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Commit ee1e0994 authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Mark Brown
Browse files

regulator: s5m8767: Use GPIO for controlling Buck9/eMMC 



Add support for GPIO control (enable/disable) over Buck9. The Buck9
Converter is used as a supply for eMMC Host Controller.

BUCK9EN GPIO of S5M8767 chip may be used by application processor to
enable or disable the Buck9. This has two benefits:
 - It is faster than toggling it over I2C bus.
 - It allows disabling the regulator during suspend to RAM; The AP will
   enable it during resume; Without the patch the regulator supplying
   eMMC must be defined as fixed-regulator.

Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent 07b19808

drivers/regulator/s5m8767.c

+84 −3
Original line number Diff line number Diff line
@@ -11,11 +11,8 @@ 
 *

 */



#include <linux/bug.h>

#include <linux/err.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/regulator/driver.h>
@@ -483,6 +480,65 @@ static struct regulator_desc regulators[] = { 
	s5m8767_regulator_desc(BUCK9),

};



/*

 * Enable GPIO control over BUCK9 in regulator_config for that regulator.

 */

static void s5m8767_regulator_config_ext_control(struct s5m8767_info *s5m8767,

		struct sec_regulator_data *rdata,

		struct regulator_config *config)

{

	int i, mode = 0;



	if (rdata->id != S5M8767_BUCK9)

		return;



	/* Check if opmode for regulator matches S5M8767_ENCTRL_USE_GPIO */

	for (i = 0; i < s5m8767->num_regulators; i++) {

		const struct sec_opmode_data *opmode = &s5m8767->opmode[i];

		if (opmode->id == rdata->id) {

			mode = s5m8767_opmode_reg[rdata->id][opmode->mode];

			break;

		}

	}

	if (mode != S5M8767_ENCTRL_USE_GPIO) {

		dev_warn(s5m8767->dev,

				"ext-control for %s: mismatched op_mode (%x), ignoring\n",

				rdata->reg_node->name, mode);

		return;

	}



	if (!gpio_is_valid(rdata->ext_control_gpio)) {

		dev_warn(s5m8767->dev,

				"ext-control for %s: GPIO not valid, ignoring\n",

				rdata->reg_node->name);

		return;

	}



	config->ena_gpio = rdata->ext_control_gpio;

	config->ena_gpio_flags = GPIOF_OUT_INIT_HIGH;

}



/*

 * Turn on GPIO control over BUCK9.

 */

static int s5m8767_enable_ext_control(struct s5m8767_info *s5m8767,

		struct regulator_dev *rdev)

{

	int ret, reg, enable_ctrl;



	if (rdev_get_id(rdev) != S5M8767_BUCK9)

		return -EINVAL;



	ret = s5m8767_get_register(rdev, &reg, &enable_ctrl);

	if (ret)

		return ret;



	return regmap_update_bits(s5m8767->iodev->regmap_pmic,

			reg, S5M8767_ENCTRL_MASK,

			S5M8767_ENCTRL_USE_GPIO << S5M8767_ENCTRL_SHIFT);

}





#ifdef CONFIG_OF

static int s5m8767_pmic_dt_parse_dvs_gpio(struct sec_pmic_dev *iodev,

			struct sec_platform_data *pdata,
@@ -520,6 +576,16 @@ static int s5m8767_pmic_dt_parse_ds_gpio(struct sec_pmic_dev *iodev, 
	return 0;

}



static void s5m8767_pmic_dt_parse_ext_control_gpio(struct sec_pmic_dev *iodev,

		struct sec_regulator_data *rdata,

		struct device_node *reg_np)

{

	rdata->ext_control_gpio = of_get_named_gpio(reg_np,

			"s5m8767,pmic-ext-control-gpios", 0);

	if (!gpio_is_valid(rdata->ext_control_gpio))

		rdata->ext_control_gpio = 0;

}



static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,

					struct sec_platform_data *pdata)

{
@@ -574,6 +640,8 @@ static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev, 
			continue;

		}



		s5m8767_pmic_dt_parse_ext_control_gpio(iodev, rdata, reg_np);



		rdata->id = i;

		rdata->initdata = of_get_regulator_init_data(

						&pdev->dev, reg_np);
@@ -940,6 +1008,9 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) 
		config.driver_data = s5m8767;

		config.regmap = iodev->regmap_pmic;

		config.of_node = pdata->regulators[i].reg_node;

		if (pdata->regulators[i].ext_control_gpio)

			s5m8767_regulator_config_ext_control(s5m8767,

					&pdata->regulators[i], &config);



		rdev[i] = devm_regulator_register(&pdev->dev, &regulators[id],

						  &config);
@@ -949,6 +1020,16 @@ static int s5m8767_pmic_probe(struct platform_device *pdev) 
					id);

			return ret;

		}



		if (pdata->regulators[i].ext_control_gpio) {

			ret = s5m8767_enable_ext_control(s5m8767, rdev[i]);

			if (ret < 0) {

				dev_err(s5m8767->dev,

						"failed to enable gpio control over %s: %d\n",

						rdev[i]->desc->name, ret);

				return ret;

			}

		}

	}



	return 0;

include/linux/mfd/samsung/core.h

+2 −1
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ struct sec_regulator_data { 
	int				id;

	struct regulator_init_data	*initdata;

	struct device_node		*reg_node;

	int				ext_control_gpio;

};



/*

include/linux/mfd/samsung/s5m8767.h

+7 −0
Original line number Diff line number Diff line
@@ -183,9 +183,16 @@ enum s5m8767_regulators { 
	S5M8767_REG_MAX,

};



/* LDO_EN/BUCK_EN field in registers */

#define S5M8767_ENCTRL_SHIFT		6

#define S5M8767_ENCTRL_MASK		(0x3 << S5M8767_ENCTRL_SHIFT)



/*

 * LDO_EN/BUCK_EN register value for controlling this Buck or LDO

 * by GPIO (PWREN, BUCKEN).

 */

#define S5M8767_ENCTRL_USE_GPIO		0x1



/*

 * Values for BUCK_RAMP field in DVS_RAMP register, matching raw values

 * in mV/us.