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path: root/drivers/iio/adc/meson_saradc.c
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2018-03-28iio: adc: meson-saradc: unlock on error in meson_sar_adc_lock()Dan Carpenter1-1/+3
commit 3c3e4b3a708a9d6451052e348981f37d2b3e92b0 upstream. The meson_sar_adc_lock() function is not supposed to hold the "indio_dev->mlock" on the error path. Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14iio: adc: meson-saradc: Meson8 and Meson8b do not have REG11 and REG13Martin Blumenstingl1-2/+15
commit 96748823c483c6eed8321f78bd128dd33f09c55c upstream. The Meson GXBB and newer SoCs have a few more registers than the older Meson8 and Meson8b SoCs. Use a separate regmap config to limit the older SoCs to the DELTA_10 register. Fixes: 6c76ed31cd05 ("iio: adc: meson-saradc: add Meson8b SoC compatibility") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14iio: adc: meson-saradc: initialize the bandgap correctly on older SoCsMartin Blumenstingl1-7/+26
commit d85eed9f576369bc90322659de96b7dbea1f9a57 upstream. Meson8 and Meson8b do not have the MESON_SAR_ADC_REG11 register. The bandgap setting for these SoCs is configured in the MESON_SAR_ADC_DELTA_10 register instead. Make the driver aware of this difference and use the correct bandgap register depending on the SoC. This has worked fine on Meson8 and Meson8b because the bootloader is already initializing the bandgap setting. Fixes: 6c76ed31cd05 ("iio: adc: meson-saradc: add Meson8b SoC compatibility") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14iio: adc: meson-saradc: fix the bit_idx of the adc_en clockMartin Blumenstingl1-1/+1
commit 7a6b0420d2fe4ce59437bd318826fe468f0d71ae upstream. Meson8 and Meson8b SoCs use the the SAR ADC gate clock provided by the MESON_SAR_ADC_REG3 register within the SAR ADC register area. According to the datasheet (and the existing MESON_SAR_ADC_REG3_CLK_EN definition) the gate is on bit 30. The fls() function returns the last set bit, which is "bit index + 1" (fls(MESON_SAR_ADC_REG3_CLK_EN) returns 31). Fix this by switching to __ffs() which returns the first set bit, which is bit 30 in our case. This off by one error results in the ADC not being usable on devices where the bootloader did not enable the clock. Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-23iio: Convert to using %pOF instead of full_nameRob Herring1-4/+4
Now that we have a custom printf format specifier, convert users of full_name to use %pOF instead. This is preparation to remove storing of the full path string for each node. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: linux-iio@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-amlogic@lists.infradead.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-07-09iio: adc: meson-saradc: add NULL check on of_match_device() return valueGustavo A. R. Silva1-0/+5
Check return value from call to of_match_device() in order to prevent a NULL pointer dereference. In case of NULL print error message and return -ENODEV Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-06-20Merge 4.12-rc6 into staging-nextGreg Kroah-Hartman1-2/+2
We want the staging fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-11iio: adc: meson-saradc: fix potential crash in meson_sar_adc_clear_fifoMartin Blumenstingl1-2/+2
meson_sar_adc_clear_fifo passes a 0 as value-pointer to regmap_read(). In case of the meson-saradc driver this ends up in regmap_mmio_read(), where the value-pointer is de-referenced unconditionally to assign the value which was read. Fix this by passing an actual pointer, even though all we want to do is to discard the value. As a side-effect this fixes a sparse warning ("Using plain integer as NULL pointer") as reported by Paolo Cretaro. Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs") Reported-by: Paolo Cretaro <paolocretaro@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-05-07iio: adc: meson-saradc: add Meson8b SoC compatibilityMartin Blumenstingl1-24/+56
Meson GX SoCs however use some magic bits to prevent simultaneous (= conflicting, because only consumer should use the FIFO buffer with the ADC results) usage by the Linux kernel and the bootloader (the BL30 bootloader uses the SAR ADC to read the CPU temperature). This patch changes guards all BL30 functionality so it is skipped on SoCs which don't have it. Since the hardware itself doesn't know whether BL30 is available the internal meson_sar_adc_data is extended so this information can be provided per of_device_id.data inside the driver. Additionally the clocks "adc_clk" and "adc_sel" are not provided by the clock-controller itself. "adc_sel" is not available at all. "adc_clk" is provided by the SAR ADC IP block itself on Meson8b (and earlier). This is already supported by the meson_saradc driver. Finally this introduces new of_device_ids for the Meson8 and Meson8b SoCs so the driver can be wired up in the corresponding DT. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-05-07iio: adc: meson-saradc: mark all meson_sar_adc_data static and constMartin Blumenstingl1-3/+3
These are only passed as of_device_id.data and never modified. Thus we can mark them as static const, just like the of_device_id instances where they are used. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-03-25iio: adc: meson-saradc: add calibrationHeiner Kallweit1-2/+75
This patch adds calibration for the Meson SAR ADC. Points 25% vref and 75% vref are used for calibration. It uses a simple linear calibration function: SCALE * val + BIAS Successfully tested on a Odroid C2. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-02-19iio: adc: meson-saradc: improve meson_sar_adc_read_raw_sampleHeiner Kallweit1-19/+17
After sampling there should always be only one value in the FIFO. This also applies to averaging mode as the averaging is done chip-internally. So we don't have to loop and let the driver complain if there's not exactly one value in the FIFO. If the value belongs to a different channel then don't silently swallow the value but complain. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-02-19iio: adc: meson-saradc: switch from polling to interrupt modeHeiner Kallweit1-5/+51
Switch from polling to interrupt mode. Successfully tested on a S905GXBB-based Odroid C2. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-01-28iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCsMartin Blumenstingl1-0/+922
This adds support for the SAR (Successive Approximation Register) ADC on the Amlogic Meson SoCs. The code is based on the public S805 (Meson8b) and S905 (GXBB) datasheets (see [0] and [1]), as well as by reading (various versions of) the vendor driver and by inspecting the registers on the vendor kernels of my testing-hardware. Currently the GXBB, GXL and GXM SoCs are supported. GXBB hardware has 10-bit ADC resolution, while GXL and GXM have 12-bit ADC resolution. The code was written to support older SoCs (Meson8 and Meson8b) as well, but due to lack of actual testing-hardware no of_device_id was added for these. Two "features" from the vendor driver are currently missing: - the vendor driver uses channel #7 for calibration (this improves the accuracy of the results - in my tests the results were less than 3% off without calibration compared to the vendor driver). Adding support for this should be easy, but is not required for most applications. - channel #6 is connected to the SoCs internal temperature sensor. Adding support for this is probably not so easy since (based on the u-boot sources) most SoC versions are using different registers and algorithms for the conversion from "ADC value" to temperature. Supported by the hardware but currently not supported by the driver: - reading multiple channels at the same time (the hardware has a FIFO buffer which stores multiple results) - continuous sampling (this would require a way to enable this individually because otherwise the ADC would be drawing power constantly) - interrupt support (similar to the vendor driver this new driver is polling the results. It is unclear if the IRQ-mode is supported on older (Meson6 or Meson8) hardware as well or if there are any errata) [0] http://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf [1] http://dn.odroid.com/S905/DataSheet/S905_Public_Datasheet_V1.1.4.pdf Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>