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Message-ID: <CAK5ve-LQ5wL+LDk0NBtqDM5bA7tA8geFUZ34SfWUzs2ZTrQguw@mail.gmail.com>
Date: Fri, 20 Jul 2012 08:08:41 +0800
From: Bryan Wu <bryan.wu@...onical.com>
To: "Kim, Milo" <Milo.Kim@...com>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"sameo@...ux.intel.com" <sameo@...ux.intel.com>,
"Girdwood, Liam" <lrg@...com>,
Mark Brown <broonie@...nsource.wolfsonmicro.com>,
"dwmw2@...radead.org" <dwmw2@...radead.org>,
Anton Vorontsov <cbouatmailru@...il.com>,
Richard Purdie <rpurdie@...ys.net>,
Andrew Morton <akpm@...ux-foundation.org>,
"a.zummo@...ertech.it" <a.zummo@...ertech.it>
Subject: Re: [PATCH 6/6] leds: add new lp8788 led driver
On Wed, Jul 18, 2012 at 10:34 PM, Kim, Milo <Milo.Kim@...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@...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@...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@...onical.com>
Kernel Developer +86.186-168-78255 Mobile
Canonical Ltd. www.canonical.com
Ubuntu - Linux for human beings | www.ubuntu.com
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