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10#include <linux/clk.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/platform_device.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/device.h>
17#include <linux/err.h>
18#include <linux/gpio/consumer.h>
19
20#include <linux/mmc/host.h>
21
22#include "pwrseq.h"
23
24struct mmc_pwrseq_simple {
25 struct mmc_pwrseq pwrseq;
26 bool clk_enabled;
27 struct clk *ext_clk;
28 struct gpio_descs *reset_gpios;
29};
30
31#define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
32
33static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
34 int value)
35{
36 struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
37
38 if (!IS_ERR(reset_gpios)) {
39 int i;
40 int values[reset_gpios->ndescs];
41
42 for (i = 0; i < reset_gpios->ndescs; i++)
43 values[i] = value;
44
45 gpiod_set_array_value_cansleep(
46 reset_gpios->ndescs, reset_gpios->desc, values);
47 }
48}
49
50static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
51{
52 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
53
54 if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
55 clk_prepare_enable(pwrseq->ext_clk);
56 pwrseq->clk_enabled = true;
57 }
58
59 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
60}
61
62static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
63{
64 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
65
66 mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
67}
68
69static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
70{
71 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
72
73 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
74
75 if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
76 clk_disable_unprepare(pwrseq->ext_clk);
77 pwrseq->clk_enabled = false;
78 }
79}
80
81static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
82 .pre_power_on = mmc_pwrseq_simple_pre_power_on,
83 .post_power_on = mmc_pwrseq_simple_post_power_on,
84 .power_off = mmc_pwrseq_simple_power_off,
85};
86
87static const struct of_device_id mmc_pwrseq_simple_of_match[] = {
88 { .compatible = "mmc-pwrseq-simple",},
89 {},
90};
91MODULE_DEVICE_TABLE(of, mmc_pwrseq_simple_of_match);
92
93static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
94{
95 struct mmc_pwrseq_simple *pwrseq;
96 struct device *dev = &pdev->dev;
97
98 pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
99 if (!pwrseq)
100 return -ENOMEM;
101
102 pwrseq->ext_clk = devm_clk_get(dev, "ext_clock");
103 if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT)
104 return PTR_ERR(pwrseq->ext_clk);
105
106 pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset",
107 GPIOD_OUT_HIGH);
108 if (IS_ERR(pwrseq->reset_gpios) &&
109 PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
110 PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
111 return PTR_ERR(pwrseq->reset_gpios);
112 }
113
114 pwrseq->pwrseq.dev = dev;
115 pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
116 pwrseq->pwrseq.owner = THIS_MODULE;
117 platform_set_drvdata(pdev, pwrseq);
118
119 return mmc_pwrseq_register(&pwrseq->pwrseq);
120}
121
122static int mmc_pwrseq_simple_remove(struct platform_device *pdev)
123{
124 struct mmc_pwrseq_simple *pwrseq = platform_get_drvdata(pdev);
125
126 mmc_pwrseq_unregister(&pwrseq->pwrseq);
127
128 return 0;
129}
130
131static struct platform_driver mmc_pwrseq_simple_driver = {
132 .probe = mmc_pwrseq_simple_probe,
133 .remove = mmc_pwrseq_simple_remove,
134 .driver = {
135 .name = "pwrseq_simple",
136 .of_match_table = mmc_pwrseq_simple_of_match,
137 },
138};
139
140module_platform_driver(mmc_pwrseq_simple_driver);
141MODULE_LICENSE("GPL v2");
142
