Re: [PATCHv2 2/2] leds: tlc59116: Driver for the TI 16 Channel i2c LED driver

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On Fri, 9 Jan 2015, Andrew Lunn wrote:

> The TLC59116 is an I2C bus controlled 16-channel LED driver.  Each LED
> output has its own 8-bit fixed-frequency PWM controller to control the
> brightness of the LED.

some minor comments inline below

> 
> This is based on a driver from Belkin, but has been extensively
> rewritten.
> 
> Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
> Cc: Matthew.Fatheree@xxxxxxxxxx
> ---
>  drivers/leds/Kconfig         |   8 ++
>  drivers/leds/Makefile        |   1 +
>  drivers/leds/leds-tlc59116.c | 252 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 261 insertions(+)
>  create mode 100644 drivers/leds/leds-tlc59116.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index a6c3d2f153f3..8fc283c01673 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -457,6 +457,14 @@ config LEDS_TCA6507
>  	  LED driver chips accessed via the I2C bus.
>  	  Driver support brightness control and hardware-assisted blinking.
>  
> +config LEDS_TLC59116
> +	tristate "LED driver for TLC59116F controllers"
> +	depends on LEDS_CLASS && I2C
> +	select REGMAP_I2C
> +	help
> +	  This option enables support for Texas Instruments TLC59116F
> +	  LED controller.
> +
>  config LEDS_MAX8997
>  	tristate "LED support for MAX8997 PMIC"
>  	depends on LEDS_CLASS && MFD_MAX8997
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 1c65a191d907..8e7d20acfa7b 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
>  obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
>  obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
>  obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
> +obj-$(CONFIG_LEDS_TLC59116)		+= leds-tlc59116.o
>  obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
>  obj-$(CONFIG_LEDS_IPAQ_MICRO)		+= leds-ipaq-micro.o
>  obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
> diff --git a/drivers/leds/leds-tlc59116.c b/drivers/leds/leds-tlc59116.c
> new file mode 100644
> index 000000000000..9ed8175e7992
> --- /dev/null
> +++ b/drivers/leds/leds-tlc59116.c
> @@ -0,0 +1,252 @@
> +/*
> + * Copyright 2014 Belkin Inc.
> + * Copyright 2014 Andrew Lunn <andrew@xxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; version 2 of the License.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +#define TLC59116_LEDS		16
> +
> +#define TLC59116_REG_MODE1	0x00	/* Mode register 0 */

why rename the registers? mode1 vs. mode0

> +#define MODE1_RESPON_ADDR_MASK	0xF0
> +#define MODE1_NORMAL_MODE	(0 << 4)
> +#define MODE1_SPEED_MODE	(1 << 4)
> +
> +#define TLC59116_REG_MODE2	0x01	/* Mode register 1 */
> +#define MODE2_DIM		(0 << 5)
> +#define MODE2_BLINK		(1 << 5)
> +#define MODE2_OCH_STOP		(0 << 3)
> +#define MODE2_OCH_ACK		(1 << 3)
> +
> +#define TLC59116_REG_PWM(x)	(0x02 + x)

it is customary to put parenthesis around the macro arguments, i.e. (0x02 + (x))

> +
> +#define TLC59116_REG_GRPPWM	0x12
> +#define TLC59116_REG_GRPFREQ	0x13
> +
> +/* LED Driver Output State, determine the source that drives LED outputs */
> +#define TLC59116_REG_LEDOUT(x)	(0x14 + (x >> 2))

(0x14 + ((x) >> 2)

> +#define TLC59116_LED_OFF	0x0	/* Output LOW */
> +#define TLC59116_LED_ON		0x1	/* Output HI-Z */
> +#define TLC59116_DIM		0x2	/* Dimming */
> +#define TLC59116_BLINK		0x3	/* Blinking */
> +#define LED_MASK		0x3
> +
> +#define ldev_to_led(c)		container_of(c, struct tlc59116_led, ldev)
> +#define work_to_led(work)	container_of(work, struct tlc59116_led, work)
> +
> +struct tlc59116_led {
> +	bool active;
> +	struct regmap *regmap;
> +	int led_no;

probably should be unsigned

> +	struct led_classdev ldev;
> +	struct work_struct work;
> +};
> +
> +struct tlc59116_priv {
> +	struct tlc59116_led leds[TLC59116_LEDS];
> +};
> +
> +static int
> +tlc59116_set_mode(struct regmap *regmap, u8 mode)
> +{
> +	u8 val = 0;

could save initialization and use 
val = MODE2_OCH_STOP | mode;
below

> +	int err;
> +
> +	if ((mode != MODE2_DIM) && (mode != MODE2_BLINK))
> +		mode = MODE2_DIM;
> +
> +	/* Configure MODE1 register */
> +	err = regmap_write(regmap, TLC59116_REG_MODE1, MODE1_NORMAL_MODE);
> +	if (err)
> +		return err;
> +
> +	/* Configure MODE2 Reg */
> +	val |= MODE2_OCH_STOP;
> +	val |= mode;
> +
> +	return regmap_write(regmap, TLC59116_REG_MODE2, val);
> +}
> +
> +static int
> +tlc59116_set_led(struct tlc59116_led *led, u8 val)
> +{
> +	struct regmap *regmap = led->regmap;
> +	int i = (led->led_no % 4) * 2;
> +	char addr = TLC59116_REG_LEDOUT(led->led_no);

int and char are funny type choices for i and addr, resp.
would prefer unsigned types

> +	unsigned int mask = LED_MASK << i;
> +
> +	val = val << i;
> +
> +	return regmap_update_bits(regmap, addr, mask, val);
> +}
> +
> +static void
> +tlc59116_led_work(struct work_struct *work)
> +{
> +	struct tlc59116_led *led = work_to_led(work);
> +	struct regmap *regmap = led->regmap;
> +	int err;
> +	u8 pwm;
> +
> +	pwm = TLC59116_REG_PWM(led->led_no);
> +	err = regmap_write(regmap, pwm, led->ldev.brightness);
> +	if (err)
> +		dev_err(led->ldev.dev, "Failed setting brightness\n");
> +}
> +
> +static void
> +tlc59116_led_set(struct led_classdev *led_cdev, enum led_brightness value)
> +{
> +	struct tlc59116_led *led = ldev_to_led(led_cdev);
> +
> +	led->ldev.brightness = value;
> +	schedule_work(&led->work);
> +}
> +
> +static void
> +tlc59116_destroy_devices(struct tlc59116_priv *priv, int i)
> +{
> +	while (--i >= 0) {
> +		if (priv->leds[i].active) {
> +			led_classdev_unregister(&priv->leds[i].ldev);
> +			cancel_work_sync(&priv->leds[i].work);
> +		}
> +	}
> +}
> +
> +static int
> +tlc59116_configure(struct device *dev,
> +		   struct tlc59116_priv *priv,
> +		   struct regmap *regmap)
> +{
> +	int i, err = 0;

i could be unsigned

> +
> +	tlc59116_set_mode(regmap, MODE2_DIM);
> +	for (i = 0; i < TLC59116_LEDS; i++) {
> +		struct tlc59116_led *led = &priv->leds[i];
> +
> +		if (!led->active)
> +			continue;
> +
> +		led->regmap = regmap;
> +		led->led_no = i;
> +		led->ldev.brightness_set = tlc59116_led_set;
> +		led->ldev.max_brightness = LED_FULL;
> +		INIT_WORK(&led->work, tlc59116_led_work);
> +		err = led_classdev_register(dev, &led->ldev);
> +		if (err < 0) {
> +			dev_err(dev, "couldn't register LED %s\n",
> +				led->ldev.name);
> +			goto exit;
> +		}
> +		tlc59116_set_led(led, TLC59116_DIM);
> +	}
> +
> +	return 0;
> +
> +exit:
> +	tlc59116_destroy_devices(priv, i);
> +	return err;
> +}
> +
> +static const struct regmap_config tlc59116_regmap = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x1e,
> +};
> +
> +static int
> +tlc59116_probe(struct i2c_client *client,
> +	       const struct i2c_device_id *id)
> +{
> +	struct tlc59116_priv *priv = i2c_get_clientdata(client);
> +	struct device *dev = &client->dev;
> +	struct device_node *np = client->dev.of_node, *child;
> +	struct regmap *regmap;
> +	int err, count, reg;
> +
> +	count = of_get_child_count(np);
> +	if (!count || count > TLC59116_LEDS)
> +		return -EINVAL;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +		I2C_FUNC_SMBUS_BYTE_DATA))
> +		return -EIO;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	regmap = devm_regmap_init_i2c(client, &tlc59116_regmap);
> +	if (IS_ERR(regmap)) {
> +		err = PTR_ERR(regmap);
> +		dev_err(dev, "Failed to allocate register map: %d\n", err);
> +		return err;
> +	}
> +
> +	i2c_set_clientdata(client, priv);
> +
> +	for_each_child_of_node(np, child) {
> +		err = of_property_read_u32(child, "reg", &reg);
> +		if (err)
> +			return err;
> +		if (reg < 0 || reg >= TLC59116_LEDS)
> +			return -EINVAL;
> +		if (priv->leds[reg].active)
> +			return -EINVAL;
> +		priv->leds[reg].active = true;
> +		priv->leds[reg].ldev.name =
> +			of_get_property(child, "label", NULL) ? : child->name;

unusual syntax to skip the 2nd argument of the ? operator (nothing wrong)

> +		priv->leds[reg].ldev.default_trigger =
> +			of_get_property(child, "linux,default-trigger", NULL);
> +	}
> +	return tlc59116_configure(dev, priv, regmap);
> +}
> +
> +static int
> +tlc59116_remove(struct i2c_client *client)
> +{
> +	struct tlc59116_priv *priv = i2c_get_clientdata(client);
> +
> +	tlc59116_destroy_devices(priv, TLC59116_LEDS);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id of_tlc59116_leds_match[] = {
> +	{ .compatible = "ti,tlc59116", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, of_tlc59116_leds_match);
> +
> +static const struct i2c_device_id tlc59116_id[] = {
> +	{ "tlc59116" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, tlc59116_id);
> +
> +static struct i2c_driver tlc59116_driver = {
> +	.driver = {
> +		.name = "tlc59116",
> +		.of_match_table = of_match_ptr(of_tlc59116_leds_match),
> +	},
> +	.probe = tlc59116_probe,
> +	.remove = tlc59116_remove,
> +	.id_table = tlc59116_id,
> +};
> +
> +module_i2c_driver(tlc59116_driver);
> +
> +MODULE_AUTHOR("Andrew Lunn <andrew@xxxxxxx>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("TLC59116 LED driver");
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)
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