Commit | Line | Data |
---|---|---|
8c96f89c UH |
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 | */ | |
c13045b1 | 10 | #include <linux/clk.h> |
8c96f89c UH |
11 | #include <linux/kernel.h> |
12 | #include <linux/slab.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/err.h> | |
934f1f48 | 15 | #include <linux/of_gpio.h> |
862b5dcf | 16 | #include <linux/gpio/consumer.h> |
8c96f89c UH |
17 | |
18 | #include <linux/mmc/host.h> | |
19 | ||
20 | #include "pwrseq.h" | |
21 | ||
22 | struct mmc_pwrseq_simple { | |
23 | struct mmc_pwrseq pwrseq; | |
c13045b1 JMC |
24 | bool clk_enabled; |
25 | struct clk *ext_clk; | |
934f1f48 JMC |
26 | int nr_gpios; |
27 | struct gpio_desc *reset_gpios[0]; | |
8c96f89c UH |
28 | }; |
29 | ||
934f1f48 JMC |
30 | static 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 | ||
862b5dcf UH |
40 | static 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 | ||
c13045b1 JMC |
45 | if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) { |
46 | clk_prepare_enable(pwrseq->ext_clk); | |
47 | pwrseq->clk_enabled = true; | |
48 | } | |
49 | ||
934f1f48 | 50 | mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); |
862b5dcf UH |
51 | } |
52 | ||
53 | static 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 | ||
934f1f48 | 58 | mmc_pwrseq_simple_set_gpios_value(pwrseq, 0); |
862b5dcf UH |
59 | } |
60 | ||
c13045b1 JMC |
61 | static 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 | ||
8c96f89c UH |
74 | static 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); | |
934f1f48 | 78 | int i; |
8c96f89c | 79 | |
934f1f48 JMC |
80 | for (i = 0; i < pwrseq->nr_gpios; i++) |
81 | if (!IS_ERR(pwrseq->reset_gpios[i])) | |
82 | gpiod_put(pwrseq->reset_gpios[i]); | |
862b5dcf | 83 | |
c13045b1 JMC |
84 | if (!IS_ERR(pwrseq->ext_clk)) |
85 | clk_put(pwrseq->ext_clk); | |
86 | ||
8c96f89c UH |
87 | kfree(pwrseq); |
88 | host->pwrseq = NULL; | |
89 | } | |
90 | ||
91 | static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = { | |
862b5dcf UH |
92 | .pre_power_on = mmc_pwrseq_simple_pre_power_on, |
93 | .post_power_on = mmc_pwrseq_simple_post_power_on, | |
c13045b1 | 94 | .power_off = mmc_pwrseq_simple_power_off, |
8c96f89c UH |
95 | .free = mmc_pwrseq_simple_free, |
96 | }; | |
97 | ||
98 | int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) | |
99 | { | |
100 | struct mmc_pwrseq_simple *pwrseq; | |
934f1f48 | 101 | int i, nr_gpios, ret = 0; |
8c96f89c | 102 | |
934f1f48 JMC |
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); | |
8c96f89c UH |
109 | if (!pwrseq) |
110 | return -ENOMEM; | |
111 | ||
c13045b1 JMC |
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 | ||
934f1f48 JMC |
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 | ||
6b7a783e | 127 | while (i--) |
934f1f48 JMC |
128 | gpiod_put(pwrseq->reset_gpios[i]); |
129 | ||
c13045b1 | 130 | goto clk_put; |
934f1f48 | 131 | } |
862b5dcf UH |
132 | } |
133 | ||
934f1f48 | 134 | pwrseq->nr_gpios = nr_gpios; |
8c96f89c UH |
135 | pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops; |
136 | host->pwrseq = &pwrseq->pwrseq; | |
137 | ||
138 | return 0; | |
c13045b1 JMC |
139 | clk_put: |
140 | if (!IS_ERR(pwrseq->ext_clk)) | |
141 | clk_put(pwrseq->ext_clk); | |
862b5dcf UH |
142 | free: |
143 | kfree(pwrseq); | |
144 | return ret; | |
8c96f89c | 145 | } |