drm/i915/dsi: add support for ICL+ native MIPI GPIO sequence

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.

v5:
- Wrap SHOTPLUG_CTL_DDI modification in spin_lock() in icp_irq_handler()
  too (Ville)
- References instead of Closes issue 6131 because this does not fix everything

v4:
- Wrap SHOTPLUG_CTL_DDI modification in spin_lock_irq() (Ville)

v3:
- Fix -Wbitwise-conditional-parentheses (kernel test robot <lkp@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()

References: https://gitlab.freedesktop.org/drm/intel/-/issues/6131
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219105955.4014451-1-jani.nikula@intel.com

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 +379,85 @@ 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. The HPD pin should not be enabled for DSI anyway,
+		 * assuming the board design and VBT are sane, and the pin isn't
+		 * used by a non-DSI encoder.
+		 *
+		 * The locking protects against concurrent SHOTPLUG_CTL_DDI
+		 * modifications in irq setup and handling.
+		 */
+		spin_lock_irq(&dev_priv->irq_lock);
+		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);
+		spin_unlock_irq(&dev_priv->irq_lock);
+		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 +465,7 @@ 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 +478,18 @@ 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);

drivers/gpu/drm/i915/i915_irq.c

@@ -1973,7 +1973,10 @@ static void icp_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 	if (ddi_hotplug_trigger) {
 		u32 dig_hotplug_reg;
 
+		/* Locking due to DSI native GPIO sequences */
+		spin_lock(&dev_priv->irq_lock);
 		dig_hotplug_reg = intel_uncore_rmw(&dev_priv->uncore, SHOTPLUG_CTL_DDI, 0, 0);
+		spin_unlock(&dev_priv->irq_lock);
 
 		intel_get_hpd_pins(dev_priv, &pin_mask, &long_mask,
 				   ddi_hotplug_trigger, dig_hotplug_reg,

drivers/gpu/drm/i915/i915_reg.h

@@ -5962,6 +5962,7 @@
 
 #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))