Commit a18983b9 authored by Daniel Mack's avatar Daniel Mack Committed by Lee Jones
Browse files

leds: is31f132xx: Add support for is31fl3293 



This chip supports 3 LED channels with 4096 possible PWM values.

Extend the driver to support this variant:

 * Make brightness steps configurable per device type
 * Handle dual-register brightness updates
 * Allow to specify values to write into the PWM update register
 * Add custom init and shutdown function for 3293 variant
 * Init registers after parsing DT properties

Signed-off-by: default avatarDaniel Mack <daniel@zonque.org>
Link: https://patch.msgid.link/20251219154521.643312-4-daniel@zonque.org


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 6f1bc453

drivers/leds/leds-is31fl32xx.c

+130 −8
Original line number Diff line number Diff line
@@ -34,10 +34,26 @@ 


#define IS31FL32XX_PWM_FREQUENCY_22KHZ  0x01



/* Registers for IS31FL3293 */

#define IS31FL3293_SHUTDOWN_REG 0x01

#define IS31FL3293_SHUTDOWN_SSD_DISABLE  BIT(0)

#define IS31FL3293_SHUTDOWN_EN1 BIT(4)

#define IS31FL3293_SHUTDOWN_EN2 BIT(5)

#define IS31FL3293_SHUTDOWN_EN3 BIT(6)

#define IS31FL3293_GCC_REG 0x03

#define IS31FL3293_GCC_LEVEL_MAX 0x3f

#define IS31FL3293_CL_REG 0x10

#define IS31FL3293_COLOR_UPDATE_REG 0x27

#define IS31FL3293_COLOR_UPDATE_MAGIC 0xc5

#define IS31FL3293_RESET_REG 0x3c

#define IS31FL3293_RESET_MAGIC 0xc5

#define IS31FL3293_MAX_MICROAMP 20000



struct is31fl32xx_priv;

struct is31fl32xx_led_data {

	struct led_classdev cdev;

	u8 channel; /* 1-based, max priv->cdef->channels */

	u32 max_microamp;

	struct is31fl32xx_priv *priv;

};
@@ -53,6 +69,7 @@ struct is31fl32xx_priv { 
 * @channels            : Number of LED channels

 * @shutdown_reg        : address of Shutdown register (optional)

 * @pwm_update_reg      : address of PWM Update register

 * @pwm_update_value    : value to write to PWM Update register

 * @global_control_reg  : address of Global Control register (optional)

 * @reset_reg           : address of Reset register (optional)

 * @output_frequency_setting_reg: address of output frequency register (optional)
@@ -60,6 +77,7 @@ struct is31fl32xx_priv { 
 * @pwm_registers_reversed: : true if PWM registers count down instead of up

 * @led_control_register_base : address of first LED control register (optional)

 * @enable_bits_per_led_control_register: number of LEDs enable bits in each

 * @brightness_steps    : number of brightness steps supported by the chip

 * @reset_func          : pointer to reset function

 * @sw_shutdown_func    : pointer to software shutdown function

 *
@@ -77,6 +95,7 @@ struct is31fl32xx_chipdef { 
	u8	channels;

	u8	shutdown_reg;

	u8	pwm_update_reg;

	u8	pwm_update_value;

	u8	global_control_reg;

	u8	reset_reg;

	u8	output_frequency_setting_reg;
@@ -84,6 +103,7 @@ struct is31fl32xx_chipdef { 
	bool	pwm_registers_reversed;

	u8	led_control_register_base;

	u8	enable_bits_per_led_control_register;

	u16	brightness_steps;

	int (*reset_func)(struct is31fl32xx_priv *priv);

	int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);

};
@@ -152,6 +172,62 @@ static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, 
	return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);

}



/*

 * Custom Reset function for IS31FL3293. We need to set the global current limit

 * and write to the color update register once.

 */

static int is31fl3293_reset(struct is31fl32xx_priv *priv)

{

	int i, ret;



	ret = is31fl32xx_write(priv, IS31FL3293_RESET_REG,

			       IS31FL3293_RESET_MAGIC);

	if (ret)

		return ret;



	/* Set the global current limit to maximum */

	ret = is31fl32xx_write(priv, IS31FL3293_GCC_REG,

			       IS31FL3293_GCC_LEVEL_MAX);

	if (ret)

		return ret;



	for (i = 0; i < priv->num_leds; i++) {

		struct is31fl32xx_led_data *led_data = &priv->leds[i];

		int current_level_reg = IS31FL3293_CL_REG + led_data->channel - 1;

		int microamp = max(led_data->max_microamp, IS31FL3293_MAX_MICROAMP);

		int current_level = (microamp * 0xff) / IS31FL3293_MAX_MICROAMP;



		ret = is31fl32xx_write(priv, current_level_reg, current_level);

		if (ret)

			return ret;

	}



	ret = is31fl32xx_write(priv, IS31FL3293_COLOR_UPDATE_REG,

			       IS31FL3293_COLOR_UPDATE_MAGIC);

	if (ret)

		return ret;



	return 0;

}



/*

 * Custom Software-Shutdown function for IS31FL3293 because the SHUTDOWN

 * register of this device also has bits to enable the channels.

 */

static int is31fl3293_software_shutdown(struct is31fl32xx_priv *priv,

					bool enable)

{

	u8 value = 0;



	if (!enable)

		value =	IS31FL3293_SHUTDOWN_SSD_DISABLE |

			IS31FL3293_SHUTDOWN_EN1 |

			IS31FL3293_SHUTDOWN_EN2 |

			IS31FL3293_SHUTDOWN_EN3;



	return is31fl32xx_write(priv, IS31FL3293_SHUTDOWN_REG, value);

}



/*

 * NOTE: A mutex is not needed in this function because:

 * - All referenced data is read-only after probe()
@@ -190,13 +266,36 @@ static int is31fl32xx_brightness_set(struct led_classdev *led_cdev, 
	else

		pwm_register_offset = led_data->channel - 1;



	switch (cdef->brightness_steps) {

	case 256:

		ret = is31fl32xx_write(led_data->priv,

				       cdef->pwm_register_base + pwm_register_offset,

				       brightness);

		if (ret)

			return ret;



	return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);

		break;

	case 4096:

		/* IS31FL329x devices use two registers to store 12 bits of brightness */

		pwm_register_offset *= 2;



		ret = is31fl32xx_write(led_data->priv,

				       cdef->pwm_register_base + pwm_register_offset,

				       brightness & 0xff);

		if (ret)

			return ret;



		ret = is31fl32xx_write(led_data->priv,

				       cdef->pwm_register_base + pwm_register_offset + 1,

				       (brightness >> 8) & 0xf);

		if (ret)

			return ret;



		break;

	}



	return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg,

				cdef->pwm_update_value);

}



static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
@@ -295,6 +394,8 @@ static int is31fl32xx_parse_child_dt(const struct device *dev, 
	}

	led_data->channel = reg;



	of_property_read_u32(child, "led-max-microamp", &led_data->max_microamp);



	cdev->brightness_set_blocking = is31fl32xx_brightness_set;



	return 0;
@@ -339,6 +440,7 @@ static int is31fl32xx_parse_dt(struct device *dev, 
		const struct is31fl32xx_led_data *other_led_data;



		led_data->priv = priv;

		led_data->cdev.max_brightness = priv->cdef->brightness_steps - 1;



		ret = is31fl32xx_parse_child_dt(dev, child, led_data);

		if (ret)
@@ -391,6 +493,7 @@ static const struct is31fl32xx_chipdef is31fl3236a_cdef = { 
	.pwm_register_base			= 0x01,

	.led_control_register_base		= 0x26,

	.enable_bits_per_led_control_register	= 1,

	.brightness_steps			= 256,

};



static const struct is31fl32xx_chipdef is31fl3235_cdef = {
@@ -403,6 +506,7 @@ static const struct is31fl32xx_chipdef is31fl3235_cdef = { 
	.pwm_register_base			= 0x05,

	.led_control_register_base		= 0x2a,

	.enable_bits_per_led_control_register	= 1,

	.brightness_steps			= 256,

};



static const struct is31fl32xx_chipdef is31fl3218_cdef = {
@@ -415,6 +519,7 @@ static const struct is31fl32xx_chipdef is31fl3218_cdef = { 
	.pwm_register_base			= 0x01,

	.led_control_register_base		= 0x13,

	.enable_bits_per_led_control_register	= 6,

	.brightness_steps			= 256,

};



static const struct is31fl32xx_chipdef is31fl3216_cdef = {
@@ -430,9 +535,25 @@ static const struct is31fl32xx_chipdef is31fl3216_cdef = { 
	.enable_bits_per_led_control_register	= 8,

	.reset_func				= is31fl3216_reset,

	.sw_shutdown_func			= is31fl3216_software_shutdown,

	.brightness_steps			= 256,

};



static const struct is31fl32xx_chipdef is31fl3293_cdef = {

	.channels				= 3,

	.shutdown_reg				= IS31FL32XX_REG_NONE,

	.pwm_update_reg				= 0x28,

	.pwm_update_value			= 0xc5,

	.global_control_reg			= IS31FL32XX_REG_NONE,

	.reset_reg				= IS31FL32XX_REG_NONE,

	.pwm_register_base			= 0x19,

	.led_control_register_base		= IS31FL32XX_REG_NONE,

	.brightness_steps			= 4096,

	.reset_func				= is31fl3293_reset,

	.sw_shutdown_func			= is31fl3293_software_shutdown,

};



static const struct of_device_id of_is31fl32xx_match[] = {

	{ .compatible = "issi,is31fl3293",  .data = &is31fl3293_cdef, },

	{ .compatible = "issi,is31fl3236",  .data = &is31fl3236_cdef, },

	{ .compatible = "issi,is31fl3236a", .data = &is31fl3236a_cdef, },

	{ .compatible = "issi,is31fl3235",  .data = &is31fl3235_cdef, },
@@ -468,11 +589,11 @@ static int is31fl32xx_probe(struct i2c_client *client) 
	priv->cdef = cdef;

	i2c_set_clientdata(client, priv);



	ret = is31fl32xx_init_regs(priv);

	ret = is31fl32xx_parse_dt(dev, priv);

	if (ret)

		return ret;



	ret = is31fl32xx_parse_dt(dev, priv);

	ret = is31fl32xx_init_regs(priv);

	if (ret)

		return ret;
@@ -495,6 +616,7 @@ static void is31fl32xx_remove(struct i2c_client *client) 
 * even though it is not used for DeviceTree based instantiation.

 */

static const struct i2c_device_id is31fl32xx_id[] = {

	{ "is31fl3293" },

	{ "is31fl3236" },

	{ "is31fl3236a" },

	{ "is31fl3235" },