/* * Backlight driver for Pandora handheld. * Pandora uses TWL4030 PWM0 -> TPS61161 combo for control backlight. * Based on pwm_bl.c * * Copyright 2009,2012 Gražvydas Ignotas * * 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 #include #include #include #include #include #include #include #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(TWL_MODULE_PWM, 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(TWL_MODULE_PWM, 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 const struct backlight_ops pandora_backlight_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = pandora_backlight_update_status, }; 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 = devm_backlight_device_register(&pdev->dev, 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(TWL_MODULE_PWM, 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 struct platform_driver pandora_backlight_driver = { .driver = { .name = "pandora-backlight", }, .probe = pandora_backlight_probe, }; module_platform_driver(pandora_backlight_driver); MODULE_AUTHOR("Gražvydas Ignotas "); MODULE_DESCRIPTION("Pandora Backlight Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pandora-backlight"); ion>space:mode:
Diffstat (limited to 'drivers/usb/mtu3/Makefile')