[Intel-gfx] [PATCH v2] drm/i915/bxt: add bxt dsi gpio element support

[Bob Paauwe]

On Tue, 13 Dec 2016 16:11:20 +0200
Jani Nikula <jani.nikula at intel.com> wrote:

> On Mon, 05 Dec 2016, Mika Kahola <mika.kahola at intel.com> wrote:
> > From: Jani Nikula <jani.nikula at intel.com>
> >
> > Request the GPIO by index through the consumer API. For now, use a quick
> > hack to store the already requested ones, simply because I have no idea
> > whether this actually works or not, and I have no way to test it.
> >
> > v2: switch *NULL* to *"panel"* when requesting gpio for MIPI/DSI panel. (Mika)
> >

Jani, Mika,

I'm working on getting a dual-link MIPI panel working on BXT and have a
problem getting the proper GPIO pins set.  This patch gets things
closer, but at least for the platform I'm working on, there's one GPIO
pin (backlight/panel control) that doesn't seem to be available via the
consumer API.  If I use the alternate#2 method that Jani posted
(legacy GPIO API) along with the proper defines I can set this pin. I'm
using:


#define BXT_PANEL1_VDDEN_PIN       196
#define BXT_PANEL1_BKLTEN_PIN      197
#define BXT_PANEL1_BKLTCTL_PIN     198

#define BXT_PANEL1_VDDEN_OFFSET    366
#define BXT_PANEL1_BKLTEN_OFFSET   367
#define BXT_PANEL1_BKLTCTL_OFFSET  368

to create my GPIO table.  

These three pins need to be set VDDEN, BKLTCTL, BKLTEN, in that order
to get the panel to turn on.

For testing, I have a call in the vbt_panel_prepare() to set the pin
and one in vbt_panel_unprepare() to clear it.  That works but that
doesn't seem like the right solution.  I was wondering if either of you
have any insights?

Bob

> > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> > Signed-off-by: Mika Kahola <mika.kahola at intel.com>  
> 
> Pushed to dinq.
> 
> BR,
> Jani.
> 
> > ---
> >  drivers/gpu/drm/i915/intel_dsi_panel_vbt.c | 38 +++++++++++++++++++++++++-----
> >  1 file changed, 32 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> > index 0d8ff00..dda678b 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> > +++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> > @@ -29,6 +29,7 @@
> >  #include <drm/drm_edid.h>
> >  #include <drm/i915_drm.h>
> >  #include <drm/drm_panel.h>
> > +#include <linux/gpio/consumer.h>
> >  #include <linux/slab.h>
> >  #include <video/mipi_display.h>
> >  #include <asm/intel-mid.h>
> > @@ -304,19 +305,44 @@ static void chv_exec_gpio(struct drm_i915_private *dev_priv,
> >  	mutex_unlock(&dev_priv->sb_lock);
> >  }
> >  
> > +static void bxt_exec_gpio(struct drm_i915_private *dev_priv,
> > +			  u8 gpio_source, u8 gpio_index, bool value)
> > +{
> > +	/* XXX: this table is a quick ugly hack. */
> > +	static struct gpio_desc *bxt_gpio_table[U8_MAX + 1];
> > +	struct gpio_desc *gpio_desc = bxt_gpio_table[gpio_index];
> > +
> > +	if (!gpio_desc) {
> > +		gpio_desc = devm_gpiod_get_index(dev_priv->drm.dev,
> > +						 "panel", gpio_index,
> > +						 value ? GPIOD_OUT_LOW :
> > +						 GPIOD_OUT_HIGH);
> > +
> > +		if (IS_ERR_OR_NULL(gpio_desc)) {
> > +			DRM_ERROR("GPIO index %u request failed (%ld)\n",
> > +				  gpio_index, PTR_ERR(gpio_desc));
> > +			return;
> > +		}
> > +
> > +		bxt_gpio_table[gpio_index] = gpio_desc;
> > +	}
> > +
> > +	gpiod_set_value(gpio_desc, value);
> > +}
> > +
> >  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 *dev_priv = to_i915(dev);
> > -	u8 gpio_source, gpio_index;
> > +	u8 gpio_source, gpio_index = 0, gpio_number;
> >  	bool value;
> >  
> >  	DRM_DEBUG_KMS("\n");
> >  
> >  	if (dev_priv->vbt.dsi.seq_version >= 3)
> > -		data++;
> > +		gpio_index = *data++;
> >  
> > -	gpio_index = *data++;
> > +	gpio_number = *data++;
> >  
> >  	/* gpio source in sequence v2 only */
> >  	if (dev_priv->vbt.dsi.seq_version == 2)
> > @@ -328,11 +354,11 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
> >  	value = *data++ & 1;
> >  
> >  	if (IS_VALLEYVIEW(dev_priv))
> > -		vlv_exec_gpio(dev_priv, gpio_source, gpio_index, value);
> > +		vlv_exec_gpio(dev_priv, gpio_source, gpio_number, value);
> >  	else if (IS_CHERRYVIEW(dev_priv))
> > -		chv_exec_gpio(dev_priv, gpio_source, gpio_index, value);
> > +		chv_exec_gpio(dev_priv, gpio_source, gpio_number, value);
> >  	else
> > -		DRM_DEBUG_KMS("GPIO element not supported on this platform\n");
> > +		bxt_exec_gpio(dev_priv, gpio_source, gpio_index, value);
> >  
> >  	return data;
> >  }  
> 



-- 
--
Bob Paauwe                  
Bob.J.Paauwe at intel.com
IOTG / PED Software Organization
Intel Corp.  Folsom, CA
(916) 356-6193