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 "sdhci-pltfm.h"
24
25 #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c
26
27 #define CLK_CTRL_TIMEOUT_SHIFT 16
28 #define CLK_CTRL_TIMEOUT_MASK (0xf << CLK_CTRL_TIMEOUT_SHIFT)
29 #define CLK_CTRL_TIMEOUT_MIN_EXP 13
30
31 /**
32 * struct sdhci_arasan_data
33 * @clk_ahb: Pointer to the AHB clock
34 */
35 struct sdhci_arasan_data {
36 struct clk *clk_ahb;
37 };
38
sdhci_arasan_get_timeout_clock(struct sdhci_host * host)39 static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
40 {
41 u32 div;
42 unsigned long freq;
43 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
44
45 div = readl(host->ioaddr + SDHCI_ARASAN_CLK_CTRL_OFFSET);
46 div = (div & CLK_CTRL_TIMEOUT_MASK) >> CLK_CTRL_TIMEOUT_SHIFT;
47
48 freq = clk_get_rate(pltfm_host->clk);
49 freq /= 1 << (CLK_CTRL_TIMEOUT_MIN_EXP + div);
50
51 return freq;
52 }
53
54 static struct sdhci_ops sdhci_arasan_ops = {
55 .set_clock = sdhci_set_clock,
56 .get_max_clock = sdhci_pltfm_clk_get_max_clock,
57 .get_timeout_clock = sdhci_arasan_get_timeout_clock,
58 .set_bus_width = sdhci_set_bus_width,
59 .reset = sdhci_reset,
60 .set_uhs_signaling = sdhci_set_uhs_signaling,
61 };
62
63 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
64 .ops = &sdhci_arasan_ops,
65 };
66
67 #ifdef CONFIG_PM_SLEEP
68 /**
69 * sdhci_arasan_suspend - Suspend method for the driver
70 * @dev: Address of the device structure
71 * Returns 0 on success and error value on error
72 *
73 * Put the device in a low power state.
74 */
sdhci_arasan_suspend(struct device * dev)75 static int sdhci_arasan_suspend(struct device *dev)
76 {
77 struct platform_device *pdev = to_platform_device(dev);
78 struct sdhci_host *host = platform_get_drvdata(pdev);
79 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
80 struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
81 int ret;
82
83 ret = sdhci_suspend_host(host);
84 if (ret)
85 return ret;
86
87 clk_disable(pltfm_host->clk);
88 clk_disable(sdhci_arasan->clk_ahb);
89
90 return 0;
91 }
92
93 /**
94 * sdhci_arasan_resume - Resume method for the driver
95 * @dev: Address of the device structure
96 * Returns 0 on success and error value on error
97 *
98 * Resume operation after suspend
99 */
sdhci_arasan_resume(struct device * dev)100 static int sdhci_arasan_resume(struct device *dev)
101 {
102 struct platform_device *pdev = to_platform_device(dev);
103 struct sdhci_host *host = platform_get_drvdata(pdev);
104 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
105 struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
106 int ret;
107
108 ret = clk_enable(sdhci_arasan->clk_ahb);
109 if (ret) {
110 dev_err(dev, "Cannot enable AHB clock.\n");
111 return ret;
112 }
113
114 ret = clk_enable(pltfm_host->clk);
115 if (ret) {
116 dev_err(dev, "Cannot enable SD clock.\n");
117 clk_disable(sdhci_arasan->clk_ahb);
118 return ret;
119 }
120
121 return sdhci_resume_host(host);
122 }
123 #endif /* ! CONFIG_PM_SLEEP */
124
125 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
126 sdhci_arasan_resume);
127
sdhci_arasan_probe(struct platform_device * pdev)128 static int sdhci_arasan_probe(struct platform_device *pdev)
129 {
130 int ret;
131 struct clk *clk_xin;
132 struct sdhci_host *host;
133 struct sdhci_pltfm_host *pltfm_host;
134 struct sdhci_arasan_data *sdhci_arasan;
135
136 sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
137 GFP_KERNEL);
138 if (!sdhci_arasan)
139 return -ENOMEM;
140
141 sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
142 if (IS_ERR(sdhci_arasan->clk_ahb)) {
143 dev_err(&pdev->dev, "clk_ahb clock not found.\n");
144 return PTR_ERR(sdhci_arasan->clk_ahb);
145 }
146
147 clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
148 if (IS_ERR(clk_xin)) {
149 dev_err(&pdev->dev, "clk_xin clock not found.\n");
150 return PTR_ERR(clk_xin);
151 }
152
153 ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
154 if (ret) {
155 dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
156 return ret;
157 }
158
159 ret = clk_prepare_enable(clk_xin);
160 if (ret) {
161 dev_err(&pdev->dev, "Unable to enable SD clock.\n");
162 goto clk_dis_ahb;
163 }
164
165 host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
166 if (IS_ERR(host)) {
167 ret = PTR_ERR(host);
168 goto clk_disable_all;
169 }
170
171 sdhci_get_of_property(pdev);
172 pltfm_host = sdhci_priv(host);
173 pltfm_host->priv = sdhci_arasan;
174 pltfm_host->clk = clk_xin;
175
176 ret = mmc_of_parse(host->mmc);
177 if (ret) {
178 dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
179 goto clk_disable_all;
180 }
181
182 ret = sdhci_add_host(host);
183 if (ret)
184 goto err_pltfm_free;
185
186 return 0;
187
188 err_pltfm_free:
189 sdhci_pltfm_free(pdev);
190 clk_disable_all:
191 clk_disable_unprepare(clk_xin);
192 clk_dis_ahb:
193 clk_disable_unprepare(sdhci_arasan->clk_ahb);
194
195 return ret;
196 }
197
sdhci_arasan_remove(struct platform_device * pdev)198 static int sdhci_arasan_remove(struct platform_device *pdev)
199 {
200 struct sdhci_host *host = platform_get_drvdata(pdev);
201 struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
202 struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
203
204 clk_disable_unprepare(sdhci_arasan->clk_ahb);
205
206 return sdhci_pltfm_unregister(pdev);
207 }
208
209 static const struct of_device_id sdhci_arasan_of_match[] = {
210 { .compatible = "arasan,sdhci-8.9a" },
211 { }
212 };
213 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
214
215 static struct platform_driver sdhci_arasan_driver = {
216 .driver = {
217 .name = "sdhci-arasan",
218 .of_match_table = sdhci_arasan_of_match,
219 .pm = &sdhci_arasan_dev_pm_ops,
220 },
221 .probe = sdhci_arasan_probe,
222 .remove = sdhci_arasan_remove,
223 };
224
225 module_platform_driver(sdhci_arasan_driver);
226
227 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
228 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
229 MODULE_LICENSE("GPL");
230