Re: [PATCH 7/8] drm/i915: Use the CRC gpio for panel enable/disable

Jani Nikula
2015-05-06T13:11:11Z

On Wed, 29 Apr 2015, Shobhit Kumar <shobhit.kumar@intel.com> wrote:
> The CRC (Crystal Cove) PMIC, controls the panel enable and disable
> signals for BYT for dsi panels. This is indicated in the VBT fields. Use
> that to initialize and use GPIO based control for these signals.
>
> v2: Use the newer gpiod interface(Alexandre)
> v3: Remove the redundant checks and unused code (Ville)
>
> CC: Samuel Ortiz <sameo@linux.intel.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Alexandre Courbot <gnurou@gmail.com>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
> ---
> drivers/gpu/drm/i915/intel_dsi.c | 32 ++++++++++++++++++++++++++++++--
> drivers/gpu/drm/i915/intel_dsi.h | 6 ++++++
> 2 files changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 5196642..be55ffa 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -31,6 +31,7 @@
> #include <drm/drm_panel.h>
> #include <drm/drm_mipi_dsi.h>
> #include <linux/slab.h>
> +#include <linux/gpio/consumer.h>
> #include "i915_drv.h"
> #include "intel_drv.h"
> #include "intel_dsi.h"
> @@ -415,6 +416,12 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
>
> DRM_DEBUG_KMS("\n");
>
> + /* Panel Enable over CRC PMIC */
> + if (intel_dsi->gpio_panel)
> + gpiod_set_value_cansleep(intel_dsi->gpio_panel, 1);
> +
> + msleep(intel_dsi->panel_on_delay);
> +
> /* Disable DPOunit clock gating, can stall pipe
> * and we need DPLL REFA always enabled */
> tmp = I915_READ(DPLL(pipe));
> @@ -432,8 +439,6 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
> /* put device in ready state */
> intel_dsi_device_ready(encoder);
>
> - msleep(intel_dsi->panel_on_delay);
> -
> drm_panel_prepare(intel_dsi->panel);
>
> for_each_dsi_port(port, intel_dsi->ports)
> @@ -576,6 +581,10 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder)
>
> msleep(intel_dsi->panel_off_delay);
> msleep(intel_dsi->panel_pwr_cycle_delay);
> +
> + /* Panel Disable over CRC PMIC */
> + if (intel_dsi->gpio_panel)
> + gpiod_set_value_cansleep(intel_dsi->gpio_panel, 0);
> }
>
> static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
> @@ -955,6 +964,11 @@ static void intel_dsi_encoder_destroy(struct drm_encoder *encoder)
> /* XXX: Logically this call belongs in the panel driver. */
> drm_panel_remove(intel_dsi->panel);
> }
> +
> + /* dispose of the gpios */
> + if (intel_dsi->gpio_panel)
> + gpiod_put(intel_dsi->gpio_panel);
> +
> intel_encoder_destroy(encoder);
> }
>
> @@ -1071,6 +1085,20 @@ void intel_dsi_init(struct drm_device *dev)
> goto err;
> }
>
> + /*
> + * In case of BYT with CRC PMIC, we need to use GPIO for
> + * Panel control.
> + */
> + if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) {
> + intel_dsi->gpio_panel =
> + gpiod_get(dev->dev, "panel", GPIOD_OUT_HIGH);
> +
> + if (IS_ERR(intel_dsi->gpio_panel)) {
> + DRM_ERROR("Failed to own gpio for panel control\n");
> + intel_dsi->gpio_panel = NULL;
> + }
> + }
> +
> intel_encoder->type = INTEL_OUTPUT_DSI;
> intel_encoder->cloneable = 0;
> drm_connector_init(dev, connector, &intel_dsi_connector_funcs,
> diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
> index 2784ac4..bf1bade 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.h
> +++ b/drivers/gpu/drm/i915/intel_dsi.h
> @@ -29,6 +29,9 @@
> #include <drm/drm_mipi_dsi.h>
> #include "intel_drv.h"
>
> +#define PPS_BLC_PMIC 0
> +#define PPS_BLC_SOC 1

Since these values are defined in the VBT, perhaps these should be in
intel_bios.h. Up to you, I'm fine either way.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> +
> /* Dual Link support */
> #define DSI_DUAL_LINK_NONE 0
> #define DSI_DUAL_LINK_FRONT_BACK 1
> @@ -42,6 +45,9 @@ struct intel_dsi {
> struct drm_panel *panel;
> struct intel_dsi_host *dsi_hosts[I915_MAX_PORTS];
>
> + /* GPIO Desc for CRC based Panel control */
> + struct gpio_desc *gpio_panel;
> +
> struct intel_connector *attached_connector;
>
> /* bit mask of ports being driven */
> --
> 2.1.0
>

--
Jani Nikula, Intel Open Source Technology Center