From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sylwester Nawrocki Subject: Re: [PATCH] thermal: exynos: Support for TMU regulator defined at device tree Date: Thu, 02 May 2013 11:27:05 +0200 Message-ID: <51823169.5050405@samsung.com> References: <1367473061-28863-1-git-send-email-amit.daniel@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1367473061-28863-1-git-send-email-amit.daniel@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Amit Daniel Kachhap , Lukasz Majewski Cc: linux-pm@vger.kernel.org, Zhang Rui , linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, amit.kachhap@gmail.com, Kukjin Kim , Eduardo Valentin List-Id: linux-pm@vger.kernel.org Hi, On 05/02/2013 07:37 AM, Amit Daniel Kachhap wrote: > TMU probe function now checks for a device tree defined regulator. > For compatibility reasons it is allowed to probe driver even without > this regulator defined. > > Signed-off-by: Lukasz Majewski > Signed-off-by: Kyungmin Park > Signed-off-by: Amit Daniel Kachhap > --- > > This patch is repost of the patch posted by Lukasz Majewski > (https://patchwork.kernel.org/patch/2488211/). I have rebased this > patch on top of my TMU re-structured patch series > (http://lwn.net/Articles/548634/). Although I thought of handling > regulator as one type of feature (newly added) but could not do > so as regulator is a board/platform property and not SOC property so > leaving the device tree to define and handle it. > > .../devicetree/bindings/thermal/exynos-thermal.txt | 4 ++++ > drivers/thermal/samsung/exynos_tmu.c | 17 +++++++++++++++++ > 2 files changed, 21 insertions(+), 0 deletions(-) > > diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt > index 970eeba..ff62f7a 100644 > --- a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt > +++ b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt > @@ -14,6 +14,9 @@ > - interrupts : Should contain interrupt for thermal system > - clocks : The main clock for TMU device > - clock-names : Thermal system clock name > +- vtmu-supply: This entry is optional and provides the regulator node supplying > + voltage to TMU. If needed this entry can be placed inside > + board/platform specific dts file. > > Example 1): > > @@ -25,6 +28,7 @@ Example 1): > clocks = <&clock 383>; > clock-names = "tmu_apbif"; > status = "disabled"; > + vtmu-supply = <&tmu_regulator_node>; > }; > > Example 2): > diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c > index 72446c9..45b50c1 100644 > --- a/drivers/thermal/samsung/exynos_tmu.c > +++ b/drivers/thermal/samsung/exynos_tmu.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > #include > #include > #include "exynos_thermal_common.h" > @@ -52,6 +53,7 @@ > * @clk: pointer to the clock structure. > * @temp_error1: fused value of the first point trim. > * @temp_error2: fused value of the second point trim. > + * @regulator: pointer to the TMU regulator structure. > * @reg_conf: pointer to structure to register with core thermal. > */ > struct exynos_tmu_data { > @@ -65,6 +67,7 @@ struct exynos_tmu_data { > struct mutex lock; > struct clk *clk; > u8 temp_error1, temp_error2; > + struct regulator *regulator; > struct thermal_sensor_conf *reg_conf; > }; > > @@ -501,10 +504,21 @@ static int exynos_map_dt_data(struct platform_device *pdev) > struct exynos_tmu_data *data = platform_get_drvdata(pdev); > struct exynos_tmu_platform_data *pdata = data->pdata; > struct resource res; > + int ret; > > if (!data) > return -ENODEV; > > + /* Try enabling the regulator if found */ > + data->regulator = devm_regulator_get(&pdev->dev, "vtmu"); Wouldn't it better to require vtmu-supply property always ? This way any errors would have not been ignored. And board/platform would have to specify real or dummy regulator supply. However, if the DT binding is already defined it might be too late to add a required property. Nevertless some log might be useful in case regulator_get fails and the driver runs without the regulator's control. > + if (!IS_ERR(data->regulator)) { > + ret = regulator_enable(data->regulator); > + if (ret) { > + dev_err(&pdev->dev, "failed to enable vtmu\n"); > + return ret; > + } > + } > + > data->id = of_alias_get_id(pdev->dev.of_node, "tmuctrl"); > if (data->id < 0) > data->id = 0; > @@ -669,6 +683,9 @@ static int exynos_tmu_remove(struct platform_device *pdev) > > clk_unprepare(data->clk); > > + if (data->regulator) Shouldn't this be: if (!IS_ERR(data->regulator)) You probably want to set data->regulator to some ERR_PTR() value in probe, unless regulator get is first thing done there. > + regulator_disable(data->regulator); > + > platform_set_drvdata(pdev, NULL); > > return 0; > Regards, Sylwester