Re: [RESUBMIT PATCH v5 2/8] backlight: Add support Skyworks SKY81452 backlight driver

Varka Bhadram
2014-10-27T07:08:42Z

On 10/27/2014 12:32 PM, gyungoh@gmail.com wrote:
> From: Gyungoh Yoo <jack.yoo@skyworksinc.com>
>
> Signed-off-by: Gyungoh Yoo <jack.yoo@skyworksinc.com>
> ---
> Changes v5:
> Move sky81452-backlight.h to include/linux/platform_data
>
> Changes v4:
> Reordering header files for readability
> Removed calling to backlight_device_unregister()
> Removed MODULE_VERSION()
> Modified license to GPLv2
>
> Changes v3:
> Modified DBG messages
>
> Changes v2:
> Added 'compatible' attribute in the driver
> Added message for exception or errors
>
> drivers/video/backlight/Kconfig | 10 +
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/sky81452-backlight.c | 344 +++++++++++++++++++++++
> include/linux/platform_data/sky81452-backlight.h | 47 ++++
> 4 files changed, 402 insertions(+)
> create mode 100644 drivers/video/backlight/sky81452-backlight.c
> create mode 100644 include/linux/platform_data/sky81452-backlight.h
>
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 8d03924..2586fdd 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -409,6 +409,16 @@ config BACKLIGHT_PANDORA
> If you have a Pandora console, say Y to enable the
> backlight driver.
>
> +config BACKLIGHT_SKY81452
> + tristate "Backlight driver for SKY81452"
> + depends on BACKLIGHT_CLASS_DEVICE && MFD_SKY81452
> + help
> + If you have a Skyworks SKY81452, say Y to enable the
> + backlight driver.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called sky81452-backlight
> +
> config BACKLIGHT_TPS65217
> tristate "TPS65217 Backlight"
> depends on BACKLIGHT_CLASS_DEVICE && MFD_TPS65217
> diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> index fcd50b73..d67073f 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -50,6 +50,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o
> obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o
> obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o
> obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o
> +obj-$(CONFIG_BACKLIGHT_SKY81452) += sky81452-backlight.o
> obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o
> obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o
> obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o
> diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
> new file mode 100644
> index 0000000..a677be6
> --- /dev/null
> +++ b/drivers/video/backlight/sky81452-backlight.c
> @@ -0,0 +1,344 @@
> +/*
> + * sky81452-backlight.c SKY81452 backlight driver
> + *
> + * Copyright 2014 Skyworks Solutions Inc.
> + * Author : Gyungoh Yoo <jack.yoo@skyworksinc.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2, or (at your option) any
> + * later version.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/err.h>
> +#include <linux/gpio.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/platform_data/sky81452-backlight.h>
> +#include <linux/slab.h>
> +
> +/* registers */
> +#define SKY81452_REG0 0x00
> +#define SKY81452_REG1 0x01
> +#define SKY81452_REG2 0x02
> +#define SKY81452_REG4 0x04
> +#define SKY81452_REG5 0x05
> +
> +/* bit mask */
> +#define SKY81452_CS 0xFF
> +#define SKY81452_EN 0x3F
> +#define SKY81452_IGPW 0x20
> +#define SKY81452_PWMMD 0x10
> +#define SKY81452_PHASE 0x08
> +#define SKY81452_ILIM 0x04
> +#define SKY81452_VSHRT 0x03
> +#define SKY81452_OCP 0x80
> +#define SKY81452_OTMP 0x40
> +#define SKY81452_SHRT 0x3F
> +#define SKY81452_OPN 0x3F
> +
> +#define SKY81452_DEFAULT_NAME "lcd-backlight"
> +#define SKY81452_MAX_BRIGHTNESS (SKY81452_CS + 1)
> +
> +#define CTZ(b) __builtin_ctz(b)
> +
> +static int sky81452_bl_update_status(struct backlight_device *bd)
> +{
> + const struct sky81452_bl_platform_data *pdata =
> + dev_get_platdata(bd->dev.parent);
> + const unsigned int brightness = (unsigned int)bd->props.brightness;
> + struct regmap *regmap = bl_get_data(bd);
> + int ret;
> +
> + if (brightness > 0) {
> + ret = regmap_write(regmap, SKY81452_REG0, brightness - 1);
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
> + pdata->enable << CTZ(SKY81452_EN));
> + }
> +
> + return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, 0);
> +}
> +
> +static int sky81452_bl_get_brightness(struct backlight_device *bd)
> +{
> + return bd->props.brightness;
> +}
> +
> +static const struct backlight_ops sky81452_bl_ops = {
> + .update_status = sky81452_bl_update_status,
> + .get_brightness = sky81452_bl_get_brightness,
> +};
> +
> +static ssize_t sky81452_bl_store_enable(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct regmap *regmap = bl_get_data(to_backlight_device(dev));
> + unsigned long value;
> + int ret;
> +
> + ret = kstrtoul(buf, 16, &value);
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + ret = regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
> + value << CTZ(SKY81452_EN));
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + return count;
> +}
> +
> +static ssize_t sky81452_bl_show_open_short(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct regmap *regmap = bl_get_data(to_backlight_device(dev));
> + unsigned int reg, value = 0;
> + char tmp[3];
> + int i, ret;
> +
> + reg = !strcmp(attr->attr.name, "open") ? SKY81452_REG5 : SKY81452_REG4;
> + ret = regmap_read(regmap, reg, &value);
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + if (value & SKY81452_SHRT) {
> + *buf = 0;
> + for (i = 0; i < 6; i++) {
> + if (value & 0x01) {
> + sprintf(tmp, "%d ", i + 1);
> + strcat(buf, tmp);
> + }
> + value >>= 1;
> + }
> + strcat(buf, "\n");
> + } else {
> + strcpy(buf, "none\n");
> + }
> +
> + return strlen(buf);
> +}
> +
> +static ssize_t sky81452_bl_show_fault(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct regmap *regmap = bl_get_data(to_backlight_device(dev));
> + unsigned int value = 0;
> + int ret;
> +
> + ret = regmap_read(regmap, SKY81452_REG4, &value);
> + if (IS_ERR_VALUE(ret))
> + return ret;
> +
> + *buf = 0;
> +
> + if (value & SKY81452_OCP)
> + strcat(buf, "over-current ");
> +
> + if (value & SKY81452_OTMP)
> + strcat(buf, "over-temperature");
> +
> + strcat(buf, "\n");
> + return strlen(buf);
> +}
> +
> +static DEVICE_ATTR(enable, S_IWGRP | S_IWUSR, NULL, sky81452_bl_store_enable);
> +static DEVICE_ATTR(open, S_IRUGO, sky81452_bl_show_open_short, NULL);
> +static DEVICE_ATTR(short, S_IRUGO, sky81452_bl_show_open_short, NULL);
> +static DEVICE_ATTR(fault, S_IRUGO, sky81452_bl_show_fault, NULL);
> +
> +static struct attribute *sky81452_bl_attribute[] = {
> + &dev_attr_enable.attr,
> + &dev_attr_open.attr,
> + &dev_attr_short.attr,
> + &dev_attr_fault.attr,
> + NULL
> +};
> +
> +static const struct attribute_group sky81452_bl_attr_group = {
> + .attrs = sky81452_bl_attribute,
> +};
> +
> +#ifdef CONFIG_OF
> +static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
> + struct device *dev)
> +{
> + struct device_node *np = of_node_get(dev->of_node);
> + struct sky81452_bl_platform_data *pdata;
> + int ret;
> +
> + if (!np) {
> + dev_err(dev, "backlight node not found");

Missed terminating new line all over the driver for debug error messages..

--
Regards,
Varka Bhadram.