sdhci-s3c: add SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK quirk
[deliverable/linux.git] / drivers / mmc / host / sdhci-s3c.c
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1/* linux/drivers/mmc/host/sdhci-s3c.c
2 *
3 * Copyright 2008 Openmoko Inc.
4 * Copyright 2008 Simtec Electronics
5 * Ben Dooks <ben@simtec.co.uk>
6 * http://armlinux.simtec.co.uk/
7 *
8 * SDHCI (HSMMC) support for Samsung SoC
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/delay.h>
16#include <linux/dma-mapping.h>
17#include <linux/platform_device.h>
5a0e3ad6 18#include <linux/slab.h>
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19#include <linux/clk.h>
20#include <linux/io.h>
21
22#include <linux/mmc/host.h>
23
24#include <plat/sdhci.h>
25#include <plat/regs-sdhci.h>
26
27#include "sdhci.h"
28
29#define MAX_BUS_CLK (4)
30
31/**
32 * struct sdhci_s3c - S3C SDHCI instance
33 * @host: The SDHCI host created
34 * @pdev: The platform device we where created from.
35 * @ioarea: The resource created when we claimed the IO area.
36 * @pdata: The platform data for this controller.
37 * @cur_clk: The index of the current bus clock.
38 * @clk_io: The clock for the internal bus interface.
39 * @clk_bus: The clocks that are available for the SD/MMC bus clock.
40 */
41struct sdhci_s3c {
42 struct sdhci_host *host;
43 struct platform_device *pdev;
44 struct resource *ioarea;
45 struct s3c_sdhci_platdata *pdata;
46 unsigned int cur_clk;
47
48 struct clk *clk_io;
49 struct clk *clk_bus[MAX_BUS_CLK];
50};
51
52static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
53{
54 return sdhci_priv(host);
55}
56
57/**
58 * get_curclk - convert ctrl2 register to clock source number
59 * @ctrl2: Control2 register value.
60 */
61static u32 get_curclk(u32 ctrl2)
62{
63 ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
64 ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
65
66 return ctrl2;
67}
68
69static void sdhci_s3c_check_sclk(struct sdhci_host *host)
70{
71 struct sdhci_s3c *ourhost = to_s3c(host);
72 u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
73
74 if (get_curclk(tmp) != ourhost->cur_clk) {
75 dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
76
77 tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
78 tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
79 writel(tmp, host->ioaddr + 0x80);
80 }
81}
82
83/**
84 * sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
85 * @host: The SDHCI host instance.
86 *
87 * Callback to return the maximum clock rate acheivable by the controller.
88*/
89static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
90{
91 struct sdhci_s3c *ourhost = to_s3c(host);
92 struct clk *busclk;
93 unsigned int rate, max;
94 int clk;
95
96 /* note, a reset will reset the clock source */
97
98 sdhci_s3c_check_sclk(host);
99
100 for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
101 busclk = ourhost->clk_bus[clk];
102 if (!busclk)
103 continue;
104
105 rate = clk_get_rate(busclk);
106 if (rate > max)
107 max = rate;
108 }
109
110 return max;
111}
112
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113/**
114 * sdhci_s3c_consider_clock - consider one the bus clocks for current setting
115 * @ourhost: Our SDHCI instance.
116 * @src: The source clock index.
117 * @wanted: The clock frequency wanted.
118 */
119static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
120 unsigned int src,
121 unsigned int wanted)
122{
123 unsigned long rate;
124 struct clk *clksrc = ourhost->clk_bus[src];
125 int div;
126
127 if (!clksrc)
128 return UINT_MAX;
129
130 rate = clk_get_rate(clksrc);
131
132 for (div = 1; div < 256; div *= 2) {
133 if ((rate / div) <= wanted)
134 break;
135 }
136
137 dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
138 src, rate, wanted, rate / div);
139
140 return (wanted - (rate / div));
141}
142
143/**
144 * sdhci_s3c_set_clock - callback on clock change
145 * @host: The SDHCI host being changed
146 * @clock: The clock rate being requested.
147 *
148 * When the card's clock is going to be changed, look at the new frequency
149 * and find the best clock source to go with it.
150*/
151static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
152{
153 struct sdhci_s3c *ourhost = to_s3c(host);
154 unsigned int best = UINT_MAX;
155 unsigned int delta;
156 int best_src = 0;
157 int src;
158 u32 ctrl;
159
160 /* don't bother if the clock is going off. */
161 if (clock == 0)
162 return;
163
164 for (src = 0; src < MAX_BUS_CLK; src++) {
165 delta = sdhci_s3c_consider_clock(ourhost, src, clock);
166 if (delta < best) {
167 best = delta;
168 best_src = src;
169 }
170 }
171
172 dev_dbg(&ourhost->pdev->dev,
173 "selected source %d, clock %d, delta %d\n",
174 best_src, clock, best);
175
176 /* select the new clock source */
177
178 if (ourhost->cur_clk != best_src) {
179 struct clk *clk = ourhost->clk_bus[best_src];
180
181 /* turn clock off to card before changing clock source */
182 writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
183
184 ourhost->cur_clk = best_src;
185 host->max_clk = clk_get_rate(clk);
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186
187 ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
188 ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
189 ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
190 writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
191 }
192
193 /* reconfigure the hardware for new clock rate */
194
195 {
196 struct mmc_ios ios;
197
198 ios.clock = clock;
199
200 if (ourhost->pdata->cfg_card)
201 (ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
202 &ios, NULL);
203 }
204}
205
206static struct sdhci_ops sdhci_s3c_ops = {
207 .get_max_clock = sdhci_s3c_get_max_clk,
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208 .set_clock = sdhci_s3c_set_clock,
209};
210
211static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
212{
213 struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
214 struct device *dev = &pdev->dev;
215 struct sdhci_host *host;
216 struct sdhci_s3c *sc;
217 struct resource *res;
218 int ret, irq, ptr, clks;
219
220 if (!pdata) {
221 dev_err(dev, "no device data specified\n");
222 return -ENOENT;
223 }
224
225 irq = platform_get_irq(pdev, 0);
226 if (irq < 0) {
227 dev_err(dev, "no irq specified\n");
228 return irq;
229 }
230
231 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
232 if (!res) {
233 dev_err(dev, "no memory specified\n");
234 return -ENOENT;
235 }
236
237 host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
238 if (IS_ERR(host)) {
239 dev_err(dev, "sdhci_alloc_host() failed\n");
240 return PTR_ERR(host);
241 }
242
243 sc = sdhci_priv(host);
244
245 sc->host = host;
246 sc->pdev = pdev;
247 sc->pdata = pdata;
248
249 platform_set_drvdata(pdev, host);
250
251 sc->clk_io = clk_get(dev, "hsmmc");
252 if (IS_ERR(sc->clk_io)) {
253 dev_err(dev, "failed to get io clock\n");
254 ret = PTR_ERR(sc->clk_io);
255 goto err_io_clk;
256 }
257
258 /* enable the local io clock and keep it running for the moment. */
259 clk_enable(sc->clk_io);
260
261 for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
262 struct clk *clk;
263 char *name = pdata->clocks[ptr];
264
265 if (name == NULL)
266 continue;
267
268 clk = clk_get(dev, name);
269 if (IS_ERR(clk)) {
270 dev_err(dev, "failed to get clock %s\n", name);
271 continue;
272 }
273
274 clks++;
275 sc->clk_bus[ptr] = clk;
276 clk_enable(clk);
277
278 dev_info(dev, "clock source %d: %s (%ld Hz)\n",
279 ptr, name, clk_get_rate(clk));
280 }
281
282 if (clks == 0) {
283 dev_err(dev, "failed to find any bus clocks\n");
284 ret = -ENOENT;
285 goto err_no_busclks;
286 }
287
288 sc->ioarea = request_mem_region(res->start, resource_size(res),
289 mmc_hostname(host->mmc));
290 if (!sc->ioarea) {
291 dev_err(dev, "failed to reserve register area\n");
292 ret = -ENXIO;
293 goto err_req_regs;
294 }
295
296 host->ioaddr = ioremap_nocache(res->start, resource_size(res));
297 if (!host->ioaddr) {
298 dev_err(dev, "failed to map registers\n");
299 ret = -ENXIO;
300 goto err_req_regs;
301 }
302
303 /* Ensure we have minimal gpio selected CMD/CLK/Detect */
304 if (pdata->cfg_gpio)
305 pdata->cfg_gpio(pdev, pdata->max_width);
306
307 host->hw_name = "samsung-hsmmc";
308 host->ops = &sdhci_s3c_ops;
309 host->quirks = 0;
310 host->irq = irq;
311
312 /* Setup quirks for the controller */
b2e75eff 313 host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
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314
315#ifndef CONFIG_MMC_SDHCI_S3C_DMA
316
317 /* we currently see overruns on errors, so disable the SDMA
318 * support as well. */
319 host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
320
321#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
322
323 /* It seems we do not get an DATA transfer complete on non-busy
324 * transfers, not sure if this is a problem with this specific
325 * SDHCI block, or a missing configuration that needs to be set. */
326 host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
327
328 host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
329 SDHCI_QUIRK_32BIT_DMA_SIZE);
330
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331 /* HSMMC on Samsung SoCs uses SDCLK as timeout clock */
332 host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;
333
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334 ret = sdhci_add_host(host);
335 if (ret) {
336 dev_err(dev, "sdhci_add_host() failed\n");
337 goto err_add_host;
338 }
339
340 return 0;
341
342 err_add_host:
343 release_resource(sc->ioarea);
344 kfree(sc->ioarea);
345
346 err_req_regs:
347 for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
348 clk_disable(sc->clk_bus[ptr]);
349 clk_put(sc->clk_bus[ptr]);
350 }
351
352 err_no_busclks:
353 clk_disable(sc->clk_io);
354 clk_put(sc->clk_io);
355
356 err_io_clk:
357 sdhci_free_host(host);
358
359 return ret;
360}
361
362static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
363{
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364 struct sdhci_host *host = platform_get_drvdata(pdev);
365 struct sdhci_s3c *sc = sdhci_priv(host);
366 int ptr;
367
368 sdhci_remove_host(host, 1);
369
370 for (ptr = 0; ptr < 3; ptr++) {
371 clk_disable(sc->clk_bus[ptr]);
372 clk_put(sc->clk_bus[ptr]);
373 }
374 clk_disable(sc->clk_io);
375 clk_put(sc->clk_io);
376
377 iounmap(host->ioaddr);
378 release_resource(sc->ioarea);
379 kfree(sc->ioarea);
380
381 sdhci_free_host(host);
382 platform_set_drvdata(pdev, NULL);
383
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384 return 0;
385}
386
387#ifdef CONFIG_PM
388
389static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm)
390{
391 struct sdhci_host *host = platform_get_drvdata(dev);
392
393 sdhci_suspend_host(host, pm);
394 return 0;
395}
396
397static int sdhci_s3c_resume(struct platform_device *dev)
398{
399 struct sdhci_host *host = platform_get_drvdata(dev);
400
401 sdhci_resume_host(host);
402 return 0;
403}
404
405#else
406#define sdhci_s3c_suspend NULL
407#define sdhci_s3c_resume NULL
408#endif
409
410static struct platform_driver sdhci_s3c_driver = {
411 .probe = sdhci_s3c_probe,
412 .remove = __devexit_p(sdhci_s3c_remove),
413 .suspend = sdhci_s3c_suspend,
414 .resume = sdhci_s3c_resume,
415 .driver = {
416 .owner = THIS_MODULE,
417 .name = "s3c-sdhci",
418 },
419};
420
421static int __init sdhci_s3c_init(void)
422{
423 return platform_driver_register(&sdhci_s3c_driver);
424}
425
426static void __exit sdhci_s3c_exit(void)
427{
428 platform_driver_unregister(&sdhci_s3c_driver);
429}
430
431module_init(sdhci_s3c_init);
432module_exit(sdhci_s3c_exit);
433
434MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
435MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
436MODULE_LICENSE("GPL v2");
437MODULE_ALIAS("platform:s3c-sdhci");
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