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Message-ID: <A874F61F95741C4A9BA573A70FE3998FD7D6@DQHE02.ent.ti.com>
Date: Wed, 18 Jul 2012 14:33:47 +0000
From: "Kim, Milo" <Milo.Kim@...com>
To: Andrew Morton <akpm@...ux-foundation.org>
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>,
Bryan Wu <bryan.wu@...onical.com>,
"a.zummo@...ertech.it" <a.zummo@...ertech.it>
Subject: [PATCH 5/6] backlight: add new lp8788 backlight driver
TI LP8788 PMU has the backlight driver.
The brightness can be controlled by the PWM or the I2C commands.
Configurable parameters can be defined in the platform data.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@...com>
---
drivers/video/backlight/Kconfig | 6 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/lp8788_bl.c | 325 +++++++++++++++++++++++++++++++++++
3 files changed, 332 insertions(+), 0 deletions(-)
create mode 100644 drivers/video/backlight/lp8788_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index cf28276..6fe0231 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -359,6 +359,12 @@ config BACKLIGHT_LP855X
This supports TI LP8550, LP8551, LP8552, LP8553 and LP8556
backlight driver.
+config BACKLIGHT_LP8788
+ tristate "Backlight driver for TI LP8788 MFD"
+ depends on BACKLIGHT_CLASS_DEVICE && MFD_LP8788
+ help
+ This supports TI LP8788 backlight driver.
+
config BACKLIGHT_OT200
tristate "Backlight driver for ot200 visualisation device"
depends on BACKLIGHT_CLASS_DEVICE && CS5535_MFGPT && GPIO_CS5535
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index a2ac9cf..f8cc7cb 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
+obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o
obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o
obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o
obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
diff --git a/drivers/video/backlight/lp8788_bl.c b/drivers/video/backlight/lp8788_bl.c
new file mode 100644
index 0000000..1c803ad
--- /dev/null
+++ b/drivers/video/backlight/lp8788_bl.c
@@ -0,0 +1,325 @@
+/*
+ * TI LP8788 MFD - backlight 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/backlight.h>
+#include <linux/mfd/lp8788.h>
+
+/* register address */
+#define LP8788_BL_CONFIG 0x96
+#define LP8788_BL_BRIGHTNESS 0x97
+#define LP8788_BL_RAMP 0x98
+
+/* mask/shift bits */
+#define LP8788_BL_I2C_EN BIT(0) /* Addr 96h */
+#define LP8788_BL_PWM_EN BIT(5)
+#define LP8788_BL_FULLSCALE_S 2
+#define LP8788_BL_DIM_MODE_S 1
+#define LP8788_BL_PWM_POLARITY_S 6
+#define LP8788_BL_RAMP_RISE_S 4 /* Addr 98h */
+
+#define BUF_SIZE 20
+#define MAX_BRIGHTNESS 127
+#define DEFAULT_BL_NAME "lcd-backlight"
+
+struct lp8788_bl_config {
+ enum lp8788_bl_ctrl_mode bl_mode;
+ enum lp8788_bl_dim_mode dim_mode;
+ enum lp8788_bl_full_scale_current full_scale;
+ enum lp8788_bl_ramp_step rise_time;
+ enum lp8788_bl_ramp_step fall_time;
+ enum lp8788_bl_pwm_polarity pwm_pol;
+};
+
+struct lp8788_bl {
+ struct lp8788 *lp;
+ struct backlight_device *bl_dev;
+ struct lp8788_backlight_platform_data *pdata;
+ enum lp8788_bl_ctrl_mode mode;
+};
+
+struct lp8788_bl_config default_bl_config = {
+ .bl_mode = LP8788_BL_REGISTER_ONLY,
+ .dim_mode = LP8788_DIM_EXPONENTIAL,
+ .full_scale = LP8788_FULLSCALE_1900uA,
+ .rise_time = LP8788_RAMP_8192us,
+ .fall_time = LP8788_RAMP_8192us,
+ .pwm_pol = LP8788_PWM_ACTIVE_HIGH,
+};
+
+static inline bool is_brightness_ctrl_by_pwm(enum lp8788_bl_ctrl_mode mode)
+{
+ return (mode == LP8788_BL_COMB_PWM_BASED);
+}
+
+static inline bool is_brightness_ctrl_by_register(enum lp8788_bl_ctrl_mode mode)
+{
+ return (mode == LP8788_BL_REGISTER_ONLY ||
+ mode == LP8788_BL_COMB_REGISTER_BASED);
+}
+
+static int lp8788_backlight_init_device(struct lp8788_bl *bl)
+{
+ struct lp8788_backlight_platform_data *pdata = bl->pdata;
+ struct lp8788_bl_config *cfg = &default_bl_config;
+ int ret;
+ u8 val;
+
+ /* update if platform data exists */
+ if (pdata) {
+ cfg->bl_mode = pdata->bl_mode;
+ cfg->dim_mode = pdata->dim_mode;
+ cfg->full_scale = pdata->full_scale;
+ cfg->rise_time = pdata->rise_time;
+ cfg->fall_time = pdata->fall_time;
+ cfg->pwm_pol = pdata->pwm_pol;
+ }
+
+ val = (cfg->rise_time << LP8788_BL_RAMP_RISE_S) | cfg->fall_time;
+ ret = lp8788_write_byte(bl->lp, LP8788_BL_RAMP, val);
+ if (ret)
+ return ret;
+
+ val = (cfg->full_scale << LP8788_BL_FULLSCALE_S) |
+ (cfg->dim_mode << LP8788_BL_DIM_MODE_S);
+
+ switch (cfg->bl_mode) {
+ case LP8788_BL_REGISTER_ONLY:
+ val |= LP8788_BL_I2C_EN;
+ break;
+ case LP8788_BL_COMB_PWM_BASED:
+ case LP8788_BL_COMB_REGISTER_BASED:
+ val |= LP8788_BL_I2C_EN;
+ val |= LP8788_BL_PWM_EN;
+ val |= cfg->pwm_pol << LP8788_BL_PWM_POLARITY_S;
+ break;
+ default:
+ dev_err(bl->lp->dev, "invalid mode: %d\n", cfg->bl_mode);
+ return -EINVAL;
+ }
+
+ bl->mode = cfg->bl_mode;
+
+ return lp8788_write_byte(bl->lp, LP8788_BL_CONFIG, val);
+}
+
+static int lp8788_bl_update_status(struct backlight_device *bl_dev)
+{
+ struct lp8788_bl *bl = bl_get_data(bl_dev);
+ enum lp8788_bl_ctrl_mode mode = bl->mode;
+
+ if (bl_dev->props.state & BL_CORE_SUSPENDED)
+ bl_dev->props.brightness = 0;
+
+ if (is_brightness_ctrl_by_pwm(mode)) {
+ struct lp8788_bl_pwm_data *pd;
+ int brt = bl_dev->props.brightness;
+ int max = bl_dev->props.max_brightness;
+
+ pd = bl->pdata ? &bl->pdata->pwm_data : NULL;
+ if (pd && pd->pwm_set_intensity)
+ pd->pwm_set_intensity(brt, max);
+ } else if (is_brightness_ctrl_by_register(mode)) {
+ u8 brt = bl_dev->props.brightness;
+
+ lp8788_write_byte(bl->lp, LP8788_BL_BRIGHTNESS, brt);
+ }
+
+ return 0;
+}
+
+static int lp8788_bl_get_brightness(struct backlight_device *bl_dev)
+{
+ struct lp8788_bl *bl = bl_get_data(bl_dev);
+ enum lp8788_bl_ctrl_mode mode = bl->mode;
+
+ if (is_brightness_ctrl_by_pwm(mode)) {
+ struct lp8788_bl_pwm_data *pd;
+ int max = bl_dev->props.max_brightness;
+
+ pd = bl->pdata ? &bl->pdata->pwm_data : NULL;
+ if (pd && pd->pwm_get_intensity)
+ bl_dev->props.brightness = pd->pwm_get_intensity(max);
+ } else if (is_brightness_ctrl_by_register(mode)) {
+ u8 val = 0;
+
+ lp8788_read_byte(bl->lp, LP8788_BL_BRIGHTNESS, &val);
+ bl_dev->props.brightness = val;
+ }
+
+ return bl_dev->props.brightness;
+}
+
+static const struct backlight_ops lp8788_bl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = lp8788_bl_update_status,
+ .get_brightness = lp8788_bl_get_brightness,
+};
+
+static int lp8788_backlight_register(struct lp8788_bl *bl)
+{
+ struct backlight_device *bl_dev;
+ struct backlight_properties props;
+ struct lp8788_backlight_platform_data *pdata = bl->pdata;
+ int init_brt = pdata ? pdata->initial_brightness : 0;
+ char *name;
+
+ props.type = BACKLIGHT_PLATFORM;
+ props.max_brightness = MAX_BRIGHTNESS;
+
+ if (init_brt > props.max_brightness)
+ init_brt = props.max_brightness;
+
+ props.brightness = init_brt;
+
+ if (!pdata || !pdata->name)
+ name = DEFAULT_BL_NAME;
+ else
+ name = pdata->name;
+
+ bl_dev = backlight_device_register(name, bl->lp->dev, bl,
+ &lp8788_bl_ops, &props);
+ if (IS_ERR(bl_dev))
+ return PTR_ERR(bl_dev);
+
+ bl->bl_dev = bl_dev;
+
+ return 0;
+}
+
+static void lp8788_backlight_unregister(struct lp8788_bl *bl)
+{
+ struct backlight_device *bl_dev = bl->bl_dev;
+
+ if (bl_dev)
+ backlight_device_unregister(bl_dev);
+}
+
+static ssize_t lp8788_get_bl_ctl_mode(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lp8788_bl *bl = dev_get_drvdata(dev);
+ enum lp8788_bl_ctrl_mode mode = bl->mode;
+ char *strmode = NULL;
+
+ switch (mode) {
+ case LP8788_BL_COMB_PWM_BASED:
+ strmode = "pwm based";
+ break;
+ case LP8788_BL_REGISTER_ONLY:
+ case LP8788_BL_COMB_REGISTER_BASED:
+ strmode = "register based";
+ break;
+ default:
+ strmode = "invalid mode";
+ break;
+ }
+
+ return scnprintf(buf, BUF_SIZE, "%s\n", strmode);
+}
+
+static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp8788_get_bl_ctl_mode, NULL);
+
+static struct attribute *lp8788_attributes[] = {
+ &dev_attr_bl_ctl_mode.attr,
+ NULL,
+};
+
+static const struct attribute_group lp8788_attr_group = {
+ .attrs = lp8788_attributes,
+};
+
+static __devinit int lp8788_backlight_probe(struct platform_device *pdev)
+{
+ struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
+ struct lp8788_bl *bl;
+ int ret;
+
+ bl = devm_kzalloc(lp->dev, sizeof(struct lp8788_bl), GFP_KERNEL);
+ if (!bl)
+ return -ENOMEM;
+
+ bl->lp = lp;
+ bl->pdata = lp->pdata ? lp->pdata->bl_pdata : NULL;
+ platform_set_drvdata(pdev, bl);
+
+ ret = lp8788_backlight_init_device(bl);
+ if (ret) {
+ dev_err(lp->dev, "backlight init device err: %d\n", ret);
+ if (is_brightness_ctrl_by_register(bl->mode))
+ goto err_dev;
+ }
+
+ ret = lp8788_backlight_register(bl);
+ if (ret) {
+ dev_err(lp->dev, "register backlight err: %d\n", ret);
+ goto err_dev;
+ }
+
+ ret = sysfs_create_group(&pdev->dev.kobj, &lp8788_attr_group);
+ if (ret) {
+ dev_err(lp->dev, "register sysfs err: %d\n", ret);
+ goto err_sysfs;
+ }
+
+ backlight_update_status(bl->bl_dev);
+ return 0;
+
+err_sysfs:
+ lp8788_backlight_unregister(bl);
+err_dev:
+ return ret;
+}
+
+static int __devexit lp8788_backlight_remove(struct platform_device *pdev)
+{
+ struct lp8788_bl *bl = platform_get_drvdata(pdev);
+ struct backlight_device *bl_dev = bl->bl_dev;
+
+ bl_dev->props.brightness = 0;
+ backlight_update_status(bl_dev);
+ sysfs_remove_group(&pdev->dev.kobj, &lp8788_attr_group);
+ lp8788_backlight_unregister(bl);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver lp8788_bl_driver = {
+ .probe = lp8788_backlight_probe,
+ .remove = __devexit_p(lp8788_backlight_remove),
+ .driver = {
+ .name = LP8788_DEV_BACKLIGHT,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init lp8788_backlight_init(void)
+{
+ return platform_driver_register(&lp8788_bl_driver);
+}
+module_init(lp8788_backlight_init);
+
+static void __exit lp8788_backlight_exit(void)
+{
+ platform_driver_unregister(&lp8788_bl_driver);
+}
+module_exit(lp8788_backlight_exit);
+
+MODULE_DESCRIPTION("Texas Instruments LP8788 Backlight Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lp8788-backlight");
--
1.7.2.5
Best Regards,
Milo
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