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Message-ID: <alpine.DEB.2.01.1310150015370.26447@pmeerw.net>
Date: Tue, 15 Oct 2013 00:38:13 +0200 (CEST)
From: Peter Meerwald <pmeerw@...erw.net>
To: Maximilian Güntner <maximilian.guentner@...il.com>
cc: Bryan Wu <cooloney@...il.com>, Richard Purdie <rpurdie@...ys.net>,
linux-kernel <linux-kernel@...r.kernel.org>,
linux-leds <linux-leds@...r.kernel.org>
Subject: Re: [PATCH] leds: Added driver for the NXP PCA9685 I2C chip
> The NXP PCA9685 supports 16 channels/leds using a 12-bit PWM (4095
> levels of brightness)
> This driver supports configuration using platform_data.
some nitpicking inline
> Signed-off-by: Maximilian Güntner <maximilian.guentner@...il.com>
> ---
> drivers/leds/Kconfig | 10 ++
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-pca9685.c | 219 +++++++++++++++++++++++++++++
> include/linux/platform_data/leds-pca9685.h | 34 +++++
> 4 files changed, 264 insertions(+)
> create mode 100644 drivers/leds/leds-pca9685.c
> create mode 100644 include/linux/platform_data/leds-pca9685.h
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 875bbe4..98268b3 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -300,6 +300,16 @@ config LEDS_PCA963X
> LED driver chip accessed via the I2C bus. Supported
> devices include PCA9633 and PCA9634
>
> +config LEDS_PCA9685
> + tristate "LED support for PCA9685 I2C chip"
> + depends on LEDS_CLASS
> + depends on I2C
> + help
> + This option enables support for LEDs connected to the PCA9685
> + LED driver chips accessed via the I2C bus.
chip
> + The PCA9685 offers 12-bit PWM (4095 levels of brightness) on
> + 16 individual channels.
> +
> config LEDS_WM831X_STATUS
> tristate "LED support for status LEDs on WM831x PMICs"
> depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 8979b0b..3cd76db 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -36,6 +36,7 @@ obj-$(CONFIG_LEDS_OT200) += leds-ot200.o
> obj-$(CONFIG_LEDS_FSG) += leds-fsg.o
> obj-$(CONFIG_LEDS_PCA955X) += leds-pca955x.o
> obj-$(CONFIG_LEDS_PCA963X) += leds-pca963x.o
> +obj-$(CONFIG_LEDS_PCA9685) += leds-pca9685.o
> obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o
> obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o
> obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
> diff --git a/drivers/leds/leds-pca9685.c b/drivers/leds/leds-pca9685.c
> new file mode 100644
> index 0000000..a2078bf
> --- /dev/null
> +++ b/drivers/leds/leds-pca9685.c
> @@ -0,0 +1,219 @@
> +/*
> + * Copyright 2013 Maximilian Güntner <maximilian.guentner@...il.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.
> + *
> + * Based on leds-pca963x.c driver by
> + * Peter Meerwald <p.meerwald@...-electronic.com>
> + *
> + * Driver for the NXP PCA9685 12-Bit I2C chip.
this could be more descriptive: 12-bit PWM LED driver chip
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <linux/delay.h>
> +#include <linux/ctype.h>
> +#include <linux/leds.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/workqueue.h>
> +#include <linux/slab.h>
> +
> +#include <linux/platform_data/leds-pca9685.h>
> +
> +/* Register Addresses */
> +#define PCA9685_MODE1 0x00
> +#define PCA9685_MODE2 0x01
> +#define PCA9685_LED0_ON_L 0x06
> +#define PCA9685_ALL_LED_ON_L 0xFA
> +
> +/* MODE1 Register */
> +#define PCA9685_ALLCALL 0x00
> +#define PCA9685_SLEEP 0x04
> +#define PCA9685_AI 0x05
> +
> +/* MODE2 Register */
> +#define PCA9685_INVRT 0x04
> +#define PCA9685_OUTDRV 0x02
> +
> +static const struct i2c_device_id pca9685_id[] = {
> + { "pca9685", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, pca9685_id);
> +
> +struct pca9685_led {
> + struct i2c_client *client;
> + struct work_struct work;
> + u16 brightness;
> + struct led_classdev led_cdev;
> + int led_num; /* 0-15 */
> + char name[32];
> +};
> +
> +static void pca9685_write_msg(struct i2c_client *client, u8 *buf, u8 len)
> +{
> + struct i2c_msg msg = {
> + .addr = client->addr,
> + .flags = 0x00,
> + .len = len,
> + .buf = buf
> + };
> + i2c_transfer(client->adapter, &msg, 1);
> +}
> +
> +static void pca9685_all_off(struct i2c_client *client)
> +{
> + u8 i2c_buffer[5] = {PCA9685_ALL_LED_ON_L, 0x00, 0x00, 0x00, 0x10};
> + pca9685_write_msg(client, i2c_buffer, 5);
> +}
> +
> +static void pca9685_led_work(struct work_struct *work)
> +{
> + struct pca9685_led *pca9685;
> + u16 brightness;
> + u8 i2c_buffer[5];
> + pca9685 = container_of(work, struct pca9685_led, work);
> + /*
> + * 4095 is the maximum brightness, so we set the ON time to 0x1000
> + * which disables the PWM generator for that LED
> + */
> + if (pca9685->brightness == 4095)
> + brightness = 4096;
why not check for 4095 instead of 4096 below and save this if statement?
> + else
> + brightness = pca9685->brightness;
> +
> + i2c_buffer[0] = PCA9685_LED0_ON_L + 4 * pca9685->led_num;
> +
> + if (brightness == 4096)
> + *((u16 *)(i2c_buffer+1)) = cpu_to_le16(0x1000);
> + else
> + *((u16 *)(i2c_buffer+1)) = 0x0000;
> + if (brightness == 0)
> + *((u16 *)(i2c_buffer+3)) = cpu_to_le16(0x1000);
> + else if (brightness == 4096)
> + *((u16 *)(i2c_buffer+3)) = 0x0000;
> + else
> + *((u16 *)(i2c_buffer+3)) = cpu_to_le16(brightness);
> +
> + pca9685_write_msg(pca9685->client, i2c_buffer, 5);
> +}
> +
> +static void pca9685_led_set(struct led_classdev *led_cdev,
> + enum led_brightness value)
> +{
> + struct pca9685_led *pca9685;
> + pca9685 = container_of(led_cdev, struct pca9685_led, led_cdev);
> + pca9685->brightness = value;
> +
> + schedule_work(&pca9685->work);
> +}
> +
> +static int pca9685_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct pca9685_led *pca9685;
> + struct pca9685_platform_data *pdata;
> + int err;
> + u8 i;
> +
> + pdata = dev_get_platdata(&client->dev);
> +
> + if (pdata) {
> + if (pdata->leds.num_leds < 1 || pdata->leds.num_leds > 15) {
> + dev_err(&client->dev, "board info must claim 1-16 LEDs");
> + return -EINVAL;
> + }
> + }
> +
> + pca9685 = devm_kzalloc(&client->dev, 16 * sizeof(*pca9685), GFP_KERNEL);
> +
> + if (!pca9685)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, pca9685);
> + pca9685_all_off(client);
> +
> + for (i = 0; i < 16; i++) {
> + pca9685[i].client = client;
> + pca9685[i].led_num = i;
> + pca9685[i].name[0] = '\0';
> + if (pdata && i < pdata->leds.num_leds) {
> + if (pdata->leds.leds[i].name)
> + strncpy(pca9685[i].name,
> + pdata->leds.leds[i].name,
> + sizeof(pca9685[i].name)-1);
> + if (pdata->leds.leds[i].default_trigger)
> + pca9685[i].led_cdev.default_trigger =
> + pdata->leds.leds[i].default_trigger;
> + }
> + if (strlen(pca9685[i].name) == 0) {
> + /*
> + * Write adapter and address to the name as well.
> + * Otherwise multiple chips attached to one host would
> + * not work.
> + */
> + snprintf(pca9685[i].name, sizeof(pca9685[i].name),
> + "pca9685:%d:x%.2x:%d",
> + client->adapter->nr, client->addr, i);
> + }
> + pca9685[i].led_cdev.name = pca9685[i].name;
> + pca9685[i].led_cdev.max_brightness = 0xfff;
> + pca9685[i].led_cdev.brightness_set = pca9685_led_set;
> +
> + INIT_WORK(&pca9685[i].work, pca9685_led_work);
> + err = led_classdev_register(&client->dev, &pca9685[i].led_cdev);
> + if (err < 0)
> + goto exit;
> + }
> + if (pdata)
> + i2c_smbus_write_byte_data(client, PCA9685_MODE2,
> + pdata->outdrv << PCA9685_OUTDRV |
> + pdata->inverted << PCA9685_INVRT);
> + else
> + i2c_smbus_write_byte_data(client, PCA9685_MODE2,
> + PCA9685_TOTEM_POLE << PCA9685_OUTDRV);
> + /* Enable Auto-Increment, enable oscillator, ALLCALL/SUBADDR disabled */
> + i2c_smbus_write_byte_data(client, PCA9685_MODE1, 1 << PCA9685_AI);
maybe BIT(PCA9685_AI)
> +
> + return 0;
> +
> +exit:
> + while (i--) {
> + led_classdev_unregister(&pca9685[i].led_cdev);
> + cancel_work_sync(&pca9685[i].work);
> + }
> + return err;
> +}
> +
> +static int pca9685_remove(struct i2c_client *client)
> +{
> + struct pca9685_led *pca9685 = i2c_get_clientdata(client);
> + u8 i;
> +
> + for (i = 0; i < 16; i++) {
> + led_classdev_unregister(&pca9685[i].led_cdev);
> + cancel_work_sync(&pca9685[i].work);
> + }
> + pca9685_all_off(client);
> + return 0;
> +}
> +
> +static struct i2c_driver pca9685_driver = {
> + .driver = {
> + .name = "leds-pca9685",
> + .owner = THIS_MODULE,
> + },
> + .probe = pca9685_probe,
> + .remove = pca9685_remove,
> + .id_table = pca9685_id,
> +};
> +
> +module_i2c_driver(pca9685_driver);
> +
> +MODULE_AUTHOR("Maximilian Güntner <maximilian.guentner@...il.com>");
> +MODULE_DESCRIPTION("PCA9685 LED Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/platform_data/leds-pca9685.h b/include/linux/platform_data/leds-pca9685.h
> new file mode 100644
> index 0000000..cce28b8
> --- /dev/null
> +++ b/include/linux/platform_data/leds-pca9685.h
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright 2013 Maximilian Güntner <maximilian.guentner@...il.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.
> + *
> + * Based on leds-pca963x.h by Peter Meerwald <p.meerwald@...-electronic.com>
> + *
> + * LED driver for the NXP PCA9685 PWM chip
> + *
> + */
> +
> +#ifndef __LINUX_PCA9685_H
> +#define __LINUX_PCA9685_H
> +#include <linux/leds.h>
> +
> +enum pca9685_outdrv {
> + PCA9685_OPEN_DRAIN,
> + PCA9685_TOTEM_POLE,
> +};
> +
> +enum pca9685_inverted {
> + PCA9685_NOT_INVERTED,
> + PCA9685_INVERTED,
> +};
> +
> +struct pca9685_platform_data {
> + struct led_platform_data leds;
> + enum pca9685_outdrv outdrv;
> + enum pca9685_inverted inverted;
> +};
> +
> +#endif /* __LINUX_PCA9685_H */
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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