drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

BugLink: https://bugs.launchpad.net/bugs/1885023
[ Upstream commit 6bd4763fd532cff43f9b15704f324c45a9806f53 ]

Config dpi pins mode to output and pull low when dpi is disabled.
Aovid leakage current from some dpi pins (Hsync Vsync DE ... ).

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index be6d95c5ff253388fc89e5b673574febe03e1f31..48de07e9059e2a066297f3c1ab76eaafde2d269f 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -10,7 +10,9 @@
 #include <linux/kernel.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/types.h>
 
@@ -73,6 +75,9 @@ 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_gpio;
+       struct pinctrl_state *pins_dpi;
        int refcount;
 };
 
@@ -378,6 +383,9 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
        if (--dpi->refcount != 0)
                return;
 
+       if (dpi->pinctrl && dpi->pins_gpio)
+               pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
        mtk_dpi_disable(dpi);
        clk_disable_unprepare(dpi->pixel_clk);
        clk_disable_unprepare(dpi->engine_clk);
@@ -402,6 +410,9 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
                goto err_pixel;
        }
 
+       if (dpi->pinctrl && dpi->pins_dpi)
+               pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
+
        mtk_dpi_enable(dpi);
        return 0;
 
@@ -689,6 +700,26 @@ static int mtk_dpi_probe(struct platform_device *pdev)
        dpi->dev = dev;
        dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
 
+       dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
+       if (IS_ERR(dpi->pinctrl)) {
+               dpi->pinctrl = NULL;
+               dev_dbg(&pdev->dev, "Cannot find pinctrl!\n");
+       }
+       if (dpi->pinctrl) {
+               dpi->pins_gpio = pinctrl_lookup_state(dpi->pinctrl, "sleep");
+               if (IS_ERR(dpi->pins_gpio)) {
+                       dpi->pins_gpio = NULL;
+                       dev_dbg(&pdev->dev, "Cannot find pinctrl idle!\n");
+               }
+               if (dpi->pins_gpio)
+                       pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
+               dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "default");
+               if (IS_ERR(dpi->pins_dpi)) {
+                       dpi->pins_dpi = NULL;
+                       dev_dbg(&pdev->dev, "Cannot find pinctrl active!\n");
+               }
+       }
        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        dpi->regs = devm_ioremap_resource(dev, mem);
        if (IS_ERR(dpi->regs)) {