1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/*
* Copyright (C) 2014 Linaro Ltd
*
* Author: Ulf Hansson <ulf.hansson@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*
* Simple MMC power sequence management
*/
#include <linux/clk.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/of_gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/mmc/host.h>
#include "pwrseq.h"
struct mmc_pwrseq_simple {
struct mmc_pwrseq pwrseq;
bool clk_enabled;
struct clk *ext_clk;
int nr_gpios;
struct gpio_desc *reset_gpios[0];
};
static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
int value)
{
int i;
for (i = 0; i < pwrseq->nr_gpios; i++)
if (!IS_ERR(pwrseq->reset_gpios[i]))
gpiod_set_value_cansleep(pwrseq->reset_gpios[i], value);
}
static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
{
struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
struct mmc_pwrseq_simple, pwrseq);
if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
clk_prepare_enable(pwrseq->ext_clk);
pwrseq->clk_enabled = true;
}
mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
}
static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
{
struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
struct mmc_pwrseq_simple, pwrseq);
mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
}
static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
{
struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
struct mmc_pwrseq_simple, pwrseq);
mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
clk_disable_unprepare(pwrseq->ext_clk);
pwrseq->clk_enabled = false;
}
}
static void mmc_pwrseq_simple_free(struct mmc_host *host)
{
struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
struct mmc_pwrseq_simple, pwrseq);
int i;
for (i = 0; i < pwrseq->nr_gpios; i++)
if (!IS_ERR(pwrseq->reset_gpios[i]))
gpiod_put(pwrseq->reset_gpios[i]);
if (!IS_ERR(pwrseq->ext_clk))
clk_put(pwrseq->ext_clk);
kfree(pwrseq);
host->pwrseq = NULL;
}
static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
.pre_power_on = mmc_pwrseq_simple_pre_power_on,
.post_power_on = mmc_pwrseq_simple_post_power_on,
.power_off = mmc_pwrseq_simple_power_off,
.free = mmc_pwrseq_simple_free,
};
int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev)
{
struct mmc_pwrseq_simple *pwrseq;
int i, nr_gpios, ret = 0;
nr_gpios = of_gpio_named_count(dev->of_node, "reset-gpios");
if (nr_gpios < 0)
nr_gpios = 0;
pwrseq = kzalloc(sizeof(struct mmc_pwrseq_simple) + nr_gpios *
sizeof(struct gpio_desc *), GFP_KERNEL);
if (!pwrseq)
return -ENOMEM;
pwrseq->ext_clk = clk_get(dev, "ext_clock");
if (IS_ERR(pwrseq->ext_clk) &&
PTR_ERR(pwrseq->ext_clk) != -ENOENT) {
ret = PTR_ERR(pwrseq->ext_clk);
goto free;
}
for (i = 0; i < nr_gpios; i++) {
pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i,
GPIOD_OUT_HIGH);
if (IS_ERR(pwrseq->reset_gpios[i]) &&
PTR_ERR(pwrseq->reset_gpios[i]) != -ENOENT &&
PTR_ERR(pwrseq->reset_gpios[i]) != -ENOSYS) {
ret = PTR_ERR(pwrseq->reset_gpios[i]);
while (--i)
gpiod_put(pwrseq->reset_gpios[i]);
goto clk_put;
}
}
pwrseq->nr_gpios = nr_gpios;
pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
host->pwrseq = &pwrseq->pwrseq;
return 0;
clk_put:
if (!IS_ERR(pwrseq->ext_clk))
clk_put(pwrseq->ext_clk);
free:
kfree(pwrseq);
return ret;
}
|
