Re: [PATCH] radeon: Expose backlight class device for legacy LVDS encoder
From: Alex Deucher
Date: Wed Sep 08 2010 - 12:58:41 EST
On Wed, Sep 8, 2010 at 12:32 PM, Matthew Garrett <mjg@xxxxxxxxxx> wrote:
> From: Michel Dänzer <michel@xxxxxxxxxxx>
>
> Allows e.g. power management daemons to control the backlight level. Inspired
> by the corresponding code in radeonfb.
>
The only problem with this is that not all oems use the internal
backlight controller; systems that don't need to use the acpi methods.
On atombios systems there is a bit in the
ATOM_FIRMWARE_CAPABILITY_ACCESS struct in the FirmwareInfo data table
to determine whether the backlight is controlled by the GPU or some
external mechanism. Combios may have something similar. If the
backlight is controlled via the GPU, it can be adjusting using the
atom OutputControl and TransmitterControl control tables depending on
the GPU family. However, if the driver chooses to control the
backlight itself, it needs to set the appropriate bit in the bios
scratch regs to tell the firmware not to attempt to change the
backlight itself.
Alex
> (Updated to add backlight type and make the connector the parent device - mjg)
>
> Signed-off-by: Michel Dänzer <daenzer@xxxxxxxxxx>
> Signed-off-by: Matthew Garrett <mjg@xxxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> drivers/gpu/drm/radeon/Kconfig | 1 +
> drivers/gpu/drm/radeon/radeon_legacy_encoders.c | 257 ++++++++++++++++++++++-
> drivers/gpu/drm/radeon/radeon_mode.h | 10 +
> 3 files changed, 262 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/Kconfig b/drivers/gpu/drm/radeon/Kconfig
> index 1c02d23..9746fee 100644
> --- a/drivers/gpu/drm/radeon/Kconfig
> +++ b/drivers/gpu/drm/radeon/Kconfig
> @@ -1,6 +1,7 @@
> config DRM_RADEON_KMS
> bool "Enable modesetting on radeon by default - NEW DRIVER"
> depends on DRM_RADEON
> + select BACKLIGHT_CLASS_DEVICE
> help
> Choose this option if you want kernel modesetting enabled by default.
>
> diff --git a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
> index 0b83970..e873935 100644
> --- a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
> +++ b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
> @@ -28,6 +28,7 @@
> #include "radeon_drm.h"
> #include "radeon.h"
> #include "atom.h"
> +#include <linux/backlight.h>
>
> static void radeon_legacy_encoder_disable(struct drm_encoder *encoder)
> {
> @@ -39,7 +40,7 @@ static void radeon_legacy_encoder_disable(struct drm_encoder *encoder)
> radeon_encoder->active_device = 0;
> }
>
> -static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
> +static void radeon_legacy_lvds_update(struct drm_encoder *encoder, int mode)
> {
> struct drm_device *dev = encoder->dev;
> struct radeon_device *rdev = dev->dev_private;
> @@ -47,15 +48,23 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
> uint32_t lvds_gen_cntl, lvds_pll_cntl, pixclks_cntl, disp_pwr_man;
> int panel_pwr_delay = 2000;
> bool is_mac = false;
> + uint8_t backlight_level;
> DRM_DEBUG_KMS("\n");
>
> + lvds_gen_cntl = RREG32(RADEON_LVDS_GEN_CNTL);
> + backlight_level = (lvds_gen_cntl >> RADEON_LVDS_BL_MOD_LEVEL_SHIFT) & 0xff;
> +
> if (radeon_encoder->enc_priv) {
> if (rdev->is_atom_bios) {
> struct radeon_encoder_atom_dig *lvds = radeon_encoder->enc_priv;
> panel_pwr_delay = lvds->panel_pwr_delay;
> + if (lvds->bl_dev)
> + backlight_level = lvds->backlight_level;
> } else {
> struct radeon_encoder_lvds *lvds = radeon_encoder->enc_priv;
> panel_pwr_delay = lvds->panel_pwr_delay;
> + if (lvds->bl_dev)
> + backlight_level = lvds->backlight_level;
> }
> }
>
> @@ -82,11 +91,13 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
> lvds_pll_cntl &= ~RADEON_LVDS_PLL_RESET;
> WREG32(RADEON_LVDS_PLL_CNTL, lvds_pll_cntl);
>
> - lvds_gen_cntl = RREG32(RADEON_LVDS_GEN_CNTL);
> - lvds_gen_cntl |= (RADEON_LVDS_ON | RADEON_LVDS_EN | RADEON_LVDS_DIGON | RADEON_LVDS_BLON);
> + lvds_gen_cntl &= ~(RADEON_LVDS_DISPLAY_DIS |
> + RADEON_LVDS_BL_MOD_LEVEL_MASK);
> + lvds_gen_cntl |= (RADEON_LVDS_ON | RADEON_LVDS_EN |
> + RADEON_LVDS_DIGON | RADEON_LVDS_BLON |
> + (backlight_level << RADEON_LVDS_BL_MOD_LEVEL_SHIFT));
> if (is_mac)
> lvds_gen_cntl |= RADEON_LVDS_BL_MOD_EN;
> - lvds_gen_cntl &= ~(RADEON_LVDS_DISPLAY_DIS);
> udelay(panel_pwr_delay * 1000);
> WREG32(RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
> break;
> @@ -95,7 +106,6 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
> case DRM_MODE_DPMS_OFF:
> pixclks_cntl = RREG32_PLL(RADEON_PIXCLKS_CNTL);
> WREG32_PLL_P(RADEON_PIXCLKS_CNTL, 0, ~RADEON_PIXCLK_LVDS_ALWAYS_ONb);
> - lvds_gen_cntl = RREG32(RADEON_LVDS_GEN_CNTL);
> lvds_gen_cntl |= RADEON_LVDS_DISPLAY_DIS;
> if (is_mac) {
> lvds_gen_cntl &= ~RADEON_LVDS_BL_MOD_EN;
> @@ -119,6 +129,25 @@ static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
>
> }
>
> +static void radeon_legacy_lvds_dpms(struct drm_encoder *encoder, int mode)
> +{
> + struct radeon_device *rdev = encoder->dev->dev_private;
> + struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
> + DRM_DEBUG("\n");
> +
> + if (radeon_encoder->enc_priv) {
> + if (rdev->is_atom_bios) {
> + struct radeon_encoder_atom_dig *lvds = radeon_encoder->enc_priv;
> + lvds->dpms_mode = mode;
> + } else {
> + struct radeon_encoder_lvds *lvds = radeon_encoder->enc_priv;
> + lvds->dpms_mode = mode;
> + }
> + }
> +
> + radeon_legacy_lvds_update(encoder, mode);
> +}
> +
> static void radeon_legacy_lvds_prepare(struct drm_encoder *encoder)
> {
> struct radeon_device *rdev = encoder->dev->dev_private;
> @@ -237,9 +266,224 @@ static const struct drm_encoder_helper_funcs radeon_legacy_lvds_helper_funcs = {
> .disable = radeon_legacy_encoder_disable,
> };
>
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
> +
> +#define MAX_RADEON_LEVEL 0xFF
> +
> +struct radeon_backlight_privdata {
> + struct radeon_encoder *encoder;
> + uint8_t negative;
> +};
> +
> +static uint8_t radeon_legacy_lvds_level(struct backlight_device *bd)
> +{
> + struct radeon_backlight_privdata *pdata = bl_get_data(bd);
> + uint8_t level;
> +
> + /* Convert brightness to hardware level */
> + if (bd->props.brightness < 0)
> + level = 0;
> + else if (bd->props.brightness > MAX_RADEON_LEVEL)
> + level = MAX_RADEON_LEVEL;
> + else
> + level = bd->props.brightness;
> +
> + if (pdata->negative)
> + level = MAX_RADEON_LEVEL - level;
> +
> + return level;
> +}
> +
> +static int radeon_legacy_backlight_update_status(struct backlight_device *bd)
> +{
> + struct radeon_backlight_privdata *pdata = bl_get_data(bd);
> + struct radeon_encoder *radeon_encoder = pdata->encoder;
> + struct drm_device *dev = radeon_encoder->base.dev;
> + struct radeon_device *rdev = dev->dev_private;
> + int dpms_mode = DRM_MODE_DPMS_ON;
> +
> + if (radeon_encoder->enc_priv) {
> + if (rdev->is_atom_bios) {
> + struct radeon_encoder_atom_dig *lvds = radeon_encoder->enc_priv;
> + dpms_mode = lvds->dpms_mode;
> + lvds->backlight_level = radeon_legacy_lvds_level(bd);
> + } else {
> + struct radeon_encoder_lvds *lvds = radeon_encoder->enc_priv;
> + dpms_mode = lvds->dpms_mode;
> + lvds->backlight_level = radeon_legacy_lvds_level(bd);
> + }
> + }
> +
> + if (bd->props.brightness > 0)
> + radeon_legacy_lvds_update(&radeon_encoder->base, dpms_mode);
> + else
> + radeon_legacy_lvds_update(&radeon_encoder->base, DRM_MODE_DPMS_OFF);
> +
> + return 0;
> +}
> +
> +static int radeon_legacy_backlight_get_brightness(struct backlight_device *bd)
> +{
> + struct radeon_backlight_privdata *pdata = bl_get_data(bd);
> + struct radeon_encoder *radeon_encoder = pdata->encoder;
> + struct drm_device *dev = radeon_encoder->base.dev;
> + struct radeon_device *rdev = dev->dev_private;
> + uint8_t backlight_level;
> +
> + backlight_level = (RREG32(RADEON_LVDS_GEN_CNTL) >>
> + RADEON_LVDS_BL_MOD_LEVEL_SHIFT) & 0xff;
> +
> + return pdata->negative ? MAX_RADEON_LEVEL - backlight_level : backlight_level;
> +}
> +
> +static const struct backlight_ops radeon_backlight_ops = {
> + .get_brightness = radeon_legacy_backlight_get_brightness,
> + .update_status = radeon_legacy_backlight_update_status,
> +};
> +
> +static void radeon_legacy_backlight_init(struct radeon_encoder *radeon_encoder)
> +{
> + struct drm_device *dev = radeon_encoder->base.dev;
> + struct radeon_device *rdev = dev->dev_private;
> + struct backlight_device *bd;
> + struct backlight_properties props;
> + struct radeon_backlight_privdata *pdata;
> + struct drm_connector *connector;
> + uint8_t backlight_level;
> +
> + if (!radeon_encoder->enc_priv)
> + return;
> +
> +#ifdef CONFIG_PMAC_BACKLIGHT
> + if (!pmac_has_backlight_type("ati") &&
> + !pmac_has_backlight_type("mnca"))
> + return;
> +#endif
> +
> + pdata = kmalloc(sizeof(struct radeon_backlight_privdata), GFP_KERNEL);
> + if (!pdata) {
> + DRM_ERROR("Memory allocation failed\n");
> + goto error;
> + }
> +
> + connector = radeon_get_connector_for_encoder(&radeon_encoder->base);
> +
> + props.max_brightness = MAX_RADEON_LEVEL;
> + props.type = BACKLIGHT_RAW;
> + bd = backlight_device_register("radeon_backlight", &connector->kdev,
> + pdata, &radeon_backlight_ops, &props);
> + if (IS_ERR(bd)) {
> + DRM_ERROR("Backlight registration failed\n");
> + goto error;
> + }
> +
> + pdata->encoder = radeon_encoder;
> +
> + backlight_level = (RREG32(RADEON_LVDS_GEN_CNTL) >>
> + RADEON_LVDS_BL_MOD_LEVEL_SHIFT) & 0xff;
> +
> + /* First, try to detect backlight level sense based on the assumption
> + * that firmware set it up at full brightness
> + */
> + if (backlight_level == 0)
> + pdata->negative = true;
> + else if (backlight_level == 0xff)
> + pdata->negative = false;
> + else {
> + /* XXX hack... maybe some day we can figure out in what direction
> + * backlight should work on a given panel?
> + */
> + pdata->negative = (rdev->family != CHIP_RV200 &&
> + rdev->family != CHIP_RV250 &&
> + rdev->family != CHIP_RV280 &&
> + rdev->family != CHIP_RV350);
> +
> +#ifdef CONFIG_PMAC_BACKLIGHT
> + pdata->negative = (pdata->negative ||
> + machine_is_compatible("PowerBook4,3") ||
> + machine_is_compatible("PowerBook6,3") ||
> + machine_is_compatible("PowerBook6,5"));
> +#endif
> + }
> +
> + if (rdev->is_atom_bios) {
> + struct radeon_encoder_atom_dig *lvds = radeon_encoder->enc_priv;
> + lvds->bl_dev = bd;
> + } else {
> + struct radeon_encoder_lvds *lvds = radeon_encoder->enc_priv;
> + lvds->bl_dev = bd;
> + }
> +
> + bd->props.brightness = radeon_legacy_backlight_get_brightness(bd);
> + bd->props.power = FB_BLANK_UNBLANK;
> + backlight_update_status(bd);
> +
> + DRM_INFO("radeon legacy LVDS backlight initialized\n");
> +
> + return;
> +
> +error:
> + kfree(pdata);
> + return;
> +}
> +
> +static void radeon_legacy_backlight_exit(struct radeon_encoder *radeon_encoder)
> +{
> + struct drm_device *dev = radeon_encoder->base.dev;
> + struct radeon_device *rdev = dev->dev_private;
> + struct backlight_device *bd = NULL;
> +
> + if (!radeon_encoder->enc_priv)
> + return;
> +
> + if (rdev->is_atom_bios) {
> + struct radeon_encoder_atom_dig *lvds = radeon_encoder->enc_priv;
> + bd = lvds->bl_dev;
> + lvds->bl_dev = NULL;
> + } else {
> + struct radeon_encoder_lvds *lvds = radeon_encoder->enc_priv;
> + bd = lvds->bl_dev;
> + lvds->bl_dev = NULL;
> + }
> +
> + if (bd) {
> + struct radeon_legacy_backlight_privdata *pdata;
> +
> + pdata = bl_get_data(bd);
> + backlight_device_unregister(bd);
> + kfree(pdata);
> +
> + DRM_INFO("radeon legacy LVDS backlight unloaded\n");
> + }
> +}
> +
> +#else /* !CONFIG_BACKLIGHT_CLASS_DEVICE */
> +
> +static void radeon_legacy_backlight_init(struct radeon_encoder *encoder)
> +{
> +}
> +
> +static void radeon_legacy_backlight_exit(struct radeon_encoder *encoder)
> +{
> +}
> +
> +#endif
> +
> +
> +static void radeon_lvds_enc_destroy(struct drm_encoder *encoder)
> +{
> + struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
> +
> + if (radeon_encoder->enc_priv) {
> + radeon_legacy_backlight_exit(radeon_encoder);
> + kfree(radeon_encoder->enc_priv);
> + }
> + drm_encoder_cleanup(encoder);
> + kfree(radeon_encoder);
> +}
>
> static const struct drm_encoder_funcs radeon_legacy_lvds_enc_funcs = {
> - .destroy = radeon_enc_destroy,
> + .destroy = radeon_lvds_enc_destroy,
> };
>
> static void radeon_legacy_primary_dac_dpms(struct drm_encoder *encoder, int mode)
> @@ -1389,6 +1633,7 @@ radeon_add_legacy_encoder(struct drm_device *dev, uint32_t encoder_enum, uint32_
> else
> radeon_encoder->enc_priv = radeon_combios_get_lvds_info(radeon_encoder);
> radeon_encoder->rmx_type = RMX_FULL;
> + radeon_legacy_backlight_init(radeon_encoder);
> break;
> case ENCODER_OBJECT_ID_INTERNAL_TMDS1:
> drm_encoder_init(dev, encoder, &radeon_legacy_tmds_int_enc_funcs, DRM_MODE_ENCODER_TMDS);
> diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
> index efbe975..dc5f51c 100644
> --- a/drivers/gpu/drm/radeon/radeon_mode.h
> +++ b/drivers/gpu/drm/radeon/radeon_mode.h
> @@ -302,6 +302,11 @@ struct radeon_encoder_lvds {
> uint32_t lvds_gen_cntl;
> /* panel mode */
> struct drm_display_mode native_mode;
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
> + struct backlight_device *bl_dev;
> + int dpms_mode;
> + uint8_t backlight_level;
> +#endif
> };
>
> struct radeon_encoder_tv_dac {
> @@ -353,6 +358,11 @@ struct radeon_encoder_atom_dig {
> struct radeon_atom_ss *ss;
> /* panel mode */
> struct drm_display_mode native_mode;
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
> + struct backlight_device *bl_dev;
> + int dpms_mode;
> + uint8_t backlight_level;
> +#endif
> };
>
> struct radeon_encoder_atom_dac {
> --
> 1.7.2.1
>
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>
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