[PATCH/RFC 8/7] drm: omapdrm: Handle DSI pin muxing internally

[Laurent Pinchart]

Don't rely on callback functions provided by the platform, but access
the syscon internally to mux the DSI pins.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 drivers/gpu/drm/omapdrm/dss/core.c | 20 ----------
 drivers/gpu/drm/omapdrm/dss/dsi.c  | 82 ++++++++++++++++++++++++++++++++++++--
 drivers/gpu/drm/omapdrm/dss/dss.h  |  2 -
 3 files changed, 79 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/core.c b/drivers/gpu/drm/omapdrm/dss/core.c
index b7c44b85b7c3..b173f2889819 100644
--- a/drivers/gpu/drm/omapdrm/dss/core.c
+++ b/drivers/gpu/drm/omapdrm/dss/core.c
@@ -76,26 +76,6 @@ struct platform_device *dss_get_core_pdev(void)
 	return core.pdev;
 }
 
-int dss_dsi_enable_pads(int dsi_id, unsigned lane_mask)
-{
-	struct omap_dss_board_info *board_data = core.pdev->dev.platform_data;
-
-	if (!board_data->dsi_enable_pads)
-		return -ENOENT;
-
-	return board_data->dsi_enable_pads(dsi_id, lane_mask);
-}
-
-void dss_dsi_disable_pads(int dsi_id, unsigned lane_mask)
-{
-	struct omap_dss_board_info *board_data = core.pdev->dev.platform_data;
-
-	if (!board_data->dsi_disable_pads)
-		return;
-
-	return board_data->dsi_disable_pads(dsi_id, lane_mask);
-}
-
 int dss_set_min_bus_tput(struct device *dev, unsigned long tput)
 {
 	struct omap_dss_board_info *pdata = core.pdev->dev.platform_data;
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index f060bda31235..febb7b73847b 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -20,6 +20,8 @@
 #define DSS_SUBSYS_NAME "DSI"
 
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/device.h>
@@ -311,6 +313,7 @@ struct dsi_data {
 	bool is_enabled;
 
 	struct clk *dss_clk;
+	struct regmap *syscon;
 
 	struct dispc_clock_info user_dispc_cinfo;
 	struct dss_pll_clock_info user_dsi_cinfo;
@@ -2060,6 +2063,64 @@ static unsigned dsi_get_lane_mask(struct platform_device *dsidev)
 	return mask;
 }
 
+/* OMAP4 CONTROL_DSIPHY */
+#define OMAP4_DSIPHY_SYSCON_OFFSET			0x78
+
+#define OMAP4_DSI2_LANEENABLE_SHIFT			29
+#define OMAP4_DSI2_LANEENABLE_MASK			(0x7 << 29)
+#define OMAP4_DSI1_LANEENABLE_SHIFT			24
+#define OMAP4_DSI1_LANEENABLE_MASK			(0x1f << 24)
+#define OMAP4_DSI1_PIPD_SHIFT				19
+#define OMAP4_DSI1_PIPD_MASK				(0x1f << 19)
+#define OMAP4_DSI2_PIPD_SHIFT				14
+#define OMAP4_DSI2_PIPD_MASK				(0x1f << 14)
+
+static int dsi_omap4_mux_pads(struct dsi_data *dsi, unsigned int lanes)
+{
+	u32 enable_mask, enable_shift;
+	u32 pipd_mask, pipd_shift;
+	u32 reg;
+
+	if (!dsi->syscon)
+		return 0;
+
+	if (dsi->module_id == 0) {
+		enable_mask = OMAP4_DSI1_LANEENABLE_MASK;
+		enable_shift = OMAP4_DSI1_LANEENABLE_SHIFT;
+		pipd_mask = OMAP4_DSI1_PIPD_MASK;
+		pipd_shift = OMAP4_DSI1_PIPD_SHIFT;
+	} else if (dsi->module_id == 1) {
+		enable_mask = OMAP4_DSI2_LANEENABLE_MASK;
+		enable_shift = OMAP4_DSI2_LANEENABLE_SHIFT;
+		pipd_mask = OMAP4_DSI2_PIPD_MASK;
+		pipd_shift = OMAP4_DSI2_PIPD_SHIFT;
+	} else {
+		return -ENODEV;
+	}
+
+	regmap_read(dsi->syscon, OMAP4_DSIPHY_SYSCON_OFFSET, &reg);
+
+	reg &= ~enable_mask;
+	reg &= ~pipd_mask;
+
+	reg |= (lanes << enable_shift) & enable_mask;
+	reg |= (lanes << pipd_shift) & pipd_mask;
+
+	regmap_write(dsi->syscon, OMAP4_DSIPHY_SYSCON_OFFSET, reg);
+
+	return 0;
+}
+
+static int dsi_enable_pads(struct dsi_data *dsi, unsigned int lane_mask)
+{
+	return dsi_omap4_mux_pads(dsi, lane_mask);
+}
+
+static void dsi_disable_pads(struct dsi_data *dsi)
+{
+	dsi_omap4_mux_pads(dsi, 0);
+}
+
 static int dsi_cio_init(struct platform_device *dsidev)
 {
 	struct dsi_data *dsi = dsi_get_dsidrv_data(dsidev);
@@ -2068,7 +2129,7 @@ static int dsi_cio_init(struct platform_device *dsidev)
 
 	DSSDBG("DSI CIO init starts");
 
-	r = dss_dsi_enable_pads(dsi->module_id, dsi_get_lane_mask(dsidev));
+	r = dsi_enable_pads(dsi, dsi_get_lane_mask(dsidev));
 	if (r)
 		return r;
 
@@ -2178,7 +2239,7 @@ static int dsi_cio_init(struct platform_device *dsidev)
 		dsi_cio_disable_lane_override(dsidev);
 err_scp_clk_dom:
 	dsi_disable_scp_clk(dsidev);
-	dss_dsi_disable_pads(dsi->module_id, dsi_get_lane_mask(dsidev));
+	dsi_disable_pads(dsi);
 	return r;
 }
 
@@ -2191,7 +2252,7 @@ static void dsi_cio_uninit(struct platform_device *dsidev)
 
 	dsi_cio_power(dsidev, DSI_COMPLEXIO_POWER_OFF);
 	dsi_disable_scp_clk(dsidev);
-	dss_dsi_disable_pads(dsi->module_id, dsi_get_lane_mask(dsidev));
+	dsi_disable_pads(dsi);
 }
 
 static void dsi_config_tx_fifo(struct platform_device *dsidev,
@@ -5411,6 +5472,21 @@ static int dsi_bind(struct device *dev, struct device *master, void *data)
 		dsi->module_id = dsidev->id;
 	}
 
+	if (of_device_is_compatible(dsidev->dev.of_node, "ti,omap4-isp")) {
+		struct device_node *np;
+
+		/*
+		 * The OMAP4 display DT bindings don't reference the padconf
+		 * syscon. Our only option to retrieve it is to find it by name.
+		 */
+		np = of_find_node_by_name(NULL, "omap4_padconf_global");
+		if (!np)
+			return -ENODEV;
+
+		dsi->syscon = syscon_node_to_regmap(np);
+		of_node_put(np);
+	}
+
 	/* DSI VCs initialization */
 	for (i = 0; i < ARRAY_SIZE(dsi->vc); i++) {
 		dsi->vc[i].source = DSI_VC_SOURCE_L4;
diff --git a/drivers/gpu/drm/omapdrm/dss/dss.h b/drivers/gpu/drm/omapdrm/dss/dss.h
index 56493b290731..32b1586719f9 100644
--- a/drivers/gpu/drm/omapdrm/dss/dss.h
+++ b/drivers/gpu/drm/omapdrm/dss/dss.h
@@ -223,8 +223,6 @@ struct platform_device;
 
 /* core */
 struct platform_device *dss_get_core_pdev(void);
-int dss_dsi_enable_pads(int dsi_id, unsigned lane_mask);
-void dss_dsi_disable_pads(int dsi_id, unsigned lane_mask);
 int dss_set_min_bus_tput(struct device *dev, unsigned long tput);
 int dss_debugfs_create_file(const char *name, void (*write)(struct seq_file *));
 
-- 
Regards,

Laurent Pinchart