2 * Copyright (C) 2014 Linaro Ltd
4 * Author: Ulf Hansson <ulf.hansson@linaro.org>
6 * License terms: GNU General Public License (GPL) version 2
8 * Simple MMC power sequence management
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>
18 #include <linux/mmc/host.h>
22 struct mmc_pwrseq_simple
{
23 struct mmc_pwrseq pwrseq
;
26 struct gpio_descs
*reset_gpios
;
29 static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple
*pwrseq
,
32 struct gpio_descs
*reset_gpios
= pwrseq
->reset_gpios
;
34 if (!IS_ERR(reset_gpios
)) {
36 int values
[reset_gpios
->ndescs
];
38 for (i
= 0; i
< reset_gpios
->ndescs
; i
++)
41 gpiod_set_array_value_cansleep(
42 reset_gpios
->ndescs
, reset_gpios
->desc
, values
);
46 static void mmc_pwrseq_simple_pre_power_on(struct mmc_host
*host
)
48 struct mmc_pwrseq_simple
*pwrseq
= container_of(host
->pwrseq
,
49 struct mmc_pwrseq_simple
, pwrseq
);
51 if (!IS_ERR(pwrseq
->ext_clk
) && !pwrseq
->clk_enabled
) {
52 clk_prepare_enable(pwrseq
->ext_clk
);
53 pwrseq
->clk_enabled
= true;
56 mmc_pwrseq_simple_set_gpios_value(pwrseq
, 1);
59 static void mmc_pwrseq_simple_post_power_on(struct mmc_host
*host
)
61 struct mmc_pwrseq_simple
*pwrseq
= container_of(host
->pwrseq
,
62 struct mmc_pwrseq_simple
, pwrseq
);
64 mmc_pwrseq_simple_set_gpios_value(pwrseq
, 0);
67 static void mmc_pwrseq_simple_power_off(struct mmc_host
*host
)
69 struct mmc_pwrseq_simple
*pwrseq
= container_of(host
->pwrseq
,
70 struct mmc_pwrseq_simple
, pwrseq
);
72 mmc_pwrseq_simple_set_gpios_value(pwrseq
, 1);
74 if (!IS_ERR(pwrseq
->ext_clk
) && pwrseq
->clk_enabled
) {
75 clk_disable_unprepare(pwrseq
->ext_clk
);
76 pwrseq
->clk_enabled
= false;
80 static void mmc_pwrseq_simple_free(struct mmc_host
*host
)
82 struct mmc_pwrseq_simple
*pwrseq
= container_of(host
->pwrseq
,
83 struct mmc_pwrseq_simple
, pwrseq
);
85 if (!IS_ERR(pwrseq
->reset_gpios
))
86 gpiod_put_array(pwrseq
->reset_gpios
);
88 if (!IS_ERR(pwrseq
->ext_clk
))
89 clk_put(pwrseq
->ext_clk
);
94 static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops
= {
95 .pre_power_on
= mmc_pwrseq_simple_pre_power_on
,
96 .post_power_on
= mmc_pwrseq_simple_post_power_on
,
97 .power_off
= mmc_pwrseq_simple_power_off
,
98 .free
= mmc_pwrseq_simple_free
,
101 struct mmc_pwrseq
*mmc_pwrseq_simple_alloc(struct mmc_host
*host
,
104 struct mmc_pwrseq_simple
*pwrseq
;
107 pwrseq
= kzalloc(sizeof(*pwrseq
), GFP_KERNEL
);
109 return ERR_PTR(-ENOMEM
);
111 pwrseq
->ext_clk
= clk_get(dev
, "ext_clock");
112 if (IS_ERR(pwrseq
->ext_clk
) &&
113 PTR_ERR(pwrseq
->ext_clk
) != -ENOENT
) {
114 ret
= PTR_ERR(pwrseq
->ext_clk
);
118 pwrseq
->reset_gpios
= gpiod_get_array(dev
, "reset", GPIOD_OUT_HIGH
);
119 if (IS_ERR(pwrseq
->reset_gpios
) &&
120 PTR_ERR(pwrseq
->reset_gpios
) != -ENOENT
&&
121 PTR_ERR(pwrseq
->reset_gpios
) != -ENOSYS
) {
122 ret
= PTR_ERR(pwrseq
->reset_gpios
);
126 pwrseq
->pwrseq
.ops
= &mmc_pwrseq_simple_ops
;
128 return &pwrseq
->pwrseq
;
130 if (!IS_ERR(pwrseq
->ext_clk
))
131 clk_put(pwrseq
->ext_clk
);