Hi Stefan,
Thanks for the patch. Please find my comments in the code below.
On 01/28/2016 09:41 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 | 8 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-sn3218.c | 254 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 263 insertions(+)
create mode 100644 drivers/leds/leds-sn3218.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 7f940c2..4a1bb4e 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -568,6 +568,14 @@ 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
+ help
+ This option enables support for the Si-EN SN3218 LED driver
+ through I2C. Say Y to enable support for the SN3218 LED.
s/through/connected through/
+
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..f52e7cc
--- /dev/null
+++ b/drivers/leds/leds-sn3218.c
@@ -0,0 +1,254 @@
+/*
+ * 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/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#define SN3218_MODE 0x00
+#define SN3218_PWM_BASE 0x01
+#define SN3218_LED_BASE 0x13 /* 6 channels per reg */
+#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
+
+static const struct i2c_device_id sn3218_id[] = {
+ { "sn3218", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, sn3218_id);
Please put the above i2c_device_id definition at the end of file,
similarly to e.g. drivers/leds/leds-lp5523.c.
+
+struct sn3218_led;
+
+/**
+ * struct sn3218 -
+ * @lock - Lock for writing the device
+ * @client - Pointer to the I2C client
+ * @leds - Pointer to the individual LEDs
+ * @leds_state - Copy of LED CTRL registers
+**/
+struct sn3218 {
+ struct mutex lock;
+ struct i2c_client *client;
+ struct sn3218_led *leds;
+ u8 leds_state[3];
+};
+
+/**
+ * struct sn3218_led -
+ * @chip - Pointer to the container
+ * @led_cdev - led class device pointer
+ * @led_num - LED index ( 0 .. 17 )
+ * @name - LED name
+**/
+struct sn3218_led {
+ struct sn3218 *chip;
+ struct led_classdev led_cdev;
+ int led_num;
+ char name[32];
You don't need to cache the LED name - it is required only
during LED class device registration. Just assign the pointer
to led_cdev->name.
+};
+
+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 i2c_client *client = led->chip->client;
+ u8 bank = led->led_num / 6;
+ u8 mask = 0x1 << (led->led_num % 6);
+ int ret;
+
+ mutex_lock(&led->chip->lock);
+
+ if (brightness == LED_OFF)
+ led->chip->leds_state[bank] &= ~mask;
+ else
+ led->chip->leds_state[bank] |= mask;
If you used regmap you could get rid of led_state, as you'd
have the caching for free. Please check regmap_update_bits().
+ ret = i2c_smbus_write_byte_data(client, SN3218_LED_BASE + bank,
+ led->chip->leds_state[bank]);
This should be switched to regmap_write then.
+ if (ret < 0)
+ goto unlock;
+
+ if (brightness > LED_OFF) {
+ ret = i2c_smbus_write_byte_data(client,
+ SN3218_PWM_BASE + led->led_num, brightness);
+ if (ret < 0)
+ goto unlock;
+ }
+
+ ret = i2c_smbus_write_byte_data(client, SN3218_UPDATE, 0xFF);
+
+unlock:
+ mutex_unlock(&led->chip->lock);
+ return ret;
+}
+
+static struct led_platform_data *sn3218_init(struct i2c_client *client)
+{
+ struct device_node *np = client->dev.of_node, *child;
+ struct led_platform_data *pdata;
+ struct led_info *sn3218_leds;
+ int count;
+
+ count = of_get_child_count(np);
+ if (!count || count > NUM_LEDS)
+ return NULL;
+
+ sn3218_leds = devm_kzalloc(&client->dev,
+ sizeof(struct led_info) * NUM_LEDS, GFP_KERNEL);
Please don't use struct led_info and struct led_platform_data.
You can assign parsed data directly to the struct sn3218_led and its
member - led_cdev. It could be allocated in sn3218_probe() and passed
here as an argument. Return type could be switched to int (error code)
then.
I'd also allocate a memory only for the number of LEDs defined in
the DT ("count" in this case).
+ if (!sn3218_leds)
+ return NULL;
+
+ for_each_child_of_node(np, child) {
+ struct led_info led = {};
+ u32 reg;
+ int ret;
+
+ ret = of_property_read_u32(child, "reg", ®);
+ if (ret != 0 || reg < 0 || reg >= NUM_LEDS)
+ continue;
I'd prefer to fail in case of DT validation error.
Please keep in mind that before breaking the loop we have to release
the child by calling of_node_put().
+ led.name =
+ of_get_property(child, "label", NULL) ? : child->name;
+ led.default_trigger =
+ of_get_property(child, "linux,default-trigger", NULL);
+ sn3218_leds[reg] = led;
+ }
+
+ pdata = devm_kzalloc(&client->dev, sizeof(struct led_platform_data),
+ GFP_KERNEL);
+
+ pdata->leds = sn3218_leds;
+ pdata->num_leds = NUM_LEDS;
+
+ return pdata;
+}
+
+static const struct of_device_id of_sn3218_match[] = {
+ { .compatible = "si-en,sn3218", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_sn3218_match);
Please put it at the end of file.
+
+static int sn3218_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct led_platform_data *pdata;
+ struct sn3218 *sn3218_chip;
+ struct sn3218_led *sn3218;
+ int i, ret;
+
+ pdata = sn3218_init(client);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+
+ sn3218_chip = devm_kzalloc(&client->dev, sizeof(*sn3218_chip),
+ GFP_KERNEL);
+ if (!sn3218_chip)
+ return -ENOMEM;
+
+ sn3218 = devm_kzalloc(&client->dev, NUM_LEDS * sizeof(*sn3218),
+ GFP_KERNEL);
+ if (!sn3218)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, sn3218_chip);
+
+ mutex_init(&sn3218_chip->lock);
+ sn3218_chip->client = client;
+ sn3218_chip->leds = sn3218;
+
+ for (i = 0; i < NUM_LEDS; i++) {
+ sn3218[i].led_num = i;
+ sn3218[i].chip = sn3218_chip;
+
+ if (i < pdata->num_leds) {
+ if (pdata->leds[i].name)
+ snprintf(sn3218[i].name,
+ sizeof(sn3218[i].name), "sn3218:%s",
+ pdata->leds[i].name);
+ if (pdata->leds[i].default_trigger)
+ sn3218[i].led_cdev.default_trigger =
+ pdata->leds[i].default_trigger;
+ }
+
+ if (i >= pdata->num_leds || !pdata->leds[i].name) {
Name will be always not NULL - either pointer to the "label" property
or to the child->name.
+ snprintf(sn3218[i].name, sizeof(sn3218[i].name),
+ "sn3218:%d:%.2x:%d", client->adapter->nr,
+ client->addr, i);
Just use the string obtained from DT.
+ }
+
+ sn3218[i].led_cdev.name = sn3218[i].name;
+ sn3218[i].led_cdev.brightness_set_blocking = sn3218_led_set;
+ sn3218[i].led_cdev.max_brightness = LED_FULL;
+
+ ret = led_classdev_register(&client->dev, &sn3218[i].led_cdev);
+ if (ret < 0)
+ goto exit;
Use devm_ prefixed version.
+ }
+
+ /* Reset chip to default, all LEDs off */
+ i2c_smbus_write_byte_data(client, SN3218_RESET, 0xFF);
+
+ /* Set normal mode */
+ i2c_smbus_write_byte_data(client, SN3218_MODE, 0x01);
+
+ return 0;
+
+exit:
+ while (i--)
+ led_classdev_unregister(&sn3218[i].led_cdev);
+
+ return ret;
+}
+
+static int sn3218_remove(struct i2c_client *client)
+{
+ struct sn3218 *sn3218 = i2c_get_clientdata(client);
+ int i;
+
+ for (i = 0; i < NUM_LEDS; i++)
+ led_classdev_unregister(&sn3218->leds[i].led_cdev);
+
+ /* Set shutdown mode */
+ i2c_smbus_write_byte_data(client, SN3218_MODE, 0x00);
+
+ return 0;
+}
+
+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");
s/GPL/GPL v2/ - to be in accordance with the statement in the beginning.
--
Best Regards,
Jacek Anaszewski
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