1 /*
2  * Arasan Secure Digital Host Controller Interface.
3  * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu>
4  * Copyright (c) 2012 Wind River Systems, Inc.
5  * Copyright (C) 2013 Pengutronix e.K.
6  * Copyright (C) 2013 Xilinx Inc.
7  *
8  * Based on sdhci-of-esdhc.c
9  *
10  * Copyright (c) 2007 Freescale Semiconductor, Inc.
11  * Copyright (c) 2009 MontaVista Software, Inc.
12  *
13  * Authors: Xiaobo Xie <X.Xie@freescale.com>
14  *	    Anton Vorontsov <avorontsov@ru.mvista.com>
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation; either version 2 of the License, or (at
19  * your option) any later version.
20  */
21 
22 #include <linux/module.h>
23 #include <linux/of_device.h>
24 #include "sdhci-pltfm.h"
25 
26 #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
27 
28 #define CLK_CTRL_TIMEOUT_SHIFT		16
29 #define CLK_CTRL_TIMEOUT_MASK		(0xf << CLK_CTRL_TIMEOUT_SHIFT)
30 #define CLK_CTRL_TIMEOUT_MIN_EXP	13
31 
32 /**
33  * struct sdhci_arasan_data
34  * @clk_ahb:	Pointer to the AHB clock
35  */
36 struct sdhci_arasan_data {
37 	struct clk	*clk_ahb;
38 };
39 
40 static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
41 {
42 	u32 div;
43 	unsigned long freq;
44 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
45 
46 	div = readl(host->ioaddr + SDHCI_ARASAN_CLK_CTRL_OFFSET);
47 	div = (div & CLK_CTRL_TIMEOUT_MASK) >> CLK_CTRL_TIMEOUT_SHIFT;
48 
49 	freq = clk_get_rate(pltfm_host->clk);
50 	freq /= 1 << (CLK_CTRL_TIMEOUT_MIN_EXP + div);
51 
52 	return freq;
53 }
54 
55 static struct sdhci_ops sdhci_arasan_ops = {
56 	.set_clock = sdhci_set_clock,
57 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
58 	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
59 	.set_bus_width = sdhci_set_bus_width,
60 	.reset = sdhci_reset,
61 	.set_uhs_signaling = sdhci_set_uhs_signaling,
62 };
63 
64 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
65 	.ops = &sdhci_arasan_ops,
66 	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
67 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
68 			SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
69 };
70 
71 #ifdef CONFIG_PM_SLEEP
72 /**
73  * sdhci_arasan_suspend - Suspend method for the driver
74  * @dev:	Address of the device structure
75  * Returns 0 on success and error value on error
76  *
77  * Put the device in a low power state.
78  */
79 static int sdhci_arasan_suspend(struct device *dev)
80 {
81 	struct platform_device *pdev = to_platform_device(dev);
82 	struct sdhci_host *host = platform_get_drvdata(pdev);
83 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
84 	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
85 	int ret;
86 
87 	ret = sdhci_suspend_host(host);
88 	if (ret)
89 		return ret;
90 
91 	clk_disable(pltfm_host->clk);
92 	clk_disable(sdhci_arasan->clk_ahb);
93 
94 	return 0;
95 }
96 
97 /**
98  * sdhci_arasan_resume - Resume method for the driver
99  * @dev:	Address of the device structure
100  * Returns 0 on success and error value on error
101  *
102  * Resume operation after suspend
103  */
104 static int sdhci_arasan_resume(struct device *dev)
105 {
106 	struct platform_device *pdev = to_platform_device(dev);
107 	struct sdhci_host *host = platform_get_drvdata(pdev);
108 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
109 	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
110 	int ret;
111 
112 	ret = clk_enable(sdhci_arasan->clk_ahb);
113 	if (ret) {
114 		dev_err(dev, "Cannot enable AHB clock.\n");
115 		return ret;
116 	}
117 
118 	ret = clk_enable(pltfm_host->clk);
119 	if (ret) {
120 		dev_err(dev, "Cannot enable SD clock.\n");
121 		clk_disable(sdhci_arasan->clk_ahb);
122 		return ret;
123 	}
124 
125 	return sdhci_resume_host(host);
126 }
127 #endif /* ! CONFIG_PM_SLEEP */
128 
129 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
130 			 sdhci_arasan_resume);
131 
132 static int sdhci_arasan_probe(struct platform_device *pdev)
133 {
134 	int ret;
135 	struct clk *clk_xin;
136 	struct sdhci_host *host;
137 	struct sdhci_pltfm_host *pltfm_host;
138 	struct sdhci_arasan_data *sdhci_arasan;
139 
140 	sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
141 			GFP_KERNEL);
142 	if (!sdhci_arasan)
143 		return -ENOMEM;
144 
145 	sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
146 	if (IS_ERR(sdhci_arasan->clk_ahb)) {
147 		dev_err(&pdev->dev, "clk_ahb clock not found.\n");
148 		return PTR_ERR(sdhci_arasan->clk_ahb);
149 	}
150 
151 	clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
152 	if (IS_ERR(clk_xin)) {
153 		dev_err(&pdev->dev, "clk_xin clock not found.\n");
154 		return PTR_ERR(clk_xin);
155 	}
156 
157 	ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
158 	if (ret) {
159 		dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
160 		return ret;
161 	}
162 
163 	ret = clk_prepare_enable(clk_xin);
164 	if (ret) {
165 		dev_err(&pdev->dev, "Unable to enable SD clock.\n");
166 		goto clk_dis_ahb;
167 	}
168 
169 	host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
170 	if (IS_ERR(host)) {
171 		ret = PTR_ERR(host);
172 		goto clk_disable_all;
173 	}
174 
175 	if (of_device_is_compatible(pdev->dev.of_node, "arasan,sdhci-4.9a")) {
176 		host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
177 		host->quirks2 |= SDHCI_QUIRK2_HOST_NO_CMD23;
178 	}
179 
180 	sdhci_get_of_property(pdev);
181 	pltfm_host = sdhci_priv(host);
182 	pltfm_host->priv = sdhci_arasan;
183 	pltfm_host->clk = clk_xin;
184 
185 	ret = mmc_of_parse(host->mmc);
186 	if (ret) {
187 		dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
188 		goto clk_disable_all;
189 	}
190 
191 	ret = sdhci_add_host(host);
192 	if (ret)
193 		goto err_pltfm_free;
194 
195 	return 0;
196 
197 err_pltfm_free:
198 	sdhci_pltfm_free(pdev);
199 clk_disable_all:
200 	clk_disable_unprepare(clk_xin);
201 clk_dis_ahb:
202 	clk_disable_unprepare(sdhci_arasan->clk_ahb);
203 
204 	return ret;
205 }
206 
207 static int sdhci_arasan_remove(struct platform_device *pdev)
208 {
209 	struct sdhci_host *host = platform_get_drvdata(pdev);
210 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
211 	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
212 
213 	clk_disable_unprepare(sdhci_arasan->clk_ahb);
214 
215 	return sdhci_pltfm_unregister(pdev);
216 }
217 
218 static const struct of_device_id sdhci_arasan_of_match[] = {
219 	{ .compatible = "arasan,sdhci-8.9a" },
220 	{ .compatible = "arasan,sdhci-5.1" },
221 	{ .compatible = "arasan,sdhci-4.9a" },
222 	{ }
223 };
224 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
225 
226 static struct platform_driver sdhci_arasan_driver = {
227 	.driver = {
228 		.name = "sdhci-arasan",
229 		.of_match_table = sdhci_arasan_of_match,
230 		.pm = &sdhci_arasan_dev_pm_ops,
231 	},
232 	.probe = sdhci_arasan_probe,
233 	.remove = sdhci_arasan_remove,
234 };
235 
236 module_platform_driver(sdhci_arasan_driver);
237 
238 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
239 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
240 MODULE_LICENSE("GPL");
241