linux-kernel - Re: [PATCH v2 2/2] drm/bridge: sii902x: add optional power supplies

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Date:   Mon, 14 May 2018 09:38:58 +0000
From:   Philippe CORNU <philippe.cornu@...com>
To:     Archit Taneja <architt@...eaurora.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        David Airlie <airlied@...ux.ie>,
        Rob Herring <robh+dt@...nel.org>,
        "Mark Rutland" <mark.rutland@....com>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Yannick FERTRE <yannick.fertre@...com>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Alexandre TORGUE <alexandre.torgue@...com>
Subject: Re: [PATCH v2 2/2] drm/bridge: sii902x: add optional power supplies

Hi Laurent, Archit, Andrzej & Yannick,

Do you have any comments on this v2 driver part?
(more details regarding v1/v2 differences in the cover letter 
https://www.spinics.net/lists/dri-devel/msg174137.html)

Thank you,
Philippe :-)


On 04/25/2018 09:53 AM, Philippe Cornu wrote:
> Add the optional power supplies using the description found in
> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)".
> 
> The sii902x input IOs are not "io safe" so it is important to
> enable/disable voltage regulators during probe/remove phases to
> avoid damages.
> 
> Signed-off-by: Philippe Cornu <philippe.cornu@...com>
> ---
>   drivers/gpu/drm/bridge/sii902x.c | 38 ++++++++++++++++++++++++++++++++++----
>   1 file changed, 34 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
> index 60373d7eb220..c367d7b91ade 100644
> --- a/drivers/gpu/drm/bridge/sii902x.c
> +++ b/drivers/gpu/drm/bridge/sii902x.c
> @@ -24,6 +24,7 @@
>   #include <linux/i2c.h>
>   #include <linux/module.h>
>   #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>   
>   #include <drm/drmP.h>
>   #include <drm/drm_atomic_helper.h>
> @@ -86,6 +87,7 @@ struct sii902x {
>   	struct drm_bridge bridge;
>   	struct drm_connector connector;
>   	struct gpio_desc *reset_gpio;
> +	struct regulator_bulk_data supplies[2];
>   };
>   
>   static inline struct sii902x *bridge_to_sii902x(struct drm_bridge *bridge)
> @@ -392,23 +394,42 @@ static int sii902x_probe(struct i2c_client *client,
>   		return PTR_ERR(sii902x->reset_gpio);
>   	}
>   
> +	sii902x->supplies[0].supply = "iovcc";
> +	sii902x->supplies[1].supply = "vcc12";
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(sii902x->supplies),
> +				      sii902x->supplies);
> +	if (ret) {
> +		dev_err(dev, "Failed to get power supplies: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(sii902x->supplies),
> +				    sii902x->supplies);
> +	if (ret) {
> +		dev_err(dev, "Failed to enable power supplies: %d\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(10000, 20000);
> +
>   	sii902x_reset(sii902x);
>   
>   	ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0);
>   	if (ret)
> -		return ret;
> +		goto err_disable_regulator;
>   
>   	ret = regmap_bulk_read(sii902x->regmap, SII902X_REG_CHIPID(0),
>   			       &chipid, 4);
>   	if (ret) {
>   		dev_err(dev, "regmap_read failed %d\n", ret);
> -		return ret;
> +		goto err_disable_regulator;
>   	}
>   
>   	if (chipid[0] != 0xb0) {
>   		dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n",
>   			chipid[0]);
> -		return -EINVAL;
> +		ret = -EINVAL;
> +		goto err_disable_regulator;
>   	}
>   
>   	/* Clear all pending interrupts */
> @@ -424,7 +445,7 @@ static int sii902x_probe(struct i2c_client *client,
>   						IRQF_ONESHOT, dev_name(dev),
>   						sii902x);
>   		if (ret)
> -			return ret;
> +			goto err_disable_regulator;
>   	}
>   
>   	sii902x->bridge.funcs = &sii902x_bridge_funcs;
> @@ -434,6 +455,12 @@ static int sii902x_probe(struct i2c_client *client,
>   	i2c_set_clientdata(client, sii902x);
>   
>   	return 0;
> +
> +err_disable_regulator:
> +	regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies),
> +			       sii902x->supplies);
> +
> +	return ret;
>   }
>   
>   static int sii902x_remove(struct i2c_client *client)
> @@ -443,6 +470,9 @@ static int sii902x_remove(struct i2c_client *client)
>   
>   	drm_bridge_remove(&sii902x->bridge);
>   
> +	regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies),
> +			       sii902x->supplies);
> +
>   	return 0;
>   }
>   
>