[PATCH 6/6] leds: add new lp8788 led driver

[PATCH 6/6] leds: add new lp8788 led driver

[Kim, Milo]

TI LP8788 PMU has the current sink as the keyboard led driver.
The brightness is controlled by the i2c commands.
Configurable parameters can be defined in the platform side.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
---
 drivers/leds/Kconfig       |    7 ++
 drivers/leds/Makefile      |    1 +
 drivers/leds/leds-lp8788.c |  178 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 186 insertions(+), 0 deletions(-)
 create mode 100644 drivers/leds/leds-lp8788.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index f028f03..a498deb 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -200,6 +200,13 @@ config LEDS_LP5523
 	  Driver provides direct control via LED class and interface for
 	  programming the engines.
 
+config LEDS_LP8788
+	tristate "LED support for the TI LP8788 PMIC"
+	depends on LEDS_CLASS
+	depends on MFD_LP8788
+	help
+	  This option enables support for the Keyboard LEDs on the LP8788 PMIC.
+
 config LEDS_CLEVO_MAIL
 	tristate "Mail LED on Clevo notebook"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 5eebd7b..f156193 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_LEDS_GPIO)			+= leds-gpio.o
 obj-$(CONFIG_LEDS_LP3944)		+= leds-lp3944.o
 obj-$(CONFIG_LEDS_LP5521)		+= leds-lp5521.o
 obj-$(CONFIG_LEDS_LP5523)		+= leds-lp5523.o
+obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
 obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
 obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
diff --git a/drivers/leds/leds-lp8788.c b/drivers/leds/leds-lp8788.c
new file mode 100644
index 0000000..d92625e
--- /dev/null
+++ b/drivers/leds/leds-lp8788.c
@@ -0,0 +1,178 @@
+/*
+ * TI LP8788 MFD - keyled driver
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/mfd/lp8788.h>
+#include <linux/mfd/lp8788-isink.h>
+
+#define MAX_BRIGHTNESS			LP8788_ISINK_MAX_PWM
+#define DEFAULT_LED_NAME		"keyboard-backlight"
+#define DEFAULT_ISINK_SCALE		LP8788_ISINK_SCALE_100mA
+#define DEFAULT_ISINK_NUM		LP8788_ISINK_3
+#define DEFAULT_ISINK_OUT		0
+
+struct lp8788_led {
+	struct lp8788 *lp;
+	struct led_classdev led_dev;
+	enum lp8788_isink_number isink_num;
+	int on;
+};
+
+static int lp8788_led_init_device(struct lp8788_led *led,
+				struct lp8788_led_platform_data *pdata)
+{
+	enum lp8788_isink_scale scale = DEFAULT_ISINK_SCALE;
+	enum lp8788_isink_number num = DEFAULT_ISINK_NUM;
+	int ret, iout = DEFAULT_ISINK_OUT;
+	u8 addr, mask, val;
+
+	if (pdata) {
+		scale = pdata->scale;
+		num = pdata->num;
+		iout = pdata->iout_code;
+	}
+
+	led->isink_num = num;
+
+	/* scale configuration */
+	addr = LP8788_ISINK_CTRL;
+	mask = 1 << (num + LP8788_ISINK_SCALE_OFFSET);
+	val = scale << num;
+	ret = lp8788_update_bits(led->lp, addr, mask, val);
+	if (ret)
+		return ret;
+
+	/* current configuration */
+	addr = lp8788_iout_addr[num];
+	mask = lp8788_iout_mask[num];
+	val = iout;
+
+	return lp8788_update_bits(led->lp, addr, mask, val);
+}
+
+static void lp8788_led_enable(struct lp8788_led *led,
+			enum lp8788_isink_number num, int on)
+{
+	u8 mask = 1 << num;
+	u8 val = on << num;
+
+	if (lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val))
+		return;
+
+	led->on = on;
+}
+
+static void lp8788_brightness_set(struct led_classdev *led_cdev,
+				enum led_brightness brt_val)
+{
+	struct lp8788_led *led =
+			container_of(led_cdev, struct lp8788_led, led_dev);
+	enum lp8788_isink_number num = led->isink_num;
+	int enable;
+
+	switch (num) {
+	case LP8788_ISINK_1:
+	case LP8788_ISINK_2:
+	case LP8788_ISINK_3:
+		lp8788_write_byte(led->lp, lp8788_pwm_addr[num], brt_val);
+		break;
+	default:
+		return;
+	}
+
+	enable = (brt_val > 0) ? 1 : 0;
+
+	if (enable != led->on)
+		lp8788_led_enable(led, num, enable);
+}
+
+static __devinit int lp8788_led_probe(struct platform_device *pdev)
+{
+	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
+	struct lp8788_led_platform_data *led_pdata;
+	struct lp8788_led *led;
+	int ret;
+
+	led = devm_kzalloc(lp->dev, sizeof(struct lp8788_led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->lp = lp;
+	led->led_dev.max_brightness = MAX_BRIGHTNESS;
+	led->led_dev.brightness_set = lp8788_brightness_set;
+
+	led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
+
+	if (!led_pdata || !led_pdata->name)
+		led->led_dev.name = DEFAULT_LED_NAME;
+	else
+		led->led_dev.name = led_pdata->name;
+
+	platform_set_drvdata(pdev, led);
+
+	ret = lp8788_led_init_device(led, led_pdata);
+	if (ret) {
+		dev_err(lp->dev, "led init device err: %d\n", ret);
+		goto err_dev;
+	}
+
+	ret = led_classdev_register(lp->dev, &led->led_dev);
+	if (ret) {
+		dev_err(lp->dev, "led register err: %d\n", ret);
+		goto err_dev;
+	}
+
+	return 0;
+
+err_dev:
+	return ret;
+}
+
+static int __devexit lp8788_led_remove(struct platform_device *pdev)
+{
+	struct lp8788_led *led = platform_get_drvdata(pdev);
+
+	led_classdev_unregister(&led->led_dev);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static struct platform_driver lp8788_led_driver = {
+	.probe = lp8788_led_probe,
+	.remove = __devexit_p(lp8788_led_remove),
+	.driver = {
+		.name = LP8788_DEV_KEYLED,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init lp8788_led_init(void)
+{
+	return platform_driver_register(&lp8788_led_driver);
+}
+module_init(lp8788_led_init);
+
+static void __exit lp8788_led_exit(void)
+{
+	platform_driver_unregister(&lp8788_led_driver);
+}
+module_exit(lp8788_led_exit);
+
+MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lp8788-keyled");
-- 
1.7.2.5


Best Regards,
Milo

Re: [PATCH 6/6] leds: add new lp8788 led driver

[Mark Brown]

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On Wed, Jul 18, 2012 at 02:34:02PM +0000, Kim, Milo wrote:

> +static void lp8788_brightness_set(struct led_classdev *led_cdev,
> +				enum led_brightness brt_val)
> +{
> +	struct lp8788_led *led =
> +			container_of(led_cdev, struct lp8788_led, led_dev);
> +	enum lp8788_isink_number num = led->isink_num;
> +	int enable;
> +
> +	switch (num) {
> +	case LP8788_ISINK_1:
> +	case LP8788_ISINK_2:
> +	case LP8788_ISINK_3:
> +		lp8788_write_byte(led->lp, lp8788_pwm_addr[num], brt_val);

The brightness_set() (and other) callbacks can be called from atomic
context so you can't interact with an I2C device here, you need to
defer to a workqueue or something (and ideally factor this out into the
framework so we don't need to keep open coding it...).

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Re: [PATCH 6/6] leds: add new lp8788 led driver

[Bryan Wu]

On Wed, Jul 18, 2012 at 10:34 PM, Kim, Milo <Milo.Kim@ti.com> wrote:
> TI LP8788 PMU has the current sink as the keyboard led driver.
> The brightness is controlled by the i2c commands.
> Configurable parameters can be defined in the platform side.
>
> Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
> ---
>  drivers/leds/Kconfig       |    7 ++
>  drivers/leds/Makefile      |    1 +
>  drivers/leds/leds-lp8788.c |  178 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 186 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/leds/leds-lp8788.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index f028f03..a498deb 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -200,6 +200,13 @@ config LEDS_LP5523
>           Driver provides direct control via LED class and interface for
>           programming the engines.
>
> +config LEDS_LP8788
> +       tristate "LED support for the TI LP8788 PMIC"
> +       depends on LEDS_CLASS
> +       depends on MFD_LP8788
> +       help
> +         This option enables support for the Keyboard LEDs on the LP8788 PMIC.
> +
>  config LEDS_CLEVO_MAIL
>         tristate "Mail LED on Clevo notebook"
>         depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 5eebd7b..f156193 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_LEDS_GPIO)                       += leds-gpio.o
>  obj-$(CONFIG_LEDS_LP3944)              += leds-lp3944.o
>  obj-$(CONFIG_LEDS_LP5521)              += leds-lp5521.o
>  obj-$(CONFIG_LEDS_LP5523)              += leds-lp5523.o
> +obj-$(CONFIG_LEDS_LP8788)              += leds-lp8788.o
>  obj-$(CONFIG_LEDS_TCA6507)             += leds-tca6507.o
>  obj-$(CONFIG_LEDS_CLEVO_MAIL)          += leds-clevo-mail.o
>  obj-$(CONFIG_LEDS_HP6XX)               += leds-hp6xx.o
> diff --git a/drivers/leds/leds-lp8788.c b/drivers/leds/leds-lp8788.c
> new file mode 100644
> index 0000000..d92625e
> --- /dev/null
> +++ b/drivers/leds/leds-lp8788.c
> @@ -0,0 +1,178 @@
> +/*
> + * TI LP8788 MFD - keyled driver
> + *
> + * Copyright 2012 Texas Instruments
> + *
> + * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
> + *
> + * 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.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/leds.h>
> +#include <linux/mfd/lp8788.h>
> +#include <linux/mfd/lp8788-isink.h>
> +
> +#define MAX_BRIGHTNESS                 LP8788_ISINK_MAX_PWM
> +#define DEFAULT_LED_NAME               "keyboard-backlight"
> +#define DEFAULT_ISINK_SCALE            LP8788_ISINK_SCALE_100mA
> +#define DEFAULT_ISINK_NUM              LP8788_ISINK_3
> +#define DEFAULT_ISINK_OUT              0
> +
> +struct lp8788_led {
> +       struct lp8788 *lp;
> +       struct led_classdev led_dev;
> +       enum lp8788_isink_number isink_num;
> +       int on;
> +};
> +
> +static int lp8788_led_init_device(struct lp8788_led *led,
> +                               struct lp8788_led_platform_data *pdata)
> +{
> +       enum lp8788_isink_scale scale = DEFAULT_ISINK_SCALE;
> +       enum lp8788_isink_number num = DEFAULT_ISINK_NUM;
> +       int ret, iout = DEFAULT_ISINK_OUT;
> +       u8 addr, mask, val;
> +
> +       if (pdata) {
> +               scale = pdata->scale;
> +               num = pdata->num;
> +               iout = pdata->iout_code;
> +       }
> +
> +       led->isink_num = num;
> +
> +       /* scale configuration */
> +       addr = LP8788_ISINK_CTRL;
> +       mask = 1 << (num + LP8788_ISINK_SCALE_OFFSET);
> +       val = scale << num;
> +       ret = lp8788_update_bits(led->lp, addr, mask, val);
> +       if (ret)
> +               return ret;
> +
> +       /* current configuration */
> +       addr = lp8788_iout_addr[num];
> +       mask = lp8788_iout_mask[num];
> +       val = iout;
> +
> +       return lp8788_update_bits(led->lp, addr, mask, val);
> +}
> +
> +static void lp8788_led_enable(struct lp8788_led *led,
> +                       enum lp8788_isink_number num, int on)
> +{
> +       u8 mask = 1 << num;
> +       u8 val = on << num;
> +
> +       if (lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val))
> +               return;
> +
> +       led->on = on;
> +}
> +
> +static void lp8788_brightness_set(struct led_classdev *led_cdev,
> +                               enum led_brightness brt_val)

    /* Must not sleep, use a workqueue if needed */
        void            (*brightness_set)(struct led_classdev *led_cdev,
                                          enum led_brightness brightness);

so you need to use workqueue here I believe, since this function will
call some i2c operations which might be sleep.

> +{
> +       struct lp8788_led *led =
> +                       container_of(led_cdev, struct lp8788_led, led_dev);
> +       enum lp8788_isink_number num = led->isink_num;
> +       int enable;
> +
> +       switch (num) {
> +       case LP8788_ISINK_1:
> +       case LP8788_ISINK_2:
> +       case LP8788_ISINK_3:
> +               lp8788_write_byte(led->lp, lp8788_pwm_addr[num], brt_val);
> +               break;
> +       default:
> +               return;
> +       }
> +
> +       enable = (brt_val > 0) ? 1 : 0;
> +
> +       if (enable != led->on)
> +               lp8788_led_enable(led, num, enable);

I think we need lock here to protect this kind of flag and low level
resource access. Please add mutex_lock()/mutex_unloc() here.

> +}
> +
> +static __devinit int lp8788_led_probe(struct platform_device *pdev)
> +{
> +       struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
> +       struct lp8788_led_platform_data *led_pdata;
> +       struct lp8788_led *led;
> +       int ret;
> +
> +       led = devm_kzalloc(lp->dev, sizeof(struct lp8788_led), GFP_KERNEL);
> +       if (!led)
> +               return -ENOMEM;
> +
> +       led->lp = lp;
> +       led->led_dev.max_brightness = MAX_BRIGHTNESS;
> +       led->led_dev.brightness_set = lp8788_brightness_set;
> +
> +       led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
> +
> +       if (!led_pdata || !led_pdata->name)
> +               led->led_dev.name = DEFAULT_LED_NAME;
> +       else
> +               led->led_dev.name = led_pdata->name;
> +
> +       platform_set_drvdata(pdev, led);
> +
> +       ret = lp8788_led_init_device(led, led_pdata);
> +       if (ret) {
> +               dev_err(lp->dev, "led init device err: %d\n", ret);
> +               goto err_dev;

you can just return ret here;

> +       }
> +
> +       ret = led_classdev_register(lp->dev, &led->led_dev);
> +       if (ret) {
> +               dev_err(lp->dev, "led register err: %d\n", ret);
> +               goto err_dev;

ditto

> +       }
> +
> +       return 0;
> +
> +err_dev:
> +       return ret;

Then we don't need this here.
> +}
> +
> +static int __devexit lp8788_led_remove(struct platform_device *pdev)
> +{
> +       struct lp8788_led *led = platform_get_drvdata(pdev);
> +
> +       led_classdev_unregister(&led->led_dev);
> +       platform_set_drvdata(pdev, NULL);

Actually this line is unnecessary here.

> +       return 0;
> +}
> +
> +static struct platform_driver lp8788_led_driver = {
> +       .probe = lp8788_led_probe,
> +       .remove = __devexit_p(lp8788_led_remove),
> +       .driver = {
> +               .name = LP8788_DEV_KEYLED,
> +               .owner = THIS_MODULE,
> +       },
> +};
> +
> +static int __init lp8788_led_init(void)
> +{
> +       return platform_driver_register(&lp8788_led_driver);
> +}
> +module_init(lp8788_led_init);
> +
> +static void __exit lp8788_led_exit(void)
> +{
> +       platform_driver_unregister(&lp8788_led_driver);
> +}
> +module_exit(lp8788_led_exit);
> +

use module_platform_driver(), please


> +MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
> +MODULE_AUTHOR("Milo Kim");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:lp8788-keyled");
> --
> 1.7.2.5
>
>
> Best Regards,
> Milo
>
>


Thanks,
-- 
Bryan Wu <bryan.wu@canonical.com>
Kernel Developer    +86.186-168-78255 Mobile
Canonical Ltd.      www.canonical.com
Ubuntu - Linux for human beings | www.ubuntu.com

RE: [PATCH 6/6] leds: add new lp8788 led driver

[Kim, Milo]

> From: cooloney@gmail.com [mailto:cooloney@gmail.com] On Behalf Of Bryan
> Wu
> Sent: Friday, July 20, 2012 9:09 AM
> To: Kim, Milo
> Cc: linux-kernel@vger.kernel.org; sameo@linux.intel.com; Girdwood, Liam;
> Mark Brown; dwmw2@infradead.org; Anton Vorontsov; Richard Purdie;
> Andrew Morton; a.zummo@towertech.it
> Subject: Re: [PATCH 6/6] leds: add new lp8788 led driver

Thanks for your review !
All code have been updated and sent as 'PATCH v2'.

Title : [PATCH v2] leds: add new lp8788 led driver

Best Regards,
Milo