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

[Gyungoh Yoo <gyungoh@gmail.com>]

On Mon, Oct 27, 2014 at 12:35:36PM +0530, Varka Bhadram wrote:
> 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.
> 

Oops. I missed them. I will re-submit.
Thank you for the comment.