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From: Jonathan Cameron <jic23@kernel.org>
To: Philipp Rossak <embed3d@gmail.com>
Cc: lee.jones@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com,
	maxime.ripard@free-electrons.com, wens@csie.org,
	linux@armlinux.org.uk, knaack.h@gmx.de, lars@metafoo.de,
	pmeerw@pmeerw.net, davem@davemloft.net, hans.verkuil@cisco.com,
	mchehab@kernel.org, rask@formelder.dk, clabbe.montjoie@gmail.com,
	sean@mess.org, krzk@kernel.org,
	quentin.schulz@free-electrons.com, icenowy@aosc.io,
	edu.molinas@gmail.com, singhalsimran0@gmail.com,
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com
Subject: Re: [PATCH 05/16] iio: adc: sun4i-gpadc-iio: rework: support clocks and reset
Date: Sun, 28 Jan 2018 08:50:36 +0000	[thread overview]
Message-ID: <20180128085036.389c2dfb@archlinux> (raw)
In-Reply-To: <20180126151941.12183-6-embed3d@gmail.com>

On Fri, 26 Jan 2018 16:19:30 +0100
Philipp Rossak <embed3d@gmail.com> wrote:

> For adding newer sensor some basic rework of the code is necessary.
> 
> The SoCs after H3 has newer thermal sensor ADCs, which have two clock
> inputs (bus clock and sampling clock) and a reset. The registers are
> also re-arranged.
> 
> This commit reworks the code, adds the process of the clocks and
> resets.
> 
> Signed-off-by: Philipp Rossak <embed3d@gmail.com>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>

Both clock and reset code is safe against null parameters, so you can
drop a lot of 'is it here' checks in this.  They could be argued to
act as documentation of the fact we really don't expect them in some cases
I suppose... 

> ---
>  drivers/iio/adc/sun4i-gpadc-iio.c | 80 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
> 
> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
> index 363936b37c5a..1a80744bd472 100644
> --- a/drivers/iio/adc/sun4i-gpadc-iio.c
> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
> @@ -22,6 +22,7 @@
>   * shutdown for not being used.
>   */
>  
> +#include <linux/clk.h>
>  #include <linux/completion.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
> @@ -31,6 +32,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
> +#include <linux/reset.h>
>  #include <linux/thermal.h>
>  #include <linux/delay.h>
>  
> @@ -75,6 +77,9 @@ struct gpadc_data {
>  	u32		ctrl2_map;
>  	u32		sensor_en_map;
>  	u32		filter_map;
> +	bool		has_bus_clk;
> +	bool		has_bus_rst;
> +	bool		has_mod_clk;
>  };
>  
>  static const struct gpadc_data sun4i_gpadc_data = {
> @@ -134,6 +139,9 @@ struct sun4i_gpadc_iio {
>  	atomic_t			ignore_temp_data_irq;
>  	const struct gpadc_data		*data;
>  	bool				no_irq;
> +	struct clk			*bus_clk;
> +	struct clk			*mod_clk;
> +	struct reset_control		*reset;
>  	/* prevents concurrent reads of temperature and ADC */
>  	struct mutex			mutex;
>  	struct thermal_zone_device	*tzd;
> @@ -435,6 +443,12 @@ static int sun4i_gpadc_runtime_suspend(struct device *dev)
>  {
>  	struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
>  
> +	if (info->data->has_mod_clk)
> +		clk_disable(info->mod_clk);

Safe against null parameter... (see below)

> +
> +	if (info->data->has_bus_clk)
> +		clk_disable(info->bus_clk);
> +
>  	return info->data->sample_end(info);
>  }
>  
> @@ -483,6 +497,12 @@ static int sun4i_gpadc_runtime_resume(struct device *dev)
>  {
>  	struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
>  
> +	if (info->data->has_mod_clk)
> +		clk_enable(info->mod_clk);

clk_enable is safe against null parameter so could do without the checks.

> +
> +	if (info->data->has_bus_clk)
> +		clk_enable(info->bus_clk);
> +
>  	return info->data->sample_start(info);
>  }
>  
> @@ -597,10 +617,61 @@ static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
>  		return ret;
>  	}
>  
> +	if (info->data->has_bus_rst) {
> +		info->reset = devm_reset_control_get(&pdev->dev, NULL);
> +		if (IS_ERR(info->reset)) {
> +			ret = PTR_ERR(info->reset);
> +			return ret;
> +		}
> +
> +		ret = reset_control_deassert(info->reset);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (info->data->has_bus_clk) {
> +		info->bus_clk = devm_clk_get(&pdev->dev, "bus");
> +		if (IS_ERR(info->bus_clk)) {
> +			ret = PTR_ERR(info->bus_clk);
> +			goto assert_reset;
> +		}
> +
> +		ret = clk_prepare_enable(info->bus_clk);
> +		if (ret)
> +			goto assert_reset;
> +	}
> +
> +	if (info->data->has_mod_clk) {
> +		info->mod_clk = devm_clk_get(&pdev->dev, "mod");
> +		if (IS_ERR(info->mod_clk)) {
> +			ret = PTR_ERR(info->mod_clk);
> +			goto disable_bus_clk;
> +		}
> +
> +		/* Running at 6MHz */
> +		ret = clk_set_rate(info->mod_clk, 4000000);
> +		if (ret)
> +			goto disable_bus_clk;
> +
> +		ret = clk_prepare_enable(info->mod_clk);
> +		if (ret)
> +			goto disable_bus_clk;
> +	}
> +
>  	if (IS_ENABLED(CONFIG_THERMAL_OF))
>  		info->sensor_device = &pdev->dev;
>  
>  	return 0;
> +
> +disable_bus_clk:
> +	if (info->data->has_bus_clk)
> +		clk_disable_unprepare(info->bus_clk);
> +
> +assert_reset:
> +	if (info->data->has_bus_rst)
> +		reset_control_assert(info->reset);
> +
> +	return ret;
>  }
>  
>  static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
> @@ -766,6 +837,15 @@ static int sun4i_gpadc_remove(struct platform_device *pdev)
>  	if (!info->no_irq)
>  		iio_map_array_unregister(indio_dev);
>  
> +	if (info->data->has_mod_clk)
> +		clk_disable_unprepare(info->mod_clk);

clk_disable_unprepare is safe against a null parameter
so I don't think the checks are needed.

> +
> +	if (info->data->has_bus_clk)
> +		clk_disable_unprepare(info->bus_clk);
> +
> +	if (info->data->has_bus_rst)
> +		reset_control_assert(info->reset);

Safe against null parameter...

> +
>  	return 0;
>  }
>  

  reply	other threads:[~2018-01-28  8:50 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-26 15:19 [PATCH 00/16] IIO-based thermal sensor driver for Allwinner H3 and A83T SoC Philipp Rossak
     [not found] ` <20180126151941.12183-1-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-26 15:19   ` [PATCH 01/16] dt-bindings: update the Allwinner GPADC device tree binding for H3 & A83T Philipp Rossak
2018-01-26 15:19   ` [PATCH 02/16] arm: config: sunxi_defconfig: enable SUN4I_GPADC Philipp Rossak
2018-01-26 15:19   ` [PATCH 03/16] iio: adc: sun4i-gpadc-iio: rename A33-specified registers to contain A33 Philipp Rossak
     [not found]     ` <20180126151941.12183-4-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-28  8:34       ` Jonathan Cameron
2018-01-26 15:19   ` [PATCH 04/16] iio: adc: sun4i-gpadc-iio: rework: sampling start/end code readout reg Philipp Rossak
2018-01-28  8:43     ` Jonathan Cameron
2018-01-28 13:34       ` Philipp Rossak
2018-01-28 13:37         ` Icenowy Zheng
     [not found]           ` <2CC367BA-766A-4384-82EE-9A38BBFB08C2-h8G6r0blFSE@public.gmane.org>
2018-01-28 14:32             ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 05/16] iio: adc: sun4i-gpadc-iio: rework: support clocks and reset Philipp Rossak
2018-01-28  8:50     ` Jonathan Cameron [this message]
2018-01-28 11:34       ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 06/16] iio: adc: sun4i-gpadc-iio: rework: support multible sensors Philipp Rossak
2018-01-28  9:08     ` Jonathan Cameron
2018-01-28 14:10       ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 07/16] iio: adc: sun4i-gpadc-iio: rework: support nvmem calibration data Philipp Rossak
2018-01-28  9:02     ` Jonathan Cameron
2018-01-28 13:46       ` Philipp Rossak
     [not found]         ` <6ebbb5e0-eb5f-afe4-50e8-eb3cee8ec7fa-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-28 13:52           ` Icenowy Zheng
     [not found]             ` <1927F24D-D3ED-49CF-9B7C-A7C8C873F0CF-h8G6r0blFSE@public.gmane.org>
2018-01-28 14:39               ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 08/16] iio: adc: sun4i-gpadc-iio: rework: add interrupt support Philipp Rossak
     [not found]     ` <20180126151941.12183-9-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-28  9:06       ` Jonathan Cameron
2018-01-28 13:48         ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 09/16] iio: adc: sun4i-gpadc-iio: add support for H3 thermal sensor Philipp Rossak
2018-01-26 15:19   ` [PATCH 10/16] iio: adc: sun4i-gpadc-iio: add support for A83T " Philipp Rossak
     [not found]     ` <20180126151941.12183-11-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-26 17:46       ` [linux-sunxi] " Ondřej Jirman
     [not found]         ` <20180126174602.qolcswhqblgmlad7-9v8tmBix7cb9zxVx7UNMDg@public.gmane.org>
2018-01-27  4:30           ` Philipp Rossak
2018-01-26 15:19   ` [PATCH 11/16] arm: dts: sunxi-h3-h5: add support for the thermal sensor in H3 and H5 Philipp Rossak
2018-01-26 15:19   ` [PATCH 12/16] arm: dts: sun8i: h3: add support for the thermal sensor in H3 Philipp Rossak
2018-01-26 15:19   ` [PATCH 13/16] arm: dts: sun8i: h3: add thermal zone to H3 Philipp Rossak
     [not found]     ` <20180126151941.12183-14-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-26 16:26       ` Samuel Holland
     [not found]         ` <4cfb1faf-a712-c882-1ef1-55845c1bb00e-RkNLwX/CsU9g9hUCZPvPmw@public.gmane.org>
2018-01-26 17:48           ` [linux-sunxi] " Philipp Rossak
2018-01-26 15:19   ` [PATCH 14/16] arm: dts: sun8i: h3: enable H3 sid controller Philipp Rossak
2018-01-26 15:19   ` [PATCH 15/16] arm: dts: sun8i: a83t: add support for the thermal sensor in A83T Philipp Rossak
2018-01-26 15:19   ` [PATCH 16/16] arm: dts: sun8i: a83t: add thermal zone to A83T Philipp Rossak
     [not found]     ` <20180126151941.12183-17-embed3d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-01-26 16:25       ` Samuel Holland
2018-01-26 17:35         ` [linux-sunxi] " Philipp Rossak

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