Commit 2b3ed701 authored by Ricardo Rivera-Matos's avatar Ricardo Rivera-Matos Committed by Carles Cufi
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regulator: cp9314: Adds support for HW I2C Lock feature 



Adds support for the control port write-lock feature introduced in
revision B1. The write-lock feature minimizes the risk of spurious
I2C writes flipping sensitive bits during device operation by blocking
writes to some or all of the register map.

If desired, the write-lock must be set in hardware by biasing PGPIO2
appropriately and setting the cirrus,hw-i2c-lock flag in the devicetree
entry.

Signed-off-by: default avatarRicardo Rivera-Matos <rriveram@opensource.cirrus.com>
parent a684c36e

drivers/regulator/regulator_cp9314.c

+133 −0
Original line number Diff line number Diff line
@@ -85,6 +85,7 @@ LOG_MODULE_REGISTER(CP9314, CONFIG_REGULATOR_LOG_LEVEL); 
#define CP9314_REG_LION_CFG_3        0x34

#define CP9314_LB_MIN_FREQ_SEL_0     GENMASK(7, 6)

#define CP9314_MODE_CTRL_UPDATE_BW_1 GENMASK(5, 3)

#define CP9314_ALLOW_HW_I2C_LOCK     BIT(0)



#define CP9314_REG_LB_CTRL       0x38

#define CP9314_LB1_DELTA_CFG_1   GENMASK(6, 3)
@@ -152,6 +153,8 @@ LOG_MODULE_REGISTER(CP9314, CONFIG_REGULATOR_LOG_LEVEL); 
#define CP9314_PTE_2_OTP_1   0x0

#define CP9314_PTE_2_OTP_2   0x1



#define CP9314_REG_BACKDOOR_CTRL 0x8C



#define CP9314_FAULT1_STS 0x9A

#define CP9314_VIN_OV_STS BIT(4)
@@ -192,17 +195,25 @@ enum cp9314_sync_roles { 
	CP9314_ROLE_STANDALONE,

};



enum cp9314_backdoor_keys {

	CP9314_BACKDOOR_LOCKED_KEY = 0x0,

	CP9314_BACKDOOR_PUBLIC_KEY = 0x0F,

};



struct regulator_cp9314_config {

	struct regulator_common_config common;

	struct i2c_dt_spec i2c;

	struct gpio_dt_spec en_pin;

	struct gpio_dt_spec pgood_pin;

	uint8_t initial_op_mode_idx;

	bool hw_i2c_lock;

};



struct regulator_cp9314_data {

	struct regulator_common_data data;

	enum cp9314_sync_roles sync_role;

	uint8_t backdoor_key;

	bool allow_hw_i2c_lock;

};



struct cp9314_reg_patch {
@@ -284,14 +295,75 @@ static int regulator_cp9314_get_error_flags(const struct device *dev, 
	return 0;

}



static int regulator_cp9314_write_lock(const struct device *dev,

				       const enum cp9314_backdoor_keys key)

{

	const struct regulator_cp9314_config *config = dev->config;

	struct regulator_cp9314_data *data = dev->data;

	int ret;



	if (data->allow_hw_i2c_lock == 0U) {

		ret = i2c_reg_update_byte_dt(&config->i2c, CP9314_REG_LION_CFG_3,

					     CP9314_ALLOW_HW_I2C_LOCK, CP9314_ALLOW_HW_I2C_LOCK);

		if (ret < 0) {

			return ret;

		}



		data->allow_hw_i2c_lock = true;

	}



	if ((uint8_t)key == data->backdoor_key) {

		return 0;

	} else {

		return i2c_reg_write_byte_dt(&config->i2c, CP9314_REG_BACKDOOR_CTRL, (uint8_t)key);

	}

}



static int regulator_cp9314_write_lock_init(const struct device *dev)

{

	const struct regulator_cp9314_config *config = dev->config;

	struct regulator_cp9314_data *data = dev->data;

	uint8_t value;

	int ret;



	ret = i2c_reg_read_byte_dt(&config->i2c, CP9314_REG_LION_CFG_3, &value);

	if (ret < 0) {

		return ret;

	}



	data->allow_hw_i2c_lock = FIELD_GET(CP9314_ALLOW_HW_I2C_LOCK, value);



	ret = i2c_reg_read_byte_dt(&config->i2c, CP9314_REG_BACKDOOR_CTRL, &data->backdoor_key);

	if (ret < 0) {

		return ret;

	}



	return 0;

}



static int regulator_cp9314_disable(const struct device *dev)

{

	const struct regulator_cp9314_config *config = dev->config;

	int ret;



	if (config->en_pin.port != NULL) {

		return gpio_pin_set_dt(&config->en_pin, 0);

	}



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_PUBLIC_KEY);

		if (ret < 0) {

			return ret;

		}



		ret = i2c_reg_update_byte_dt(&config->i2c, CP9314_REG_CTRL1, CP9314_CP_EN, 0);

		if (ret < 0) {

			return ret;

		}



		return regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_LOCKED_KEY);

	}



	return i2c_reg_update_byte_dt(&config->i2c, CP9314_REG_CTRL1, CP9314_CP_EN, 0);

}
@@ -301,6 +373,13 @@ static int regulator_cp9314_enable(const struct device *dev) 
	uint8_t value;

	int ret;



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_PUBLIC_KEY);

		if (ret < 0) {

			return ret;

		}

	}



	ret = i2c_reg_read_byte_dt(&config->i2c, CP9314_REG_CONVERTER, &value);

	if (ret < 0) {

		return ret;
@@ -353,6 +432,13 @@ static int regulator_cp9314_enable(const struct device *dev) 
		}

	}



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_LOCKED_KEY);

		if (ret < 0) {

			return ret;

		}

	}



	return 0;

}
@@ -403,6 +489,19 @@ static int cp9314_do_soft_reset(const struct device *dev) 
	const struct regulator_cp9314_config *config = dev->config;

	int ret;



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_PUBLIC_KEY);

		if (ret < 0) {

			return ret;

		}



		ret = i2c_reg_update_byte_dt(&config->i2c, CP9314_REG_LION_CFG_3,

					     CP9314_ALLOW_HW_I2C_LOCK, 0);

		if (ret < 0) {

			return ret;

		}

	}



	ret = i2c_reg_write_byte_dt(&config->i2c, CP9314_REG_CRUS_CTRL, CP9314_CRUS_KEY_SOFT_RESET);

	if (ret < 0) {

		return ret;
@@ -416,6 +515,13 @@ static int cp9314_do_soft_reset(const struct device *dev) 


	k_msleep(CP9314_SOFT_RESET_DELAY_MSEC);



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock_init(dev);

		if (ret < 0) {

			return ret;

		}

	}



	return 0;

}
@@ -507,11 +613,30 @@ static int regulator_cp9314_init(const struct device *dev) 
		k_usleep(CP9314_EN_DEBOUNCE_USEC);

	}



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock_init(dev);

		if (ret < 0) {

			return ret;

		}

	} else {

		data->allow_hw_i2c_lock = 0;

	}



	ret = cp9314_do_soft_reset(dev);

	if (ret < 0) {

		return ret;

	}



	if (data->allow_hw_i2c_lock != 0U) {

		ret = i2c_reg_update_byte_dt(&config->i2c, CP9314_REG_LION_CFG_3,

					     CP9314_ALLOW_HW_I2C_LOCK, 0x0);

		if (ret < 0) {

			return ret;

		}



		data->allow_hw_i2c_lock = false;

	}



	ret = i2c_reg_read_byte_dt(&config->i2c, CP9314_REG_BC_STS_C, &value);

	if (ret < 0) {

		return ret;
@@ -597,6 +722,13 @@ static int regulator_cp9314_init(const struct device *dev) 
		}

	}



	if (config->hw_i2c_lock != 0U) {

		ret = regulator_cp9314_write_lock(dev, CP9314_BACKDOOR_LOCKED_KEY);

		if (ret < 0) {

			return ret;

		}

	}



	regulator_common_data_init(dev);



	return regulator_common_init(dev, false);
@@ -618,6 +750,7 @@ static const struct regulator_driver_api api = { 
		.pgood_pin = GPIO_DT_SPEC_INST_GET_OR(inst, cirrus_pgood_gpios, {}),               \

		.initial_op_mode_idx =                                                             \

			DT_INST_ENUM_IDX_OR(inst, cirrus_initial_switched_capacitor_mode, -1) + 1, \

		.hw_i2c_lock = DT_INST_PROP(inst, cirrus_hw_i2c_lock),                             \

	};                                                                                         \

                                                                                                   \

	DEVICE_DT_INST_DEFINE(inst, regulator_cp9314_init, NULL, &data_##inst, &config_##inst,     \

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