[PATCH v1] drm/i915/bxt: use NULL for GPIO connection ID

[Andy Shevchenko]

The commit 213e08ad60ba ("drm/i915/bxt: add bxt dsi gpio element
support") enables GPIO support for Broxton based platforms.

While using that API we might get into troubles in the future, because
we can't rely on label "panel" in the driver since vendor firmware might
provide any GPIO pin there, e.g. "reset", and even mark it in _DSD (in
which case the request will fail).

To avoid inconsistency and potential issues we have two options:
a) generate GPIO ACPI mapping table and supply it via
acpi_dev_add_driver_gpios(), or
b) just pass NULL as connection ID.

The b) approach is much simplier and would work since the driver relies
on GPIO indeces only. Moreover, the _CRS fallback mechanism, when
requesting GPIO, is going to be stricter, and supplying non-NULL
connection ID when neither _DSD, nor GPIO ACPI mapping is present, will
make request fail.

Cc: Mika Kahola <mika.kahola at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dsi_panel_vbt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
index 8f683b8b1816..493d5ec2b53a 100644
--- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
+++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
@@ -315,7 +315,7 @@ static void bxt_exec_gpio(struct drm_i915_private *dev_priv,
 
 	if (!gpio_desc) {
 		gpio_desc = devm_gpiod_get_index(dev_priv->drm.dev,
-						 "panel", gpio_index,
+						 NULL, gpio_index,
 						 value ? GPIOD_OUT_LOW :
 						 GPIOD_OUT_HIGH);
 
-- 
2.11.0