483d216a57c61bb9ef5b1c751b3b08466b740f61
[openwrt.git] / target / linux / sunxi / patches-3.14 / 146-2-spi-add-a10-spi.patch
1 From 1ae7667375308c27023d793372d6be1f3b89f5b5 Mon Sep 17 00:00:00 2001
2 From: Maxime Ripard <maxime.ripard@free-electrons.com>
3 Date: Sat, 22 Feb 2014 22:35:53 +0100
4 Subject: [PATCH] spi: sunxi: Add Allwinner A10 SPI controller driver
5
6 The older Allwinner SoCs (A10, A13, A10s and A20) all have the same SPI
7 controller.
8
9 Unfortunately, this SPI controller, even though quite similar, is significantly
10 different from the recently supported A31 SPI controller (different registers
11 offset, split/merged registers, etc.). Supporting both controllers in a single
12 driver would be unreasonable, hence the addition of a new driver.
13
14 Like its more recent counterpart, it supports DMA, but the driver only does PIO
15 until we have a dmaengine driver for this platform.
16
17 Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
18 ---
19  .../devicetree/bindings/spi/spi-sun4i.txt          |  24 ++
20  drivers/spi/Kconfig                                |   6 +
21  drivers/spi/Makefile                               |   1 +
22  drivers/spi/spi-sun4i.c                            | 477 +++++++++++++++++++++
23  4 files changed, 508 insertions(+)
24  create mode 100644 Documentation/devicetree/bindings/spi/spi-sun4i.txt
25  create mode 100644 drivers/spi/spi-sun4i.c
26
27 --- /dev/null
28 +++ b/Documentation/devicetree/bindings/spi/spi-sun4i.txt
29 @@ -0,0 +1,24 @@
30 +Allwinner A10 SPI controller
31 +
32 +Required properties:
33 +- compatible: Should be "allwinner,sun4-a10-spi".
34 +- reg: Should contain register location and length.
35 +- interrupts: Should contain interrupt.
36 +- clocks: phandle to the clocks feeding the SPI controller. Two are
37 +          needed:
38 +  - "ahb": the gated AHB parent clock
39 +  - "mod": the parent module clock
40 +- clock-names: Must contain the clock names described just above
41 +
42 +Example:
43 +
44 +spi1: spi@01c06000 {
45 +       compatible = "allwinner,sun4i-a10-spi";
46 +       reg = <0x01c06000 0x1000>;
47 +       interrupts = <11>;
48 +       clocks = <&ahb_gates 21>, <&spi1_clk>;
49 +       clock-names = "ahb", "mod";
50 +       status = "disabled";
51 +       #address-cells = <1>;
52 +       #size-cells = <0>;
53 +};
54 --- a/drivers/spi/Kconfig
55 +++ b/drivers/spi/Kconfig
56 @@ -455,6 +455,12 @@ config SPI_SIRF
57         help
58           SPI driver for CSR SiRFprimaII SoCs
59  
60 +config SPI_SUN4I
61 +       tristate "Allwinner A10 SoCs SPI controller"
62 +       depends on ARCH_SUNXI || COMPILE_TEST
63 +       help
64 +         SPI driver for Allwinner sun4i, sun5i and sun7i SoCs
65 +
66  config SPI_SUN6I
67         tristate "Allwinner A31 SPI controller"
68         depends on ARCH_SUNXI || COMPILE_TEST
69 --- a/drivers/spi/Makefile
70 +++ b/drivers/spi/Makefile
71 @@ -71,6 +71,7 @@ obj-$(CONFIG_SPI_SH_HSPI)             += spi-sh-hsp
72  obj-$(CONFIG_SPI_SH_MSIOF)             += spi-sh-msiof.o
73  obj-$(CONFIG_SPI_SH_SCI)               += spi-sh-sci.o
74  obj-$(CONFIG_SPI_SIRF)         += spi-sirf.o
75 +obj-$(CONFIG_SPI_SUN4I)                        += spi-sun4i.o
76  obj-$(CONFIG_SPI_SUN6I)                        += spi-sun6i.o
77  obj-$(CONFIG_SPI_TEGRA114)             += spi-tegra114.o
78  obj-$(CONFIG_SPI_TEGRA20_SFLASH)       += spi-tegra20-sflash.o
79 --- /dev/null
80 +++ b/drivers/spi/spi-sun4i.c
81 @@ -0,0 +1,477 @@
82 +/*
83 + * Copyright (C) 2012 - 2014 Allwinner Tech
84 + * Pan Nan <pannan@allwinnertech.com>
85 + *
86 + * Copyright (C) 2014 Maxime Ripard
87 + * Maxime Ripard <maxime.ripard@free-electrons.com>
88 + *
89 + * This program is free software; you can redistribute it and/or
90 + * modify it under the terms of the GNU General Public License as
91 + * published by the Free Software Foundation; either version 2 of
92 + * the License, or (at your option) any later version.
93 + */
94 +
95 +#include <linux/clk.h>
96 +#include <linux/delay.h>
97 +#include <linux/device.h>
98 +#include <linux/interrupt.h>
99 +#include <linux/io.h>
100 +#include <linux/module.h>
101 +#include <linux/platform_device.h>
102 +#include <linux/pm_runtime.h>
103 +#include <linux/workqueue.h>
104 +
105 +#include <linux/spi/spi.h>
106 +
107 +#define SUN4I_FIFO_DEPTH               64
108 +
109 +#define SUN4I_RXDATA_REG               0x00
110 +
111 +#define SUN4I_TXDATA_REG               0x04
112 +
113 +#define SUN4I_CTL_REG                  0x08
114 +#define SUN4I_CTL_ENABLE                       BIT(0)
115 +#define SUN4I_CTL_MASTER                       BIT(1)
116 +#define SUN4I_CTL_CPHA                         BIT(2)
117 +#define SUN4I_CTL_CPOL                         BIT(3)
118 +#define SUN4I_CTL_CS_ACTIVE_LOW                        BIT(4)
119 +#define SUN4I_CTL_LMTF                         BIT(6)
120 +#define SUN4I_CTL_TF_RST                       BIT(8)
121 +#define SUN4I_CTL_RF_RST                       BIT(9)
122 +#define SUN4I_CTL_XCH                          BIT(10)
123 +#define SUN4I_CTL_CS_MASK                      0x3000
124 +#define SUN4I_CTL_CS(cs)                       (((cs) << 12) & SUN4I_CTL_CS_MASK)
125 +#define SUN4I_CTL_DHB                          BIT(15)
126 +#define SUN4I_CTL_CS_MANUAL                    BIT(16)
127 +#define SUN4I_CTL_CS_LEVEL                     BIT(17)
128 +#define SUN4I_CTL_TP                           BIT(18)
129 +
130 +#define SUN4I_INT_CTL_REG              0x0c
131 +#define SUN4I_INT_CTL_TC                       BIT(16)
132 +
133 +#define SUN4I_INT_STA_REG              0x10
134 +
135 +#define SUN4I_DMA_CTL_REG              0x14
136 +
137 +#define SUN4I_WAIT_REG                 0x18
138 +
139 +#define SUN4I_CLK_CTL_REG              0x1c
140 +#define SUN4I_CLK_CTL_CDR2_MASK                        0xff
141 +#define SUN4I_CLK_CTL_CDR2(div)                        ((div) & SUN4I_CLK_CTL_CDR2_MASK)
142 +#define SUN4I_CLK_CTL_CDR1_MASK                        0xf
143 +#define SUN4I_CLK_CTL_CDR1(div)                        (((div) & SUN4I_CLK_CTL_CDR1_MASK) << 8)
144 +#define SUN4I_CLK_CTL_DRS                      BIT(12)
145 +
146 +#define SUN4I_BURST_CNT_REG            0x20
147 +#define SUN4I_BURST_CNT(cnt)                   ((cnt) & 0xffffff)
148 +
149 +#define SUN4I_XMIT_CNT_REG             0x24
150 +#define SUN4I_XMIT_CNT(cnt)                    ((cnt) & 0xffffff)
151 +
152 +#define SUN4I_FIFO_STA_REG             0x28
153 +#define SUN4I_FIFO_STA_RF_CNT_MASK             0x7f
154 +#define SUN4I_FIFO_STA_RF_CNT_BITS             0
155 +#define SUN4I_FIFO_STA_TF_CNT_MASK             0x7f
156 +#define SUN4I_FIFO_STA_TF_CNT_BITS             16
157 +
158 +struct sun4i_spi {
159 +       struct spi_master       *master;
160 +       void __iomem            *base_addr;
161 +       struct clk              *hclk;
162 +       struct clk              *mclk;
163 +
164 +       struct completion       done;
165 +
166 +       const u8                *tx_buf;
167 +       u8                      *rx_buf;
168 +       int                     len;
169 +};
170 +
171 +static inline u32 sun4i_spi_read(struct sun4i_spi *sspi, u32 reg)
172 +{
173 +       return readl(sspi->base_addr + reg);
174 +}
175 +
176 +static inline void sun4i_spi_write(struct sun4i_spi *sspi, u32 reg, u32 value)
177 +{
178 +       writel(value, sspi->base_addr + reg);
179 +}
180 +
181 +static inline void sun4i_spi_drain_fifo(struct sun4i_spi *sspi, int len)
182 +{
183 +       u32 reg, cnt;
184 +       u8 byte;
185 +
186 +       /* See how much data is available */
187 +       reg = sun4i_spi_read(sspi, SUN4I_FIFO_STA_REG);
188 +       reg &= SUN4I_FIFO_STA_RF_CNT_MASK;
189 +       cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS;
190 +
191 +       if (len > cnt)
192 +               len = cnt;
193 +
194 +       while (len--) {
195 +               byte = readb(sspi->base_addr + SUN4I_RXDATA_REG);
196 +               if (sspi->rx_buf)
197 +                       *sspi->rx_buf++ = byte;
198 +       }
199 +}
200 +
201 +static inline void sun4i_spi_fill_fifo(struct sun4i_spi *sspi, int len)
202 +{
203 +       u8 byte;
204 +
205 +       if (len > sspi->len)
206 +               len = sspi->len;
207 +
208 +       while (len--) {
209 +               byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
210 +               writeb(byte, sspi->base_addr + SUN4I_TXDATA_REG);
211 +               sspi->len--;
212 +       }
213 +}
214 +
215 +static void sun4i_spi_set_cs(struct spi_device *spi, bool enable)
216 +{
217 +       struct sun4i_spi *sspi = spi_master_get_devdata(spi->master);
218 +       u32 reg;
219 +
220 +       reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
221 +
222 +       reg &= ~SUN4I_CTL_CS_MASK;
223 +       reg |= SUN4I_CTL_CS(spi->chip_select);
224 +
225 +       if (enable)
226 +               reg |= SUN4I_CTL_CS_LEVEL;
227 +       else
228 +               reg &= ~SUN4I_CTL_CS_LEVEL;
229 +
230 +       /*
231 +        * Even though this looks irrelevant since we are supposed to
232 +        * be controlling the chip select manually, this bit also
233 +        * controls the levels of the chip select for inactive
234 +        * devices.
235 +        *
236 +        * If we don't set it, the chip select level will go low by
237 +        * default when the device is idle, which is not really
238 +        * expected in the common case where the chip select is active
239 +        * low.
240 +        */
241 +       if (spi->mode & SPI_CS_HIGH)
242 +               reg &= ~SUN4I_CTL_CS_ACTIVE_LOW;
243 +       else
244 +               reg |= SUN4I_CTL_CS_ACTIVE_LOW;
245 +
246 +       sun4i_spi_write(sspi, SUN4I_CTL_REG, reg);
247 +}
248 +
249 +static int sun4i_spi_transfer_one(struct spi_master *master,
250 +                                 struct spi_device *spi,
251 +                                 struct spi_transfer *tfr)
252 +{
253 +       struct sun4i_spi *sspi = spi_master_get_devdata(master);
254 +       unsigned int mclk_rate, div, timeout;
255 +       unsigned int tx_len = 0;
256 +       int ret = 0;
257 +       u32 reg;
258 +
259 +       /* We don't support transfer larger than the FIFO */
260 +       if (tfr->len > SUN4I_FIFO_DEPTH)
261 +               return -EINVAL;
262 +
263 +       reinit_completion(&sspi->done);
264 +       sspi->tx_buf = tfr->tx_buf;
265 +       sspi->rx_buf = tfr->rx_buf;
266 +       sspi->len = tfr->len;
267 +
268 +       /* Clear pending interrupts */
269 +       sun4i_spi_write(sspi, SUN4I_INT_STA_REG, ~0);
270 +
271 +
272 +       reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
273 +
274 +       /* Reset FIFOs */
275 +       sun4i_spi_write(sspi, SUN4I_CTL_REG,
276 +                       reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST);
277 +
278 +       /*
279 +        * Setup the transfer control register: Chip Select,
280 +        * polarities, etc.
281 +        */
282 +       if (spi->mode & SPI_CPOL)
283 +               reg |= SUN4I_CTL_CPOL;
284 +       else
285 +               reg &= ~SUN4I_CTL_CPOL;
286 +
287 +       if (spi->mode & SPI_CPHA)
288 +               reg |= SUN4I_CTL_CPHA;
289 +       else
290 +               reg &= ~SUN4I_CTL_CPHA;
291 +
292 +       if (spi->mode & SPI_LSB_FIRST)
293 +               reg |= SUN4I_CTL_LMTF;
294 +       else
295 +               reg &= ~SUN4I_CTL_LMTF;
296 +
297 +
298 +       /*
299 +        * If it's a TX only transfer, we don't want to fill the RX
300 +        * FIFO with bogus data
301 +        */
302 +       if (sspi->rx_buf)
303 +               reg &= ~SUN4I_CTL_DHB;
304 +       else
305 +               reg |= SUN4I_CTL_DHB;
306 +
307 +       /* We want to control the chip select manually */
308 +       reg |= SUN4I_CTL_CS_MANUAL;
309 +
310 +       sun4i_spi_write(sspi, SUN4I_CTL_REG, reg);
311 +
312 +       /* Ensure that we have a parent clock fast enough */
313 +       mclk_rate = clk_get_rate(sspi->mclk);
314 +       if (mclk_rate < (2 * spi->max_speed_hz)) {
315 +               clk_set_rate(sspi->mclk, 2 * spi->max_speed_hz);
316 +               mclk_rate = clk_get_rate(sspi->mclk);
317 +       }
318 +
319 +       /*
320 +        * Setup clock divider.
321 +        *
322 +        * We have two choices there. Either we can use the clock
323 +        * divide rate 1, which is calculated thanks to this formula:
324 +        * SPI_CLK = MOD_CLK / (2 ^ (cdr + 1))
325 +        * Or we can use CDR2, which is calculated with the formula:
326 +        * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
327 +        * Wether we use the former or the latter is set through the
328 +        * DRS bit.
329 +        *
330 +        * First try CDR2, and if we can't reach the expected
331 +        * frequency, fall back to CDR1.
332 +        */
333 +       div = mclk_rate / (2 * spi->max_speed_hz);
334 +       if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) {
335 +               if (div > 0)
336 +                       div--;
337 +
338 +               reg = SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS;
339 +       } else {
340 +               div = ilog2(mclk_rate) - ilog2(spi->max_speed_hz);
341 +               reg = SUN4I_CLK_CTL_CDR1(div);
342 +       }
343 +
344 +       sun4i_spi_write(sspi, SUN4I_CLK_CTL_REG, reg);
345 +
346 +       /* Setup the transfer now... */
347 +       if (sspi->tx_buf)
348 +               tx_len = tfr->len;
349 +
350 +       /* Setup the counters */
351 +       sun4i_spi_write(sspi, SUN4I_BURST_CNT_REG, SUN4I_BURST_CNT(tfr->len));
352 +       sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len));
353 +
354 +       /* Fill the TX FIFO */
355 +       sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH);
356 +
357 +       /* Enable the interrupts */
358 +       sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, SUN4I_INT_CTL_TC);
359 +
360 +       /* Start the transfer */
361 +       reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
362 +       sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH);
363 +
364 +       timeout = wait_for_completion_timeout(&sspi->done,
365 +                                             msecs_to_jiffies(1000));
366 +       if (!timeout) {
367 +               ret = -ETIMEDOUT;
368 +               goto out;
369 +       }
370 +
371 +       sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH);
372 +
373 +out:
374 +       sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, 0);
375 +
376 +       return ret;
377 +}
378 +
379 +static irqreturn_t sun4i_spi_handler(int irq, void *dev_id)
380 +{
381 +       struct sun4i_spi *sspi = dev_id;
382 +       u32 status = sun4i_spi_read(sspi, SUN4I_INT_STA_REG);
383 +
384 +       /* Transfer complete */
385 +       if (status & SUN4I_INT_CTL_TC) {
386 +               sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_TC);
387 +               complete(&sspi->done);
388 +               return IRQ_HANDLED;
389 +       }
390 +
391 +       return IRQ_NONE;
392 +}
393 +
394 +static int sun4i_spi_runtime_resume(struct device *dev)
395 +{
396 +       struct spi_master *master = dev_get_drvdata(dev);
397 +       struct sun4i_spi *sspi = spi_master_get_devdata(master);
398 +       int ret;
399 +
400 +       ret = clk_prepare_enable(sspi->hclk);
401 +       if (ret) {
402 +               dev_err(dev, "Couldn't enable AHB clock\n");
403 +               goto out;
404 +       }
405 +
406 +       ret = clk_prepare_enable(sspi->mclk);
407 +       if (ret) {
408 +               dev_err(dev, "Couldn't enable module clock\n");
409 +               goto err;
410 +       }
411 +
412 +       sun4i_spi_write(sspi, SUN4I_CTL_REG,
413 +                       SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP);
414 +
415 +       return 0;
416 +
417 +err:
418 +       clk_disable_unprepare(sspi->hclk);
419 +out:
420 +       return ret;
421 +}
422 +
423 +static int sun4i_spi_runtime_suspend(struct device *dev)
424 +{
425 +       struct spi_master *master = dev_get_drvdata(dev);
426 +       struct sun4i_spi *sspi = spi_master_get_devdata(master);
427 +
428 +       clk_disable_unprepare(sspi->mclk);
429 +       clk_disable_unprepare(sspi->hclk);
430 +
431 +       return 0;
432 +}
433 +
434 +static int sun4i_spi_probe(struct platform_device *pdev)
435 +{
436 +       struct spi_master *master;
437 +       struct sun4i_spi *sspi;
438 +       struct resource *res;
439 +       int ret = 0, irq;
440 +
441 +       master = spi_alloc_master(&pdev->dev, sizeof(struct sun4i_spi));
442 +       if (!master) {
443 +               dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
444 +               return -ENOMEM;
445 +       }
446 +
447 +       platform_set_drvdata(pdev, master);
448 +       sspi = spi_master_get_devdata(master);
449 +
450 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
451 +       sspi->base_addr = devm_ioremap_resource(&pdev->dev, res);
452 +       if (IS_ERR(sspi->base_addr)) {
453 +               ret = PTR_ERR(sspi->base_addr);
454 +               goto err_free_master;
455 +       }
456 +
457 +       irq = platform_get_irq(pdev, 0);
458 +       if (irq < 0) {
459 +               dev_err(&pdev->dev, "No spi IRQ specified\n");
460 +               ret = -ENXIO;
461 +               goto err_free_master;
462 +       }
463 +
464 +       ret = devm_request_irq(&pdev->dev, irq, sun4i_spi_handler,
465 +                              0, "sun4i-spi", sspi);
466 +       if (ret) {
467 +               dev_err(&pdev->dev, "Cannot request IRQ\n");
468 +               goto err_free_master;
469 +       }
470 +
471 +       sspi->master = master;
472 +       master->set_cs = sun4i_spi_set_cs;
473 +       master->transfer_one = sun4i_spi_transfer_one;
474 +       master->num_chipselect = 4;
475 +       master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
476 +       master->dev.of_node = pdev->dev.of_node;
477 +       master->auto_runtime_pm = true;
478 +
479 +       sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
480 +       if (IS_ERR(sspi->hclk)) {
481 +               dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
482 +               ret = PTR_ERR(sspi->hclk);
483 +               goto err_free_master;
484 +       }
485 +
486 +       sspi->mclk = devm_clk_get(&pdev->dev, "mod");
487 +       if (IS_ERR(sspi->mclk)) {
488 +               dev_err(&pdev->dev, "Unable to acquire module clock\n");
489 +               ret = PTR_ERR(sspi->mclk);
490 +               goto err_free_master;
491 +       }
492 +
493 +       init_completion(&sspi->done);
494 +
495 +       /*
496 +        * This wake-up/shutdown pattern is to be able to have the
497 +        * device woken up, even if runtime_pm is disabled
498 +        */
499 +       ret = sun4i_spi_runtime_resume(&pdev->dev);
500 +       if (ret) {
501 +               dev_err(&pdev->dev, "Couldn't resume the device\n");
502 +               goto err_free_master;
503 +       }
504 +
505 +       pm_runtime_set_active(&pdev->dev);
506 +       pm_runtime_enable(&pdev->dev);
507 +       pm_runtime_idle(&pdev->dev);
508 +
509 +       ret = devm_spi_register_master(&pdev->dev, master);
510 +       if (ret) {
511 +               dev_err(&pdev->dev, "cannot register SPI master\n");
512 +               goto err_pm_disable;
513 +       }
514 +
515 +       return 0;
516 +
517 +err_pm_disable:
518 +       pm_runtime_disable(&pdev->dev);
519 +       sun4i_spi_runtime_suspend(&pdev->dev);
520 +err_free_master:
521 +       spi_master_put(master);
522 +       return ret;
523 +}
524 +
525 +static int sun4i_spi_remove(struct platform_device *pdev)
526 +{
527 +       pm_runtime_disable(&pdev->dev);
528 +
529 +       return 0;
530 +}
531 +
532 +static const struct of_device_id sun4i_spi_match[] = {
533 +       { .compatible = "allwinner,sun4i-a10-spi", },
534 +       {}
535 +};
536 +MODULE_DEVICE_TABLE(of, sun4i_spi_match);
537 +
538 +static const struct dev_pm_ops sun4i_spi_pm_ops = {
539 +       .runtime_resume         = sun4i_spi_runtime_resume,
540 +       .runtime_suspend        = sun4i_spi_runtime_suspend,
541 +};
542 +
543 +static struct platform_driver sun4i_spi_driver = {
544 +       .probe  = sun4i_spi_probe,
545 +       .remove = sun4i_spi_remove,
546 +       .driver = {
547 +               .name           = "sun4i-spi",
548 +               .owner          = THIS_MODULE,
549 +               .of_match_table = sun4i_spi_match,
550 +               .pm             = &sun4i_spi_pm_ops,
551 +       },
552 +};
553 +module_platform_driver(sun4i_spi_driver);
554 +
555 +MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
556 +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
557 +MODULE_DESCRIPTION("Allwinner A1X/A20 SPI controller driver");
558 +MODULE_LICENSE("GPL");