1
2
3
4
5
6
7
8
9
10#include <linux/clk.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/of_gpio.h>
16#include <linux/gpio/consumer.h>
17
18#include <linux/mmc/host.h>
19
20#include "pwrseq.h"
21
22struct mmc_pwrseq_simple {
23 struct mmc_pwrseq pwrseq;
24 bool clk_enabled;
25 struct clk *ext_clk;
26 int nr_gpios;
27 struct gpio_desc *reset_gpios[0];
28};
29
30static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
31 int value)
32{
33 int i;
34
35 for (i = 0; i < pwrseq->nr_gpios; i++)
36 if (!IS_ERR(pwrseq->reset_gpios[i]))
37 gpiod_set_value_cansleep(pwrseq->reset_gpios[i], value);
38}
39
40static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
41{
42 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
43 struct mmc_pwrseq_simple, pwrseq);
44
45 if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
46 clk_prepare_enable(pwrseq->ext_clk);
47 pwrseq->clk_enabled = true;
48 }
49
50 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
51}
52
53static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
54{
55 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
56 struct mmc_pwrseq_simple, pwrseq);
57
58 mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
59}
60
61static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
62{
63 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
64 struct mmc_pwrseq_simple, pwrseq);
65
66 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
67
68 if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
69 clk_disable_unprepare(pwrseq->ext_clk);
70 pwrseq->clk_enabled = false;
71 }
72}
73
74static void mmc_pwrseq_simple_free(struct mmc_host *host)
75{
76 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
77 struct mmc_pwrseq_simple, pwrseq);
78 int i;
79
80 for (i = 0; i < pwrseq->nr_gpios; i++)
81 if (!IS_ERR(pwrseq->reset_gpios[i]))
82 gpiod_put(pwrseq->reset_gpios[i]);
83
84 if (!IS_ERR(pwrseq->ext_clk))
85 clk_put(pwrseq->ext_clk);
86
87 kfree(pwrseq);
88 host->pwrseq = NULL;
89}
90
91static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
92 .pre_power_on = mmc_pwrseq_simple_pre_power_on,
93 .post_power_on = mmc_pwrseq_simple_post_power_on,
94 .power_off = mmc_pwrseq_simple_power_off,
95 .free = mmc_pwrseq_simple_free,
96};
97
98int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
99{
100 struct mmc_pwrseq_simple *pwrseq;
101 int i, nr_gpios, ret = 0;
102
103 nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
104 if (nr_gpios < 0)
105 nr_gpios = 0;
106
107 pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple) + nr_gpios *
108 sizeof(struct gpio_desc *), GFP_KERNEL);
109 if (!pwrseq)
110 return -ENOMEM;
111
112 pwrseq->ext_clk = clk_get(dev, "ext_clock");
113 if (IS_ERR(pwrseq->ext_clk) &&
114 PTR_ERR(pwrseq->ext_clk) != -ENOENT) {
115 ret = PTR_ERR(pwrseq->ext_clk);
116 goto free;
117 }
118
119 for (i = 0; i < nr_gpios; i++) {
120 pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i,
121 GPIOD_OUT_HIGH);
122 if (IS_ERR(pwrseq->reset_gpios[i]) &&
123 PTR_ERR(pwrseq->reset_gpios[i]) != -ENOENT &&
124 PTR_ERR(pwrseq->reset_gpios[i]) != -ENOSYS) {
125 ret = PTR_ERR(pwrseq->reset_gpios[i]);
126
127 while (i--)
128 gpiod_put(pwrseq->reset_gpios[i]);
129
130 goto clk_put;
131 }
132 }
133
134 pwrseq->nr_gpios = nr_gpios;
135 pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
136 host->pwrseq = &pwrseq->pwrseq;
137
138 return 0;
139clk_put:
140 if (!IS_ERR(pwrseq->ext_clk))
141 clk_put(pwrseq->ext_clk);
142free:
143 kfree(pwrseq);
144 return ret;
145}
146
