs, RAMIPS_SPI_DATA);
323 + }
324 + }
325 +
326 +out:
327 + return count;
328 +}
329 +
330 +static int rt2880_spi_transfer_one_message(struct spi_master *master,
331 + struct spi_message *m)
332 +{
333 + struct rt2880_spi *rs = spi_master_get_devdata(master);
334 + struct spi_device *spi = m->spi;
335 + struct spi_transfer *t = NULL;
336 + int par_override = 0;
337 + int status = 0;
338 + int cs_active = 0;
339 +
340 + /* Load defaults */
341 + status = rt2880_spi_setup_transfer(spi, NULL);
342 + if (status < 0)
343 + goto msg_done;
344 +
345 + list_for_each_entry(t, &m->transfers, transfer_list) {
346 + if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
347 + dev_err(&spi->dev,
348 + "message rejected: invalid transfer data buffers\n");
349 + status = -EIO;
350 + goto msg_done;
351 + }
352 +
353 + if (t->speed_hz && t->speed_hz < (rs->sys_freq / 128)) {
354 + dev_err(&spi->dev,
355 + "message rejected: device min speed (%d Hz) exceeds required transfer speed (%d Hz)\n",
356 + (rs->sys_freq / 128), t->speed_hz);
357 + status = -EIO;
358 + goto msg_done;
359 + }
360 +
361 + if (par_override || t->speed_hz || t->bits_per_word) {
362 + par_override = 1;
363 + status = rt2880_spi_setup_transfer(spi, t);
364 + if (status < 0)
365 + goto msg_done;
366 + if (!t->speed_hz && !t->bits_per_word)
367 + par_override = 0;
368 + }
369 +
370 + if (!cs_active) {
371 + rt2880_spi_set_cs(rs, 1);
372 + cs_active = 1;
373 + }
374 +
375 + if (t->len)
376 + m->actual_length += rt2880_spi_write_read(spi, t);
377 +
378 + if (t->delay_usecs)
379 + udelay(t->delay_usecs);
380 +
381 + if (t->cs_change) {
382 + rt2880_spi_set_cs(rs, 0);
383 + cs_active = 0;
384 + }
385 + }
386 +
387 +msg_done:
388 + if (cs_active)
389 + rt2880_spi_set_cs(rs, 0);
390 +
391 + m->status = status;
392 + spi_finalize_current_message(master);
393 +
394 + return 0;
395 +}
396 +
397 +static int rt2880_spi_setup(struct spi_device *spi)
398 +{
399 + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
400 +
401 + if ((spi->max_speed_hz == 0) ||
402 + (spi->max_speed_hz > (rs->sys_freq / 2)))
403 + spi->max_speed_hz = (rs->sys_freq / 2);
404 +
405 + if (spi->max_speed_hz < (rs->sys_freq / 128)) {
406 + dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
407 + spi->max_speed_hz);
408 + return -EINVAL;
409 + }
410 +
411 + /*
412 + * baudrate & width will be set rt2880_spi_setup_transfer
413 + */
414 + return 0;
415 +}
416 +
417 +static void rt2880_spi_reset(struct rt2880_spi *rs)
418 +{
419 + rt2880_spi_write(rs, RAMIPS_SPI_CFG,
420 + SPICFG_MSBFIRST | SPICFG_TXCLKEDGE_FALLING |
421 + SPICFG_SPICLK_DIV16 | SPICFG_SPICLKPOL);
422 + rt2880_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
423 +}
424 +
425 +static int rt2880_spi_probe(struct platform_device *pdev)
426 +{
427 + struct spi_master *master;
428 + struct rt2880_spi *rs;
429 + void __iomem *base;
430 + struct resource *r;
431 + struct clk *clk;
432 + int ret;
433 +
434 + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
435 + base = devm_ioremap_resource(&pdev->dev, r);
436 + if (IS_ERR(base))
437 + return PTR_ERR(base);
438 +
439 + clk = devm_clk_get(&pdev->dev, NULL);
440 + if (IS_ERR(clk)) {
441 + dev_err(&pdev->dev, "unable to get SYS clock\n");
442 + return PTR_ERR(clk);
443 + }
444 +
445 + ret = clk_prepare_enable(clk);
446 + if (ret)
447 + goto err_clk;
448 +
449 + master = spi_alloc_master(&pdev->dev, sizeof(*rs));
450 + if (master == NULL) {
451 + dev_dbg(&pdev->dev, "master allocation failed\n");
452 + ret = -ENOMEM;
453 + goto err_clk;
454 + }
455 +
456 + master->dev.of_node = pdev->dev.of_node;
457 + master->mode_bits = RT2880_SPI_MODE_BITS;
458 + master->bits_per_word_mask = SPI_BPW_MASK(8);
459 + master->min_speed_hz = clk_get_rate(clk) / 128;
460 + master->max_speed_hz = clk_get_rate(clk) / 2;
461 + master->flags = SPI_MASTER_HALF_DUPLEX;
462 + master->setup = rt2880_spi_setup;
463 + master->transfer_one_message = rt2880_spi_transfer_one_message;
464 + master->num_chipselect = RALINK_NUM_CHIPSELECTS;
465 +
466 + dev_set_drvdata(&pdev->dev, master);
467 +
468 + rs = spi_master_get_devdata(master);
469 + rs->master = master;
470 + rs->base = base;
471 + rs->clk = clk;
472 + rs->sys_freq = clk_get_rate(rs->clk);
473 + dev_dbg(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
474 +
475 + device_reset(&pdev->dev);
476 +
477 + rt2880_spi_reset(rs);
478 +
479 + ret = devm_spi_register_master(&pdev->dev, master);
480 + if (ret < 0) {
481 + dev_err(&pdev->dev, "devm_spi_register_master error.\n");
482 + goto err_master;
483 + }
484 +
485 + return ret;
486 +
487 +err_master:
488 + spi_master_put(master);
489 + kfree(master);
490 +err_clk:
491 + clk_disable_unprepare(clk);
492 +
493 + return ret;
494 +}
495 +
496 +static int rt2880_spi_remove(struct platform_device *pdev)
497 +{
498 + struct spi_master *master;
499 + struct rt2880_spi *rs;
500 +
501 + master = dev_get_drvdata(&pdev->dev);
502 + rs = spi_master_get_devdata(master);
503 +
504 + clk_disable_unprepare(rs->clk);
505 +
506 + return 0;
507 +}
508 +
509 +MODULE_ALIAS("platform:" DRIVER_NAME);
510 +
511 +static const struct of_device_id rt2880_spi_match[] = {
512 + { .compatible = "ralink,rt2880-spi" },
513 + {},
514 +};
515 +MODULE_DEVICE_TABLE(of, rt2880_spi_match);
516 +
517 +static struct platform_driver rt2880_spi_driver = {
518 + .driver = {
519 + .name = DRIVER_NAME,
520 + .owner = THIS_MODULE,
521 + .of_match_table = rt2880_spi_match,
522 + },
523 + .probe = rt2880_spi_probe,
524 + .remove = rt2880_spi_remove,
525 +};
526 +
527 +module_platform_driver(rt2880_spi_driver);
528 +
529 +MODULE_DESCRIPTION("Ralink SPI driver");
530 +MODULE_AUTHOR("Sergiy <piratfm@gmail.com>");
531 +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
532 +MODULE_LICENSE("GPL");