[PATCH 2/3] backlight: lp855x_bl: support new LP8557 device

From: Kim, Milo
Date: Tue Feb 19 2013 - 23:40:37 EST

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LP8557 is one of LP855x family device, but it has different register map
and initialization process.
To support this device, device specific configuration is done through the
lp855x_device_config structure.

Few register definitions are fixed for better readability.
BRIGHTNESS_CTRL -> LP855X_BRIGHTNESS_CTRL
DEVICE_CTRL -> LP855X_DEVICE_CTRL
EEPROM_START -> LP855X_EEPROM_START
EEPROM_END -> LP855X_EEPROM_END
EPROM_START -> LP8556_EPROM_START
EPROM_END -> LP8556_EPROM_END

And LP8557 register definitions are added.
New register function, lp855x_update_bit() is added.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@xxxxxx>
---
Documentation/backlight/lp855x-driver.txt | 4 +-
drivers/video/backlight/Kconfig | 2 +-
drivers/video/backlight/lp855x_bl.c | 87 ++++++++++++++++++++++++-----
include/linux/platform_data/lp855x.h | 19 +++++++
4 files changed, 94 insertions(+), 18 deletions(-)

diff --git a/Documentation/backlight/lp855x-driver.txt b/Documentation/backlight/lp855x-driver.txt
index 1529394..18b06ca 100644
--- a/Documentation/backlight/lp855x-driver.txt
+++ b/Documentation/backlight/lp855x-driver.txt
@@ -4,7 +4,7 @@ Kernel driver lp855x
Backlight driver for LP855x ICs

Supported chips:
- Texas Instruments LP8550, LP8551, LP8552, LP8553 and LP8556
+ Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8556 and LP8557

Author: Milo(Woogyom) Kim <milo.kim@xxxxxx>

@@ -24,7 +24,7 @@ Value : pwm based or register based

2) chip_id
The lp855x chip id.
-Value : lp8550/lp8551/lp8552/lp8553/lp8556
+Value : lp8550/lp8551/lp8552/lp8553/lp8556/lp8557

Platform data for lp855x
------------------------
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 765a945..f24bc79 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -366,7 +366,7 @@ config BACKLIGHT_LP855X
tristate "Backlight driver for TI LP855X"
depends on BACKLIGHT_CLASS_DEVICE && I2C
help
- This supports TI LP8550, LP8551, LP8552, LP8553 and LP8556
+ This supports TI LP8550, LP8551, LP8552, LP8553, LP8556 and LP8557
backlight driver.

config BACKLIGHT_OT200
diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index 050cfbb..edd2041 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -17,13 +17,23 @@
#include <linux/platform_data/lp855x.h>
#include <linux/pwm.h>

-/* Registers */
-#define BRIGHTNESS_CTRL 0x00
-#define DEVICE_CTRL 0x01
-#define EEPROM_START 0xA0
-#define EEPROM_END 0xA7
-#define EPROM_START 0xA0
-#define EPROM_END 0xAF
+/* LP8550/1/2/3/6 Registers */
+#define LP855X_BRIGHTNESS_CTRL 0x00
+#define LP855X_DEVICE_CTRL 0x01
+#define LP855X_EEPROM_START 0xA0
+#define LP855X_EEPROM_END 0xA7
+#define LP8556_EPROM_START 0xA0
+#define LP8556_EPROM_END 0xAF
+
+/* LP8557 Registers */
+#define LP8557_BL_CMD 0x00
+#define LP8557_BL_MASK 0x01
+#define LP8557_BL_ON 0x01
+#define LP8557_BL_OFF 0x00
+#define LP8557_BRIGHTNESS_CTRL 0x04
+#define LP8557_CONFIG 0x10
+#define LP8557_EPROM_START 0x10
+#define LP8557_EPROM_END 0x1E

#define BUF_SIZE 20
#define DEFAULT_BL_NAME "lcd-backlight"
@@ -75,6 +85,24 @@ static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
return i2c_smbus_write_byte_data(lp->client, reg, data);
}

+static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
+{
+ int ret;
+ u8 tmp;
+
+ ret = i2c_smbus_read_byte_data(lp->client, reg);
+ if (ret < 0) {
+ dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
+ return ret;
+ }
+
+ tmp = (u8)ret;
+ tmp &= ~mask;
+ tmp |= data & mask;
+
+ return lp855x_write_byte(lp, reg, tmp);
+}
+
static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
{
u8 start, end;
@@ -84,12 +112,16 @@ static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
case LP8551:
case LP8552:
case LP8553:
- start = EEPROM_START;
- end = EEPROM_END;
+ start = LP855X_EEPROM_START;
+ end = LP855X_EEPROM_END;
break;
case LP8556:
- start = EPROM_START;
- end = EPROM_END;
+ start = LP8556_EPROM_START;
+ end = LP8556_EPROM_END;
+ break;
+ case LP8557:
+ start = LP8557_EPROM_START;
+ end = LP8557_EPROM_END;
break;
default:
return false;
@@ -98,9 +130,30 @@ static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
return (addr >= start && addr <= end);
}

+static int lp8557_bl_off(struct lp855x *lp)
+{
+ /* BL_ON = 0 before updating EPROM settings */
+ return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
+ LP8557_BL_OFF);
+}
+
+static int lp8557_bl_on(struct lp855x *lp)
+{
+ /* BL_ON = 1 after updating EPROM settings */
+ return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
+ LP8557_BL_ON);
+}
+
static struct lp855x_device_config lp855x_dev_cfg = {
- .reg_brightness = BRIGHTNESS_CTRL,
- .reg_devicectrl = DEVICE_CTRL,
+ .reg_brightness = LP855X_BRIGHTNESS_CTRL,
+ .reg_devicectrl = LP855X_DEVICE_CTRL,
+};
+
+static struct lp855x_device_config lp8557_dev_cfg = {
+ .reg_brightness = LP8557_BRIGHTNESS_CTRL,
+ .reg_devicectrl = LP8557_CONFIG,
+ .pre_init_device = lp8557_bl_off,
+ .post_init_device = lp8557_bl_on,
};

/*
@@ -123,6 +176,9 @@ static int lp855x_configure(struct lp855x *lp)
case LP8550 ... LP8556:
lp->cfg = &lp855x_dev_cfg;
break;
+ case LP8557:
+ lp->cfg = &lp8557_dev_cfg;
+ break;
default:
return -EINVAL;
}
@@ -210,7 +266,7 @@ static int lp855x_bl_update_status(struct backlight_device *bl)

} else if (mode == REGISTER_BASED) {
u8 val = bl->props.brightness;
- lp855x_write_byte(lp, BRIGHTNESS_CTRL, val);
+ lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
}

return 0;
@@ -224,7 +280,7 @@ static int lp855x_bl_get_brightness(struct backlight_device *bl)
if (mode == REGISTER_BASED) {
u8 val = 0;

- lp855x_read_byte(lp, BRIGHTNESS_CTRL, &val);
+ lp855x_read_byte(lp, lp->cfg->reg_brightness, &val);
bl->props.brightness = val;
}

@@ -376,6 +432,7 @@ static const struct i2c_device_id lp855x_ids[] = {
{"lp8552", LP8552},
{"lp8553", LP8553},
{"lp8556", LP8556},
+ {"lp8557", LP8557},
{ }
};
MODULE_DEVICE_TABLE(i2c, lp855x_ids);
diff --git a/include/linux/platform_data/lp855x.h b/include/linux/platform_data/lp855x.h
index e81f62d..20ee8b2 100644
--- a/include/linux/platform_data/lp855x.h
+++ b/include/linux/platform_data/lp855x.h
@@ -49,12 +49,24 @@
#define LP8556_FAST_CONFIG BIT(7) /* use it if EPROMs should be maintained
when exiting the low power mode */

+/* CONFIG register - LP8557 */
+#define LP8557_PWM_STANDBY BIT(7)
+#define LP8557_PWM_FILTER BIT(6)
+#define LP8557_RELOAD_EPROM BIT(3) /* use it if EPROMs should be reset
+ when the backlight turns on */
+#define LP8557_OFF_OPENLEDS BIT(2)
+#define LP8557_PWM_CONFIG LP8557_PWM_ONLY
+#define LP8557_I2C_CONFIG LP8557_I2C_ONLY
+#define LP8557_COMB1_CONFIG LP8557_COMBINED1
+#define LP8557_COMB2_CONFIG LP8557_COMBINED2
+
enum lp855x_chip_id {
LP8550,
LP8551,
LP8552,
LP8553,
LP8556,
+ LP8557,
};

enum lp855x_brightness_ctrl_mode {
@@ -89,6 +101,13 @@ enum lp8556_brightness_source {
LP8556_COMBINED2, /* pwm + i2c after the shaper block */
};

+enum lp8557_brightness_source {
+ LP8557_PWM_ONLY,
+ LP8557_I2C_ONLY,
+ LP8557_COMBINED1, /* pwm + i2c after the shaper block */
+ LP8557_COMBINED2, /* pwm + i2c before the shaper block */
+};
+
struct lp855x_rom_data {
u8 addr;
u8 val;
--
1.7.9.5

Best Regards,
Milo

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Next message: Kim, Milo: "[PATCH 3/3] backlight: lp855x_bl: simplify bl_get_brightness()"
Previous message: Kim, Milo: "[PATCH 1/3] backlight: lp855x_bl: introduce device configurationflow"
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