| Message ID | 20090817075650.GA8024@zhen-devel.sh.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Mon, 2009-08-17 at 15:56 +0800, Zhenyu Wang wrote: > On 2009.08.14 19:54:05 +0200, Matthias Hopf wrote: > > What we're supposing is > > > > - a kernel driver for the /sys/class/backlight/ api for the legacy method > > yeah, I think /sys/class/backlight/ should be the only backlight interface for > any user space apps or X RandR property creation. So we need to add backlight > device inside i915 KMS driver, when !acpi_video_backlight_support(). the function of acpi_video_backlight_support only checks whether the generic acpi video method is supported.(_BCL/_BCM acpi video extension method). And we should also check whether the platform driver will register the backlight interface. Only when there is neither generic acpi video nor platform backlight interface, we will register the i915 backlight interface. In such case the dependency is too strict. And it is not easy to handle the three interface. > > Current KMS driver like LVDS only do PWM operation, maybe combo will be better > if it's supposed to be, Jesse? > > > - support in the driver to actually open this one (trivial) > > yeah. > > > - support for the BACKLIGHT property in KMS case, *only* using the > > kernel api method for now (will need some abstraction) > > Current x-v-i driver in KMS could setup any property for all connectors, > like attached testing patch which will hook the property up. But if we just go > with opening /sys/class/backlight/ in xorg driver, we simply don't need it... If the backlight is controlled by using the /sys/class/backlight/* interface, then we can hook up this interface in video driver so that the xrandr can adjust the brightness. Thanks. > > So for X BACKLIGHT property creation, we'll have a checklist for acpi_video, > platform_driver, and new backlight device maybe like 'intel_lvds'. >
On Mon, 17 Aug 2009 15:56:50 +0800 Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > On 2009.08.14 19:54:05 +0200, Matthias Hopf wrote: > > What we're supposing is > > > > - a kernel driver for the /sys/class/backlight/ api for the legacy > > method > > yeah, I think /sys/class/backlight/ should be the only backlight > interface for any user space apps or X RandR property creation. So we > need to add backlight device inside i915 KMS driver, > when !acpi_video_backlight_support(). > > Current KMS driver like LVDS only do PWM operation, maybe combo will > be better if it's supposed to be, Jesse? We'll want PWM+LBB and plain LBB at a minimum; not sure if we need a plain PWM variant. > Current x-v-i driver in KMS could setup any property for all > connectors, like attached testing patch which will hook the property > up. But if we just go with opening /sys/class/backlight/ in xorg > driver, we simply don't need it... Right, we can just expose whatever /sys/class/backlight interface we find through x-v-i for xrandr/xbacklight. No need for the BACKLIGHT_CONTROL property. > So for X BACKLIGHT property creation, we'll have a checklist for > acpi_video, platform_driver, and new backlight device maybe like > 'intel_lvds'. If we see more than one interface in /sys/class/backlight we should also consider it a kernel bug (unless they control different displays somehow; but the /sys/class/backlight API would need work for that).
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 3f445a8..e1affea 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -53,6 +53,7 @@ struct intel_lvds_priv { int fitting_mode; u32 pfit_control; u32 pfit_pgm_ratios; + struct drm_property *backlight; }; /** @@ -75,6 +76,20 @@ static void intel_lvds_set_backlight(struct drm_device *dev, int level) (level << BACKLIGHT_DUTY_CYCLE_SHIFT))); } +static u32 intel_lvds_get_backlight(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + u32 blc_pwm_ctl, reg; + + if (IS_IGDNG(dev)) + reg = BLC_PWM_CPU_CTL; + else + reg = BLC_PWM_CTL; + + blc_pwm_ctl = I915_READ(reg) & BACKLIGHT_DUTY_CYCLE_MASK; + return blc_pwm_ctl; +} + /** * Returns the maximum level of the backlight duty cycle field. */ @@ -667,6 +682,7 @@ static int intel_lvds_set_property(struct drm_connector *connector, struct drm_device *dev = connector->dev; struct intel_output *intel_output = to_intel_output(connector); + struct intel_lvds_priv *lvds_priv = intel_output->dev_priv; if (property == dev->mode_config.scaling_mode_property && connector->encoder) { @@ -690,6 +706,8 @@ static int intel_lvds_set_property(struct drm_connector *connector, drm_crtc_helper_set_mode(crtc, &crtc->mode, crtc->x, crtc->y, crtc->fb); } + } else if (property == lvds_priv->backlight) { + intel_lvds_set_backlight(dev, value); } return 0; @@ -1009,7 +1028,17 @@ void intel_lvds_init(struct drm_device *dev) if (!dev_priv->panel_fixed_mode) goto failed; + out: + /* backlight property */ + lvds_priv->backlight = drm_property_create(dev, DRM_MODE_PROP_RANGE, + "BACKLIGHT", 2); + lvds_priv->backlight->values[0] = 0; + lvds_priv->backlight->values[1] = intel_lvds_get_max_backlight(dev); + drm_connector_attach_property(&intel_output->base, + lvds_priv->backlight, + (uint64_t)intel_lvds_get_backlight(dev)); + if (IS_IGDNG(dev)) { u32 pwm; /* make sure PWM is enabled */