Re: [PATCH 2/2] drm/i915: Set invert bit for hpd based on VBT

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Mar 24, 2016 at 05:40:51PM +0530, Shubhangi Shrivastava wrote:
> This patch sets the invert bit for hpd detection for each port
> based on VBT configuration. Since each AOB can be designed to
> depend on invert bit or not, it is expected if an AOB requires
> invert bit, the user will set respective bit in VBT.
> 
> v2: Separated VBT parsing from the rest of the logic. (Jani)
> 
> v3: Moved setting invert bit logic to bxt_hpd_irq_setup()
>     and changed its logic to avoid looping twice. (Ville)
> 
> v4: Changed the logic to mask out the bits first and then
>     set them to remove need of temporary variable. (Ville)
> 
> v5: Moved defines to existing set of defines for the register
>     Changed logic to incorporate required breaks. (Ville)
> 
> Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
> Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
> Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava@intel.com>
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h   |  2 ++
>  drivers/gpu/drm/i915/i915_irq.c   | 20 ++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h   |  6 ++++++
>  drivers/gpu/drm/i915/intel_bios.c | 32 ++++++++++++++++++++++++++++++++
>  4 files changed, 60 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 9d29ab0..86fb5cb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3396,6 +3396,8 @@ bool intel_bios_is_tv_present(struct drm_i915_private *dev_priv);
>  bool intel_bios_is_lvds_present(struct drm_i915_private *dev_priv, u8 *i2c_pin);
>  bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
>  bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv, enum port *port);
> +bool intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
> +				     enum port port);
>  
>  /* intel_opregion.c */
>  #ifdef CONFIG_ACPI
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index a55a7cc..8fbec3e 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3504,6 +3504,26 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
>  	hotplug = I915_READ(PCH_PORT_HOTPLUG);
>  	hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
>  		PORTA_HOTPLUG_ENABLE;
> +
> +	DRM_DEBUG_KMS("Invert bit setting: hp_ctl:%x hp_port:%x\n",
> +			hotplug, enabled_irqs);
> +	hotplug &= ~BXT_DDI_HPD_INVERT_MASK;
> +
> +	/*
> +	 * For BXT invert bit has to be set based on AOB design
> +	 * for HPD detection logic, update it based on VBT fields.
> +	 */
> +
> +	if ((enabled_irqs & BXT_DE_PORT_HP_DDIA) &&
> +	     intel_bios_is_port_hpd_inverted(dev_priv, PORT_A))
> +		hotplug |= BXT_DDIA_HPD_INVERT;
> +	if ((enabled_irqs & BXT_DE_PORT_HP_DDIB) &&
> +	     intel_bios_is_port_hpd_inverted(dev_priv, PORT_B))
> +		hotplug |= BXT_DDIB_HPD_INVERT;
> +	if ((enabled_irqs & BXT_DE_PORT_HP_DDIC) &&
> +	     intel_bios_is_port_hpd_inverted(dev_priv, PORT_C))
> +		hotplug |= BXT_DDIC_HPD_INVERT;
> +
>  	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f3ba43c..73a806c 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6185,6 +6185,7 @@ enum skl_disp_power_wells {
>  /* digital port hotplug */
>  #define PCH_PORT_HOTPLUG		_MMIO(0xc4030)	/* SHOTPLUG_CTL */
>  #define  PORTA_HOTPLUG_ENABLE		(1 << 28) /* LPT:LP+ & BXT */
> +#define  BXT_DDIA_HPD_INVERT            (1 << 27)
>  #define  PORTA_HOTPLUG_STATUS_MASK	(3 << 24) /* SPT+ & BXT */
>  #define  PORTA_HOTPLUG_NO_DETECT	(0 << 24) /* SPT+ & BXT */
>  #define  PORTA_HOTPLUG_SHORT_DETECT	(1 << 24) /* SPT+ & BXT */
> @@ -6200,6 +6201,7 @@ enum skl_disp_power_wells {
>  #define  PORTD_HOTPLUG_SHORT_DETECT	(1 << 16)
>  #define  PORTD_HOTPLUG_LONG_DETECT	(2 << 16)
>  #define  PORTC_HOTPLUG_ENABLE		(1 << 12)
> +#define  BXT_DDIC_HPD_INVERT            (1 << 11)
>  #define  PORTC_PULSE_DURATION_2ms	(0 << 10) /* pre-LPT */
>  #define  PORTC_PULSE_DURATION_4_5ms	(1 << 10) /* pre-LPT */
>  #define  PORTC_PULSE_DURATION_6ms	(2 << 10) /* pre-LPT */
> @@ -6210,6 +6212,7 @@ enum skl_disp_power_wells {
>  #define  PORTC_HOTPLUG_SHORT_DETECT	(1 << 8)
>  #define  PORTC_HOTPLUG_LONG_DETECT	(2 << 8)
>  #define  PORTB_HOTPLUG_ENABLE		(1 << 4)
> +#define  BXT_DDIB_HPD_INVERT            (1 << 3)
>  #define  PORTB_PULSE_DURATION_2ms	(0 << 2) /* pre-LPT */
>  #define  PORTB_PULSE_DURATION_4_5ms	(1 << 2) /* pre-LPT */
>  #define  PORTB_PULSE_DURATION_6ms	(2 << 2) /* pre-LPT */
> @@ -6219,6 +6222,9 @@ enum skl_disp_power_wells {
>  #define  PORTB_HOTPLUG_NO_DETECT	(0 << 0)
>  #define  PORTB_HOTPLUG_SHORT_DETECT	(1 << 0)
>  #define  PORTB_HOTPLUG_LONG_DETECT	(2 << 0)
> +#define  BXT_DDI_HPD_INVERT_MASK	(BXT_DDIA_HPD_INVERT | \
> +					BXT_DDIB_HPD_INVERT | \
> +					BXT_DDIC_HPD_INVERT)
>  
>  #define PCH_PORT_HOTPLUG2		_MMIO(0xc403C)	/* SHOTPLUG_CTL2 SPT+ */
>  #define  PORTE_HOTPLUG_ENABLE		(1 << 4)
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index e2f636c..e015a95 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -107,6 +107,38 @@ find_section(const void *_bdb, int section_id)
>  	return NULL;
>  }
>  
> +bool
> +intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
> +				enum port port)
> +{
> +	int i;
> +
> +	if (WARN_ON_ONCE(!IS_BROXTON(dev_priv)))
> +		return false;
> +
> +	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
> +
> +		if (!dev_priv->vbt.child_dev[i].common.hpd_invert)
> +			continue;
> +
> +		switch (dev_priv->vbt.child_dev[i].common.dvo_port) {
> +		case DVO_PORT_DPA:
> +		case DVO_PORT_HDMIA:
> +			return port == PORT_A;
> +		case DVO_PORT_DPB:
> +		case DVO_PORT_HDMIB:
> +			return port == PORT_B;
> +		case DVO_PORT_DPC:
> +		case DVO_PORT_HDMIC:
> +			return port == PORT_C;

That doesn't actually work. Eg. if called with port==PORT_B and there's
a port A listed first in the VBT with hpd_invert==true, we'll end up
returning false always for PORT_B regardless of what VBT says we should
return for port B.

> +		default:
> +			break;
> +		}
> +	}
> +
> +	return false;
> +}
> +
>  static void
>  fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
>  			const struct lvds_dvo_timing *dvo_timing)
> -- 
> 2.6.1

-- 
Ville Syrjälä
Intel OTC
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