diff mbox series

[v4,2/2] leds: lp8864: New driver

Message ID 20241217133713.326853-3-alexander.sverdlin@siemens.com (mailing list archive)
State New, archived
Headers show
Series leds: TI LP8864/LP8866 support | expand

Commit Message

Sverdlin, Alexander Dec. 17, 2024, 1:37 p.m. UTC
From: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Add driver for TI LP8864, LP8864S, LP8866 4/6 channel LED-backlight drivers
with I2C interface.

Link: https://www.ti.com/lit/gpn/lp8864-q1
Link: https://www.ti.com/lit/gpn/lp8864s-q1
Link: https://www.ti.com/lit/gpn/lp8866-q1
Link: https://www.ti.com/lit/gpn/lp8866s-q1
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
---
Changelog:
v4:
- better separated comments from register defines
- removed NULL from fault text arrays for two regs with odd-even structure
- changed HW fault printf from errors to warnings
- renamed "buf" -> "val"
- reflowed the code with up to 100 symbols per line
- added comments for 8<->16-bit linear scaling in set/get callbacks
- removed register names from error messages
v3:
- dropped lp8864_init(), REGCACHE_NONE, %pe in dev_err_probe(),
  i2c_set_clientdata()
- added devm_add_action_or_reset() return value check, dev_err_probe() after
  devm_regmap_init_i2c()
v2: no changes

 MAINTAINERS                |   7 +
 drivers/leds/Kconfig       |  12 ++
 drivers/leds/Makefile      |   1 +
 drivers/leds/leds-lp8864.c | 296 +++++++++++++++++++++++++++++++++++++
 4 files changed, 316 insertions(+)
 create mode 100644 drivers/leds/leds-lp8864.c

Comments

Andrew Davis Dec. 17, 2024, 3:56 p.m. UTC | #1
On 12/17/24 7:37 AM, A. Sverdlin wrote:
> From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> 
> Add driver for TI LP8864, LP8864S, LP8866 4/6 channel LED-backlight drivers
> with I2C interface.
> 
> Link: https://www.ti.com/lit/gpn/lp8864-q1
> Link: https://www.ti.com/lit/gpn/lp8864s-q1
> Link: https://www.ti.com/lit/gpn/lp8866-q1
> Link: https://www.ti.com/lit/gpn/lp8866s-q1
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> ---
> Changelog:
> v4:
> - better separated comments from register defines
> - removed NULL from fault text arrays for two regs with odd-even structure
> - changed HW fault printf from errors to warnings
> - renamed "buf" -> "val"
> - reflowed the code with up to 100 symbols per line
> - added comments for 8<->16-bit linear scaling in set/get callbacks
> - removed register names from error messages
> v3:
> - dropped lp8864_init(), REGCACHE_NONE, %pe in dev_err_probe(),
>    i2c_set_clientdata()
> - added devm_add_action_or_reset() return value check, dev_err_probe() after
>    devm_regmap_init_i2c()
> v2: no changes
> 
>   MAINTAINERS                |   7 +
>   drivers/leds/Kconfig       |  12 ++
>   drivers/leds/Makefile      |   1 +
>   drivers/leds/leds-lp8864.c | 296 +++++++++++++++++++++++++++++++++++++
>   4 files changed, 316 insertions(+)
>   create mode 100644 drivers/leds/leds-lp8864.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b332995b3350..d4268a3bbc5a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -23322,6 +23322,13 @@ S:	Supported
>   F:	Documentation/devicetree/bindings/iio/dac/ti,dac7612.yaml
>   F:	drivers/iio/dac/ti-dac7612.c
>   
> +TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER
> +M:	Alexander Sverdlin <alexander.sverdlin@siemens.com>
> +L:	linux-leds@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml
> +F:	drivers/leds/leds-lp8864.c
> +
>   TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
>   M:	Nishanth Menon <nm@ti.com>
>   M:	Tero Kristo <kristo@kernel.org>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 3bf51a4e01d7..5dde8f46100c 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -513,6 +513,18 @@ config LEDS_LP8860
>   	  on the LP8860 4 channel LED driver using the I2C communication
>   	  bus.
>   
> +config LEDS_LP8864
> +	tristate "LED support for the TI LP8864/LP8866 4/6 channel LED drivers"
> +	depends on LEDS_CLASS && I2C && OF
> +	select REGMAP_I2C
> +	help
> +	  If you say yes here you get support for the TI LP8864-Q1,
> +	  LP8864S-Q1, LP8866-Q1, LP8866S-Q1 4/6 channel LED backlight
> +	  drivers with I2C interface.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called leds-lp8864.
> +
>   config LEDS_CLEVO_MAIL
>   	tristate "Mail LED on Clevo notebook"
>   	depends on LEDS_CLASS && BROKEN
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index e7982938ddc1..8a2caa48343b 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -57,6 +57,7 @@ obj-$(CONFIG_LEDS_LP55XX_COMMON)	+= leds-lp55xx-common.o
>   obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
>   obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
>   obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
> +obj-$(CONFIG_LEDS_LP8864)		+= leds-lp8864.o
>   obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
>   obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
>   obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
> diff --git a/drivers/leds/leds-lp8864.c b/drivers/leds/leds-lp8864.c
> new file mode 100644
> index 000000000000..9ee9e5e0df3c
> --- /dev/null
> +++ b/drivers/leds/leds-lp8864.c
> @@ -0,0 +1,296 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TI LP8864/LP8866 4/6 Channel LED Driver
> + *
> + * Copyright (C) 2024 Siemens AG
> + *
> + * Based on LP8860 driver by Dan Murphy <dmurphy@ti.com>
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#define LP8864_BRT_CONTROL		0x00
> +#define LP8864_USER_CONFIG1		0x04
> +#define   LP8864_BRT_MODE_MASK		GENMASK(9, 8)
> +#define   LP8864_BRT_MODE_REG		BIT(9)		/* Brightness control by DISPLAY_BRT reg */
> +#define LP8864_SUPPLY_STATUS		0x0e
> +#define LP8864_BOOST_STATUS		0x10
> +#define LP8864_LED_STATUS		0x12
> +#define   LP8864_LED_STATUS_WR_MASK	GENMASK(14, 9	/* Writeable bits in the LED_STATUS reg */

Missing the closing ) ?

> +
> +/* Textual meaning for status bits, starting from bit 1 */
> +static const char *const lp8864_supply_status_msg[] = {
> +	"Vin under-voltage fault",
> +	"Vin over-voltage fault",
> +	"Vdd under-voltage fault",
> +	"Vin over-current fault",
> +	"Missing charge pump fault",
> +	"Charge pump fault",
> +	"Missing boost sync fault",
> +	"CRC error fault ",
> +};
> +
> +/* Textual meaning for status bits, starting from bit 1 */
> +static const char *const lp8864_boost_status_msg[] = {
> +	"Boost OVP low fault",
> +	"Boost OVP high fault",
> +	"Boost over-current fault",
> +	"Missing boost FSET resistor fault",
> +	"Missing MODE SEL resistor fault",
> +	"Missing LED resistor fault",
> +	"ISET resistor short to ground fault",
> +	"Thermal shutdown fault",
> +};
> +
> +/* Textual meaning for every register bit */
> +static const char *const lp8864_led_status_msg[] = {
> +	"LED 1 fault",
> +	"LED 2 fault",
> +	"LED 3 fault",
> +	"LED 4 fault",
> +	"LED 5 fault",
> +	"LED 6 fault",
> +	"LED open fault",
> +	"LED internal short fault",
> +	"LED short to GND fault",
> +	NULL, NULL, NULL,
> +	"Invalid string configuration fault",
> +	NULL,
> +	"I2C time out fault",
> +};
> +
> +/**
> + * struct lp8864_led
> + * @client: Pointer to the I2C client
> + * @led_dev: led class device pointer
> + * @regmap: Devices register map
> + * @led_status_mask: Helps to report LED fault only once
> + */
> +struct lp8864_led {
> +	struct i2c_client *client;
> +	struct led_classdev led_dev;
> +	struct regmap *regmap;
> +	u16 led_status_mask;
> +};
> +
> +static int lp8864_fault_check(struct lp8864_led *led)
> +{
> +	int ret, i;
> +	unsigned int val;
> +
> +	ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
> +	if (ret)
> +		goto err;

You could probably keep this simple and print the exact error here
and return, vs the common error message at the end

> +
> +	/* Odd bits are status bits, even bits are clear bits */
> +	for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
> +		if (val & BIT(i * 2 + 1))
> +			dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);
> +
> +	/*
> +	 * Clear bits have an index preceding the corresponding Status bits;
> +	 * both have to be written "1" simultaneously to clear the corresponding
> +	 * Status bit.
> +	 */
> +	if (val)
> +		ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 | val);
> +	if (ret)
> +		goto err;
> +
> +	ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
> +	if (ret)
> +		goto err;
> +
> +	/* Odd bits are status bits, even bits are clear bits */
> +	for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
> +		if (val & BIT(i * 2 + 1))
> +			dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);
> +
> +	if (val)
> +		ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 | val);
> +	if (ret)
> +		goto err;
> +
> +	ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
> +	if (ret)
> +		goto err;
> +
> +	/*
> +	 * Clear already reported faults that maintain their value until device
> +	 * power-down
> +	 */
> +	val &= ~led->led_status_mask;
> +
> +	for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
> +		if (lp8864_led_status_msg[i] && val & BIT(i))
> +			dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);
> +
> +	/*
> +	 * Mark those which maintain their value until device power-down as
> +	 * "already reported"
> +	 */
> +	led->led_status_mask |= val & ~LP8864_LED_STATUS_WR_MASK;
> +
> +	/*
> +	 * Only bits 14, 12, 10 have to be cleared here, but others are RO,
> +	 * we don't care what we write to them.
> +	 */
> +	if (val & LP8864_LED_STATUS_WR_MASK)
> +		ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 | val);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));
> +
> +	return ret;
> +}
> +
> +static int lp8864_brightness_set(struct led_classdev *led_cdev,
> +				 enum led_brightness brt_val)
> +{
> +	struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
> +	/* Scale 0..LED_FULL into 16-bit HW brightness */
> +	unsigned int val = brt_val * 0xffff / LED_FULL;
> +	int ret;
> +
> +	ret = lp8864_fault_check(led);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_write(led->regmap, LP8864_BRT_CONTROL, val);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed to write brightness value\n");
> +
> +	return ret;
> +}
> +
> +static enum led_brightness lp8864_brightness_get(struct led_classdev *led_cdev)
> +{
> +	struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(led->regmap, LP8864_BRT_CONTROL, &val);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Failed to read brightness value\n");
> +		return ret;
> +	}
> +
> +	/* Scale 16-bit HW brightness into 0..LED_FULL */
> +	return val * LED_FULL / 0xffff;
> +}
> +
> +static const struct regmap_config lp8864_regmap_config = {
> +	.reg_bits		= 8,
> +	.val_bits		= 16,
> +	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
> +};
> +
> +static void lp8864_disable_gpio(void *data)
> +{
> +	struct gpio_desc *gpio = data;
> +
> +	gpiod_set_value(gpio, 0);
> +}
> +
> +static int lp8864_probe(struct i2c_client *client)
> +{
> +	int ret;
> +	struct lp8864_led *led;
> +	struct device_node *np = dev_of_node(&client->dev);
> +	struct device_node *child_node;
> +	struct led_init_data init_data = {};
> +	struct gpio_desc *enable_gpio;
> +
> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	child_node = of_get_next_available_child(np, NULL);
> +	if (!child_node) {
> +		dev_err(&client->dev, "No LED function defined\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = devm_regulator_get_enable_optional(&client->dev, "vled");
> +	if (ret && ret != -ENODEV)
> +		return dev_err_probe(&client->dev, ret, "Failed to enable vled regulator\n");
> +
> +	enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
> +	if (IS_ERR(enable_gpio))
> +		return dev_err_probe(&client->dev, PTR_ERR(enable_gpio),
> +				     "Failed to get enable GPIO\n");
> +
> +	ret = devm_add_action_or_reset(&client->dev, lp8864_disable_gpio, enable_gpio);
> +	if (ret)
> +		return ret;
> +
> +	led->client = client;
> +	led->led_dev.brightness_set_blocking = lp8864_brightness_set;
> +	led->led_dev.brightness_get = lp8864_brightness_get;
> +
> +	led->regmap = devm_regmap_init_i2c(client, &lp8864_regmap_config);
> +	if (IS_ERR(led->regmap))
> +		return dev_err_probe(&client->dev, PTR_ERR(led->regmap),
> +				     "Failed to allocate regmap\n");
> +
> +	/* Control brightness by DISPLAY_BRT register */
> +	ret = regmap_update_bits(led->regmap, LP8864_USER_CONFIG1, LP8864_BRT_MODE_MASK,
> +								   LP8864_BRT_MODE_REG);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Failed to set brightness control mode\n");
> +		return ret;
> +	}
> +
> +	ret = lp8864_fault_check(led);
> +	if (ret)
> +		return ret;
> +
> +	init_data.fwnode = of_fwnode_handle(child_node);
> +	init_data.devicename = "lp8864";
> +	init_data.default_label = ":display_cluster";
> +
> +	ret = devm_led_classdev_register_ext(&client->dev, &led->led_dev, &init_data);
> +	if (ret)
> +		dev_err(&client->dev, "Failed to register LED device (%pe)\n", ERR_PTR(ret));
> +
> +	return ret;
> +}
> +
> +static const struct i2c_device_id lp8864_id[] = {
> +	{ "lp8864" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, lp8864_id);
> +
> +static const struct of_device_id of_lp8864_leds_match[] = {
> +	{ .compatible = "ti,lp8864" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, of_lp8864_leds_match);
> +
> +static struct i2c_driver lp8864_driver = {
> +	.driver = {
> +		.name	= "lp8864",
> +		.of_match_table = of_lp8864_leds_match,
> +	},
> +	.probe		= lp8864_probe,
> +	.id_table	= lp8864_id,
> +};
> +module_i2c_driver(lp8864_driver);
> +
> +MODULE_DESCRIPTION("Texas Instruments LP8864/LP8866 LED driver");
> +MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@siemens.com>");
> +MODULE_LICENSE("GPL");
Sverdlin, Alexander Dec. 17, 2024, 5:26 p.m. UTC | #2
Hi Andrew!

On Tue, 2024-12-17 at 09:56 -0600, Andrew Davis wrote:
> On 12/17/24 7:37 AM, A. Sverdlin wrote:
> > From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> > 
> > Add driver for TI LP8864, LP8864S, LP8866 4/6 channel LED-backlight drivers
> > with I2C interface.
> > 
> > Link: https://www.ti.com/lit/gpn/lp8864-q1
> > Link: https://www.ti.com/lit/gpn/lp8864s-q1
> > Link: https://www.ti.com/lit/gpn/lp8866-q1
> > Link: https://www.ti.com/lit/gpn/lp8866s-q1
> > Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> > ---
> > Changelog:
> > v4:
> > - better separated comments from register defines
> > - removed NULL from fault text arrays for two regs with odd-even structure
> > - changed HW fault printf from errors to warnings
> > - renamed "buf" -> "val"
> > - reflowed the code with up to 100 symbols per line
> > - added comments for 8<->16-bit linear scaling in set/get callbacks
> > - removed register names from error messages
> > v3:
> > - dropped lp8864_init(), REGCACHE_NONE, %pe in dev_err_probe(),
> >     i2c_set_clientdata()
> > - added devm_add_action_or_reset() return value check, dev_err_probe() after
> >     devm_regmap_init_i2c()
> > v2: no changes
> > 
> >    MAINTAINERS                |   7 +
> >    drivers/leds/Kconfig       |  12 ++
> >    drivers/leds/Makefile      |   1 +
> >    drivers/leds/leds-lp8864.c | 296 +++++++++++++++++++++++++++++++++++++
> >    4 files changed, 316 insertions(+)
> >    create mode 100644 drivers/leds/leds-lp8864.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index b332995b3350..d4268a3bbc5a 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -23322,6 +23322,13 @@ S:	Supported
> >    F:	Documentation/devicetree/bindings/iio/dac/ti,dac7612.yaml
> >    F:	drivers/iio/dac/ti-dac7612.c
> >    
> > +TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER
> > +M:	Alexander Sverdlin <alexander.sverdlin@siemens.com>
> > +L:	linux-leds@vger.kernel.org
> > +S:	Maintained
> > +F:	Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml
> > +F:	drivers/leds/leds-lp8864.c
> > +
> >    TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
> >    M:	Nishanth Menon <nm@ti.com>
> >    M:	Tero Kristo <kristo@kernel.org>
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index 3bf51a4e01d7..5dde8f46100c 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -513,6 +513,18 @@ config LEDS_LP8860
> >    	  on the LP8860 4 channel LED driver using the I2C communication
> >    	  bus.
> >    
> > +config LEDS_LP8864
> > +	tristate "LED support for the TI LP8864/LP8866 4/6 channel LED drivers"
> > +	depends on LEDS_CLASS && I2C && OF
> > +	select REGMAP_I2C
> > +	help
> > +	  If you say yes here you get support for the TI LP8864-Q1,
> > +	  LP8864S-Q1, LP8866-Q1, LP8866S-Q1 4/6 channel LED backlight
> > +	  drivers with I2C interface.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called leds-lp8864.
> > +
> >    config LEDS_CLEVO_MAIL
> >    	tristate "Mail LED on Clevo notebook"
> >    	depends on LEDS_CLASS && BROKEN
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index e7982938ddc1..8a2caa48343b 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -57,6 +57,7 @@ obj-$(CONFIG_LEDS_LP55XX_COMMON)	+= leds-lp55xx-common.o
> >    obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
> >    obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
> >    obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
> > +obj-$(CONFIG_LEDS_LP8864)		+= leds-lp8864.o
> >    obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
> >    obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
> >    obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
> > diff --git a/drivers/leds/leds-lp8864.c b/drivers/leds/leds-lp8864.c
> > new file mode 100644
> > index 000000000000..9ee9e5e0df3c
> > --- /dev/null
> > +++ b/drivers/leds/leds-lp8864.c
> > @@ -0,0 +1,296 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * TI LP8864/LP8866 4/6 Channel LED Driver
> > + *
> > + * Copyright (C) 2024 Siemens AG
> > + *
> > + * Based on LP8860 driver by Dan Murphy <dmurphy@ti.com>
> > + */
> > +
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/init.h>
> > +#include <linux/leds.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of.h>
> > +#include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/slab.h>
> > +
> > +#define LP8864_BRT_CONTROL		0x00
> > +#define LP8864_USER_CONFIG1		0x04
> > +#define   LP8864_BRT_MODE_MASK		GENMASK(9, 8)
> > +#define   LP8864_BRT_MODE_REG		BIT(9)		/* Brightness control by DISPLAY_BRT reg */
> > +#define LP8864_SUPPLY_STATUS		0x0e
> > +#define LP8864_BOOST_STATUS		0x10
> > +#define LP8864_LED_STATUS		0x12
> > +#define   LP8864_LED_STATUS_WR_MASK	GENMASK(14, 9	/* Writeable bits in the LED_STATUS reg */
> 
> Missing the closing ) ?

Thanks for the review!
Seems that my testing went seriously wrong :[ ]
Sverdlin, Alexander Dec. 18, 2024, 2:45 p.m. UTC | #3
Hi Andrew!

On Tue, 2024-12-17 at 09:56 -0600, Andrew Davis wrote:
> > +static int lp8864_fault_check(struct lp8864_led *led)
> > +{
> > +	int ret, i;
> > +	unsigned int val;
> > +
> > +	ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
> > +	if (ret)
> > +		goto err;
> 
> You could probably keep this simple and print the exact error here
> and return, vs the common error message at the end

This would mean 6x dev_err() instead of one? While I have no idea
what we could do with individual error messages here.

> > +
> > +	/* Odd bits are status bits, even bits are clear bits */
> > +	for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
> > +		if (val & BIT(i * 2 + 1))
> > +			dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);
> > +
> > +	/*
> > +	 * Clear bits have an index preceding the corresponding Status bits;
> > +	 * both have to be written "1" simultaneously to clear the corresponding
> > +	 * Status bit.
> > +	 */
> > +	if (val)
> > +		ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 | val);
> > +	if (ret)
> > +		goto err;
> > +
> > +	ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
> > +	if (ret)
> > +		goto err;
> > +
> > +	/* Odd bits are status bits, even bits are clear bits */
> > +	for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
> > +		if (val & BIT(i * 2 + 1))
> > +			dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);
> > +
> > +	if (val)
> > +		ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 | val);
> > +	if (ret)
> > +		goto err;
> > +
> > +	ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
> > +	if (ret)
> > +		goto err;
> > +
> > +	/*
> > +	 * Clear already reported faults that maintain their value until device
> > +	 * power-down
> > +	 */
> > +	val &= ~led->led_status_mask;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
> > +		if (lp8864_led_status_msg[i] && val & BIT(i))
> > +			dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);
> > +
> > +	/*
> > +	 * Mark those which maintain their value until device power-down as
> > +	 * "already reported"
> > +	 */
> > +	led->led_status_mask |= val & ~LP8864_LED_STATUS_WR_MASK;
> > +
> > +	/*
> > +	 * Only bits 14, 12, 10 have to be cleared here, but others are RO,
> > +	 * we don't care what we write to them.
> > +	 */
> > +	if (val & LP8864_LED_STATUS_WR_MASK)
> > +		ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 | val);
> > +	if (ret)
> > +		goto err;
> > +
> > +	return 0;
> > +
> > +err:
> > +	dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));
> > +
> > +	return ret;
> > +}
Andrew Davis Dec. 18, 2024, 3:01 p.m. UTC | #4
On 12/18/24 8:45 AM, Sverdlin, Alexander wrote:
> Hi Andrew!
> 
> On Tue, 2024-12-17 at 09:56 -0600, Andrew Davis wrote:
>>> +static int lp8864_fault_check(struct lp8864_led *led)
>>> +{
>>> +	int ret, i;
>>> +	unsigned int val;
>>> +
>>> +	ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
>>> +	if (ret)
>>> +		goto err;
>>
>> You could probably keep this simple and print the exact error here
>> and return, vs the common error message at the end
> 
> This would mean 6x dev_err() instead of one? While I have no idea
> what we could do with individual error messages here.
> 

If giving specific error messages is not important, then this is
fine how it is.

Andrew

>>> +
>>> +	/* Odd bits are status bits, even bits are clear bits */
>>> +	for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
>>> +		if (val & BIT(i * 2 + 1))
>>> +			dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);
>>> +
>>> +	/*
>>> +	 * Clear bits have an index preceding the corresponding Status bits;
>>> +	 * both have to be written "1" simultaneously to clear the corresponding
>>> +	 * Status bit.
>>> +	 */
>>> +	if (val)
>>> +		ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 | val);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	/* Odd bits are status bits, even bits are clear bits */
>>> +	for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
>>> +		if (val & BIT(i * 2 + 1))
>>> +			dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);
>>> +
>>> +	if (val)
>>> +		ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 | val);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	/*
>>> +	 * Clear already reported faults that maintain their value until device
>>> +	 * power-down
>>> +	 */
>>> +	val &= ~led->led_status_mask;
>>> +
>>> +	for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
>>> +		if (lp8864_led_status_msg[i] && val & BIT(i))
>>> +			dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);
>>> +
>>> +	/*
>>> +	 * Mark those which maintain their value until device power-down as
>>> +	 * "already reported"
>>> +	 */
>>> +	led->led_status_mask |= val & ~LP8864_LED_STATUS_WR_MASK;
>>> +
>>> +	/*
>>> +	 * Only bits 14, 12, 10 have to be cleared here, but others are RO,
>>> +	 * we don't care what we write to them.
>>> +	 */
>>> +	if (val & LP8864_LED_STATUS_WR_MASK)
>>> +		ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 | val);
>>> +	if (ret)
>>> +		goto err;
>>> +
>>> +	return 0;
>>> +
>>> +err:
>>> +	dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));
>>> +
>>> +	return ret;
>>> +}
>
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index b332995b3350..d4268a3bbc5a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23322,6 +23322,13 @@  S:	Supported
 F:	Documentation/devicetree/bindings/iio/dac/ti,dac7612.yaml
 F:	drivers/iio/dac/ti-dac7612.c
 
+TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER
+M:	Alexander Sverdlin <alexander.sverdlin@siemens.com>
+L:	linux-leds@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml
+F:	drivers/leds/leds-lp8864.c
+
 TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
 M:	Nishanth Menon <nm@ti.com>
 M:	Tero Kristo <kristo@kernel.org>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 3bf51a4e01d7..5dde8f46100c 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -513,6 +513,18 @@  config LEDS_LP8860
 	  on the LP8860 4 channel LED driver using the I2C communication
 	  bus.
 
+config LEDS_LP8864
+	tristate "LED support for the TI LP8864/LP8866 4/6 channel LED drivers"
+	depends on LEDS_CLASS && I2C && OF
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the TI LP8864-Q1,
+	  LP8864S-Q1, LP8866-Q1, LP8866S-Q1 4/6 channel LED backlight
+	  drivers with I2C interface.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called leds-lp8864.
+
 config LEDS_CLEVO_MAIL
 	tristate "Mail LED on Clevo notebook"
 	depends on LEDS_CLASS && BROKEN
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e7982938ddc1..8a2caa48343b 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -57,6 +57,7 @@  obj-$(CONFIG_LEDS_LP55XX_COMMON)	+= leds-lp55xx-common.o
 obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
 obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
 obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
+obj-$(CONFIG_LEDS_LP8864)		+= leds-lp8864.o
 obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
 obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
 obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
diff --git a/drivers/leds/leds-lp8864.c b/drivers/leds/leds-lp8864.c
new file mode 100644
index 000000000000..9ee9e5e0df3c
--- /dev/null
+++ b/drivers/leds/leds-lp8864.c
@@ -0,0 +1,296 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI LP8864/LP8866 4/6 Channel LED Driver
+ *
+ * Copyright (C) 2024 Siemens AG
+ *
+ * Based on LP8860 driver by Dan Murphy <dmurphy@ti.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define LP8864_BRT_CONTROL		0x00
+#define LP8864_USER_CONFIG1		0x04
+#define   LP8864_BRT_MODE_MASK		GENMASK(9, 8)
+#define   LP8864_BRT_MODE_REG		BIT(9)		/* Brightness control by DISPLAY_BRT reg */
+#define LP8864_SUPPLY_STATUS		0x0e
+#define LP8864_BOOST_STATUS		0x10
+#define LP8864_LED_STATUS		0x12
+#define   LP8864_LED_STATUS_WR_MASK	GENMASK(14, 9	/* Writeable bits in the LED_STATUS reg */
+
+/* Textual meaning for status bits, starting from bit 1 */
+static const char *const lp8864_supply_status_msg[] = {
+	"Vin under-voltage fault",
+	"Vin over-voltage fault",
+	"Vdd under-voltage fault",
+	"Vin over-current fault",
+	"Missing charge pump fault",
+	"Charge pump fault",
+	"Missing boost sync fault",
+	"CRC error fault ",
+};
+
+/* Textual meaning for status bits, starting from bit 1 */
+static const char *const lp8864_boost_status_msg[] = {
+	"Boost OVP low fault",
+	"Boost OVP high fault",
+	"Boost over-current fault",
+	"Missing boost FSET resistor fault",
+	"Missing MODE SEL resistor fault",
+	"Missing LED resistor fault",
+	"ISET resistor short to ground fault",
+	"Thermal shutdown fault",
+};
+
+/* Textual meaning for every register bit */
+static const char *const lp8864_led_status_msg[] = {
+	"LED 1 fault",
+	"LED 2 fault",
+	"LED 3 fault",
+	"LED 4 fault",
+	"LED 5 fault",
+	"LED 6 fault",
+	"LED open fault",
+	"LED internal short fault",
+	"LED short to GND fault",
+	NULL, NULL, NULL,
+	"Invalid string configuration fault",
+	NULL,
+	"I2C time out fault",
+};
+
+/**
+ * struct lp8864_led
+ * @client: Pointer to the I2C client
+ * @led_dev: led class device pointer
+ * @regmap: Devices register map
+ * @led_status_mask: Helps to report LED fault only once
+ */
+struct lp8864_led {
+	struct i2c_client *client;
+	struct led_classdev led_dev;
+	struct regmap *regmap;
+	u16 led_status_mask;
+};
+
+static int lp8864_fault_check(struct lp8864_led *led)
+{
+	int ret, i;
+	unsigned int val;
+
+	ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
+	if (ret)
+		goto err;
+
+	/* Odd bits are status bits, even bits are clear bits */
+	for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
+		if (val & BIT(i * 2 + 1))
+			dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);
+
+	/*
+	 * Clear bits have an index preceding the corresponding Status bits;
+	 * both have to be written "1" simultaneously to clear the corresponding
+	 * Status bit.
+	 */
+	if (val)
+		ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 | val);
+	if (ret)
+		goto err;
+
+	ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
+	if (ret)
+		goto err;
+
+	/* Odd bits are status bits, even bits are clear bits */
+	for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
+		if (val & BIT(i * 2 + 1))
+			dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);
+
+	if (val)
+		ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 | val);
+	if (ret)
+		goto err;
+
+	ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
+	if (ret)
+		goto err;
+
+	/*
+	 * Clear already reported faults that maintain their value until device
+	 * power-down
+	 */
+	val &= ~led->led_status_mask;
+
+	for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
+		if (lp8864_led_status_msg[i] && val & BIT(i))
+			dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);
+
+	/*
+	 * Mark those which maintain their value until device power-down as
+	 * "already reported"
+	 */
+	led->led_status_mask |= val & ~LP8864_LED_STATUS_WR_MASK;
+
+	/*
+	 * Only bits 14, 12, 10 have to be cleared here, but others are RO,
+	 * we don't care what we write to them.
+	 */
+	if (val & LP8864_LED_STATUS_WR_MASK)
+		ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 | val);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));
+
+	return ret;
+}
+
+static int lp8864_brightness_set(struct led_classdev *led_cdev,
+				 enum led_brightness brt_val)
+{
+	struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
+	/* Scale 0..LED_FULL into 16-bit HW brightness */
+	unsigned int val = brt_val * 0xffff / LED_FULL;
+	int ret;
+
+	ret = lp8864_fault_check(led);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(led->regmap, LP8864_BRT_CONTROL, val);
+	if (ret)
+		dev_err(&led->client->dev, "Failed to write brightness value\n");
+
+	return ret;
+}
+
+static enum led_brightness lp8864_brightness_get(struct led_classdev *led_cdev)
+{
+	struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(led->regmap, LP8864_BRT_CONTROL, &val);
+	if (ret) {
+		dev_err(&led->client->dev, "Failed to read brightness value\n");
+		return ret;
+	}
+
+	/* Scale 16-bit HW brightness into 0..LED_FULL */
+	return val * LED_FULL / 0xffff;
+}
+
+static const struct regmap_config lp8864_regmap_config = {
+	.reg_bits		= 8,
+	.val_bits		= 16,
+	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
+};
+
+static void lp8864_disable_gpio(void *data)
+{
+	struct gpio_desc *gpio = data;
+
+	gpiod_set_value(gpio, 0);
+}
+
+static int lp8864_probe(struct i2c_client *client)
+{
+	int ret;
+	struct lp8864_led *led;
+	struct device_node *np = dev_of_node(&client->dev);
+	struct device_node *child_node;
+	struct led_init_data init_data = {};
+	struct gpio_desc *enable_gpio;
+
+	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	child_node = of_get_next_available_child(np, NULL);
+	if (!child_node) {
+		dev_err(&client->dev, "No LED function defined\n");
+		return -EINVAL;
+	}
+
+	ret = devm_regulator_get_enable_optional(&client->dev, "vled");
+	if (ret && ret != -ENODEV)
+		return dev_err_probe(&client->dev, ret, "Failed to enable vled regulator\n");
+
+	enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(enable_gpio))
+		return dev_err_probe(&client->dev, PTR_ERR(enable_gpio),
+				     "Failed to get enable GPIO\n");
+
+	ret = devm_add_action_or_reset(&client->dev, lp8864_disable_gpio, enable_gpio);
+	if (ret)
+		return ret;
+
+	led->client = client;
+	led->led_dev.brightness_set_blocking = lp8864_brightness_set;
+	led->led_dev.brightness_get = lp8864_brightness_get;
+
+	led->regmap = devm_regmap_init_i2c(client, &lp8864_regmap_config);
+	if (IS_ERR(led->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(led->regmap),
+				     "Failed to allocate regmap\n");
+
+	/* Control brightness by DISPLAY_BRT register */
+	ret = regmap_update_bits(led->regmap, LP8864_USER_CONFIG1, LP8864_BRT_MODE_MASK,
+								   LP8864_BRT_MODE_REG);
+	if (ret) {
+		dev_err(&led->client->dev, "Failed to set brightness control mode\n");
+		return ret;
+	}
+
+	ret = lp8864_fault_check(led);
+	if (ret)
+		return ret;
+
+	init_data.fwnode = of_fwnode_handle(child_node);
+	init_data.devicename = "lp8864";
+	init_data.default_label = ":display_cluster";
+
+	ret = devm_led_classdev_register_ext(&client->dev, &led->led_dev, &init_data);
+	if (ret)
+		dev_err(&client->dev, "Failed to register LED device (%pe)\n", ERR_PTR(ret));
+
+	return ret;
+}
+
+static const struct i2c_device_id lp8864_id[] = {
+	{ "lp8864" },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, lp8864_id);
+
+static const struct of_device_id of_lp8864_leds_match[] = {
+	{ .compatible = "ti,lp8864" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_lp8864_leds_match);
+
+static struct i2c_driver lp8864_driver = {
+	.driver = {
+		.name	= "lp8864",
+		.of_match_table = of_lp8864_leds_match,
+	},
+	.probe		= lp8864_probe,
+	.id_table	= lp8864_id,
+};
+module_i2c_driver(lp8864_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8864/LP8866 LED driver");
+MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@siemens.com>");
+MODULE_LICENSE("GPL");