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

From: Varka Bhadram
Date: Mon Oct 27 2014 - 03:08:45 EST


On 10/27/2014 12:32 PM, gyungoh@xxxxxxxxx wrote:
From: Gyungoh Yoo <jack.yoo@xxxxxxxxxxxxxxx>

Signed-off-by: Gyungoh Yoo <jack.yoo@xxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxxx>
+ *
+ * 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.

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