Re: [PATCH v8 7/7] drm/mediatek: set dpi pin mode to gpio low to avoid leakage current

Hi, Jitao:

On Tue, 2020-02-25 at 17:40 +0800, Jitao Shi wrote:

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 | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index db3272f7a4c4..d6a570c03ee9 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;

@@ -719,6 +730,25 @@ static int mtk_dpi_probe(struct platform_device *pdev) of_property_read_u32_index(dev->of_node, "pclk-sample", 1, &dpi->pclk_sample);

• dpi->pinctrl = devm_pinctrl_get(&pdev->dev);
• if (IS_ERR(dpi->pinctrl)) {

• dpi->pinctrl = NULL;
  

• dev_dbg(&pdev->dev, "Cannot find pinctrl!\n");
  

• }
• dpi->pins_gpio = pinctrl_lookup_state(dpi->pinctrl, "gpiomode");

When dpi->pinctrl is NULL, you pass it into pinctrl_lookup_state() would get something wrong, so call this function only when dpi->pinctrl is not NULL.

• if (IS_ERR(dpi->pins_gpio)) {

• dpi->pins_gpio = NULL;
  

• dev_dbg(&pdev->dev, "Cannot find pinctrl gpiomode!\n");
  

• }
• if (dpi->pinctrl && dpi->pins_gpio)

• pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
  

• dpi->pins_dpi = pinctrl_lookup_state(dpi->pinctrl, "dpimode");

Ditto.

Regards, CK

• if (IS_ERR(dpi->pins_dpi)) {

• dpi->pins_dpi = NULL;
  

• dev_dbg(&pdev->dev, "Cannot find pinctrl dpimode!\n");
  

• }
• mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); dpi->regs = devm_ioremap_resource(dev, mem); if (IS_ERR(dpi->regs)) {