[PATCH v11 6/6] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

Jitao Shi
2020-02-28T08:16:28Z

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>
---
drivers/gpu/drm/mediatek/mtk_dpi.c | 44 ++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index db3272f7a4c4..fece8661d8b6 100644
--- 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>

@@ -74,6 +76,9 @@ 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;
u32 pclk_sample;
};
@@ -387,6 +392,9 @@ 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);
@@ -411,6 +419,9 @@ 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;

@@ -705,6 +716,7 @@ static const struct mtk_dpi_conf mt8183_conf = {
static int mtk_dpi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
+ struct device_node *ep;
struct mtk_dpi *dpi;
struct resource *mem;
int comp_id;
@@ -716,9 +728,37 @@ static int mtk_dpi_probe(struct platform_device *pdev)

dpi->dev = dev;
dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
- of_property_read_u32_index(dev->of_node, "pclk-sample", 1,
- &dpi->pclk_sample);

+ ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+ if (!ep) {
+ dev_err(dev, "Failed get the endpoint port\n");
+ return -EINVAL;
+ }
+
+ /* Get the sampling edge from the endpoint. */
+ of_property_read_u32(ep, "pclk-sample", &dpi->pclk_sample);
+ of_node_put(ep);
+
+ 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, "idle");
+ 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, "active");
+ 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)) {
--
2.21.0