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

gyungoh
2014-10-27T07:03:26Z

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");
+ return ERR_PTR(-ENODATA);
+ }
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ of_node_put(np);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ of_property_read_string(np, "name", &pdata->name);
+ pdata->ignore_pwm = of_property_read_bool(np, "ignore-pwm");
+ pdata->dpwm_mode = of_property_read_bool(np, "dpwm-mode");
+ pdata->phase_shift = of_property_read_bool(np, "phase-shift");
+
+ pdata->gpio_enable = of_get_named_gpio(np, "gpio-enable", 0);
+ if (IS_ERR_VALUE(pdata->gpio_enable))
+ pdata->gpio_enable = -1;
+
+ ret = of_property_read_u32(np, "enable", &pdata->enable);
+ if (IS_ERR_VALUE(ret))
+ pdata->enable = SKY81452_EN >> CTZ(SKY81452_EN);
+
+ ret = of_property_read_u32(np, "short-detection-threshold",
+ &pdata->short_detection_threshold);
+ if (IS_ERR_VALUE(ret))
+ pdata->short_detection_threshold = 7;
+
+ ret = of_property_read_u32(np, "boost-current-limit",
+ &pdata->boost_current_limit);
+ if (IS_ERR_VALUE(ret))
+ pdata->boost_current_limit = 2750;
+
+ of_node_put(np);
+ return pdata;
+}
+#else
+static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
+ struct device *dev)
+{
+ return ERR_PTR(-EINVAL);
+}
+#endif
+
+static int sky81452_bl_init_device(struct regmap *regmap,
+ struct sky81452_bl_platform_data *pdata)
+{
+ unsigned int value;
+
+ value = pdata->ignore_pwm ? SKY81452_IGPW : 0;
+ value |= pdata->dpwm_mode ? SKY81452_PWMMD : 0;
+ value |= pdata->phase_shift ? 0 : SKY81452_PHASE;
+
+ if (pdata->boost_current_limit == 2300)
+ value |= SKY81452_ILIM;
+ else if (pdata->boost_current_limit != 2720)
+ return -EINVAL;
+
+ if (pdata->short_detection_threshold < 4 ||
+ pdata->short_detection_threshold > 7)
+ return -EINVAL;
+ value |= (7 - pdata->short_detection_threshold) << CTZ(SKY81452_VSHRT);
+
+ return regmap_write(regmap, SKY81452_REG2, value);
+}
+
+static int sky81452_bl_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct regmap *regmap = dev_get_drvdata(dev->parent);
+ struct sky81452_bl_platform_data *pdata = dev_get_platdata(dev);
+ struct backlight_device *bd;
+ struct backlight_properties props;
+ const char *name;
+ int ret;
+
+ if (!pdata) {
+ pdata = sky81452_bl_parse_dt(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ }
+
+ if (pdata->gpio_enable >= 0) {
+ ret = devm_gpio_request_one(dev, pdata->gpio_enable,
+ GPIOF_OUT_INIT_HIGH, "sky81452-en");
+ if (IS_ERR_VALUE(ret)) {
+ dev_err(dev, "failed to request GPIO. err=%d", ret);
+ return ret;
+ }
+ }
+
+ ret = sky81452_bl_init_device(regmap, pdata);
+ if (IS_ERR_VALUE(ret)) {
+ dev_err(dev, "failed to initialize. err=%d", ret);
+ return ret;
+ }
+
+ memset(&props, 0, sizeof(props));
+ props.max_brightness = SKY81452_MAX_BRIGHTNESS,
+ name = pdata->name ? pdata->name : SKY81452_DEFAULT_NAME;
+ bd = devm_backlight_device_register(dev, name, dev, regmap,
+ &sky81452_bl_ops, &props);
+ if (IS_ERR(bd)) {
+ dev_err(dev, "failed to register. err=%ld", PTR_ERR(bd));
+ return PTR_ERR(bd);
+ }
+
+ platform_set_drvdata(pdev, bd);
+
+ ret = sysfs_create_group(&bd->dev.kobj, &sky81452_bl_attr_group);
+ if (IS_ERR_VALUE(ret)) {
+ dev_err(dev, "failed to create attribute. err=%d", ret);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int sky81452_bl_remove(struct platform_device *pdev)
+{
+ const struct sky81452_bl_platform_data *pdata =
+ dev_get_platdata(&pdev->dev);
+ struct backlight_device *bd = platform_get_drvdata(pdev);
+
+ sysfs_remove_group(&bd->dev.kobj, &sky81452_bl_attr_group);
+
+ bd->props.power = FB_BLANK_UNBLANK;
+ bd->props.brightness = 0;
+ backlight_update_status(bd);
+
+ if (pdata->gpio_enable >= 0)
+ gpio_set_value_cansleep(pdata->gpio_enable, 0);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sky81452_bl_of_match[] = {
+ { .compatible = "skyworks,sky81452-backlight", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sky81452_bl_of_match);
+#endif
+
+static struct platform_driver sky81452_bl_driver = {
+ .driver = {
+ .name = "sky81452-backlight",
+ .of_match_table = of_match_ptr(sky81452_bl_of_match),
+ },
+ .probe = sky81452_bl_probe,
+ .remove = sky81452_bl_remove,
+};
+
+module_platform_driver(sky81452_bl_driver);
+
+MODULE_DESCRIPTION("Skyworks SKY81452 backlight driver");
+MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@skyworksinc.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/sky81452-backlight.h b/include/linux/platform_data/sky81452-backlight.h
new file mode 100644
index 0000000..b3635f9
--- /dev/null
+++ b/include/linux/platform_data/sky81452-backlight.h
@@ -0,0 +1,47 @@
+/*
+ * sky81452.h 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/>.
+ */
+
+#ifndef _SKY81452_BACKLIGHT_H
+#define _SKY81452_BACKLIGHT_H
+
+/**
+ * struct sky81452_platform_data
+ * @name: backlight driver name.
+ If it is not defined, default name is lcd-backlight.
+ * @gpio_enable:GPIO number which control EN pin
+ * @enable: Enable mask for current sink channel 1, 2, 3, 4, 5 and 6.
+ * @ignore_pwm: true if DPWMI should be ignored.
+ * @dpwm_mode: true is DPWM dimming mode, otherwise Analog dimming mode.
+ * @phase_shift:true is phase shift mode.
+ * @short_detecion_threshold: It should be one of 4, 5, 6 and 7V.
+ * @boost_current_limit: It should be one of 2300, 2750mA.
+ */
+struct sky81452_bl_platform_data {
+ const char *name;
+ int gpio_enable;
+ unsigned int enable;
+ bool ignore_pwm;
+ bool dpwm_mode;
+ bool phase_shift;
+ unsigned int short_detection_threshold;
+ unsigned int boost_current_limit;
+};
+
+#endif
--
1.9.1