xref: /openbmc/linux/drivers/mmc/host/sdhci-tegra.c (revision f0de8369)
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 <mach/gpio.h>
25 #include <mach/sdhci.h>
26 
27 #include "sdhci-pltfm.h"
28 
29 static u32 tegra_sdhci_readl(struct sdhci_host *host, int reg)
30 {
31 	u32 val;
32 
33 	if (unlikely(reg == SDHCI_PRESENT_STATE)) {
34 		/* Use wp_gpio here instead? */
35 		val = readl(host->ioaddr + reg);
36 		return val | SDHCI_WRITE_PROTECT;
37 	}
38 
39 	return readl(host->ioaddr + reg);
40 }
41 
42 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
43 {
44 	if (unlikely(reg == SDHCI_HOST_VERSION)) {
45 		/* Erratum: Version register is invalid in HW. */
46 		return SDHCI_SPEC_200;
47 	}
48 
49 	return readw(host->ioaddr + reg);
50 }
51 
52 static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
53 {
54 	/* Seems like we're getting spurious timeout and crc errors, so
55 	 * disable signalling of them. In case of real errors software
56 	 * timers should take care of eventually detecting them.
57 	 */
58 	if (unlikely(reg == SDHCI_SIGNAL_ENABLE))
59 		val &= ~(SDHCI_INT_TIMEOUT|SDHCI_INT_CRC);
60 
61 	writel(val, host->ioaddr + reg);
62 
63 	if (unlikely(reg == SDHCI_INT_ENABLE)) {
64 		/* Erratum: Must enable block gap interrupt detection */
65 		u8 gap_ctrl = readb(host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
66 		if (val & SDHCI_INT_CARD_INT)
67 			gap_ctrl |= 0x8;
68 		else
69 			gap_ctrl &= ~0x8;
70 		writeb(gap_ctrl, host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
71 	}
72 }
73 
74 static unsigned int tegra_sdhci_get_ro(struct sdhci_host *sdhci)
75 {
76 	struct platform_device *pdev = to_platform_device(mmc_dev(sdhci->mmc));
77 	struct tegra_sdhci_platform_data *plat;
78 
79 	plat = pdev->dev.platform_data;
80 
81 	if (!gpio_is_valid(plat->wp_gpio))
82 		return -1;
83 
84 	return gpio_get_value(plat->wp_gpio);
85 }
86 
87 static irqreturn_t carddetect_irq(int irq, void *data)
88 {
89 	struct sdhci_host *sdhost = (struct sdhci_host *)data;
90 
91 	tasklet_schedule(&sdhost->card_tasklet);
92 	return IRQ_HANDLED;
93 };
94 
95 static int tegra_sdhci_8bit(struct sdhci_host *host, int bus_width)
96 {
97 	struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
98 	struct tegra_sdhci_platform_data *plat;
99 	u32 ctrl;
100 
101 	plat = pdev->dev.platform_data;
102 
103 	ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
104 	if (plat->is_8bit && bus_width == MMC_BUS_WIDTH_8) {
105 		ctrl &= ~SDHCI_CTRL_4BITBUS;
106 		ctrl |= SDHCI_CTRL_8BITBUS;
107 	} else {
108 		ctrl &= ~SDHCI_CTRL_8BITBUS;
109 		if (bus_width == MMC_BUS_WIDTH_4)
110 			ctrl |= SDHCI_CTRL_4BITBUS;
111 		else
112 			ctrl &= ~SDHCI_CTRL_4BITBUS;
113 	}
114 	sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
115 	return 0;
116 }
117 
118 static struct sdhci_ops tegra_sdhci_ops = {
119 	.get_ro     = tegra_sdhci_get_ro,
120 	.read_l     = tegra_sdhci_readl,
121 	.read_w     = tegra_sdhci_readw,
122 	.write_l    = tegra_sdhci_writel,
123 	.platform_8bit_width = tegra_sdhci_8bit,
124 };
125 
126 static struct sdhci_pltfm_data sdhci_tegra_pdata = {
127 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
128 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
129 		  SDHCI_QUIRK_NO_HISPD_BIT |
130 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC,
131 	.ops  = &tegra_sdhci_ops,
132 };
133 
134 static int __devinit sdhci_tegra_probe(struct platform_device *pdev)
135 {
136 	struct sdhci_pltfm_host *pltfm_host;
137 	struct tegra_sdhci_platform_data *plat;
138 	struct sdhci_host *host;
139 	struct clk *clk;
140 	int rc;
141 
142 	host = sdhci_pltfm_init(pdev, &sdhci_tegra_pdata);
143 	if (IS_ERR(host))
144 		return PTR_ERR(host);
145 
146 	pltfm_host = sdhci_priv(host);
147 
148 	plat = pdev->dev.platform_data;
149 
150 	if (plat == NULL) {
151 		dev_err(mmc_dev(host->mmc), "missing platform data\n");
152 		rc = -ENXIO;
153 		goto err_no_plat;
154 	}
155 
156 	if (gpio_is_valid(plat->power_gpio)) {
157 		rc = gpio_request(plat->power_gpio, "sdhci_power");
158 		if (rc) {
159 			dev_err(mmc_dev(host->mmc),
160 				"failed to allocate power gpio\n");
161 			goto err_power_req;
162 		}
163 		tegra_gpio_enable(plat->power_gpio);
164 		gpio_direction_output(plat->power_gpio, 1);
165 	}
166 
167 	if (gpio_is_valid(plat->cd_gpio)) {
168 		rc = gpio_request(plat->cd_gpio, "sdhci_cd");
169 		if (rc) {
170 			dev_err(mmc_dev(host->mmc),
171 				"failed to allocate cd gpio\n");
172 			goto err_cd_req;
173 		}
174 		tegra_gpio_enable(plat->cd_gpio);
175 		gpio_direction_input(plat->cd_gpio);
176 
177 		rc = request_irq(gpio_to_irq(plat->cd_gpio), carddetect_irq,
178 				 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
179 				 mmc_hostname(host->mmc), host);
180 
181 		if (rc)	{
182 			dev_err(mmc_dev(host->mmc), "request irq error\n");
183 			goto err_cd_irq_req;
184 		}
185 
186 	}
187 
188 	if (gpio_is_valid(plat->wp_gpio)) {
189 		rc = gpio_request(plat->wp_gpio, "sdhci_wp");
190 		if (rc) {
191 			dev_err(mmc_dev(host->mmc),
192 				"failed to allocate wp gpio\n");
193 			goto err_wp_req;
194 		}
195 		tegra_gpio_enable(plat->wp_gpio);
196 		gpio_direction_input(plat->wp_gpio);
197 	}
198 
199 	clk = clk_get(mmc_dev(host->mmc), NULL);
200 	if (IS_ERR(clk)) {
201 		dev_err(mmc_dev(host->mmc), "clk err\n");
202 		rc = PTR_ERR(clk);
203 		goto err_clk_get;
204 	}
205 	clk_enable(clk);
206 	pltfm_host->clk = clk;
207 
208 	host->mmc->pm_caps = plat->pm_flags;
209 
210 	if (plat->is_8bit)
211 		host->mmc->caps |= MMC_CAP_8_BIT_DATA;
212 
213 	rc = sdhci_add_host(host);
214 	if (rc)
215 		goto err_add_host;
216 
217 	return 0;
218 
219 err_add_host:
220 	clk_disable(pltfm_host->clk);
221 	clk_put(pltfm_host->clk);
222 err_clk_get:
223 	if (gpio_is_valid(plat->wp_gpio)) {
224 		tegra_gpio_disable(plat->wp_gpio);
225 		gpio_free(plat->wp_gpio);
226 	}
227 err_wp_req:
228 	if (gpio_is_valid(plat->cd_gpio))
229 		free_irq(gpio_to_irq(plat->cd_gpio), host);
230 err_cd_irq_req:
231 	if (gpio_is_valid(plat->cd_gpio)) {
232 		tegra_gpio_disable(plat->cd_gpio);
233 		gpio_free(plat->cd_gpio);
234 	}
235 err_cd_req:
236 	if (gpio_is_valid(plat->power_gpio)) {
237 		tegra_gpio_disable(plat->power_gpio);
238 		gpio_free(plat->power_gpio);
239 	}
240 err_power_req:
241 err_no_plat:
242 	sdhci_pltfm_free(pdev);
243 	return rc;
244 }
245 
246 static int __devexit sdhci_tegra_remove(struct platform_device *pdev)
247 {
248 	struct sdhci_host *host = platform_get_drvdata(pdev);
249 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
250 	struct tegra_sdhci_platform_data *plat;
251 	int dead = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
252 
253 	sdhci_remove_host(host, dead);
254 
255 	plat = pdev->dev.platform_data;
256 
257 	if (gpio_is_valid(plat->wp_gpio)) {
258 		tegra_gpio_disable(plat->wp_gpio);
259 		gpio_free(plat->wp_gpio);
260 	}
261 
262 	if (gpio_is_valid(plat->cd_gpio)) {
263 		free_irq(gpio_to_irq(plat->cd_gpio), host);
264 		tegra_gpio_disable(plat->cd_gpio);
265 		gpio_free(plat->cd_gpio);
266 	}
267 
268 	if (gpio_is_valid(plat->power_gpio)) {
269 		tegra_gpio_disable(plat->power_gpio);
270 		gpio_free(plat->power_gpio);
271 	}
272 
273 	clk_disable(pltfm_host->clk);
274 	clk_put(pltfm_host->clk);
275 
276 	sdhci_pltfm_free(pdev);
277 
278 	return 0;
279 }
280 
281 static struct platform_driver sdhci_tegra_driver = {
282 	.driver		= {
283 		.name	= "sdhci-tegra",
284 		.owner	= THIS_MODULE,
285 	},
286 	.probe		= sdhci_tegra_probe,
287 	.remove		= __devexit_p(sdhci_tegra_remove),
288 #ifdef CONFIG_PM
289 	.suspend	= sdhci_pltfm_suspend,
290 	.resume		= sdhci_pltfm_resume,
291 #endif
292 };
293 
294 static int __init sdhci_tegra_init(void)
295 {
296 	return platform_driver_register(&sdhci_tegra_driver);
297 }
298 module_init(sdhci_tegra_init);
299 
300 static void __exit sdhci_tegra_exit(void)
301 {
302 	platform_driver_unregister(&sdhci_tegra_driver);
303 }
304 module_exit(sdhci_tegra_exit);
305 
306 MODULE_DESCRIPTION("SDHCI driver for Tegra");
307 MODULE_AUTHOR(" Google, Inc.");
308 MODULE_LICENSE("GPL v2");
309