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

From: H. Nikolaus Schaller
Date: Tue Jul 19 2016 - 08:35:22 EST

Hi,

> Am 19.07.2016 um 14:29 schrieb Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>:
>
> 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@xxxxxxxxxxxxx>
>> Signed-off-by: Andrey Utkin <andrey_utkin@xxxxxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxxxx>
>> + *
>> + * 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@xxxxxxxxxxxxx>");
>> +MODULE_AUTHOR("Andrey Utkin <andrey_utkin@xxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("IS31FL319X LED driver");
>> +MODULE_LICENSE("GPL v2");
>>