drm/i915/dsi: add support for gpio elements on CHV

Add support for CHV gpio programming in DSI gpio elements.

v2: Overhaul macros according to Ville's review.

v3: Address Ville's review:
 - swap E and SE gpio ranges
 - add a note about max SE index
 - use GPO, not HIZ
 - swap cfg0 and cfg1

v4: fix port for dsi sequence versions 1 and 2

[Rewritten by Jani, based on earlier work by Yogesh and Deepak.]
Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: Deepak M <m.deepak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/bdaaf9915a5005305b31bb26cf619a5a82472f2a.1461666263.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_dsi_panel_vbt.c

@@ -95,6 +95,24 @@ static struct gpio_map vlv_gpio_table[] = {
 	{ VLV_GPIO_NC_11_PANEL1_BKLTCTL },
 };
 
+#define CHV_GPIO_IDX_START_N		0
+#define CHV_GPIO_IDX_START_E		73
+#define CHV_GPIO_IDX_START_SW		100
+#define CHV_GPIO_IDX_START_SE		198
+
+#define CHV_VBT_MAX_PINS_PER_FMLY	15
+
+#define CHV_GPIO_PAD_CFG0(f, i)		(0x4400 + (f) * 0x400 + (i) * 8)
+#define  CHV_GPIO_GPIOEN		(1 << 15)
+#define  CHV_GPIO_GPIOCFG_GPIO		(0 << 8)
+#define  CHV_GPIO_GPIOCFG_GPO		(1 << 8)
+#define  CHV_GPIO_GPIOCFG_GPI		(2 << 8)
+#define  CHV_GPIO_GPIOCFG_HIZ		(3 << 8)
+#define  CHV_GPIO_GPIOTXSTATE(state)	((!!(state)) << 1)
+
+#define CHV_GPIO_PAD_CFG1(f, i)		(0x4400 + (f) * 0x400 + (i) * 8 + 4)
+#define  CHV_GPIO_CFGLOCK		(1 << 31)
+
 static inline enum port intel_dsi_seq_port_to_port(u8 port)
 {
 	return port ? PORT_C : PORT_A;
@@ -232,6 +250,56 @@ static void vlv_exec_gpio(struct drm_i915_private *dev_priv,
 	mutex_unlock(&dev_priv->sb_lock);
 }
 
+static void chv_exec_gpio(struct drm_i915_private *dev_priv,
+			  u8 gpio_source, u8 gpio_index, bool value)
+{
+	u16 cfg0, cfg1;
+	u16 family_num;
+	u8 port;
+
+	if (dev_priv->vbt.dsi.seq_version >= 3) {
+		if (gpio_index >= CHV_GPIO_IDX_START_SE) {
+			/* XXX: it's unclear whether 255->57 is part of SE. */
+			gpio_index -= CHV_GPIO_IDX_START_SE;
+			port = CHV_IOSF_PORT_GPIO_SE;
+		} else if (gpio_index >= CHV_GPIO_IDX_START_SW) {
+			gpio_index -= CHV_GPIO_IDX_START_SW;
+			port = CHV_IOSF_PORT_GPIO_SW;
+		} else if (gpio_index >= CHV_GPIO_IDX_START_E) {
+			gpio_index -= CHV_GPIO_IDX_START_E;
+			port = CHV_IOSF_PORT_GPIO_E;
+		} else {
+			port = CHV_IOSF_PORT_GPIO_N;
+		}
+	} else {
+		/* XXX: The spec is unclear about CHV GPIO on seq v2 */
+		if (gpio_source != 0) {
+			DRM_DEBUG_KMS("unknown gpio source %u\n", gpio_source);
+			return;
+		}
+
+		if (gpio_index >= CHV_GPIO_IDX_START_E) {
+			DRM_DEBUG_KMS("invalid gpio index %u for GPIO N\n",
+				      gpio_index);
+			return;
+		}
+
+		port = CHV_IOSF_PORT_GPIO_N;
+	}
+
+	family_num = gpio_index / CHV_VBT_MAX_PINS_PER_FMLY;
+	gpio_index = gpio_index % CHV_VBT_MAX_PINS_PER_FMLY;
+
+	cfg0 = CHV_GPIO_PAD_CFG0(family_num, gpio_index);
+	cfg1 = CHV_GPIO_PAD_CFG1(family_num, gpio_index);
+
+	mutex_lock(&dev_priv->sb_lock);
+	vlv_iosf_sb_write(dev_priv, port, cfg1, 0);
+	vlv_iosf_sb_write(dev_priv, port, cfg0,
+			  CHV_GPIO_GPIOCFG_GPO | CHV_GPIO_GPIOTXSTATE(value));
+	mutex_unlock(&dev_priv->sb_lock);
+}
+
 static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
 {
 	struct drm_device *dev = intel_dsi->base.base.dev;
@@ -255,6 +323,8 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
 
 	if (IS_VALLEYVIEW(dev_priv))
 		vlv_exec_gpio(dev_priv, gpio_source, gpio_index, value);
+	else if (IS_CHERRYVIEW(dev_priv))
+		chv_exec_gpio(dev_priv, gpio_source, gpio_index, value);
 	else
 		DRM_DEBUG_KMS("GPIO element not supported on this platform\n");