[Letux-kernel] [PATCH v6 1/2] led: is31fl319x: 1/3/6/9-channel light effect led driver

H. Nikolaus Schaller hns at goldelico.com
Tue Jul 19 14:34:53 CEST 2016


Hi,

> Am 19.07.2016 um 14:29 schrieb Jacek Anaszewski <j.anaszewski at samsung.com>:
> 
> Tweaked the tabulation of macro values a bit more and applied

thanks!
I think you better know how you want to have them exactly (checkpatch didn't complain).

> the patches to the for-4.9 branch of linux-leds.git.

Fine!

> 
> Thanks,
> Jacek Anaszewski

BR and thanks as well,
Nikolaus

> 
> On 07/19/2016 01:47 PM, H. Nikolaus Schaller wrote:
>> This is a driver for the Integrated Silicon Solution Inc. LED driver
>> chips series IS31FL319x. They can drive 1, 3, 6  or up to 9
>> LEDs.
>> 
>> Each LED is individually controllable in brightness (through pwm)
>> in 256 steps so that RGB LEDs can show any of ca. 16 Mio colors.
>> 
>> The maximum current of the LEDs can be programmed and limited to
>> 5 .. 40mA through a device tree property.
>> 
>> The chip is connected through I2C and can have one of 4 addresses
>> in the range 0x64 .. 0x67 depending on how the AD pin is connected. The
>> address is defined by the reg property as usual.
>> 
>> The chip also has a shutdown input which could be connected to a GPIO,
>> but this driver uses software shutdown if all LEDs are inactivated.
>> 
>> The chip also has breathing and audio features which are not fully
>> supported by this driver.
>> 
>> Tested-on: OMAP5 based Pyra handheld prototype.
>> Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
>> Signed-off-by: Andrey Utkin <andrey_utkin at fastmail.com>
>> ---
>>  drivers/leds/Kconfig           |  12 ++
>>  drivers/leds/Makefile          |   1 +
>>  drivers/leds/leds-is31fl319x.c | 450 +++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 463 insertions(+)
>>  create mode 100644 drivers/leds/leds-is31fl319x.c
>> 
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 5ae2834..6439a7d 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -570,6 +570,18 @@ config LEDS_SEAD3
>>  	  This driver can also be built as a module. If so the module
>>  	  will be called leds-sead3.
>> 
>> +config LEDS_IS31FL319X
>> +	tristate "LED Support for ISSI IS31FL319x I2C LED controller family"
>> +	depends on LEDS_CLASS && I2C && OF
>> +	select REGMAP_I2C
>> +	help
>> +	  This option enables support for LEDs connected to ISSI IS31FL319x
>> +	  fancy LED driver chips accessed via the I2C bus.
>> +	  Driver supports individual PWM brightness control for each channel.
>> +
>> +	  This driver can also be built as a module. If so the module will be
>> +	  called leds-is31fl319x.
>> +
>>  config LEDS_IS31FL32XX
>>  	tristate "LED support for ISSI IS31FL32XX I2C LED controller family"
>>  	depends on LEDS_CLASS && I2C && OF
>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>> index cb2013d..b6ce9f9 100644
>> --- a/drivers/leds/Makefile
>> +++ b/drivers/leds/Makefile
>> @@ -66,6 +66,7 @@ obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
>>  obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
>>  obj-$(CONFIG_LEDS_POWERNV)		+= leds-powernv.o
>>  obj-$(CONFIG_LEDS_SEAD3)		+= leds-sead3.o
>> +obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-is31fl319x.o
>>  obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
>> 
>>  # LED SPI Drivers
>> diff --git a/drivers/leds/leds-is31fl319x.c b/drivers/leds/leds-is31fl319x.c
>> new file mode 100644
>> index 0000000..dbdcfdd
>> --- /dev/null
>> +++ b/drivers/leds/leds-is31fl319x.c
>> @@ -0,0 +1,450 @@
>> +/*
>> + * Copyright 2015-16 Golden Delicious Computers
>> + *
>> + * Author: Nikolaus Schaller <hns at goldelico.com>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License.  See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
>> + * effect LEDs.
>> + *
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/i2c.h>
>> +#include <linux/leds.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +
>> +/* register numbers */
>> +#define IS31FL319X_SHUTDOWN     0x00
>> +#define IS31FL319X_CTRL1        0x01
>> +#define IS31FL319X_CTRL2        0x02
>> +#define IS31FL319X_CONFIG1      0x03
>> +#define IS31FL319X_CONFIG2      0x04
>> +#define IS31FL319X_RAMP_MODE    0x05
>> +#define IS31FL319X_BREATH_MASK  0x06
>> +#define IS31FL319X_PWM(channel) (0x07 + channel)
>> +#define IS31FL319X_DATA_UPDATE  0x10
>> +#define IS31FL319X_T0(channel)  (0x11 + channel)
>> +#define IS31FL319X_T123_1       0x1a
>> +#define IS31FL319X_T123_2       0x1b
>> +#define IS31FL319X_T123_3       0x1c
>> +#define IS31FL319X_T4(channel)  (0x1d + channel)
>> +#define IS31FL319X_TIME_UPDATE  0x26
>> +#define IS31FL319X_RESET        0xff
>> +
>> +#define IS31FL319X_REG_CNT      (IS31FL319X_RESET + 1)
>> +
>> +#define IS31FL319X_MAX_LEDS 9
>> +
>> +/* CS (Current Setting) in CONFIG2 register */
>> +#define IS31FL319X_CONFIG2_CS_SHIFT    4
>> +#define IS31FL319X_CONFIG2_CS_MASK     0x7
>> +#define IS31FL319X_CONFIG2_CS_STEP_REF 12
>> +
>> +#define IS31FL319X_CURRENT_MIN     ((u32)5000)
>> +#define IS31FL319X_CURRENT_MAX     ((u32)40000)
>> +#define IS31FL319X_CURRENT_STEP    ((u32)5000)
>> +#define IS31FL319X_CURRENT_DEFAULT ((u32)20000)
>> +
>> +/* Audio gain in CONFIG2 register */
>> +#define IS31FL319X_AUDIO_GAIN_DB_MAX  ((u32)21)
>> +#define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3)
>> +
>> +/*
>> + * regmap is used as a cache of chip's register space,
>> + * to avoid reading back brightness values from chip,
>> + * which is known to hang.
>> + */
>> +struct is31fl319x_chip {
>> +	const struct is31fl319x_chipdef *cdef;
>> +	struct i2c_client               *client;
>> +	struct regmap                   *regmap;
>> +	struct mutex                    lock;
>> +	u32                             audio_gain_db;
>> +
>> +	struct is31fl319x_led {
>> +		struct is31fl319x_chip  *chip;
>> +		struct led_classdev     cdev;
>> +		u32                     max_microamp;
>> +		bool                    configured;
>> +	} leds[IS31FL319X_MAX_LEDS];
>> +};
>> +
>> +struct is31fl319x_chipdef {
>> +	int num_leds;
>> +};
>> +
>> +static const struct is31fl319x_chipdef is31fl3190_cdef = {
>> +	.num_leds = 1,
>> +};
>> +
>> +static const struct is31fl319x_chipdef is31fl3193_cdef = {
>> +	.num_leds = 3,
>> +};
>> +
>> +static const struct is31fl319x_chipdef is31fl3196_cdef = {
>> +	.num_leds = 6,
>> +};
>> +
>> +static const struct is31fl319x_chipdef is31fl3199_cdef = {
>> +	.num_leds = 9,
>> +};
>> +
>> +static const struct of_device_id of_is31fl319x_match[] = {
>> +	{ .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
>> +	{ .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
>> +	{ .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
>> +	{ .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
>> +	{ .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
>> +	{ .compatible = "si-en,sn3199",    .data = &is31fl3199_cdef, },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
>> +
>> +static int is31fl319x_brightness_set(struct led_classdev *cdev,
>> +				     enum led_brightness brightness)
>> +{
>> +	struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
>> +						  cdev);
>> +	struct is31fl319x_chip *is31 = led->chip;
>> +	int chan = led - is31->leds;
>> +	int ret;
>> +	int i;
>> +	u8 ctrl1 = 0, ctrl2 = 0;
>> +
>> +	dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);
>> +
>> +	mutex_lock(&is31->lock);
>> +
>> +	/* update PWM register */
>> +	ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
>> +	if (ret < 0)
>> +		goto out;
>> +
>> +	/* read current brightness of all PWM channels */
>> +	for (i = 0; i < is31->cdef->num_leds; i++) {
>> +		unsigned int pwm_value;
>> +		bool on;
>> +
>> +		/*
>> +		 * since neither cdev nor the chip can provide
>> +		 * the current setting, we read from the regmap cache
>> +		 */
>> +
>> +		ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
>> +		dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
>> +			__func__, i, ret, pwm_value);
>> +		on = ret >= 0 && pwm_value > LED_OFF;
>> +
>> +		if (i < 3)
>> +			ctrl1 |= on << i;       /* 0..2 => bit 0..2 */
>> +		else if (i < 6)
>> +			ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
>> +		else
>> +			ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
>> +	}
>> +
>> +	if (ctrl1 > 0 || ctrl2 > 0) {
>> +		dev_dbg(&is31->client->dev, "power up %02x %02x\n",
>> +			ctrl1, ctrl2);
>> +		regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
>> +		regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
>> +		/* update PWMs */
>> +		regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
>> +		/* enable chip from shut down */
>> +		ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
>> +	} else {
>> +		dev_dbg(&is31->client->dev, "power down\n");
>> +		/* shut down (no need to clear CTRL1/2) */
>> +		ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
>> +	}
>> +
>> +out:
>> +	mutex_unlock(&is31->lock);
>> +
>> +	return ret;
>> +}
>> +
>> +static int is31fl319x_parse_child_dt(const struct device *dev,
>> +				     const struct device_node *child,
>> +				     struct is31fl319x_led *led)
>> +{
>> +	struct led_classdev *cdev = &led->cdev;
>> +	int ret;
>> +
>> +	if (of_property_read_string(child, "label", &cdev->name))
>> +		cdev->name = child->name;
>> +
>> +	ret = of_property_read_string(child, "linux,default-trigger",
>> +				      &cdev->default_trigger);
>> +	if (ret < 0 && ret != -EINVAL) /* is optional */
>> +		return ret;
>> +
>> +	led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
>> +	ret = of_property_read_u32(child, "led-max-microamp",
>> +				   &led->max_microamp);
>> +	if (!ret) {
>> +		if (led->max_microamp < IS31FL319X_CURRENT_MIN)
>> +			return -EINVAL;	/* not supported */
>> +		led->max_microamp = min(led->max_microamp,
>> +					  IS31FL319X_CURRENT_MAX);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int is31fl319x_parse_dt(struct device *dev,
>> +			       struct is31fl319x_chip *is31)
>> +{
>> +	struct device_node *np = dev->of_node, *child;
>> +	const struct of_device_id *of_dev_id;
>> +	int count;
>> +	int ret;
>> +
>> +	if (!np)
>> +		return -ENODEV;
>> +
>> +	of_dev_id = of_match_device(of_is31fl319x_match, dev);
>> +	if (!of_dev_id) {
>> +		dev_err(dev, "Failed to match device with supported chips\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	is31->cdef = of_dev_id->data;
>> +
>> +	count = of_get_child_count(np);
>> +
>> +	dev_dbg(dev, "probe %s with %d leds defined in DT\n",
>> +		of_dev_id->compatible, count);
>> +
>> +	if (!count || count > is31->cdef->num_leds) {
>> +		dev_err(dev, "Number of leds defined must be between 1 and %u\n",
>> +			is31->cdef->num_leds);
>> +		return -ENODEV;
>> +	}
>> +
>> +	for_each_child_of_node(np, child) {
>> +		struct is31fl319x_led *led;
>> +		u32 reg;
>> +
>> +		ret = of_property_read_u32(child, "reg", &reg);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to read led 'reg' property\n");
>> +			goto put_child_node;
>> +		}
>> +
>> +		if (reg < 1 || reg > is31->cdef->num_leds) {
>> +			dev_err(dev, "invalid led reg %u\n", reg);
>> +			ret = -EINVAL;
>> +			goto put_child_node;
>> +		}
>> +
>> +		led = &is31->leds[reg - 1];
>> +
>> +		if (led->configured) {
>> +			dev_err(dev, "led %u is already configured\n", reg);
>> +			ret = -EINVAL;
>> +			goto put_child_node;
>> +		}
>> +
>> +		ret = is31fl319x_parse_child_dt(dev, child, led);
>> +		if (ret) {
>> +			dev_err(dev, "led %u DT parsing failed\n", reg);
>> +			goto put_child_node;
>> +		}
>> +
>> +		led->configured = true;
>> +	}
>> +
>> +	is31->audio_gain_db = 0;
>> +	ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
>> +	if (!ret)
>> +		is31->audio_gain_db = min(is31->audio_gain_db,
>> +					  IS31FL319X_AUDIO_GAIN_DB_MAX);
>> +
>> +	return 0;
>> +
>> +put_child_node:
>> +	of_node_put(child);
>> +	return ret;
>> +}
>> +
>> +static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
>> +{ /* we have no readable registers */
>> +	return false;
>> +}
>> +
>> +static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
>> +{ /* volatile registers are not cached */
>> +	switch (reg) {
>> +	case IS31FL319X_DATA_UPDATE:
>> +	case IS31FL319X_TIME_UPDATE:
>> +	case IS31FL319X_RESET:
>> +		return true; /* always write-through */
>> +	default:
>> +		return false;
>> +	}
>> +}
>> +
>> +static const struct reg_default is31fl319x_reg_defaults[] = {
>> +	{ IS31FL319X_CONFIG1, 0x00},
>> +	{ IS31FL319X_CONFIG2, 0x00},
>> +	{ IS31FL319X_PWM(0), 0x00},
>> +	{ IS31FL319X_PWM(1), 0x00},
>> +	{ IS31FL319X_PWM(2), 0x00},
>> +	{ IS31FL319X_PWM(3), 0x00},
>> +	{ IS31FL319X_PWM(4), 0x00},
>> +	{ IS31FL319X_PWM(5), 0x00},
>> +	{ IS31FL319X_PWM(6), 0x00},
>> +	{ IS31FL319X_PWM(7), 0x00},
>> +	{ IS31FL319X_PWM(8), 0x00},
>> +};
>> +
>> +static struct regmap_config regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +	.max_register = IS31FL319X_REG_CNT,
>> +	.cache_type = REGCACHE_FLAT,
>> +	.readable_reg = is31fl319x_readable_reg,
>> +	.volatile_reg = is31fl319x_volatile_reg,
>> +	.reg_defaults = is31fl319x_reg_defaults,
>> +	.num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
>> +};
>> +
>> +static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
>> +{ /* round down to nearest supported value (range check done by caller) */
>> +	u32 step = microamp / IS31FL319X_CURRENT_STEP;
>> +
>> +	return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
>> +		IS31FL319X_CONFIG2_CS_MASK) <<
>> +		IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
>> +}
>> +
>> +static inline int is31fl319x_db_to_gain(u32 dezibel)
>> +{ /* round down to nearest supported value (range check done by caller) */
>> +	return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
>> +}
>> +
>> +static int is31fl319x_probe(struct i2c_client *client,
>> +			    const struct i2c_device_id *id)
>> +{
>> +	struct is31fl319x_chip *is31;
>> +	struct device *dev = &client->dev;
>> +	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
>> +	int err;
>> +	int i = 0;
>> +	u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
>> +
>> +	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
>> +		return -EIO;
>> +
>> +	is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
>> +	if (!is31)
>> +		return -ENOMEM;
>> +
>> +	mutex_init(&is31->lock);
>> +
>> +	err = is31fl319x_parse_dt(&client->dev, is31);
>> +	if (err)
>> +		goto free_mutex;
>> +
>> +	is31->client = client;
>> +	is31->regmap = devm_regmap_init_i2c(client, &regmap_config);
>> +	if (IS_ERR(is31->regmap)) {
>> +		dev_err(&client->dev, "failed to allocate register map\n");
>> +		err = PTR_ERR(is31->regmap);
>> +		goto free_mutex;
>> +	}
>> +
>> +	i2c_set_clientdata(client, is31);
>> +
>> +	/* check for write-reply from chip (we can't read any registers) */
>> +	err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
>> +	if (err < 0) {
>> +		dev_err(&client->dev, "no response from chip write: err = %d\n",
>> +			err);
>> +		err = -EIO; /* does not answer */
>> +		goto free_mutex;
>> +	}
>> +
>> +	/*
>> +	 * Kernel conventions require per-LED led-max-microamp property.
>> +	 * But the chip does not allow to limit individual LEDs.
>> +	 * So we take minimum from all subnodes for safety of hardware.
>> +	 */
>> +	for (i = 0; i < is31->cdef->num_leds; i++)
>> +		if (is31->leds[i].configured &&
>> +		    is31->leds[i].max_microamp < aggregated_led_microamp)
>> +			aggregated_led_microamp = is31->leds[i].max_microamp;
>> +
>> +	regmap_write(is31->regmap, IS31FL319X_CONFIG2,
>> +		     is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
>> +		     is31fl319x_db_to_gain(is31->audio_gain_db));
>> +
>> +	for (i = 0; i < is31->cdef->num_leds; i++) {
>> +		struct is31fl319x_led *led = &is31->leds[i];
>> +
>> +		if (!led->configured)
>> +			continue;
>> +
>> +		led->chip = is31;
>> +		led->cdev.brightness_set_blocking = is31fl319x_brightness_set;
>> +
>> +		err = devm_led_classdev_register(&client->dev, &led->cdev);
>> +		if (err < 0)
>> +			goto free_mutex;
>> +	}
>> +
>> +	return 0;
>> +
>> +free_mutex:
>> +	mutex_destroy(&is31->lock);
>> +	return err;
>> +}
>> +
>> +static int is31fl319x_remove(struct i2c_client *client)
>> +{
>> +	struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
>> +
>> +	mutex_destroy(&is31->lock);
>> +	return 0;
>> +}
>> +
>> +/*
>> + * i2c-core (and modalias) requires that id_table be properly filled,
>> + * even though it is not used for DeviceTree based instantiation.
>> + */
>> +static const struct i2c_device_id is31fl319x_id[] = {
>> +	{ "is31fl3190" },
>> +	{ "is31fl3191" },
>> +	{ "is31fl3193" },
>> +	{ "is31fl3196" },
>> +	{ "is31fl3199" },
>> +	{ "sn3199" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
>> +
>> +static struct i2c_driver is31fl319x_driver = {
>> +	.driver   = {
>> +		.name           = "leds-is31fl319x",
>> +		.of_match_table = of_match_ptr(of_is31fl319x_match),
>> +	},
>> +	.probe    = is31fl319x_probe,
>> +	.remove   = is31fl319x_remove,
>> +	.id_table = is31fl319x_id,
>> +};
>> +
>> +module_i2c_driver(is31fl319x_driver);
>> +
>> +MODULE_AUTHOR("H. Nikolaus Schaller <hns at goldelico.com>");
>> +MODULE_AUTHOR("Andrey Utkin <andrey_utkin at fastmail.com>");
>> +MODULE_DESCRIPTION("IS31FL319X LED driver");
>> +MODULE_LICENSE("GPL v2");
>> 



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