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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
113static unsigned int sdhci_s3c_get_timeout_clk(struct sdhci_host *host)
114{
115 return sdhci_s3c_get_max_clk(host) / 1000000;
116}
117
118/**
119 * sdhci_s3c_consider_clock - consider one the bus clocks for current setting
120 * @ourhost: Our SDHCI instance.
121 * @src: The source clock index.
122 * @wanted: The clock frequency wanted.
123 */
124static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
125 unsigned int src,
126 unsigned int wanted)
127{
128 unsigned long rate;
129 struct clk *clksrc = ourhost->clk_bus[src];
130 int div;
131
132 if (!clksrc)
133 return UINT_MAX;
134
135 rate = clk_get_rate(clksrc);
136
137 for (div = 1; div < 256; div *= 2) {
138 if ((rate / div) <= wanted)
139 break;
140 }
141
142 dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
143 src, rate, wanted, rate / div);
144
145 return (wanted - (rate / div));
146}
147
148/**
149 * sdhci_s3c_set_clock - callback on clock change
150 * @host: The SDHCI host being changed
151 * @clock: The clock rate being requested.
152 *
153 * When the card's clock is going to be changed, look at the new frequency
154 * and find the best clock source to go with it.
155*/
156static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
157{
158 struct sdhci_s3c *ourhost = to_s3c(host);
159 unsigned int best = UINT_MAX;
160 unsigned int delta;
161 int best_src = 0;
162 int src;
163 u32 ctrl;
164
165 /* don't bother if the clock is going off. */
166 if (clock == 0)
167 return;
168
169 for (src = 0; src < MAX_BUS_CLK; src++) {
170 delta = sdhci_s3c_consider_clock(ourhost, src, clock);
171 if (delta < best) {
172 best = delta;
173 best_src = src;
174 }
175 }
176
177 dev_dbg(&ourhost->pdev->dev,
178 "selected source %d, clock %d, delta %d\n",
179 best_src, clock, best);
180
181 /* select the new clock source */
182
183 if (ourhost->cur_clk != best_src) {
184 struct clk *clk = ourhost->clk_bus[best_src];
185
186 /* turn clock off to card before changing clock source */
187 writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
188
189 ourhost->cur_clk = best_src;
190 host->max_clk = clk_get_rate(clk);
191 host->timeout_clk = sdhci_s3c_get_timeout_clk(host);
192
193 ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
194 ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
195 ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
196 writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
197 }
198
199 /* reconfigure the hardware for new clock rate */
200
201 {
202 struct mmc_ios ios;
203
204 ios.clock = clock;
205
206 if (ourhost->pdata->cfg_card)
207 (ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
208 &ios, NULL);
209 }
210}
211
212static struct sdhci_ops sdhci_s3c_ops = {
213 .get_max_clock = sdhci_s3c_get_max_clk,
214 .get_timeout_clock = sdhci_s3c_get_timeout_clk,
215 .set_clock = sdhci_s3c_set_clock,
216};
217
218static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
219{
220 struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
221 struct device *dev = &pdev->dev;
222 struct sdhci_host *host;
223 struct sdhci_s3c *sc;
224 struct resource *res;
225 int ret, irq, ptr, clks;
226
227 if (!pdata) {
228 dev_err(dev, "no device data specified\n");
229 return -ENOENT;
230 }
231
232 irq = platform_get_irq(pdev, 0);
233 if (irq < 0) {
234 dev_err(dev, "no irq specified\n");
235 return irq;
236 }
237
238 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
239 if (!res) {
240 dev_err(dev, "no memory specified\n");
241 return -ENOENT;
242 }
243
244 host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
245 if (IS_ERR(host)) {
246 dev_err(dev, "sdhci_alloc_host() failed\n");
247 return PTR_ERR(host);
248 }
249
250 sc = sdhci_priv(host);
251
252 sc->host = host;
253 sc->pdev = pdev;
254 sc->pdata = pdata;
255
256 platform_set_drvdata(pdev, host);
257
258 sc->clk_io = clk_get(dev, "hsmmc");
259 if (IS_ERR(sc->clk_io)) {
260 dev_err(dev, "failed to get io clock\n");
261 ret = PTR_ERR(sc->clk_io);
262 goto err_io_clk;
263 }
264
265 /* enable the local io clock and keep it running for the moment. */
266 clk_enable(sc->clk_io);
267
268 for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
269 struct clk *clk;
270 char *name = pdata->clocks[ptr];
271
272 if (name == NULL)
273 continue;
274
275 clk = clk_get(dev, name);
276 if (IS_ERR(clk)) {
277 dev_err(dev, "failed to get clock %s\n", name);
278 continue;
279 }
280
281 clks++;
282 sc->clk_bus[ptr] = clk;
283 clk_enable(clk);
284
285 dev_info(dev, "clock source %d: %s (%ld Hz)\n",
286 ptr, name, clk_get_rate(clk));
287 }
288
289 if (clks == 0) {
290 dev_err(dev, "failed to find any bus clocks\n");
291 ret = -ENOENT;
292 goto err_no_busclks;
293 }
294
295 sc->ioarea = request_mem_region(res->start, resource_size(res),
296 mmc_hostname(host->mmc));
297 if (!sc->ioarea) {
298 dev_err(dev, "failed to reserve register area\n");
299 ret = -ENXIO;
300 goto err_req_regs;
301 }
302
303 host->ioaddr = ioremap_nocache(res->start, resource_size(res));
304 if (!host->ioaddr) {
305 dev_err(dev, "failed to map registers\n");
306 ret = -ENXIO;
307 goto err_req_regs;
308 }
309
310 /* Ensure we have minimal gpio selected CMD/CLK/Detect */
311 if (pdata->cfg_gpio)
312 pdata->cfg_gpio(pdev, pdata->max_width);
313
314 host->hw_name = "samsung-hsmmc";
315 host->ops = &sdhci_s3c_ops;
316 host->quirks = 0;
317 host->irq = irq;
318
319 /* Setup quirks for the controller */
b2e75eff 320 host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
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321
322#ifndef CONFIG_MMC_SDHCI_S3C_DMA
323
324 /* we currently see overruns on errors, so disable the SDMA
325 * support as well. */
326 host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
327
328#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
329
330 /* It seems we do not get an DATA transfer complete on non-busy
331 * transfers, not sure if this is a problem with this specific
332 * SDHCI block, or a missing configuration that needs to be set. */
333 host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
334
335 host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
336 SDHCI_QUIRK_32BIT_DMA_SIZE);
337
338 ret = sdhci_add_host(host);
339 if (ret) {
340 dev_err(dev, "sdhci_add_host() failed\n");
341 goto err_add_host;
342 }
343
344 return 0;
345
346 err_add_host:
347 release_resource(sc->ioarea);
348 kfree(sc->ioarea);
349
350 err_req_regs:
351 for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
352 clk_disable(sc->clk_bus[ptr]);
353 clk_put(sc->clk_bus[ptr]);
354 }
355
356 err_no_busclks:
357 clk_disable(sc->clk_io);
358 clk_put(sc->clk_io);
359
360 err_io_clk:
361 sdhci_free_host(host);
362
363 return ret;
364}
365
366static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
367{
368 return 0;
369}
370
371#ifdef CONFIG_PM
372
373static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm)
374{
375 struct sdhci_host *host = platform_get_drvdata(dev);
376
377 sdhci_suspend_host(host, pm);
378 return 0;
379}
380
381static int sdhci_s3c_resume(struct platform_device *dev)
382{
383 struct sdhci_host *host = platform_get_drvdata(dev);
384
385 sdhci_resume_host(host);
386 return 0;
387}
388
389#else
390#define sdhci_s3c_suspend NULL
391#define sdhci_s3c_resume NULL
392#endif
393
394static struct platform_driver sdhci_s3c_driver = {
395 .probe = sdhci_s3c_probe,
396 .remove = __devexit_p(sdhci_s3c_remove),
397 .suspend = sdhci_s3c_suspend,
398 .resume = sdhci_s3c_resume,
399 .driver = {
400 .owner = THIS_MODULE,
401 .name = "s3c-sdhci",
402 },
403};
404
405static int __init sdhci_s3c_init(void)
406{
407 return platform_driver_register(&sdhci_s3c_driver);
408}
409
410static void __exit sdhci_s3c_exit(void)
411{
412 platform_driver_unregister(&sdhci_s3c_driver);
413}
414
415module_init(sdhci_s3c_init);
416module_exit(sdhci_s3c_exit);
417
418MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
419MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
420MODULE_LICENSE("GPL v2");
421MODULE_ALIAS("platform:s3c-sdhci");