1 /*
2 * drivers/mmc/host/sdhci-spear.c
3 *
4 * Support of SDHCI platform devices for spear soc family
5 *
6 * Copyright (C) 2010 ST Microelectronics
7 * Viresh Kumar <vireshk@kernel.org>
8 *
9 * Inspired by sdhci-pltfm.c
10 *
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
14 */
15
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/highmem.h>
19 #include <linux/module.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm.h>
25 #include <linux/slab.h>
26 #include <linux/mmc/host.h>
27 #include <linux/mmc/slot-gpio.h>
28 #include <linux/io.h>
29 #include "sdhci.h"
30
31 struct spear_sdhci {
32 struct clk *clk;
33 };
34
35 /* sdhci ops */
36 static const struct sdhci_ops sdhci_pltfm_ops = {
37 .set_clock = sdhci_set_clock,
38 .set_bus_width = sdhci_set_bus_width,
39 .reset = sdhci_reset,
40 .set_uhs_signaling = sdhci_set_uhs_signaling,
41 };
42
sdhci_probe(struct platform_device * pdev)43 static int sdhci_probe(struct platform_device *pdev)
44 {
45 struct sdhci_host *host;
46 struct spear_sdhci *sdhci;
47 struct device *dev;
48 int ret;
49
50 dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
51 host = sdhci_alloc_host(dev, sizeof(*sdhci));
52 if (IS_ERR(host)) {
53 ret = PTR_ERR(host);
54 dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
55 goto err;
56 }
57
58 host->ioaddr = devm_platform_ioremap_resource(pdev, 0);
59 if (IS_ERR(host->ioaddr)) {
60 ret = PTR_ERR(host->ioaddr);
61 dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
62 goto err_host;
63 }
64
65 host->hw_name = "sdhci";
66 host->ops = &sdhci_pltfm_ops;
67 host->irq = platform_get_irq(pdev, 0);
68 if (host->irq < 0) {
69 ret = host->irq;
70 goto err_host;
71 }
72 host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
73
74 sdhci = sdhci_priv(host);
75
76 /* clk enable */
77 sdhci->clk = devm_clk_get(&pdev->dev, NULL);
78 if (IS_ERR(sdhci->clk)) {
79 ret = PTR_ERR(sdhci->clk);
80 dev_dbg(&pdev->dev, "Error getting clock\n");
81 goto err_host;
82 }
83
84 ret = clk_prepare_enable(sdhci->clk);
85 if (ret) {
86 dev_dbg(&pdev->dev, "Error enabling clock\n");
87 goto err_host;
88 }
89
90 ret = clk_set_rate(sdhci->clk, 50000000);
91 if (ret)
92 dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
93 clk_get_rate(sdhci->clk));
94
95 /*
96 * It is optional to use GPIOs for sdhci card detection. If we
97 * find a descriptor using slot GPIO, we use it.
98 */
99 ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0);
100 if (ret == -EPROBE_DEFER)
101 goto disable_clk;
102
103 ret = sdhci_add_host(host);
104 if (ret)
105 goto disable_clk;
106
107 platform_set_drvdata(pdev, host);
108
109 return 0;
110
111 disable_clk:
112 clk_disable_unprepare(sdhci->clk);
113 err_host:
114 sdhci_free_host(host);
115 err:
116 dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
117 return ret;
118 }
119
sdhci_remove(struct platform_device * pdev)120 static void sdhci_remove(struct platform_device *pdev)
121 {
122 struct sdhci_host *host = platform_get_drvdata(pdev);
123 struct spear_sdhci *sdhci = sdhci_priv(host);
124 int dead = 0;
125 u32 scratch;
126
127 scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
128 if (scratch == (u32)-1)
129 dead = 1;
130
131 sdhci_remove_host(host, dead);
132 clk_disable_unprepare(sdhci->clk);
133 sdhci_free_host(host);
134 }
135
136 #ifdef CONFIG_PM_SLEEP
sdhci_suspend(struct device * dev)137 static int sdhci_suspend(struct device *dev)
138 {
139 struct sdhci_host *host = dev_get_drvdata(dev);
140 struct spear_sdhci *sdhci = sdhci_priv(host);
141 int ret;
142
143 if (host->tuning_mode != SDHCI_TUNING_MODE_3)
144 mmc_retune_needed(host->mmc);
145
146 ret = sdhci_suspend_host(host);
147 if (!ret)
148 clk_disable(sdhci->clk);
149
150 return ret;
151 }
152
sdhci_resume(struct device * dev)153 static int sdhci_resume(struct device *dev)
154 {
155 struct sdhci_host *host = dev_get_drvdata(dev);
156 struct spear_sdhci *sdhci = sdhci_priv(host);
157 int ret;
158
159 ret = clk_enable(sdhci->clk);
160 if (ret) {
161 dev_dbg(dev, "Resume: Error enabling clock\n");
162 return ret;
163 }
164
165 return sdhci_resume_host(host);
166 }
167 #endif
168
169 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
170
171 static const struct of_device_id sdhci_spear_id_table[] = {
172 { .compatible = "st,spear300-sdhci" },
173 {}
174 };
175 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
176
177 static struct platform_driver sdhci_driver = {
178 .driver = {
179 .name = "sdhci",
180 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
181 .pm = &sdhci_pm_ops,
182 .of_match_table = sdhci_spear_id_table,
183 },
184 .probe = sdhci_probe,
185 .remove_new = sdhci_remove,
186 };
187
188 module_platform_driver(sdhci_driver);
189
190 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
191 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
192 MODULE_LICENSE("GPL v2");
193