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

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Message-ID: <1558334909.7311.27.camel@mtksdaap41>
Date:   Mon, 20 May 2019 14:48:29 +0800
From:   CK Hu <ck.hu@...iatek.com>
To:     Jitao Shi <jitao.shi@...iatek.com>
CC:     Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>,
        "Mark Rutland" <mark.rutland@....com>,
        Ian Campbell <ijc+devicetree@...lion.org.uk>,
        Kumar Gala <galak@...eaurora.org>, <linux-pwm@...r.kernel.org>,
        David Airlie <airlied@...ux.ie>,
        "Matthias Brugger" <matthias.bgg@...il.com>,
        Thierry Reding <treding@...dia.com>,
        "Ajay Kumar" <ajaykumar.rs@...sung.com>,
        Inki Dae <inki.dae@...sung.com>,
        "Rahul Sharma" <rahul.sharma@...sung.com>,
        Sean Paul <seanpaul@...omium.org>,
        Vincent Palatin <vpalatin@...omium.org>,
        Andy Yan <andy.yan@...k-chips.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        "Russell King" <rmk+kernel@....linux.org.uk>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <dri-devel@...ts.freedesktop.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>,
        Sascha Hauer <kernel@...gutronix.de>,
        <yingjoe.chen@...iatek.com>, <eddie.huang@...iatek.com>,
        <cawa.cheng@...iatek.com>, <bibby.hsieh@...iatek.com>,
        <stonea168@....com>
Subject: Re: [v4 4/5] drm/mediatek: control dpi pins dpi or gpio mode in on
 or off

Hi, Jitao:

On Sat, 2019-05-18 at 17:56 +0800, Jitao Shi wrote:
> 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@...iatek.com>
> ---
>  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);

Please describe this in binding document.

Regards,
CK

> +		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)) {