drm/i915/dsi: clarify GPIO exec sequence

With the various sequence versions and pointer increments interleaved,
it's a bit hard to decipher what's going on. Add separate paths for
different sequence versions.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231103201831.1037416-4-andriy.shevchenko@linux.intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
index 8b962f2ac475a7d7456dd832cd1c99fa3c2ff03b..11073efe26c041ea4fc816bb9689585a120e2bcb 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
@@ -456,26 +456,29 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
        struct drm_device *dev = intel_dsi->base.base.dev;
        struct drm_i915_private *i915 = to_i915(dev);
        struct intel_connector *connector = intel_dsi->attached_connector;
-       u8 gpio_source, gpio_index = 0, gpio_number;
+       u8 gpio_source = 0, gpio_index = 0, gpio_number;
        bool value;
+       int size;
        bool native = DISPLAY_VER(i915) >= 11;
 
-       if (connector->panel.vbt.dsi.seq_version >= 3)
-               gpio_index = *data++;
+       if (connector->panel.vbt.dsi.seq_version >= 3) {
+               size = 3;
 
-       gpio_number = *data++;
+               gpio_index = data[0];
+               gpio_number = data[1];
+               value = data[2] & BIT(0);
 
-       /* gpio source in sequence v2 only */
-       if (connector->panel.vbt.dsi.seq_version == 2)
-               gpio_source = (*data >> 1) & 3;
-       else
-               gpio_source = 0;
+               if (connector->panel.vbt.dsi.seq_version >= 4 && data[2] & BIT(1))
+                       native = false;
+       } else {
+               size = 2;
 
-       if (connector->panel.vbt.dsi.seq_version >= 4 && *data & BIT(1))
-               native = false;
+               gpio_number = data[0];
+               value = data[1] & BIT(0);
 
-       /* pull up/down */
-       value = *data++ & 1;
+               if (connector->panel.vbt.dsi.seq_version == 2)
+                       gpio_source = (data[1] >> 1) & 3;
+       }
 
        drm_dbg_kms(&i915->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));
@@ -491,7 +494,7 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
        else
                bxt_exec_gpio(connector, gpio_source, gpio_index, value);
 
-       return data;
+       return data + size;
 }
 
 #ifdef CONFIG_ACPI