Re: [PATCH 3/3] leds: add SN3218 LED driver
From: Jacek Anaszewski
Date: Mon Feb 01 2016 - 07:54:10 EST
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@xxxxxxxx>
---
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@xxxxxxxx>
+ *
+ * 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@xxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
Best Regards,
Jacek Anaszewski