diff options
Diffstat (limited to 'drivers/staging/gma500/psb_bl.c')
| -rw-r--r-- | drivers/staging/gma500/psb_bl.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/drivers/staging/gma500/psb_bl.c b/drivers/staging/gma500/psb_bl.c new file mode 100644 index 000000000000..70c17b352f9f --- /dev/null +++ b/drivers/staging/gma500/psb_bl.c @@ -0,0 +1,169 @@ +/* + * psb backlight interface + * + * Copyright (c) 2009, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * + * Authors: Eric Knopp + * + */ + +#include <linux/backlight.h> +#include <linux/version.h> +#include "psb_drv.h" +#include "psb_intel_reg.h" +#include "psb_intel_drv.h" +#include "psb_intel_bios.h" +#include "psb_powermgmt.h" + +#define MRST_BLC_MAX_PWM_REG_FREQ 0xFFFF +#define BLC_PWM_PRECISION_FACTOR 100 /* 10000000 */ +#define BLC_PWM_FREQ_CALC_CONSTANT 32 +#define MHz 1000000 +#define BRIGHTNESS_MIN_LEVEL 1 +#define BRIGHTNESS_MAX_LEVEL 100 +#define BRIGHTNESS_MASK 0xFF +#define BLC_POLARITY_NORMAL 0 +#define BLC_POLARITY_INVERSE 1 +#define BLC_ADJUSTMENT_MAX 100 + +#define PSB_BLC_PWM_PRECISION_FACTOR 10 +#define PSB_BLC_MAX_PWM_REG_FREQ 0xFFFE +#define PSB_BLC_MIN_PWM_REG_FREQ 0x2 + +#define PSB_BACKLIGHT_PWM_POLARITY_BIT_CLEAR (0xFFFE) +#define PSB_BACKLIGHT_PWM_CTL_SHIFT (16) + +static int psb_brightness; +static struct backlight_device *psb_backlight_device; +static u8 blc_brightnesscmd; +static u8 blc_pol; +static u8 blc_type; + +int psb_set_brightness(struct backlight_device *bd) +{ + struct drm_device *dev = bl_get_data(psb_backlight_device); + int level = bd->props.brightness; + + DRM_DEBUG_DRIVER("backlight level set to %d\n", level); + + /* Perform value bounds checking */ + if (level < BRIGHTNESS_MIN_LEVEL) + level = BRIGHTNESS_MIN_LEVEL; + + psb_intel_lvds_set_brightness(dev, level); + psb_brightness = level; + return 0; +} + +int psb_get_brightness(struct backlight_device *bd) +{ + DRM_DEBUG_DRIVER("brightness = 0x%x\n", psb_brightness); + + /* return locally cached var instead of HW read (due to DPST etc.) */ + /* FIXME: ideally return actual value in case firmware fiddled with + it */ + return psb_brightness; +} + +static const struct backlight_ops psb_ops = { + .get_brightness = psb_get_brightness, + .update_status = psb_set_brightness, +}; + +static int device_backlight_init(struct drm_device *dev) +{ + unsigned long core_clock; + /* u32 bl_max_freq; */ + /* unsigned long value; */ + u16 bl_max_freq; + uint32_t value; + uint32_t blc_pwm_precision_factor; + struct drm_psb_private *dev_priv = dev->dev_private; + + /* get bl_max_freq and pol from dev_priv*/ + if (!dev_priv->lvds_bl) { + DRM_ERROR("Has no valid LVDS backlight info\n"); + return 1; + } + bl_max_freq = dev_priv->lvds_bl->freq; + blc_pol = dev_priv->lvds_bl->pol; + blc_pwm_precision_factor = PSB_BLC_PWM_PRECISION_FACTOR; + blc_brightnesscmd = dev_priv->lvds_bl->brightnesscmd; + blc_type = dev_priv->lvds_bl->type; + + core_clock = dev_priv->core_freq; + + value = (core_clock * MHz) / BLC_PWM_FREQ_CALC_CONSTANT; + value *= blc_pwm_precision_factor; + value /= bl_max_freq; + value /= blc_pwm_precision_factor; + + if (ospm_power_using_hw_begin(OSPM_DISPLAY_ISLAND, + OSPM_UHB_ONLY_IF_ON)) { + /* Check: may be MFLD only */ + if ( + value > (unsigned long long)PSB_BLC_MAX_PWM_REG_FREQ || + value < (unsigned long long)PSB_BLC_MIN_PWM_REG_FREQ) + return 2; + else { + value &= PSB_BACKLIGHT_PWM_POLARITY_BIT_CLEAR; + REG_WRITE(BLC_PWM_CTL, + (value << PSB_BACKLIGHT_PWM_CTL_SHIFT) | + (value)); + } + ospm_power_using_hw_end(OSPM_DISPLAY_ISLAND); + } + return 0; +} + +int psb_backlight_init(struct drm_device *dev) +{ +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE + int ret = 0; + + struct backlight_properties props; + memset(&props, 0, sizeof(struct backlight_properties)); + props.max_brightness = BRIGHTNESS_MAX_LEVEL; + + psb_backlight_device = backlight_device_register("psb-bl", NULL, + (void *)dev, &psb_ops, &props); + if (IS_ERR(psb_backlight_device)) + return PTR_ERR(psb_backlight_device); + + ret = device_backlight_init(dev); + if (ret < 0) + return ret; + + psb_backlight_device->props.brightness = BRIGHTNESS_MAX_LEVEL; + psb_backlight_device->props.max_brightness = BRIGHTNESS_MAX_LEVEL; + backlight_update_status(psb_backlight_device); +#endif + return 0; +} + +void psb_backlight_exit(void) +{ +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE + psb_backlight_device->props.brightness = 0; + backlight_update_status(psb_backlight_device); + backlight_device_unregister(psb_backlight_device); +#endif +} + +struct backlight_device *psb_get_backlight_device(void) +{ + return psb_backlight_device; +} |