Re: [GLK MIPI DSI V2 3/9] drm/i915/glk: Add MIPIIO Enable/disable sequence

[Jani Nikula <jani.nikula@intel.com>]

On Thu, 15 Dec 2016, Madhav Chauhan <madhav.chauhan@intel.com> wrote:
> From: Deepak M <m.deepak@intel.com>
>
> v2: Addressed Jani's Review comments(renamed bit field macros)
>
> Signed-off-by: Deepak M <m.deepak@intel.com>
> Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dsi.c | 134 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 134 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index b78c686..c0697e9 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -357,6 +357,134 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
>  	return true;
>  }
>  
> +static void intel_dsi_disable_mipiio(struct intel_encoder *encoder)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> +	enum port port;
> +	u32 tmp;
> +
> +	/* Put the IO into reset */
> +	tmp = I915_READ(MIPI_CTRL(PORT_A));
> +	tmp &= ~GLK_MIPIIO_RESET_RELEASED;
> +	I915_WRITE(MIPI_CTRL(PORT_A), tmp);
> +
> +	/* Wait for MIPI PHY status bit to unset */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (intel_wait_for_register(dev_priv,
> +				MIPI_CTRL(port),
> +				GLK_PHY_STATUS_PORT_READY, 0, 20))
> +			DRM_ERROR("PHY is not turning OFF\n");
> +	}
> +
> +	/* Clear MIPI mode */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		tmp = I915_READ(MIPI_CTRL(port));
> +		tmp &= ~GLK_MIPIIO_ENABLE;
> +		I915_WRITE(MIPI_CTRL(port), tmp);
> +	}
> +}
> +
> +static void intel_dsi_enable_mipiio(struct intel_encoder *encoder)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> +	enum port port;
> +	u32 tmp, val;
> +
> +	/* Put the IO into reset */
> +	tmp = I915_READ(MIPI_CTRL(PORT_A));
> +	tmp &= ~GLK_MIPIIO_RESET_RELEASED;
> +	I915_WRITE(MIPI_CTRL(PORT_A), tmp);
> +
> +	/* Program LP Wake */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		tmp = I915_READ(MIPI_CTRL(port));
> +		tmp &= ~GLK_LP_WAKE;
> +		I915_WRITE(MIPI_CTRL(port), tmp);
> +	}
> +
> +	/* Set the MIPI mode */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		tmp = I915_READ(MIPI_CTRL(port));
> +		I915_WRITE(MIPI_CTRL(port), tmp | GLK_MIPIIO_ENABLE);
> +	}
> +
> +	/* Wait for Pwr ACK */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (intel_wait_for_register(dev_priv,
> +				MIPI_CTRL(port), GLK_MIPIIO_PORT_POWERED,
> +				GLK_MIPIIO_PORT_POWERED, 20))
> +			DRM_ERROR("Power ACK not received\n");
> +	}
> +
> +	/* Wait for MIPI PHY status bit to set */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (intel_wait_for_register(dev_priv,
> +				MIPI_CTRL(port), GLK_MIPIIO_PORT_POWERED,
> +				GLK_MIPIIO_PORT_POWERED, 20))
> +			DRM_ERROR("PHY is not ON\n");
> +	}
> +
> +	/* Get IO out of reset */
> +	tmp = I915_READ(MIPI_CTRL(PORT_A));
> +	I915_WRITE(MIPI_CTRL(PORT_A), tmp | GLK_MIPIIO_RESET_RELEASED);
> +
> +	/* Get IO out of Low power state*/
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (!(I915_READ(MIPI_DEVICE_READY(port)) & DEVICE_READY)) {
> +			val = I915_READ(MIPI_DEVICE_READY(port));
> +			val &= ~ULPS_STATE_MASK;
> +			val |= DEVICE_READY;
> +			I915_WRITE(MIPI_DEVICE_READY(port), val);
> +			usleep_range(10, 15);
> +		}
> +
> +		/* Enter ULPS */
> +		val = I915_READ(MIPI_DEVICE_READY(port));
> +		val &= ~ULPS_STATE_MASK;
> +		val |= (ULPS_STATE_ENTER | DEVICE_READY);
> +		I915_WRITE(MIPI_DEVICE_READY(port), val);
> +
> +		/* Wait for ULPS Not active */
> +		if (intel_wait_for_register(dev_priv,
> +				MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE,
> +				GLK_ULPS_NOT_ACTIVE, 20))
> +
> +		/* Exit ULPS */
> +		val = I915_READ(MIPI_DEVICE_READY(port));
> +		val &= ~ULPS_STATE_MASK;
> +		val |= (ULPS_STATE_EXIT | DEVICE_READY);
> +		I915_WRITE(MIPI_DEVICE_READY(port), val);
> +
> +		/* Enter Normal Mode */
> +		val = I915_READ(MIPI_DEVICE_READY(port));
> +		val &= ~ULPS_STATE_MASK;
> +		val |= (ULPS_STATE_NORMAL_OPERATION | DEVICE_READY);
> +		I915_WRITE(MIPI_DEVICE_READY(port), val);
> +
> +		tmp = I915_READ(MIPI_CTRL(port));
> +		tmp &= ~GLK_LP_WAKE;
> +		I915_WRITE(MIPI_CTRL(port), tmp);
> +	}
> +
> +	/* Wait for Stop state */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (intel_wait_for_register(dev_priv,
> +				MIPI_CTRL(port), GLK_DATA_LANE_STOP_STATE,
> +				GLK_DATA_LANE_STOP_STATE, 20))
> +			DRM_ERROR("Date lane not in STOP state\n");
> +	}
> +
> +	/* Wait for AFE LATCH */
> +	for_each_dsi_port(port, intel_dsi->ports) {
> +		if (intel_wait_for_register(dev_priv,
> +				BXT_MIPI_PORT_CTRL(port), AFE_LATCHOUT,
> +				AFE_LATCHOUT, 20))
> +			DRM_ERROR("D-PHY not entering LP-11 state\n");
> +	}
> +}
> +

I'm wondering if these should just be GLK versions of
intel_dsi_device_ready and intel_dsi_clear_device_ready. It seems
totally wrong that you're doing device ready stuff twice on GLK...


>  static void bxt_dsi_device_ready(struct intel_encoder *encoder)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> @@ -559,6 +687,9 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder,
>  
>  	intel_dsi_prepare(encoder, pipe_config);
>  
> +	if (IS_GEMINILAKE(dev_priv))
> +		intel_dsi_enable_mipiio(encoder);
> +
>  	/* Panel Enable over CRC PMIC */
>  	if (intel_dsi->gpio_panel)
>  		gpiod_set_value_cansleep(intel_dsi->gpio_panel, 1);
> @@ -699,6 +830,9 @@ static void intel_dsi_clear_device_ready(struct intel_encoder *encoder)
>  		usleep_range(2000, 2500);
>  	}
>  
> +	if (IS_GEMINILAKE(dev_priv))
> +		intel_dsi_disable_mipiio(encoder);
> +

When you're doing enable/disable of something, they should be called
from the corresponding functions in the enable/disable paths. But this
is just a general remark, if we conclude that these should be
alternative device ready/unready calls instead.

BR,
Jani.


>  	intel_disable_dsi_pll(encoder);
>  }

-- 
Jani Nikula, Intel Open Source Technology Center
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