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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014 Linaro Ltd
4 *
5 * Author: Ulf Hansson <ulf.hansson@linaro.org>
6 *
7 * Simple MMC power sequence management
8 */
9#include <linux/clk.h>
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/platform_device.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/gpio/consumer.h>
18#include <linux/delay.h>
19#include <linux/property.h>
20
21#include <linux/mmc/host.h>
22
23#include "pwrseq.h"
24
25struct mmc_pwrseq_simple {
26 struct mmc_pwrseq pwrseq;
27 bool clk_enabled;
28 u32 post_power_on_delay_ms;
29 u32 power_off_delay_us;
30 struct clk *ext_clk;
31 struct gpio_descs *reset_gpios;
32};
33
34#define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
35
36static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
37 int value)
38{
39 struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
40
41 if (!IS_ERR(reset_gpios)) {
42 unsigned long *values;
43 int nvalues = reset_gpios->ndescs;
44
45 values = bitmap_alloc(nvalues, GFP_KERNEL);
46 if (!values)
47 return;
48
49 if (value)
50 bitmap_fill(values, nvalues);
51 else
52 bitmap_zero(values, nvalues);
53
54 gpiod_set_array_value_cansleep(nvalues, reset_gpios->desc,
55 reset_gpios->info, values);
56
57 bitmap_free(values);
58 }
59}
60
61static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
62{
63 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
64
65 if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
66 clk_prepare_enable(pwrseq->ext_clk);
67 pwrseq->clk_enabled = true;
68 }
69
70 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
71}
72
73static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
74{
75 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
76
77 mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
78
79 if (pwrseq->post_power_on_delay_ms)
80 msleep(pwrseq->post_power_on_delay_ms);
81}
82
83static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
84{
85 struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
86
87 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
88
89 if (pwrseq->power_off_delay_us)
90 usleep_range(pwrseq->power_off_delay_us,
91 2 * pwrseq->power_off_delay_us);
92
93 if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
94 clk_disable_unprepare(pwrseq->ext_clk);
95 pwrseq->clk_enabled = false;
96 }
97}
98
99static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
100 .pre_power_on = mmc_pwrseq_simple_pre_power_on,
101 .post_power_on = mmc_pwrseq_simple_post_power_on,
102 .power_off = mmc_pwrseq_simple_power_off,
103};
104
105static const struct of_device_id mmc_pwrseq_simple_of_match[] = {
106 { .compatible = "mmc-pwrseq-simple",},
107 {/* sentinel */},
108};
109MODULE_DEVICE_TABLE(of, mmc_pwrseq_simple_of_match);
110
111static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
112{
113 struct mmc_pwrseq_simple *pwrseq;
114 struct device *dev = &pdev->dev;
115
116 pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
117 if (!pwrseq)
118 return -ENOMEM;
119
120 pwrseq->ext_clk = devm_clk_get(dev, "ext_clock");
121 if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT)
122 return PTR_ERR(pwrseq->ext_clk);
123
124 pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset",
125 GPIOD_OUT_HIGH);
126 if (IS_ERR(pwrseq->reset_gpios) &&
127 PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
128 PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
129 return PTR_ERR(pwrseq->reset_gpios);
130 }
131
132 device_property_read_u32(dev, "post-power-on-delay-ms",
133 &pwrseq->post_power_on_delay_ms);
134 device_property_read_u32(dev, "power-off-delay-us",
135 &pwrseq->power_off_delay_us);
136
137 pwrseq->pwrseq.dev = dev;
138 pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
139 pwrseq->pwrseq.owner = THIS_MODULE;
140 platform_set_drvdata(pdev, pwrseq);
141
142 return mmc_pwrseq_register(&pwrseq->pwrseq);
143}
144
145static int mmc_pwrseq_simple_remove(struct platform_device *pdev)
146{
147 struct mmc_pwrseq_simple *pwrseq = platform_get_drvdata(pdev);
148
149 mmc_pwrseq_unregister(&pwrseq->pwrseq);
150
151 return 0;
152}
153
154static struct platform_driver mmc_pwrseq_simple_driver = {
155 .probe = mmc_pwrseq_simple_probe,
156 .remove = mmc_pwrseq_simple_remove,
157 .driver = {
158 .name = "pwrseq_simple",
159 .of_match_table = mmc_pwrseq_simple_of_match,
160 },
161};
162
163module_platform_driver(mmc_pwrseq_simple_driver);
164MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) 2014 Linaro Ltd
3 *
4 * Author: Ulf Hansson <ulf.hansson@linaro.org>
5 *
6 * License terms: GNU General Public License (GPL) version 2
7 *
8 * Simple MMC power sequence management
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/gpio/consumer.h>
16
17#include <linux/mmc/host.h>
18
19#include "pwrseq.h"
20
21struct mmc_pwrseq_simple {
22 struct mmc_pwrseq pwrseq;
23 bool clk_enabled;
24 struct clk *ext_clk;
25 struct gpio_descs *reset_gpios;
26};
27
28static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
29 int value)
30{
31 struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
32
33 if (!IS_ERR(reset_gpios)) {
34 int i;
35 int values[reset_gpios->ndescs];
36
37 for (i = 0; i < reset_gpios->ndescs; i++)
38 values[i] = value;
39
40 gpiod_set_array_value_cansleep(
41 reset_gpios->ndescs, reset_gpios->desc, values);
42 }
43}
44
45static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
46{
47 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
48 struct mmc_pwrseq_simple, pwrseq);
49
50 if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
51 clk_prepare_enable(pwrseq->ext_clk);
52 pwrseq->clk_enabled = true;
53 }
54
55 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
56}
57
58static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
59{
60 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
61 struct mmc_pwrseq_simple, pwrseq);
62
63 mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
64}
65
66static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
67{
68 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
69 struct mmc_pwrseq_simple, pwrseq);
70
71 mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
72
73 if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
74 clk_disable_unprepare(pwrseq->ext_clk);
75 pwrseq->clk_enabled = false;
76 }
77}
78
79static void mmc_pwrseq_simple_free(struct mmc_host *host)
80{
81 struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
82 struct mmc_pwrseq_simple, pwrseq);
83
84 if (!IS_ERR(pwrseq->reset_gpios))
85 gpiod_put_array(pwrseq->reset_gpios);
86
87 if (!IS_ERR(pwrseq->ext_clk))
88 clk_put(pwrseq->ext_clk);
89
90 kfree(pwrseq);
91}
92
93static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
94 .pre_power_on = mmc_pwrseq_simple_pre_power_on,
95 .post_power_on = mmc_pwrseq_simple_post_power_on,
96 .power_off = mmc_pwrseq_simple_power_off,
97 .free = mmc_pwrseq_simple_free,
98};
99
100struct mmc_pwrseq *mmc_pwrseq_simple_alloc(struct mmc_host *host,
101 struct device *dev)
102{
103 struct mmc_pwrseq_simple *pwrseq;
104 int ret = 0;
105
106 pwrseq = kzalloc(sizeof(*pwrseq), GFP_KERNEL);
107 if (!pwrseq)
108 return ERR_PTR(-ENOMEM);
109
110 pwrseq->ext_clk = clk_get(dev, "ext_clock");
111 if (IS_ERR(pwrseq->ext_clk) &&
112 PTR_ERR(pwrseq->ext_clk) != -ENOENT) {
113 ret = PTR_ERR(pwrseq->ext_clk);
114 goto free;
115 }
116
117 pwrseq->reset_gpios = gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);
118 if (IS_ERR(pwrseq->reset_gpios) &&
119 PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
120 PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
121 ret = PTR_ERR(pwrseq->reset_gpios);
122 goto clk_put;
123 }
124
125 pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
126
127 return &pwrseq->pwrseq;
128clk_put:
129 if (!IS_ERR(pwrseq->ext_clk))
130 clk_put(pwrseq->ext_clk);
131free:
132 kfree(pwrseq);
133 return ERR_PTR(ret);
134}