2 * Atmel SDMMC controller driver.
4 * Copyright (C) 2015 Atmel,
5 * 2015 Ludovic Desroches <ludovic.desroches@atmel.com>
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
21 #include <linux/kernel.h>
22 #include <linux/mmc/host.h>
23 #include <linux/mmc/slot-gpio.h>
24 #include <linux/module.h>
26 #include <linux/of_device.h>
28 #include <linux/pm_runtime.h>
30 #include "sdhci-pltfm.h"
32 #define SDMMC_CACR 0x230
33 #define SDMMC_CACR_CAPWREN BIT(0)
34 #define SDMMC_CACR_KEY (0x46 << 8)
36 #define SDHCI_AT91_PRESET_COMMON_CONF 0x400 /* drv type B, programmable clock mode */
38 struct sdhci_at91_priv {
44 static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
47 unsigned long timeout;
49 host->mmc->actual_clock = 0;
52 * There is no requirement to disable the internal clock before
53 * changing the SD clock configuration. Moreover, disabling the
54 * internal clock, changing the configuration and re-enabling the
55 * internal clock causes some bugs. It can prevent to get the internal
56 * clock stable flag ready and an unexpected switch to the base clock
59 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
60 clk &= SDHCI_CLOCK_INT_EN;
61 sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
66 clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
68 clk |= SDHCI_CLOCK_INT_EN;
69 sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
73 while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
74 & SDHCI_CLOCK_INT_STABLE)) {
76 pr_err("%s: Internal clock never stabilised.\n",
77 mmc_hostname(host->mmc));
84 clk |= SDHCI_CLOCK_CARD_EN;
85 sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
88 static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
89 .set_clock = sdhci_at91_set_clock,
90 .set_bus_width = sdhci_set_bus_width,
92 .set_uhs_signaling = sdhci_set_uhs_signaling,
95 static const struct sdhci_pltfm_data soc_data_sama5d2 = {
96 .ops = &sdhci_at91_sama5d2_ops,
99 static const struct of_device_id sdhci_at91_dt_match[] = {
100 { .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
103 MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
106 static int sdhci_at91_runtime_suspend(struct device *dev)
108 struct sdhci_host *host = dev_get_drvdata(dev);
109 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
110 struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
113 ret = sdhci_runtime_suspend_host(host);
115 clk_disable_unprepare(priv->gck);
116 clk_disable_unprepare(priv->hclock);
117 clk_disable_unprepare(priv->mainck);
122 static int sdhci_at91_runtime_resume(struct device *dev)
124 struct sdhci_host *host = dev_get_drvdata(dev);
125 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
126 struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
129 ret = clk_prepare_enable(priv->mainck);
131 dev_err(dev, "can't enable mainck\n");
135 ret = clk_prepare_enable(priv->hclock);
137 dev_err(dev, "can't enable hclock\n");
141 ret = clk_prepare_enable(priv->gck);
143 dev_err(dev, "can't enable gck\n");
147 return sdhci_runtime_resume_host(host);
149 #endif /* CONFIG_PM */
151 static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
152 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
153 pm_runtime_force_resume)
154 SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
155 sdhci_at91_runtime_resume,
159 static int sdhci_at91_probe(struct platform_device *pdev)
161 const struct of_device_id *match;
162 const struct sdhci_pltfm_data *soc_data;
163 struct sdhci_host *host;
164 struct sdhci_pltfm_host *pltfm_host;
165 struct sdhci_at91_priv *priv;
166 unsigned int caps0, caps1;
167 unsigned int clk_base, clk_mul;
168 unsigned int gck_rate, real_gck_rate;
170 unsigned int preset_div;
172 match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
175 soc_data = match->data;
177 host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
179 return PTR_ERR(host);
181 pltfm_host = sdhci_priv(host);
182 priv = sdhci_pltfm_priv(pltfm_host);
184 priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
185 if (IS_ERR(priv->mainck)) {
186 dev_err(&pdev->dev, "failed to get baseclk\n");
187 return PTR_ERR(priv->mainck);
190 priv->hclock = devm_clk_get(&pdev->dev, "hclock");
191 if (IS_ERR(priv->hclock)) {
192 dev_err(&pdev->dev, "failed to get hclock\n");
193 return PTR_ERR(priv->hclock);
196 priv->gck = devm_clk_get(&pdev->dev, "multclk");
197 if (IS_ERR(priv->gck)) {
198 dev_err(&pdev->dev, "failed to get multclk\n");
199 return PTR_ERR(priv->gck);
203 * The mult clock is provided by as a generated clock by the PMC
204 * controller. In order to set the rate of gck, we have to get the
205 * base clock rate and the clock mult from capabilities.
207 clk_prepare_enable(priv->hclock);
208 caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
209 caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
210 clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
211 clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
212 gck_rate = clk_base * 1000000 * (clk_mul + 1);
213 ret = clk_set_rate(priv->gck, gck_rate);
215 dev_err(&pdev->dev, "failed to set gck");
216 goto hclock_disable_unprepare;
219 * We need to check if we have the requested rate for gck because in
220 * some cases this rate could be not supported. If it happens, the rate
221 * is the closest one gck can provide. We have to update the value
224 real_gck_rate = clk_get_rate(priv->gck);
225 if (real_gck_rate != gck_rate) {
226 clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
227 caps1 &= (~SDHCI_CLOCK_MUL_MASK);
228 caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
229 /* Set capabilities in r/w mode. */
230 writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
231 writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
232 /* Set capabilities in ro mode. */
233 writel(0, host->ioaddr + SDMMC_CACR);
234 dev_info(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",
235 clk_mul, real_gck_rate);
239 * We have to set preset values because it depends on the clk_mul
240 * value. Moreover, SDR104 is supported in a degraded mode since the
241 * maximum sd clock value is 120 MHz instead of 208 MHz. For that
242 * reason, we need to use presets to support SDR104.
244 preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
245 writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
246 host->ioaddr + SDHCI_PRESET_FOR_SDR12);
247 preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
248 writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
249 host->ioaddr + SDHCI_PRESET_FOR_SDR25);
250 preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
251 writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
252 host->ioaddr + SDHCI_PRESET_FOR_SDR50);
253 preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
254 writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
255 host->ioaddr + SDHCI_PRESET_FOR_SDR104);
256 preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
257 writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
258 host->ioaddr + SDHCI_PRESET_FOR_DDR50);
260 clk_prepare_enable(priv->mainck);
261 clk_prepare_enable(priv->gck);
263 ret = mmc_of_parse(host->mmc);
265 goto clocks_disable_unprepare;
267 sdhci_get_of_property(pdev);
269 pm_runtime_get_noresume(&pdev->dev);
270 pm_runtime_set_active(&pdev->dev);
271 pm_runtime_enable(&pdev->dev);
272 pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
273 pm_runtime_use_autosuspend(&pdev->dev);
275 ret = sdhci_add_host(host);
277 goto pm_runtime_disable;
280 * When calling sdhci_runtime_suspend_host(), the sdhci layer makes
281 * the assumption that all the clocks of the controller are disabled.
282 * It means we can't get irq from it when it is runtime suspended.
283 * For that reason, it is not planned to wake-up on a card detect irq
284 * from the controller.
285 * If we want to use runtime PM and to be able to wake-up on card
286 * insertion, we have to use a GPIO for the card detection or we can
287 * use polling. Be aware that using polling will resume/suspend the
288 * controller between each attempt.
289 * Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries
290 * to enable polling via device tree with broken-cd property.
292 if (mmc_card_is_removable(host->mmc) &&
293 mmc_gpio_get_cd(host->mmc) < 0) {
294 host->mmc->caps |= MMC_CAP_NEEDS_POLL;
295 host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
298 pm_runtime_put_autosuspend(&pdev->dev);
303 pm_runtime_disable(&pdev->dev);
304 pm_runtime_set_suspended(&pdev->dev);
305 pm_runtime_put_noidle(&pdev->dev);
306 clocks_disable_unprepare:
307 clk_disable_unprepare(priv->gck);
308 clk_disable_unprepare(priv->mainck);
309 hclock_disable_unprepare:
310 clk_disable_unprepare(priv->hclock);
311 sdhci_pltfm_free(pdev);
315 static int sdhci_at91_remove(struct platform_device *pdev)
317 struct sdhci_host *host = platform_get_drvdata(pdev);
318 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
319 struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
320 struct clk *gck = priv->gck;
321 struct clk *hclock = priv->hclock;
322 struct clk *mainck = priv->mainck;
324 pm_runtime_get_sync(&pdev->dev);
325 pm_runtime_disable(&pdev->dev);
326 pm_runtime_put_noidle(&pdev->dev);
328 sdhci_pltfm_unregister(pdev);
330 clk_disable_unprepare(gck);
331 clk_disable_unprepare(hclock);
332 clk_disable_unprepare(mainck);
337 static struct platform_driver sdhci_at91_driver = {
339 .name = "sdhci-at91",
340 .of_match_table = sdhci_at91_dt_match,
341 .pm = &sdhci_at91_dev_pm_ops,
343 .probe = sdhci_at91_probe,
344 .remove = sdhci_at91_remove,
347 module_platform_driver(sdhci_at91_driver);
349 MODULE_DESCRIPTION("SDHCI driver for at91");
350 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
351 MODULE_LICENSE("GPL v2");