xref: /openbmc/linux/drivers/mmc/host/sdhci-st.c (revision 5e29a910)
1 /*
2  * Support for SDHCI on STMicroelectronics SoCs
3  *
4  * Copyright (C) 2014 STMicroelectronics Ltd
5  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
6  * Contributors: Peter Griffin <peter.griffin@linaro.org>
7  *
8  * Based on sdhci-cns3xxx.c
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  */
20 
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/module.h>
24 #include <linux/err.h>
25 #include <linux/mmc/host.h>
26 
27 #include "sdhci-pltfm.h"
28 
29 static u32 sdhci_st_readl(struct sdhci_host *host, int reg)
30 {
31 	u32 ret;
32 
33 	switch (reg) {
34 	case SDHCI_CAPABILITIES:
35 		ret = readl_relaxed(host->ioaddr + reg);
36 		/* Support 3.3V and 1.8V */
37 		ret &= ~SDHCI_CAN_VDD_300;
38 		break;
39 	default:
40 		ret = readl_relaxed(host->ioaddr + reg);
41 	}
42 	return ret;
43 }
44 
45 static const struct sdhci_ops sdhci_st_ops = {
46 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
47 	.set_clock = sdhci_set_clock,
48 	.set_bus_width = sdhci_set_bus_width,
49 	.read_l = sdhci_st_readl,
50 	.reset = sdhci_reset,
51 };
52 
53 static const struct sdhci_pltfm_data sdhci_st_pdata = {
54 	.ops = &sdhci_st_ops,
55 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
56 	    SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
57 };
58 
59 
60 static int sdhci_st_probe(struct platform_device *pdev)
61 {
62 	struct sdhci_host *host;
63 	struct sdhci_pltfm_host *pltfm_host;
64 	struct clk *clk;
65 	int ret = 0;
66 	u16 host_version;
67 
68 	clk =  devm_clk_get(&pdev->dev, "mmc");
69 	if (IS_ERR(clk)) {
70 		dev_err(&pdev->dev, "Peripheral clk not found\n");
71 		return PTR_ERR(clk);
72 	}
73 
74 	host = sdhci_pltfm_init(pdev, &sdhci_st_pdata, 0);
75 	if (IS_ERR(host)) {
76 		dev_err(&pdev->dev, "Failed sdhci_pltfm_init\n");
77 		return PTR_ERR(host);
78 	}
79 
80 	ret = mmc_of_parse(host->mmc);
81 	if (ret) {
82 		dev_err(&pdev->dev, "Failed mmc_of_parse\n");
83 		goto err_of;
84 	}
85 
86 	clk_prepare_enable(clk);
87 
88 	pltfm_host = sdhci_priv(host);
89 	pltfm_host->clk = clk;
90 
91 	ret = sdhci_add_host(host);
92 	if (ret) {
93 		dev_err(&pdev->dev, "Failed sdhci_add_host\n");
94 		goto err_out;
95 	}
96 
97 	platform_set_drvdata(pdev, host);
98 
99 	host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
100 
101 	dev_info(&pdev->dev, "SDHCI ST Initialised: Host Version: 0x%x Vendor Version 0x%x\n",
102 		((host_version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT),
103 		((host_version & SDHCI_VENDOR_VER_MASK) >>
104 		SDHCI_VENDOR_VER_SHIFT));
105 
106 	return 0;
107 
108 err_out:
109 	clk_disable_unprepare(clk);
110 err_of:
111 	sdhci_pltfm_free(pdev);
112 
113 	return ret;
114 }
115 
116 static int sdhci_st_remove(struct platform_device *pdev)
117 {
118 	struct sdhci_host *host = platform_get_drvdata(pdev);
119 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
120 
121 	clk_disable_unprepare(pltfm_host->clk);
122 
123 	return sdhci_pltfm_unregister(pdev);
124 }
125 
126 #ifdef CONFIG_PM_SLEEP
127 static int sdhci_st_suspend(struct device *dev)
128 {
129 	struct sdhci_host *host = dev_get_drvdata(dev);
130 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
131 	int ret = sdhci_suspend_host(host);
132 
133 	if (ret)
134 		goto out;
135 
136 	clk_disable_unprepare(pltfm_host->clk);
137 out:
138 	return ret;
139 }
140 
141 static int sdhci_st_resume(struct device *dev)
142 {
143 	struct sdhci_host *host = dev_get_drvdata(dev);
144 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
145 
146 	clk_prepare_enable(pltfm_host->clk);
147 
148 	return sdhci_resume_host(host);
149 }
150 #endif
151 
152 static SIMPLE_DEV_PM_OPS(sdhci_st_pmops, sdhci_st_suspend, sdhci_st_resume);
153 
154 static const struct of_device_id st_sdhci_match[] = {
155 	{ .compatible = "st,sdhci" },
156 	{},
157 };
158 
159 MODULE_DEVICE_TABLE(of, st_sdhci_match);
160 
161 static struct platform_driver sdhci_st_driver = {
162 	.probe = sdhci_st_probe,
163 	.remove = sdhci_st_remove,
164 	.driver = {
165 		   .name = "sdhci-st",
166 		   .pm = &sdhci_st_pmops,
167 		   .of_match_table = of_match_ptr(st_sdhci_match),
168 		  },
169 };
170 
171 module_platform_driver(sdhci_st_driver);
172 
173 MODULE_DESCRIPTION("SDHCI driver for STMicroelectronics SoCs");
174 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
175 MODULE_LICENSE("GPL v2");
176 MODULE_ALIAS("platform:st-sdhci");
177