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Message-id: <56AF5567.4090102@samsung.com>
Date: Mon, 01 Feb 2016 13:53:59 +0100
From: Jacek Anaszewski <j.anaszewski@...sung.com>
To: Stefan Wahren <stefan.wahren@...e.com>
Cc: Richard Purdie <rpurdie@...ys.net>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-leds@...r.kernel.org
Subject: Re: [PATCH 3/3] leds: add SN3218 LED driver
On 02/01/2016 10:58 AM, Jacek Anaszewski wrote:
> Hi Stefan,
>
> Thanks for the update. A few more comments below.
>
> On 01/31/2016 01:59 PM, Stefan Wahren wrote:
>> This patch adds support for Si-En SN3218 18 Channel LED Driver.
>>
>> Signed-off-by: Stefan Wahren <stefan.wahren@...e.com>
>> ---
>> drivers/leds/Kconfig | 12 ++
>> drivers/leds/Makefile | 1 +
>> drivers/leds/leds-sn3218.c | 297
>> ++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 310 insertions(+)
>> create mode 100644 drivers/leds/leds-sn3218.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 7f940c2..920c2da 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -568,6 +568,18 @@ config LEDS_SEAD3
>> This driver can also be built as a module. If so the module
>> will be called leds-sead3.
>>
>> +config LEDS_SN3218
>> + tristate "LED support for Si-En SN3218 I2C chip"
>> + depends on LEDS_CLASS && I2C
>> + depends on OF
>> + select REGMAP_I2C
>> + help
>> + This option enables support for the Si-EN SN3218 LED driver
>> + connected through I2C. Say Y to enable support for the SN3218 LED.
>> +
>> + This driver can also be built as a module. If so the module
>> + will be called leds-sn3218.
>> +
>> comment "LED driver for blink(1) USB RGB LED is under Special HID
>> drivers (HID_THINGM)"
>>
>> config LEDS_BLINKM
>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>> index e9d5309..89c9b6f 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-$(CONFIG_LEDS_SN3218) += leds-sn3218.o
>>
>> # LED SPI Drivers
>> obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
>> diff --git a/drivers/leds/leds-sn3218.c b/drivers/leds/leds-sn3218.c
>> new file mode 100644
>> index 0000000..7a96323
>> --- /dev/null
>> +++ b/drivers/leds/leds-sn3218.c
>> @@ -0,0 +1,297 @@
>> +/*
>> + * Si-En SN3218 18 Channel LED Driver
>> + *
>> + * Copyright (C) 2016 Stefan Wahren <stefan.wahren@...e.com>
>> + *
>> + * Based on leds-pca963x.c
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + *
>> + * Datasheet: http://www.si-en.com/uploadpdf/s2011517171720.pdf
>> + *
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/i2c.h>
>> +#include <linux/leds.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +
>> +#define SN3218_MODE 0x00
>> +#define SN3218_PWM_1 0x01
>> +#define SN3218_PWM_2 0x02
>> +#define SN3218_PWM_3 0x03
>> +#define SN3218_PWM_4 0x04
>> +#define SN3218_PWM_5 0x05
>> +#define SN3218_PWM_6 0x06
>> +#define SN3218_PWM_7 0x07
>> +#define SN3218_PWM_8 0x08
>> +#define SN3218_PWM_9 0x09
>> +#define SN3218_PWM_10 0x0a
>> +#define SN3218_PWM_11 0x0b
>> +#define SN3218_PWM_12 0x0c
>> +#define SN3218_PWM_13 0x0d
>> +#define SN3218_PWM_14 0x0e
>> +#define SN3218_PWM_15 0x0f
>> +#define SN3218_PWM_16 0x10
>> +#define SN3218_PWM_17 0x11
>> +#define SN3218_PWM_18 0x12
>> +#define SN3218_LED_1_6 0x13
>> +#define SN3218_LED_7_12 0x14
>> +#define SN3218_LED_13_18 0x15
>> +#define SN3218_UPDATE 0x16 /* applies to reg 0x01 .. 0x15 */
>> +#define SN3218_RESET 0x17
>> +
>> +#define SN3218_LED_MASK 0x3f
>> +#define SN3218_LED_ON 0x01
>> +#define SN3218_LED_OFF 0x00
>> +
>> +#define NUM_LEDS 18
>> +
>> +struct sn3218_led;
>> +
>> +/**
>> + * struct sn3218 -
>> + * @client - Pointer to the I2C client
>> + * @leds - Pointer to the individual LEDs
>> + * @num_leds - Actual number of LEDs
>> +**/
>> +struct sn3218 {
>> + struct i2c_client *client;
>> + struct regmap *regmap;
>> + struct sn3218_led *leds;
>> + int num_leds;
>> +};
>> +
>> +/**
>> + * struct sn3218_led -
>> + * @chip - Pointer to the container
>> + * @led_cdev - led class device pointer
>> + * @led_num - LED index ( 0 .. 17 )
>> +**/
>> +struct sn3218_led {
>> + struct sn3218 *chip;
>
> You don't need this if you have led id here. Please refer to
> drivers/leds/leds-max77693.c, sub_led_to_led() to check how to get
> a pointer to the parent structure in similar case.
Hmm, it would work only if leds was a static array in struct sn3218.
So, let's better leave this "chip" pointer intact.
>> + struct led_classdev led_cdev;
>> + int led_num;
>> +};
>> +
>> +static int sn3218_led_set(struct led_classdev *led_cdev,
>> + enum led_brightness brightness)
>> +{
>> + struct sn3218_led *led =
>> + container_of(led_cdev, struct sn3218_led, led_cdev);
>> + struct regmap *regmap = led->chip->regmap;
>> + u8 bank = led->led_num / 6;
>> + u8 mask = 0x1 << (led->led_num % 6);
>> + u8 val;
>> + int ret;
>> +
>> + if (brightness == LED_OFF)
>> + val = 0;
>> + else
>> + val = mask;
>> +
>> + ret = regmap_update_bits(regmap, SN3218_LED_1_6 + bank, mask, val);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (brightness > LED_OFF) {
>> + ret = regmap_write(regmap, SN3218_PWM_1 + led->led_num,
>> + brightness);
>> + if (ret < 0)
>> + return ret;
>> + }
>> +
>> + ret = regmap_write(regmap, SN3218_UPDATE, 0xff);
>> +
>> + return ret;
>> +}
>> +
>> +void sn3218_led_init(struct sn3218 *sn3218, struct device_node *node,
>> u32 reg)
>
> s/void/static void/
>
>> +{
>> + struct sn3218_led *leds = sn3218->leds;
>> + struct led_classdev *cdev = &leds[reg].led_cdev;
>> +
>> + leds[reg].led_num = reg;
>> + leds[reg].chip = sn3218;
>> +
>> + if (of_property_read_string(node, "label", &cdev->name))
>> + cdev->name = node->name;
>> +
>> + of_property_read_string(node, "linux,default-trigger",
>> + &cdev->default_trigger);
>> +
>> + cdev->brightness_set_blocking = sn3218_led_set;
>> + cdev->max_brightness = LED_FULL;
>
> Skip this line. If max_brightness is 0 led_classdev_register()
> automatically initializes it to LED_FULL.
>
>> +}
>> +
>> +static const struct reg_default sn3218_reg_defs[] = {
>> + { SN3218_MODE, 0x00},
>> + { SN3218_PWM_1, 0x00},
>> + { SN3218_PWM_2, 0x00},
>> + { SN3218_PWM_3, 0x00},
>> + { SN3218_PWM_4, 0x00},
>> + { SN3218_PWM_5, 0x00},
>> + { SN3218_PWM_6, 0x00},
>> + { SN3218_PWM_7, 0x00},
>> + { SN3218_PWM_8, 0x00},
>> + { SN3218_PWM_9, 0x00},
>> + { SN3218_PWM_10, 0x00},
>> + { SN3218_PWM_11, 0x00},
>> + { SN3218_PWM_12, 0x00},
>> + { SN3218_PWM_13, 0x00},
>> + { SN3218_PWM_14, 0x00},
>> + { SN3218_PWM_15, 0x00},
>> + { SN3218_PWM_16, 0x00},
>> + { SN3218_PWM_17, 0x00},
>> + { SN3218_PWM_18, 0x00},
>> + { SN3218_LED_1_6, 0x00},
>> + { SN3218_LED_7_12, 0x00},
>> + { SN3218_LED_13_18, 0x00},
>> + { SN3218_UPDATE, 0x00},
>> + { SN3218_RESET, 0x00},
>> +};
>> +
>> +static const struct regmap_config sn3218_regmap_config = {
>> + .reg_bits = 8,
>> + .val_bits = 8,
>> +
>> + .max_register = SN3218_RESET,
>> + .reg_defaults = sn3218_reg_defs,
>> + .num_reg_defaults = ARRAY_SIZE(sn3218_reg_defs),
>> + .cache_type = REGCACHE_RBTREE,
>> +};
>> +
>> +static int sn3218_init(struct i2c_client *client, struct sn3218 *sn3218)
>> +{
>> + struct device_node *np = client->dev.of_node, *child;
>> + struct sn3218_led *leds;
>> + int ret, count;
>> +
>> + count = of_get_child_count(np);
>> + if (!count)
>> + return -ENODEV;
>> +
>> + if (count > NUM_LEDS) {
>> + dev_err(&client->dev, "Invalid LED count %d\n", count);
>> + return -EINVAL;
>> + }
>> +
>> + leds = devm_kzalloc(&client->dev, count * sizeof(*leds),
>> GFP_KERNEL);
>> + if (!leds)
>> + return -ENOMEM;
>> +
>> + sn3218->leds = leds;
>> + sn3218->num_leds = count;
>> + sn3218->client = client;
>> +
>> + sn3218->regmap = devm_regmap_init_i2c(client,
>> &sn3218_regmap_config);
>> + if (IS_ERR(sn3218->regmap)) {
>> + ret = PTR_ERR(sn3218->regmap);
>> + dev_err(&client->dev, "Failed to allocate register map: %d\n",
>> + ret);
>> + return ret;
>> + }
>> +
>> + for_each_child_of_node(np, child) {
>> + u32 reg;
>> +
>> + ret = of_property_read_u32(child, "reg", ®);
>> + if (ret)
>> + goto fail;
>> +
>> + if (reg >= count) {
>> + dev_err(&client->dev, "Invalid LED (%u >= %d)\n", reg,
>> + count);
>> + ret = -EINVAL;
>> + goto fail;
>> + }
>> +
>> + sn3218_led_init(sn3218, child, reg);
>> + }
>> +
>> + return 0;
>> +
>> +fail:
>> + of_node_put(np);
>
> s/np/child/
>
>> + return ret;
>> +}
>> +
>> +static int sn3218_probe(struct i2c_client *client,
>> + const struct i2c_device_id *id)
>> +{
>> + struct sn3218 *sn3218;
>> + struct sn3218_led *leds;
>> + struct device *dev = &client->dev;
>> + int i, ret;
>> +
>> + sn3218 = devm_kzalloc(dev, sizeof(*sn3218), GFP_KERNEL);
>> + if (!sn3218)
>> + return -ENOMEM;
>> +
>> + ret = sn3218_init(client, sn3218);
>> + if (ret)
>> + return ret;
>> +
>> + i2c_set_clientdata(client, sn3218);
>> + leds = sn3218->leds;
>> +
>> + /*
>> + * Since the chip is write-only we need to reset him into
>> + * a defined state (all LEDs off).
>> + */
>> + ret = regmap_write(sn3218->regmap, SN3218_RESET, 0xff);
>> + if (ret)
>> + return ret;
>> +
>> + for (i = 0; i < sn3218->num_leds; i++) {
>> + ret = devm_led_classdev_register(dev, &leds[i].led_cdev);
>> + if (ret < 0)
>> + return ret;
>> + }
>> +
>> + /* Set normal mode */
>> + return regmap_write(sn3218->regmap, SN3218_MODE, 0x01);
>> +}
>> +
>> +static int sn3218_remove(struct i2c_client *client)
>> +{
>> + struct sn3218 *sn3218 = i2c_get_clientdata(client);
>> +
>> + /* Set shutdown mode */
>> + regmap_write(sn3218->regmap, SN3218_MODE, 0x00);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct i2c_device_id sn3218_id[] = {
>> + { "sn3218", 0 },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, sn3218_id);
>> +
>> +static const struct of_device_id of_sn3218_match[] = {
>> + { .compatible = "si-en,sn3218", },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, of_sn3218_match);
>> +
>> +static struct i2c_driver sn3218_driver = {
>> + .driver = {
>> + .name = "leds-sn3218",
>> + .of_match_table = of_match_ptr(of_sn3218_match),
>> + },
>> + .probe = sn3218_probe,
>> + .remove = sn3218_remove,
>> + .id_table = sn3218_id,
>> +};
>> +
>> +module_i2c_driver(sn3218_driver);
>> +
>> +MODULE_DESCRIPTION("Si-En SN3218 LED Driver");
>> +MODULE_AUTHOR("Stefan Wahren <stefan.wahren@...e.com>");
>> +MODULE_LICENSE("GPL v2");
>>
>
>
--
Best Regards,
Jacek Anaszewski
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