Re: [PATCH v3] leds: Added driver for the NXP PCA9685 I2C chip

[Bryan Wu]

On Wed, Oct 16, 2013 at 6:09 PM, Maximilian Güntner
<maximilian.guentner@xxxxxxxxx> wrote:
> The NXP PCA9685 supports 16 channels/leds using a 12-bit PWM (4095
> levels of brightness)
> This driver supports configuration using platform_data.
>
> Signed-off-by: Maximilian Güntner <maximilian.guentner@xxxxxxxxx>
> ---
>  v3:
>    fixed warnings when running make C=1 CF=-D__CHECK_ENDIAN__:
>     * replaced u16* by __le16*
>

OK, replaced the old one in my tree.

Thanks,
-Bryan

>  v2:
>    addresses bryan wu's comments:
>     * removed/added some empty lines
>    addresses peter meerwald's comments:
>     * fixed typos
>     * replaced/moved one if statement
>     * replaced (1 << pca9685_ai) with bit(pca9685_ai)
>    addresses jingoo han's comments:
>     * added an empty line
>     * sorted the header inclusions alphabetically
>
>  drivers/leds/Kconfig                       |  10 ++
>  drivers/leds/Makefile                      |   1 +
>  drivers/leds/leds-pca9685.c                | 213 +++++++++++++++++++++++++++++
>  include/linux/platform_data/leds-pca9685.h |  35 +++++
>  4 files changed, 259 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..72156c1 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 chip accessed via the I2C bus.
> +         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..6e1ef3a
> --- /dev/null
> +++ b/drivers/leds/leds-pca9685.c
> @@ -0,0 +1,213 @@
> +/*
> + * Copyright 2013 Maximilian Güntner <maximilian.guentner@xxxxxxxxx>
> + *
> + * 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@xxxxxxxxxxxxxxxxxx>
> + *
> + * Driver for the NXP PCA9685 12-Bit PWM LED driver chip.
> + *
> + */
> +
> +#include <linux/ctype.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/workqueue.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;
> +       u8 i2c_buffer[5];
> +
> +       pca9685 = container_of(work, struct pca9685_led, work);
> +       i2c_buffer[0] = PCA9685_LED0_ON_L + 4 * pca9685->led_num;
> +       /*
> +        * 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)
> +               *((__le16 *)(i2c_buffer+1)) = cpu_to_le16(0x1000);
> +       else
> +               *((__le16 *)(i2c_buffer+1)) = 0x0000;
> +
> +       if (pca9685->brightness == 0)
> +               *((__le16 *)(i2c_buffer+3)) = cpu_to_le16(0x1000);
> +       else if (pca9685->brightness == 4095)
> +               *((__le16 *)(i2c_buffer+3)) = 0x0000;
> +       else
> +               *((__le16 *)(i2c_buffer+3)) = cpu_to_le16(pca9685->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, 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@xxxxxxxxx>");
> +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..778e9e4
> --- /dev/null
> +++ b/include/linux/platform_data/leds-pca9685.h
> @@ -0,0 +1,35 @@
> +/*
> + * Copyright 2013 Maximilian Güntner <maximilian.guentner@xxxxxxxxx>
> + *
> + * 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@xxxxxxxxxxxxxxxxxx>
> + *
> + * 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 */
> --
> 1.8.4
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/