xref: /openbmc/linux/drivers/mmc/host/sdhci-tegra.c (revision ea5abbd2)
1 /*
2  * Copyright (C) 2010 Google, Inc.
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/platform_device.h>
18 #include <linux/clk.h>
19 #include <linux/io.h>
20 #include <linux/gpio.h>
21 #include <linux/mmc/card.h>
22 #include <linux/mmc/host.h>
23 
24 #include <asm/gpio.h>
25 
26 #include <mach/gpio-tegra.h>
27 #include <mach/sdhci.h>
28 
29 #include "sdhci-pltfm.h"
30 
31 static u32 tegra_sdhci_readl(struct sdhci_host *host, int reg)
32 {
33 	u32 val;
34 
35 	if (unlikely(reg == SDHCI_PRESENT_STATE)) {
36 		/* Use wp_gpio here instead? */
37 		val = readl(host->ioaddr + reg);
38 		return val | SDHCI_WRITE_PROTECT;
39 	}
40 
41 	return readl(host->ioaddr + reg);
42 }
43 
44 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
45 {
46 	if (unlikely(reg == SDHCI_HOST_VERSION)) {
47 		/* Erratum: Version register is invalid in HW. */
48 		return SDHCI_SPEC_200;
49 	}
50 
51 	return readw(host->ioaddr + reg);
52 }
53 
54 static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
55 {
56 	/* Seems like we're getting spurious timeout and crc errors, so
57 	 * disable signalling of them. In case of real errors software
58 	 * timers should take care of eventually detecting them.
59 	 */
60 	if (unlikely(reg == SDHCI_SIGNAL_ENABLE))
61 		val &= ~(SDHCI_INT_TIMEOUT|SDHCI_INT_CRC);
62 
63 	writel(val, host->ioaddr + reg);
64 
65 	if (unlikely(reg == SDHCI_INT_ENABLE)) {
66 		/* Erratum: Must enable block gap interrupt detection */
67 		u8 gap_ctrl = readb(host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
68 		if (val & SDHCI_INT_CARD_INT)
69 			gap_ctrl |= 0x8;
70 		else
71 			gap_ctrl &= ~0x8;
72 		writeb(gap_ctrl, host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
73 	}
74 }
75 
76 static unsigned int tegra_sdhci_get_ro(struct sdhci_host *sdhci)
77 {
78 	struct platform_device *pdev = to_platform_device(mmc_dev(sdhci->mmc));
79 	struct tegra_sdhci_platform_data *plat;
80 
81 	plat = pdev->dev.platform_data;
82 
83 	if (!gpio_is_valid(plat->wp_gpio))
84 		return -1;
85 
86 	return gpio_get_value(plat->wp_gpio);
87 }
88 
89 static irqreturn_t carddetect_irq(int irq, void *data)
90 {
91 	struct sdhci_host *sdhost = (struct sdhci_host *)data;
92 
93 	tasklet_schedule(&sdhost->card_tasklet);
94 	return IRQ_HANDLED;
95 };
96 
97 static int tegra_sdhci_8bit(struct sdhci_host *host, int bus_width)
98 {
99 	struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
100 	struct tegra_sdhci_platform_data *plat;
101 	u32 ctrl;
102 
103 	plat = pdev->dev.platform_data;
104 
105 	ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
106 	if (plat->is_8bit && bus_width == MMC_BUS_WIDTH_8) {
107 		ctrl &= ~SDHCI_CTRL_4BITBUS;
108 		ctrl |= SDHCI_CTRL_8BITBUS;
109 	} else {
110 		ctrl &= ~SDHCI_CTRL_8BITBUS;
111 		if (bus_width == MMC_BUS_WIDTH_4)
112 			ctrl |= SDHCI_CTRL_4BITBUS;
113 		else
114 			ctrl &= ~SDHCI_CTRL_4BITBUS;
115 	}
116 	sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
117 	return 0;
118 }
119 
120 static struct sdhci_ops tegra_sdhci_ops = {
121 	.get_ro     = tegra_sdhci_get_ro,
122 	.read_l     = tegra_sdhci_readl,
123 	.read_w     = tegra_sdhci_readw,
124 	.write_l    = tegra_sdhci_writel,
125 	.platform_8bit_width = tegra_sdhci_8bit,
126 };
127 
128 static struct sdhci_pltfm_data sdhci_tegra_pdata = {
129 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
130 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
131 		  SDHCI_QUIRK_NO_HISPD_BIT |
132 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC,
133 	.ops  = &tegra_sdhci_ops,
134 };
135 
136 static int __devinit sdhci_tegra_probe(struct platform_device *pdev)
137 {
138 	struct sdhci_pltfm_host *pltfm_host;
139 	struct tegra_sdhci_platform_data *plat;
140 	struct sdhci_host *host;
141 	struct clk *clk;
142 	int rc;
143 
144 	host = sdhci_pltfm_init(pdev, &sdhci_tegra_pdata);
145 	if (IS_ERR(host))
146 		return PTR_ERR(host);
147 
148 	pltfm_host = sdhci_priv(host);
149 
150 	plat = pdev->dev.platform_data;
151 
152 	if (plat == NULL) {
153 		dev_err(mmc_dev(host->mmc), "missing platform data\n");
154 		rc = -ENXIO;
155 		goto err_no_plat;
156 	}
157 
158 	if (gpio_is_valid(plat->power_gpio)) {
159 		rc = gpio_request(plat->power_gpio, "sdhci_power");
160 		if (rc) {
161 			dev_err(mmc_dev(host->mmc),
162 				"failed to allocate power gpio\n");
163 			goto err_power_req;
164 		}
165 		tegra_gpio_enable(plat->power_gpio);
166 		gpio_direction_output(plat->power_gpio, 1);
167 	}
168 
169 	if (gpio_is_valid(plat->cd_gpio)) {
170 		rc = gpio_request(plat->cd_gpio, "sdhci_cd");
171 		if (rc) {
172 			dev_err(mmc_dev(host->mmc),
173 				"failed to allocate cd gpio\n");
174 			goto err_cd_req;
175 		}
176 		tegra_gpio_enable(plat->cd_gpio);
177 		gpio_direction_input(plat->cd_gpio);
178 
179 		rc = request_irq(gpio_to_irq(plat->cd_gpio), carddetect_irq,
180 				 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
181 				 mmc_hostname(host->mmc), host);
182 
183 		if (rc)	{
184 			dev_err(mmc_dev(host->mmc), "request irq error\n");
185 			goto err_cd_irq_req;
186 		}
187 
188 	}
189 
190 	if (gpio_is_valid(plat->wp_gpio)) {
191 		rc = gpio_request(plat->wp_gpio, "sdhci_wp");
192 		if (rc) {
193 			dev_err(mmc_dev(host->mmc),
194 				"failed to allocate wp gpio\n");
195 			goto err_wp_req;
196 		}
197 		tegra_gpio_enable(plat->wp_gpio);
198 		gpio_direction_input(plat->wp_gpio);
199 	}
200 
201 	clk = clk_get(mmc_dev(host->mmc), NULL);
202 	if (IS_ERR(clk)) {
203 		dev_err(mmc_dev(host->mmc), "clk err\n");
204 		rc = PTR_ERR(clk);
205 		goto err_clk_get;
206 	}
207 	clk_enable(clk);
208 	pltfm_host->clk = clk;
209 
210 	host->mmc->pm_caps = plat->pm_flags;
211 
212 	if (plat->is_8bit)
213 		host->mmc->caps |= MMC_CAP_8_BIT_DATA;
214 
215 	rc = sdhci_add_host(host);
216 	if (rc)
217 		goto err_add_host;
218 
219 	return 0;
220 
221 err_add_host:
222 	clk_disable(pltfm_host->clk);
223 	clk_put(pltfm_host->clk);
224 err_clk_get:
225 	if (gpio_is_valid(plat->wp_gpio)) {
226 		tegra_gpio_disable(plat->wp_gpio);
227 		gpio_free(plat->wp_gpio);
228 	}
229 err_wp_req:
230 	if (gpio_is_valid(plat->cd_gpio))
231 		free_irq(gpio_to_irq(plat->cd_gpio), host);
232 err_cd_irq_req:
233 	if (gpio_is_valid(plat->cd_gpio)) {
234 		tegra_gpio_disable(plat->cd_gpio);
235 		gpio_free(plat->cd_gpio);
236 	}
237 err_cd_req:
238 	if (gpio_is_valid(plat->power_gpio)) {
239 		tegra_gpio_disable(plat->power_gpio);
240 		gpio_free(plat->power_gpio);
241 	}
242 err_power_req:
243 err_no_plat:
244 	sdhci_pltfm_free(pdev);
245 	return rc;
246 }
247 
248 static int __devexit sdhci_tegra_remove(struct platform_device *pdev)
249 {
250 	struct sdhci_host *host = platform_get_drvdata(pdev);
251 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
252 	struct tegra_sdhci_platform_data *plat;
253 	int dead = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
254 
255 	sdhci_remove_host(host, dead);
256 
257 	plat = pdev->dev.platform_data;
258 
259 	if (gpio_is_valid(plat->wp_gpio)) {
260 		tegra_gpio_disable(plat->wp_gpio);
261 		gpio_free(plat->wp_gpio);
262 	}
263 
264 	if (gpio_is_valid(plat->cd_gpio)) {
265 		free_irq(gpio_to_irq(plat->cd_gpio), host);
266 		tegra_gpio_disable(plat->cd_gpio);
267 		gpio_free(plat->cd_gpio);
268 	}
269 
270 	if (gpio_is_valid(plat->power_gpio)) {
271 		tegra_gpio_disable(plat->power_gpio);
272 		gpio_free(plat->power_gpio);
273 	}
274 
275 	clk_disable(pltfm_host->clk);
276 	clk_put(pltfm_host->clk);
277 
278 	sdhci_pltfm_free(pdev);
279 
280 	return 0;
281 }
282 
283 static struct platform_driver sdhci_tegra_driver = {
284 	.driver		= {
285 		.name	= "sdhci-tegra",
286 		.owner	= THIS_MODULE,
287 	},
288 	.probe		= sdhci_tegra_probe,
289 	.remove		= __devexit_p(sdhci_tegra_remove),
290 #ifdef CONFIG_PM
291 	.suspend	= sdhci_pltfm_suspend,
292 	.resume		= sdhci_pltfm_resume,
293 #endif
294 };
295 
296 static int __init sdhci_tegra_init(void)
297 {
298 	return platform_driver_register(&sdhci_tegra_driver);
299 }
300 module_init(sdhci_tegra_init);
301 
302 static void __exit sdhci_tegra_exit(void)
303 {
304 	platform_driver_unregister(&sdhci_tegra_driver);
305 }
306 module_exit(sdhci_tegra_exit);
307 
308 MODULE_DESCRIPTION("SDHCI driver for Tegra");
309 MODULE_AUTHOR(" Google, Inc.");
310 MODULE_LICENSE("GPL v2");
311