[Intel-gfx] [PATCH v3] drm/i915/dsi: add support for ICL+ native MIPI GPIO sequence

Jani Nikula jani.nikula at intel.com
Tue Dec 13 09:56:40 UTC 2022


On Tue, 13 Dec 2022, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Mon, Dec 12, 2022 at 04:37:53PM +0200, Jani Nikula wrote:
>> Starting from ICL, the default for MIPI GPIO sequences seems to be using
>> native GPIOs i.e. GPIOs available in the GPU. These native GPIOs reuse
>> many pins that quite frankly seem scary to poke based on the VBT
>> sequences. We pretty much have to trust that the board is configured
>> such that the relevant HPD, PP_CONTROL and GPIO bits aren't used for
>> anything else.
>> 
>> MIPI sequence v4 also adds a flag to fall back to non-native sequences.
>> 
>> v3:
>> - Fix -Wbitwise-conditional-parentheses (kernel test robot <lkp at intel.com>)
>> 
>> v2:
>> - Fix HPD pin output set (impacts GPIOs 0 and 5)
>> - Fix GPIO data output direction set (impacts GPIOs 4 and 9)
>> - Reduce register accesses to single intel_de_rwm()
>> 
>> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6131
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 84 +++++++++++++++++++-
>>  drivers/gpu/drm/i915/i915_reg.h              |  1 +
>>  2 files changed, 82 insertions(+), 3 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
>> index fce69fa446d5..f19020074ee3 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
>> @@ -41,9 +41,11 @@
>>  
>>  #include "i915_drv.h"
>>  #include "i915_reg.h"
>> +#include "intel_de.h"
>>  #include "intel_display_types.h"
>>  #include "intel_dsi.h"
>>  #include "intel_dsi_vbt.h"
>> +#include "intel_gmbus_regs.h"
>>  #include "vlv_dsi.h"
>>  #include "vlv_dsi_regs.h"
>>  #include "vlv_sideband.h"
>> @@ -377,6 +379,75 @@ static void icl_exec_gpio(struct intel_connector *connector,
>>  	drm_dbg_kms(&dev_priv->drm, "Skipping ICL GPIO element execution\n");
>>  }
>>  
>> +enum {
>> +	MIPI_RESET_1 = 0,
>> +	MIPI_AVDD_EN_1,
>> +	MIPI_BKLT_EN_1,
>> +	MIPI_AVEE_EN_1,
>> +	MIPI_VIO_EN_1,
>> +	MIPI_RESET_2,
>> +	MIPI_AVDD_EN_2,
>> +	MIPI_BKLT_EN_2,
>> +	MIPI_AVEE_EN_2,
>> +	MIPI_VIO_EN_2,
>> +};
>> +
>> +static void icl_native_gpio_set_value(struct drm_i915_private *dev_priv,
>> +				      int gpio, bool value)
>> +{
>> +	int index;
>> +
>> +	if (drm_WARN_ON(&dev_priv->drm, DISPLAY_VER(dev_priv) == 11 && gpio >= MIPI_RESET_2))
>> +		return;
>> +
>> +	switch (gpio) {
>> +	case MIPI_RESET_1:
>> +	case MIPI_RESET_2:
>> +		index = gpio == MIPI_RESET_1 ? HPD_PORT_A : HPD_PORT_B;
>> +
>> +		/* Disable HPD to set the pin to output, and set output value */
>> +		intel_de_rmw(dev_priv, SHOTPLUG_CTL_DDI,
>> +			     SHOTPLUG_CTL_DDI_HPD_ENABLE(index) |
>> +			     SHOTPLUG_CTL_DDI_HPD_OUTPUT_DATA(index),
>> +			     value ? SHOTPLUG_CTL_DDI_HPD_OUTPUT_DATA(index) : 0);
>
> This looks like it could race with hpd irq handling/setup. Assuming
> one of the pins could be used for DSI and other for eg. HDMI.

Right. Looks like it should be enough to wrap the above in
spin_lock_irq(&dev_priv->irq_lock).

AFAICT the DSI encoder having encoder->hpd_pin == HPD_NONE covers not
clobbering SHOTPLUG_CTL_DDI_HPD_ENABLE(index) in irq setup *assuming*
the board design and VBT are sane, and the pin doesn't conflict with
some other encoder.

BR,
Jani.


>
>> +		break;
>> +	case MIPI_AVDD_EN_1:
>> +	case MIPI_AVDD_EN_2:
>> +		index = gpio == MIPI_AVDD_EN_1 ? 0 : 1;
>> +
>> +		intel_de_rmw(dev_priv, PP_CONTROL(index), PANEL_POWER_ON,
>> +			     value ? PANEL_POWER_ON : 0);
>> +		break;
>> +	case MIPI_BKLT_EN_1:
>> +	case MIPI_BKLT_EN_2:
>> +		index = gpio == MIPI_AVDD_EN_1 ? 0 : 1;
>> +
>> +		intel_de_rmw(dev_priv, PP_CONTROL(index), EDP_BLC_ENABLE,
>> +			     value ? EDP_BLC_ENABLE : 0);
>> +		break;
>> +	case MIPI_AVEE_EN_1:
>> +	case MIPI_AVEE_EN_2:
>> +		index = gpio == MIPI_AVEE_EN_1 ? 1 : 2;
>> +
>> +		intel_de_rmw(dev_priv, GPIO(dev_priv, index),
>> +			     GPIO_CLOCK_VAL_OUT,
>> +			     GPIO_CLOCK_DIR_MASK | GPIO_CLOCK_DIR_OUT |
>> +			     GPIO_CLOCK_VAL_MASK | (value ? GPIO_CLOCK_VAL_OUT : 0));
>> +		break;
>> +	case MIPI_VIO_EN_1:
>> +	case MIPI_VIO_EN_2:
>> +		index = gpio == MIPI_VIO_EN_1 ? 1 : 2;
>> +
>> +		intel_de_rmw(dev_priv, GPIO(dev_priv, index),
>> +			     GPIO_DATA_VAL_OUT,
>> +			     GPIO_DATA_DIR_MASK | GPIO_DATA_DIR_OUT |
>> +			     GPIO_DATA_VAL_MASK | (value ? GPIO_DATA_VAL_OUT : 0));
>> +		break;
>> +	default:
>> +		MISSING_CASE(gpio);
>> +	}
>> +}
>> +
>>  static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
>>  {
>>  	struct drm_device *dev = intel_dsi->base.base.dev;
>> @@ -384,8 +455,7 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
>>  	struct intel_connector *connector = intel_dsi->attached_connector;
>>  	u8 gpio_source, gpio_index = 0, gpio_number;
>>  	bool value;
>> -
>> -	drm_dbg_kms(&dev_priv->drm, "\n");
>> +	bool native = DISPLAY_VER(dev_priv) >= 11;
>>  
>>  	if (connector->panel.vbt.dsi.seq_version >= 3)
>>  		gpio_index = *data++;
>> @@ -398,10 +468,18 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
>>  	else
>>  		gpio_source = 0;
>>  
>> +	if (connector->panel.vbt.dsi.seq_version >= 4 && *data & BIT(1))
>> +		native = false;
>> +
>>  	/* pull up/down */
>>  	value = *data++ & 1;
>>  
>> -	if (DISPLAY_VER(dev_priv) >= 11)
>> +	drm_dbg_kms(&dev_priv->drm, "GPIO index %u, number %u, source %u, native %s, set to %s\n",
>> +		    gpio_index, gpio_number, gpio_source, str_yes_no(native), str_on_off(value));
>> +
>> +	if (native)
>> +		icl_native_gpio_set_value(dev_priv, gpio_number, value);
>> +	else if (DISPLAY_VER(dev_priv) >= 11)
>>  		icl_exec_gpio(connector, gpio_source, gpio_index, value);
>>  	else if (IS_VALLEYVIEW(dev_priv))
>>  		vlv_exec_gpio(connector, gpio_source, gpio_number, value);
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 2b7a63754e4d..7008d04a06b8 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -5965,6 +5965,7 @@
>>  
>>  #define SHOTPLUG_CTL_DDI				_MMIO(0xc4030)
>>  #define   SHOTPLUG_CTL_DDI_HPD_ENABLE(hpd_pin)			(0x8 << (_HPD_PIN_DDI(hpd_pin) * 4))
>> +#define   SHOTPLUG_CTL_DDI_HPD_OUTPUT_DATA(hpd_pin)		(0x4 << (_HPD_PIN_DDI(hpd_pin) * 4))
>>  #define   SHOTPLUG_CTL_DDI_HPD_STATUS_MASK(hpd_pin)		(0x3 << (_HPD_PIN_DDI(hpd_pin) * 4))
>>  #define   SHOTPLUG_CTL_DDI_HPD_NO_DETECT(hpd_pin)		(0x0 << (_HPD_PIN_DDI(hpd_pin) * 4))
>>  #define   SHOTPLUG_CTL_DDI_HPD_SHORT_DETECT(hpd_pin)		(0x1 << (_HPD_PIN_DDI(hpd_pin) * 4))
>> -- 
>> 2.34.1

-- 
Jani Nikula, Intel Open Source Graphics Center


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