From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH v2 2/5] iio: adc: stm32: make core adc clock optional by default Date: Sat, 3 Jun 2017 10:28:25 +0100 Message-ID: <20170603102825.00a0d229@kernel.org> References: <1496050100-25854-1-git-send-email-fabrice.gasnier@st.com> <1496050100-25854-3-git-send-email-fabrice.gasnier@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1496050100-25854-3-git-send-email-fabrice.gasnier@st.com> Sender: linux-kernel-owner@vger.kernel.org To: Fabrice Gasnier Cc: linux@armlinux.org.uk, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, mark.rutland@arm.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, lars@metafoo.de, knaack.h@gmx.de, pmeerw@pmeerw.net, benjamin.gaignard@linaro.org, benjamin.gaignard@st.com List-Id: devicetree@vger.kernel.org On Mon, 29 May 2017 11:28:17 +0200 Fabrice Gasnier wrote: > Analog clock input is mandatory on stm32f4. But newer version of > ADC hardware block allow to select either bus clock or asynchronous > clock, for analog circuitry. > > So, make it optional by default, but enforce clk presence on stm32f4. > > Signed-off-by: Fabrice Gasnier Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/adc/stm32-adc-core.c | 38 ++++++++++++++++++++++++++------------ > 1 file changed, 26 insertions(+), 12 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c > index 22b7c93..597ab7a 100644 > --- a/drivers/iio/adc/stm32-adc-core.c > +++ b/drivers/iio/adc/stm32-adc-core.c > @@ -85,13 +85,21 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev, > u32 val; > int i; > > + /* stm32f4 has one clk input for analog (mandatory), enforce it here */ > + if (!priv->aclk) { > + dev_err(&pdev->dev, "No 'adc' clock found\n"); > + return -ENOENT; > + } > + > rate = clk_get_rate(priv->aclk); > for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { > if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE) > break; > } > - if (i >= ARRAY_SIZE(stm32f4_pclk_div)) > + if (i >= ARRAY_SIZE(stm32f4_pclk_div)) { > + dev_err(&pdev->dev, "adc clk selection failed\n"); > return -EINVAL; > + } > > val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR); > val &= ~STM32F4_ADC_ADCPRE_MASK; > @@ -227,21 +235,25 @@ static int stm32_adc_probe(struct platform_device *pdev) > priv->aclk = devm_clk_get(&pdev->dev, "adc"); > if (IS_ERR(priv->aclk)) { > ret = PTR_ERR(priv->aclk); > - dev_err(&pdev->dev, "Can't get 'adc' clock\n"); > - goto err_regulator_disable; > + if (ret == -ENOENT) { > + priv->aclk = NULL; > + } else { > + dev_err(&pdev->dev, "Can't get 'adc' clock\n"); > + goto err_regulator_disable; > + } > } > > - ret = clk_prepare_enable(priv->aclk); > - if (ret < 0) { > - dev_err(&pdev->dev, "adc clk enable failed\n"); > - goto err_regulator_disable; > + if (priv->aclk) { > + ret = clk_prepare_enable(priv->aclk); > + if (ret < 0) { > + dev_err(&pdev->dev, "adc clk enable failed\n"); > + goto err_regulator_disable; > + } > } > > ret = stm32f4_adc_clk_sel(pdev, priv); > - if (ret < 0) { > - dev_err(&pdev->dev, "adc clk selection failed\n"); > + if (ret < 0) > goto err_clk_disable; > - } > > ret = stm32_adc_irq_probe(pdev, priv); > if (ret < 0) > @@ -261,7 +273,8 @@ static int stm32_adc_probe(struct platform_device *pdev) > stm32_adc_irq_remove(pdev, priv); > > err_clk_disable: > - clk_disable_unprepare(priv->aclk); > + if (priv->aclk) > + clk_disable_unprepare(priv->aclk); > > err_regulator_disable: > regulator_disable(priv->vref); > @@ -276,7 +289,8 @@ static int stm32_adc_remove(struct platform_device *pdev) > > of_platform_depopulate(&pdev->dev); > stm32_adc_irq_remove(pdev, priv); > - clk_disable_unprepare(priv->aclk); > + if (priv->aclk) > + clk_disable_unprepare(priv->aclk); > regulator_disable(priv->vref); > > return 0;