xref: /openbmc/linux/drivers/mmc/core/pwrseq_sd8787.c (revision 2326f3cd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * pwrseq_sd8787.c - power sequence support for Marvell SD8787 BT + Wifi chip
4  *
5  * Copyright (C) 2016 Matt Ranostay <matt@ranostay.consulting>
6  *
7  * Based on the original work pwrseq_simple.c
8  *  Copyright (C) 2014 Linaro Ltd
9  *  Author: Ulf Hansson <ulf.hansson@linaro.org>
10  */
11 
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/platform_device.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/slab.h>
19 #include <linux/device.h>
20 #include <linux/err.h>
21 #include <linux/gpio/consumer.h>
22 
23 #include <linux/mmc/host.h>
24 
25 #include "pwrseq.h"
26 
27 struct mmc_pwrseq_sd8787 {
28 	struct mmc_pwrseq pwrseq;
29 	struct gpio_desc *reset_gpio;
30 	struct gpio_desc *pwrdn_gpio;
31 	u32 reset_pwrdwn_delay_ms;
32 };
33 
34 #define to_pwrseq_sd8787(p) container_of(p, struct mmc_pwrseq_sd8787, pwrseq)
35 
36 static void mmc_pwrseq_sd8787_pre_power_on(struct mmc_host *host)
37 {
38 	struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
39 
40 	gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
41 
42 	msleep(pwrseq->reset_pwrdwn_delay_ms);
43 	gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 1);
44 }
45 
46 static void mmc_pwrseq_sd8787_power_off(struct mmc_host *host)
47 {
48 	struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
49 
50 	gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 0);
51 	gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
52 }
53 
54 static const struct mmc_pwrseq_ops mmc_pwrseq_sd8787_ops = {
55 	.pre_power_on = mmc_pwrseq_sd8787_pre_power_on,
56 	.power_off = mmc_pwrseq_sd8787_power_off,
57 };
58 
59 static const u32 sd8787_delay_ms = 300;
60 static const u32 wilc1000_delay_ms = 5;
61 
62 static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
63 	{ .compatible = "mmc-pwrseq-sd8787", .data = &sd8787_delay_ms },
64 	{ .compatible = "mmc-pwrseq-wilc1000", .data = &wilc1000_delay_ms },
65 	{/* sentinel */},
66 };
67 MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
68 
69 static int mmc_pwrseq_sd8787_probe(struct platform_device *pdev)
70 {
71 	struct mmc_pwrseq_sd8787 *pwrseq;
72 	struct device *dev = &pdev->dev;
73 	const struct of_device_id *match;
74 
75 	pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
76 	if (!pwrseq)
77 		return -ENOMEM;
78 
79 	match = of_match_node(mmc_pwrseq_sd8787_of_match, pdev->dev.of_node);
80 	pwrseq->reset_pwrdwn_delay_ms = *(u32 *)match->data;
81 
82 	pwrseq->pwrdn_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_LOW);
83 	if (IS_ERR(pwrseq->pwrdn_gpio))
84 		return PTR_ERR(pwrseq->pwrdn_gpio);
85 
86 	pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
87 	if (IS_ERR(pwrseq->reset_gpio))
88 		return PTR_ERR(pwrseq->reset_gpio);
89 
90 	pwrseq->pwrseq.dev = dev;
91 	pwrseq->pwrseq.ops = &mmc_pwrseq_sd8787_ops;
92 	pwrseq->pwrseq.owner = THIS_MODULE;
93 	platform_set_drvdata(pdev, pwrseq);
94 
95 	return mmc_pwrseq_register(&pwrseq->pwrseq);
96 }
97 
98 static int mmc_pwrseq_sd8787_remove(struct platform_device *pdev)
99 {
100 	struct mmc_pwrseq_sd8787 *pwrseq = platform_get_drvdata(pdev);
101 
102 	mmc_pwrseq_unregister(&pwrseq->pwrseq);
103 
104 	return 0;
105 }
106 
107 static struct platform_driver mmc_pwrseq_sd8787_driver = {
108 	.probe = mmc_pwrseq_sd8787_probe,
109 	.remove = mmc_pwrseq_sd8787_remove,
110 	.driver = {
111 		.name = "pwrseq_sd8787",
112 		.of_match_table = mmc_pwrseq_sd8787_of_match,
113 	},
114 };
115 
116 module_platform_driver(mmc_pwrseq_sd8787_driver);
117 MODULE_LICENSE("GPL v2");
118