[v4 4/5] drm/mediatek: control dpi pins dpi or gpio mode in on or off

[Jitao Shi <jitao.shi@xxxxxxxxxxxx>]

Pull dpi pins low when dpi has nothing to display. Aovid leakage
current from some dpi pins (Hsync Vsync DE ... ).

Some chips have dpi pins, but there are some chip don't have pins.
So this function is controlled by chips driver data.

Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 35 +++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 77e6e0f99188..0c4ba0a2be27 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -17,10 +17,12 @@
 #include <drm/drm_of.h>
 #include <linux/kernel.h>
 #include <linux/component.h>
-#include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/of_graph.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/types.h>
 #include <linux/clk.h>
@@ -79,6 +81,9 @@ struct mtk_dpi {
 	enum mtk_dpi_out_yc_map yc_map;
 	enum mtk_dpi_out_bit_num bit_num;
 	enum mtk_dpi_out_channel_swap channel_swap;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pins_default;
+	struct pinctrl_state *pins_dpi;
 	int refcount;
 };
 
@@ -118,6 +123,7 @@ struct mtk_dpi_conf {
 	u32 reg_h_fre_con;
 	bool edge_sel_en;
 	bool dual_edge;
+	bool dpi_pin_ctrl;
 };
 
 static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -392,6 +398,9 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 	if (--dpi->refcount != 0)
 		return;
 
+	if (dpi->conf->dpi_pin_ctrl)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_default);
+
 	mtk_dpi_disable(dpi);
 	clk_disable_unprepare(dpi->pixel_clk);
 	clk_disable_unprepare(dpi->engine_clk);
@@ -416,6 +425,9 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 		goto err_pixel;
 	}
 
+	if (dpi->conf->dpi_pin_ctrl)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
+
 	mtk_dpi_enable(dpi);
 	return 0;
 
@@ -724,6 +736,27 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 	dpi->dev = dev;
 	dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
 
+	if (dpi->conf->dpi_pin_ctrl) {
+		dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
+		if (IS_ERR(dpi->pinctrl)) {
+			dev_err(&pdev->dev, "Cannot find pinctrl!\n");
+			return PTR_ERR(dpi->pinctrl);
+		}
+
+		dpi->pins_default = pinctrl_lookup_state(dpi->pinctrl,
+							 "default");
+		if (IS_ERR(dpi->pins_default)) {
+			dev_err(&pdev->dev, "Cannot find pinctrl default!\n");
+			return PTR_ERR(dpi->pins_default);
+		}
+
+		dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "dpimode");
+		if (IS_ERR(dpi->pins_dpi)) {
+			dev_err(&pdev->dev, "Cannot find pinctrl dpimode!\n");
+			return PTR_ERR(dpi->pins_dpi);
+		}
+	}
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dpi->regs = devm_ioremap_resource(dev, mem);
 	if (IS_ERR(dpi->regs)) {
-- 
2.21.0