1 // SPDX-License-Identifier: GPL-2.0-only
7  *  Simple MMC power sequence management
23 #include <linux/mmc/host.h>
25 #include "pwrseq.h"
28 	struct mmc_pwrseq pwrseq;  member
37 #define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
39 static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,  in mmc_pwrseq_simple_set_gpios_value()  argument
42 	struct gpio_descs *reset_gpios = pwrseq->reset_gpios;  in mmc_pwrseq_simple_set_gpios_value()
46 		int nvalues = reset_gpios->ndescs;  in mmc_pwrseq_simple_set_gpios_value()
65 	struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);  in mmc_pwrseq_simple_pre_power_on()  local
67 	if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {  in mmc_pwrseq_simple_pre_power_on()
68 		clk_prepare_enable(pwrseq->ext_clk);  in mmc_pwrseq_simple_pre_power_on()
69 		pwrseq->clk_enabled = true;  in mmc_pwrseq_simple_pre_power_on()
72 	if (pwrseq->reset_ctrl) {  in mmc_pwrseq_simple_pre_power_on()
73 		reset_control_deassert(pwrseq->reset_ctrl);  in mmc_pwrseq_simple_pre_power_on()
74 		reset_control_assert(pwrseq->reset_ctrl);  in mmc_pwrseq_simple_pre_power_on()
76 		mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);  in mmc_pwrseq_simple_pre_power_on()
81 	struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);  in mmc_pwrseq_simple_post_power_on()  local
83 	if (pwrseq->reset_ctrl)  in mmc_pwrseq_simple_post_power_on()
84 		reset_control_deassert(pwrseq->reset_ctrl);  in mmc_pwrseq_simple_post_power_on()
86 		mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);  in mmc_pwrseq_simple_post_power_on()
88 	if (pwrseq->post_power_on_delay_ms)  in mmc_pwrseq_simple_post_power_on()
89 		msleep(pwrseq->post_power_on_delay_ms);  in mmc_pwrseq_simple_post_power_on()
94 	struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);  in mmc_pwrseq_simple_power_off()  local
96 	if (pwrseq->reset_ctrl)  in mmc_pwrseq_simple_power_off()
97 		reset_control_assert(pwrseq->reset_ctrl);  in mmc_pwrseq_simple_power_off()
99 		mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);  in mmc_pwrseq_simple_power_off()
101 	if (pwrseq->power_off_delay_us)  in mmc_pwrseq_simple_power_off()
102 		usleep_range(pwrseq->power_off_delay_us,  in mmc_pwrseq_simple_power_off()
103 			2 * pwrseq->power_off_delay_us);  in mmc_pwrseq_simple_power_off()
105 	if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {  in mmc_pwrseq_simple_power_off()
106 		clk_disable_unprepare(pwrseq->ext_clk);  in mmc_pwrseq_simple_power_off()
107 		pwrseq->clk_enabled = false;  in mmc_pwrseq_simple_power_off()
118 	{ .compatible = "mmc-pwrseq-simple",},
125 	struct mmc_pwrseq_simple *pwrseq;  in mmc_pwrseq_simple_probe()  local
126 	struct device *dev = &pdev->dev;  in mmc_pwrseq_simple_probe()
129 	pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);  in mmc_pwrseq_simple_probe()
130 	if (!pwrseq)  in mmc_pwrseq_simple_probe()
131 		return -ENOMEM;  in mmc_pwrseq_simple_probe()
133 	pwrseq->ext_clk = devm_clk_get(dev, "ext_clock");  in mmc_pwrseq_simple_probe()
134 	if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT)  in mmc_pwrseq_simple_probe()
135 		return dev_err_probe(dev, PTR_ERR(pwrseq->ext_clk), "external clock not ready\n");  in mmc_pwrseq_simple_probe()
137 	ngpio = of_count_phandle_with_args(dev->of_node, "reset-gpios", "#gpio-cells");  in mmc_pwrseq_simple_probe()
139 		pwrseq->reset_ctrl = devm_reset_control_get_optional_shared(dev, NULL);  in mmc_pwrseq_simple_probe()
140 		if (IS_ERR(pwrseq->reset_ctrl))  in mmc_pwrseq_simple_probe()
141 			return dev_err_probe(dev, PTR_ERR(pwrseq->reset_ctrl),  in mmc_pwrseq_simple_probe()
149 	if (!pwrseq->reset_ctrl) {  in mmc_pwrseq_simple_probe()
150 		pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);  in mmc_pwrseq_simple_probe()
151 		if (IS_ERR(pwrseq->reset_gpios) &&  in mmc_pwrseq_simple_probe()
152 		    PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&  in mmc_pwrseq_simple_probe()
153 		    PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {  in mmc_pwrseq_simple_probe()
154 			return dev_err_probe(dev, PTR_ERR(pwrseq->reset_gpios),  in mmc_pwrseq_simple_probe()
159 	device_property_read_u32(dev, "post-power-on-delay-ms",  in mmc_pwrseq_simple_probe()
160 				 &pwrseq->post_power_on_delay_ms);  in mmc_pwrseq_simple_probe()
161 	device_property_read_u32(dev, "power-off-delay-us",  in mmc_pwrseq_simple_probe()
162 				 &pwrseq->power_off_delay_us);  in mmc_pwrseq_simple_probe()
164 	pwrseq->pwrseq.dev = dev;  in mmc_pwrseq_simple_probe()
165 	pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;  in mmc_pwrseq_simple_probe()
166 	pwrseq->pwrseq.owner = THIS_MODULE;  in mmc_pwrseq_simple_probe()
167 	platform_set_drvdata(pdev, pwrseq);  in mmc_pwrseq_simple_probe()
169 	return mmc_pwrseq_register(&pwrseq->pwrseq);  in mmc_pwrseq_simple_probe()
174 	struct mmc_pwrseq_simple *pwrseq = platform_get_drvdata(pdev);  in mmc_pwrseq_simple_remove()  local
176 	mmc_pwrseq_unregister(&pwrseq->pwrseq);  in mmc_pwrseq_simple_remove()
189 MODULE_DESCRIPTION("Simple power sequence management for MMC");