diff options
| -rw-r--r-- | drivers/video/backlight/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/video/backlight/Makefile | 1 | ||||
| -rw-r--r-- | drivers/video/backlight/pandora_bl.c | 171 |
3 files changed, 179 insertions, 0 deletions
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 248d6c0858dd..ed68fde54454 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -348,6 +348,13 @@ config BACKLIGHT_OT200 To compile this driver as a module, choose M here: the module will be called ot200_bl. +config BACKLIGHT_PANDORA + tristate "Backlight driver for Pandora console" + depends on TWL4030_CORE + help + If you have a Pandora console, say Y to enable the + backlight driver. + endif # BACKLIGHT_CLASS_DEVICE endif # BACKLIGHT_LCD_SUPPORT diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index c71dd793363d..8071eb656147 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_LOCOMO) += locomolcd.o obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o +obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o diff --git a/drivers/video/backlight/pandora_bl.c b/drivers/video/backlight/pandora_bl.c new file mode 100644 index 000000000000..4ec30748b447 --- /dev/null +++ b/drivers/video/backlight/pandora_bl.c @@ -0,0 +1,171 @@ +/* + * Backlight driver for Pandora handheld. + * Pandora uses TWL4030 PWM0 -> TPS61161 combo for control backlight. + * Based on pwm_bl.c + * + * Copyright 2009,2012 Gražvydas Ignotas <notasas@gmail.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/kernel.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/fb.h> +#include <linux/backlight.h> +#include <linux/i2c/twl.h> +#include <linux/err.h> + +#define TWL_PWM0_ON 0x00 +#define TWL_PWM0_OFF 0x01 + +#define TWL_INTBR_GPBR1 0x0c +#define TWL_INTBR_PMBR1 0x0d + +#define TWL_PMBR1_PWM0_MUXMASK 0x0c +#define TWL_PMBR1_PWM0 0x04 +#define PWM0_CLK_ENABLE BIT(0) +#define PWM0_ENABLE BIT(2) + +/* range accepted by hardware */ +#define MIN_VALUE 9 +#define MAX_VALUE 63 +#define MAX_USER_VALUE (MAX_VALUE - MIN_VALUE) + +#define PANDORABL_WAS_OFF BL_CORE_DRIVER1 + +static int pandora_backlight_update_status(struct backlight_device *bl) +{ + int brightness = bl->props.brightness; + u8 r; + + if (bl->props.power != FB_BLANK_UNBLANK) + brightness = 0; + if (bl->props.state & BL_CORE_FBBLANK) + brightness = 0; + if (bl->props.state & BL_CORE_SUSPENDED) + brightness = 0; + + if ((unsigned int)brightness > MAX_USER_VALUE) + brightness = MAX_USER_VALUE; + + if (brightness == 0) { + if (bl->props.state & PANDORABL_WAS_OFF) + goto done; + + /* first disable PWM0 output, then clock */ + twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1); + r &= ~PWM0_ENABLE; + twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1); + r &= ~PWM0_CLK_ENABLE; + twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1); + + goto done; + } + + if (bl->props.state & PANDORABL_WAS_OFF) { + /* + * set PWM duty cycle to max. TPS61161 seems to use this + * to calibrate it's PWM sensitivity when it starts. + */ + twl_i2c_write_u8(TWL4030_MODULE_PWM0, MAX_VALUE, + TWL_PWM0_OFF); + + /* first enable clock, then PWM0 out */ + twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1); + r &= ~PWM0_ENABLE; + r |= PWM0_CLK_ENABLE; + twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1); + r |= PWM0_ENABLE; + twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1); + + /* + * TI made it very easy to enable digital control, so easy that + * it often triggers unintentionally and disabes PWM control, + * so wait until 1 wire mode detection window ends. + */ + usleep_range(2000, 10000); + } + + twl_i2c_write_u8(TWL4030_MODULE_PWM0, MIN_VALUE + brightness, + TWL_PWM0_OFF); + +done: + if (brightness != 0) + bl->props.state &= ~PANDORABL_WAS_OFF; + else + bl->props.state |= PANDORABL_WAS_OFF; + + return 0; +} + +static int pandora_backlight_get_brightness(struct backlight_device *bl) +{ + return bl->props.brightness; +} + +static const struct backlight_ops pandora_backlight_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = pandora_backlight_update_status, + .get_brightness = pandora_backlight_get_brightness, +}; + +static int pandora_backlight_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct backlight_device *bl; + u8 r; + + memset(&props, 0, sizeof(props)); + props.max_brightness = MAX_USER_VALUE; + props.type = BACKLIGHT_RAW; + bl = backlight_device_register(pdev->name, &pdev->dev, + NULL, &pandora_backlight_ops, &props); + if (IS_ERR(bl)) { + dev_err(&pdev->dev, "failed to register backlight\n"); + return PTR_ERR(bl); + } + + platform_set_drvdata(pdev, bl); + + /* 64 cycle period, ON position 0 */ + twl_i2c_write_u8(TWL4030_MODULE_PWM0, 0x80, TWL_PWM0_ON); + + bl->props.state |= PANDORABL_WAS_OFF; + bl->props.brightness = MAX_USER_VALUE; + backlight_update_status(bl); + + /* enable PWM function in pin mux */ + twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_PMBR1); + r &= ~TWL_PMBR1_PWM0_MUXMASK; + r |= TWL_PMBR1_PWM0; + twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_PMBR1); + + return 0; +} + +static int pandora_backlight_remove(struct platform_device *pdev) +{ + struct backlight_device *bl = platform_get_drvdata(pdev); + backlight_device_unregister(bl); + return 0; +} + +static struct platform_driver pandora_backlight_driver = { + .driver = { + .name = "pandora-backlight", + .owner = THIS_MODULE, + }, + .probe = pandora_backlight_probe, + .remove = pandora_backlight_remove, +}; + +module_platform_driver(pandora_backlight_driver); + +MODULE_AUTHOR("Gražvydas Ignotas <notasas@gmail.com>"); +MODULE_DESCRIPTION("Pandora Backlight Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pandora-backlight"); |