[Intel-gfx] [PATCH] drm/i915/glk: Enable cold boot for GLK DSI
Jani Nikula
jani.nikula at intel.com
Thu Jun 8 12:21:10 UTC 2017
On Sun, 04 Jun 2017, Madhav Chauhan <madhav.chauhan at intel.com> wrote:
> As per BSEPC, if device ready bit is '0' in enable IO sequence
> then its a cold boot/reset scenario eg: S3/S4 resume. In these
> conditions we need to program certain registers and prepare port
> from the middle of DSI enable sequence otherwise feature like S3/S4
> doesn't work.
>
> V2: Do not assume that on enable when power has not been lost,
> all the registers contain the correct information already.
> Program DSI registers for normal boot scenario from
> glk_dsi_device_ready() (Jani N).
Here's a few additional notes following our discussion.
First, please do this in two patches. Patch 1/2 to split
glk_dsi_device_ready into two parts, with no functional changes, and
calling the first part from intel_dsi_pre_enable. Patch 2/2 to make the
functional changes here.
> Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> ---
> drivers/gpu/drm/i915/intel_dsi.c | 82 +++++++++++++++++++++++++---------------
> 1 file changed, 51 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index fc0ef49..5582859 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -346,12 +346,17 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
> return true;
> }
>
> -static void glk_dsi_device_ready(struct intel_encoder *encoder)
> +static void intel_dsi_prepare(struct intel_encoder *intel_encoder,
> + struct intel_crtc_state *pipe_config);
> +
> +static void glk_dsi_device_ready(struct intel_encoder *encoder,
> + struct intel_crtc_state *pipe_config)
> {
> 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;
> + bool cold_boot = false;
>
> /* Set the MIPI mode
> * If MIPI_Mode is off, then writing to LP_Wake bit is not reflecting.
> @@ -370,7 +375,10 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
> /* Program LP Wake */
> for_each_dsi_port(port, intel_dsi->ports) {
> tmp = I915_READ(MIPI_CTRL(port));
> - tmp |= GLK_LP_WAKE;
> + if (!(I915_READ(MIPI_DEVICE_READY(port)) & DEVICE_READY))
> + tmp &= ~GLK_LP_WAKE;
> + else
> + tmp |= GLK_LP_WAKE;
> I915_WRITE(MIPI_CTRL(port), tmp);
> }
>
> @@ -382,6 +390,15 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
> DRM_ERROR("MIPIO port is powergated\n");
> }
>
> + /* Check if cold boot scenario */
> + for_each_dsi_port(port, intel_dsi->ports) {
> + cold_boot |= !(I915_READ(MIPI_DEVICE_READY(port)) &
> + DEVICE_READY);
> + }
Does device ready change mid-function here? Could you collect the cold
boot info in the previous loop above already?
BR,
Jani.
> +
> + if (cold_boot)
> + intel_dsi_prepare(encoder, pipe_config);
> +
> /* Wait for MIPI PHY status bit to set */
> for_each_dsi_port(port, intel_dsi->ports) {
> if (intel_wait_for_register(dev_priv,
> @@ -402,34 +419,34 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
> 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);
> + } else {
> + /* 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 active */
> - if (intel_wait_for_register(dev_priv,
> + /* Wait for ULPS active */
> + if (intel_wait_for_register(dev_priv,
> MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE, 0, 20))
> - DRM_ERROR("ULPS not active\n");
> + DRM_ERROR("ULPS not active\n");
>
> - /* 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);
> + /* 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);
> + /* 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);
> + tmp = I915_READ(MIPI_CTRL(port));
> + tmp &= ~GLK_LP_WAKE;
> + I915_WRITE(MIPI_CTRL(port), tmp);
> + }
> }
>
> /* Wait for Stop state */
> @@ -447,6 +464,9 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
> AFE_LATCHOUT, 20))
> DRM_ERROR("D-PHY not entering LP-11 state\n");
> }
> +
> + if (!cold_boot)
> + intel_dsi_prepare(encoder, pipe_config);
> }
>
> static void bxt_dsi_device_ready(struct intel_encoder *encoder)
> @@ -515,7 +535,8 @@ static void vlv_dsi_device_ready(struct intel_encoder *encoder)
> }
> }
>
> -static void intel_dsi_device_ready(struct intel_encoder *encoder)
> +static void intel_dsi_device_ready(struct intel_encoder *encoder,
> + struct intel_crtc_state *pipe_config)
> {
> struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>
> @@ -524,7 +545,7 @@ static void intel_dsi_device_ready(struct intel_encoder *encoder)
> else if (IS_BROXTON(dev_priv))
> bxt_dsi_device_ready(encoder);
> else if (IS_GEMINILAKE(dev_priv))
> - glk_dsi_device_ready(encoder);
> + glk_dsi_device_ready(encoder, pipe_config);
> }
>
> static void glk_dsi_enter_low_power_mode(struct intel_encoder *encoder)
> @@ -710,8 +731,6 @@ static void intel_dsi_port_disable(struct intel_encoder *encoder)
> }
> }
>
> -static void intel_dsi_prepare(struct intel_encoder *intel_encoder,
> - struct intel_crtc_state *pipe_config);
> static void intel_dsi_unprepare(struct intel_encoder *encoder);
>
> static void intel_dsi_msleep(struct intel_dsi *intel_dsi, int msec)
> @@ -800,7 +819,8 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder,
> I915_WRITE(DSPCLK_GATE_D, val);
> }
>
> - intel_dsi_prepare(encoder, pipe_config);
> + if (!IS_GEMINILAKE(dev_priv))
> + intel_dsi_prepare(encoder, pipe_config);
>
> /* Power on, try both CRC pmic gpio and VBT */
> if (intel_dsi->gpio_panel)
> @@ -812,7 +832,7 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder,
> intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
>
> /* Put device in ready state (LP-11) */
> - intel_dsi_device_ready(encoder);
> + intel_dsi_device_ready(encoder, pipe_config);
>
> /* Send initialization commands in LP mode */
> intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_INIT_OTP);
--
Jani Nikula, Intel Open Source Technology Center
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