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path: root/drivers/iio/adc/stm32-adc-core.c
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2020-11-01iio: adc: stm32-adc: fix a regression when using dma and irqOlivier Moysan
Since overrun interrupt support has been added, there's a regression when two ADCs are used at the same time, with: - an ADC configured to use IRQs. EOCIE bit is set. The handler is normally called in this case. - an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA request. It's then automatically cleared by DMA read. But the handler gets called due to status bit is temporarily set (IRQ triggered by the other ADC). This is a regression as similar issue had been fixed earlier by commit dcb10920179a ("iio: adc: stm32-adc: fix a race when using several adcs with dma and irq"). Issue is that stm32_adc_eoc_enabled() returns non-zero value (always) since OVR bit has been added and enabled for both DMA and IRQ case. Remove OVR mask in IER register, and rely only on CSR status for overrun. To avoid subsequent calls to interrupt routine on overrun, CSR OVR bit has to be cleared. CSR OVR bit cannot be cleared directly by software. To do this ADC must be stopped first, and OVR bit in ADC ISR has to be cleared. Also add a check in ADC IRQ handler to report spurious IRQs. Fixes: cc06e67d8fa5 ("iio: adc: stm32-adc: Add check on overrun interrupt") Signed-off-by: Olivier Moysan <olivier.moysan@st.com> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Cc: <Stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201021085313.5335-1-olivier.moysan@st.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-09-29iio: adc: stm32-adc: fix runtime autosuspend delay when slow pollingFabrice Gasnier
When the ADC is runtime suspended and starting a conversion, the stm32-adc driver calls pm_runtime_get_sync() that gets cascaded to the parent (e.g. runtime resume of stm32-adc-core driver). This also kicks the autosuspend delay (e.g. 2s) of the parent. Once the ADC is active, calling pm_runtime_get_sync() again (upon a new capture) won't kick the autosuspend delay for the parent (stm32-adc-core driver) as already active. Currently, this makes the stm32-adc-core driver go in suspend state every 2s when doing slow polling. As an example, doing a capture, e.g. cat in_voltageY_raw at a 0.2s rate, the auto suspend delay for the parent isn't refreshed. Once it expires, the parent immediately falls into runtime suspended state, in between two captures, as soon as the child driver falls into runtime suspend state: - e.g. after 2s, + child calls pm_runtime_put_autosuspend() + 100ms autosuspend delay of the child. - stm32-adc-core switches off regulators, clocks and so on. - They get switched on back again 100ms later in this example (at 2.2s). So, use runtime_idle() callback in stm32-adc-core driver to call pm_runtime_mark_last_busy() for the parent driver (stm32-adc-core), to avoid this. Fixes: 9bdbb1139ca1 ("iio: adc: stm32-adc: add power management support") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/r/1593615328-5180-1-git-send-email-fabrice.gasnier@st.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-09-13iio: adc: stm32: Fix missing return in booster error pathKrzysztof Kozlowski
Conversion of error paths to dev_err_probe() dropped one return statement. The driver will continue to probe if getting booster regulator fails. Fixes: ce30eeb613cb ("iio: adc: stm32: Simplify with dev_err_probe()") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Link: https://lore.kernel.org/r/1599727927-7776-1-git-send-email-krzk@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-09-03iio: adc: stm32: Simplify with dev_err_probe()Krzysztof Kozlowski
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and also it prints the error value. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20200829064726.26268-8-krzk@kernel.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-05-22iio: adc: stm32-adc: fix a wrong error message when probing interruptsFabrice Gasnier
A wrong error message is printed out currently, like on STM32MP15: - stm32-adc-core 48003000.adc: IRQ index 2 not found. This is seen since commit 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()"). The STM32 ADC core driver wrongly requests up to 3 interrupt lines. It should request only the necessary IRQs, based on the compatible: - stm32f4/h7 ADCs share a common interrupt - stm32mp1, has one interrupt line per ADC. So add the number of required interrupts to the compatible data. Fixes: d58c67d1d851 ("iio: adc: stm32-adc: add support for STM32MP1") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-01-18iio: adc: stm32-adc: don't print an error on probe deferralEtienne Carriere
Do not print an error trace when deferring probe for some resource. Signed-off-by: Etienne Carriere <etienne.carriere@st.com> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-12-15iio: adc: stm32-adc: Add check on overrun interruptFabrice Gasnier
Enable overrun interrupt on STM32 ADC. In case data register hasn't been read (by CPU or DMA), overrun condition is detected when there's new conversion data available. Stop grabbing data and log an error message. Use a threaded irq to avoid printing the error message from hard irq context. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-11-09iio: adc: stm32: allow to tune analog clockFabrice Gasnier
Add new optional dt property to tune analog clock prescaler. Driver looks for optional "st,max-clk-rate-hz", then computes best approximation below that rate, using ADC internal prescaler. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-22iio: adc: stm32-adc: fix kernel-doc warningsFabrice Gasnier
Fix the following warnings when documentation is built: drivers/iio/adc/stm32-adc-core.c:62: warning: cannot understand function prototype: 'struct stm32_adc_common_regs ' drivers/iio/adc/stm32-adc-core.c:78: warning: cannot understand function prototype: 'struct stm32_adc_priv_cfg ' drivers/iio/adc/stm32-adc-core.c:123: warning: Function parameter or member 'pdev' not described in 'stm32f4_adc_clk_sel' drivers/iio/adc/stm32-adc.c:219: warning: cannot understand function prototype: 'struct stm32_adc_regs ' drivers/iio/adc/stm32-adc.c:237: warning: cannot understand function prototype: 'struct stm32_adc_regspec ' drivers/iio/adc/stm32-adc.c:264: warning: cannot understand function prototype: 'struct stm32_adc_cfg ' drivers/iio/adc/stm32-adc.c:323: warning: Function parameter or member 'difsel' not described in 'N' drivers/iio/adc/stm32-adc.c:323: warning: Function parameter or member 'pcsel' not described in 'stm32_adc' drivers/iio/adc/stm32-adc.c:371: warning: cannot understand function prototype: 'const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] drivers/iio/adc/stm32-adc.c:417: warning: cannot understand function prototype: 'const struct stm32_adc_regs stm32f4_smp_bits[] = ' drivers/iio/adc/stm32-adc.c:508: warning: cannot understand function prototype: 'const struct stm32_adc_regs stm32h7_smp_bits[] = ' drivers/iio/adc/stm32-adc.c:1112: warning: Function parameter or member 'indio_dev' not described in 'stm32_adc_get_trig_extsel' drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member 'indio_dev' not described in 'stm32_adc_debugfs_reg_access' drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member 'reg' not described in 'stm32_adc_debugfs_reg_access' drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member 'writeval' not described in 'stm32_adc_debugfs_reg_access' drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member 'readval' not described in 'stm32_adc_debugfs_reg_access' Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-09iio: adc: stm32-adc: fix a race when using several adcs with dma and irqFabrice Gasnier
End of conversion may be handled by using IRQ or DMA. There may be a race when two conversions complete at the same time on several ADCs. EOC can be read as 'set' for several ADCs, with: - an ADC configured to use IRQs. EOCIE bit is set. The handler is normally called in this case. - an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA request instead. It's then automatically cleared by DMA read. But the handler gets called due to status bit is temporarily set (IRQ triggered by the other ADC). So both EOC status bit in CSR and EOCIE control bit must be checked before invoking the interrupt handler (e.g. call ISR only for IRQ-enabled ADCs). Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-09iio: adc: stm32-adc: move registers definitionsFabrice Gasnier
Move STM32 ADC registers definitions to common header. This is precursor patch to: - iio: adc: stm32-adc: fix a race when using several adcs with dma and irq It keeps registers definitions as a whole block, to ease readability and allow simple access path to EOC bits (readl) in stm32-adc-core driver. Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-08-05iio: Remove dev_err() usage after platform_get_irq()Stephen Boyd
We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). 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: linux-iio@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-07-27iio: adc: stm32-adc: add analog switches supply controlFabrice Gasnier
On stm32h7 and stm32mp1, the ADC inputs are multiplexed with analog switches which have reduced performances when their supply is below 2.7V (vdda by default): - 3.3V embedded booster can be used, to get full ADC performances (increases power consumption). - vdd supply can be selected if above 2.7V by setting ANASWVDD syscfg bit, on STM32MP1 only. Make this optional, since this is a trade-off between analog performance and power consumption. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-06-22iio: adc: stm32-adc: add missing vdda-supplyFabrice Gasnier
Add missing vdda-supply, analog power supply, to STM32 ADC. When vdda is an independent supply, it needs to be properly turned on or off to supply the ADC. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Fixes: 1add69880240 ("iio: adc: Add support for STM32 ADC core"). Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-11-25iio: adc: stm32-adc: add power management supportFabrice Gasnier
Add support for runtime PM & sleep. Move all regulator and clock management to dedicated HW start/stop routines. Then rely on (runtime) PM OPS to call them. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-05-07iio: adc: stm32-adc: add support for STM32MP1Fabrice Gasnier
Add support for STM32MP1 ADC. It's quite similar to STM32H7 ADC. Introduce new compatible to handle variants of this hardware such as vregready flag, trigger list, interrupts, clock rate. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-01-08iio: stm32: Adopt SPDX identifierBenjamin Gaignard
Add SPDX identifier in stm32's files in IIO directory Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21iio: adc: stm32: add check on clock rateFabrice Gasnier
Add check on STM32 ADC clock rate to report an explicit error. This may avoid division by 0 later in stm32-adc driver. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-08-28Merge 4.13-rc7 into staging-nextGreg Kroah-Hartman
We want the staging and iio fixes in here to handle the merge issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30iio: adc: stm32: fix common clock rateFabrice Gasnier
ADC clock input is provided to internal prescaler (that decreases its frequency). It's then used as reference clock for conversions. - Fix common clock rate used then by stm32-adc sub-devices. Take common prescaler into account. Currently, rate is used to set "boost" mode. It may unnecessarily be set. This impacts power consumption. - Fix ADC max clock rate on STM32H7 (fADC from datasheet). Currently, prescaler may be set too low. This can result in ADC reference clock used for conversion to exceed max allowed clock frequency. Fixes: 95e339b6e85d ("iio: adc: stm32: add support for STM32H7") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-07-02iio: adc: stm32: make array stm32h7_adc_ckmodes_spec staticColin Ian King
The array stm32h7_adc_ckmodes_spec does not need to be in global scope, so make it static. Cleans up sparse warning: "symbol 'stm32h7_adc_ckmodes_spec' was not declared. Should it be static?" Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-06-11iio: adc: stm32: add support for STM32H7Fabrice Gasnier
Add support for STM32H7 Analog to Digital Converter. It has up to 20 external channels, resolution ranges from 8 to 16bits. Either bus or asynchronous adc clock may be used. Add registers & bitfields definition. Also add new configuration options to enter/exit powerdown and perform self-calibration. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-06-11iio: adc: stm32: introduce compatible data cfgFabrice Gasnier
Prepare support for stm32h7 adc variant by introducing compatible configuration data. Move STM32F4 specific stuff to compatible data structure: - registers & bit fields - input channels data - start/stop procedures - trigger definitions Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-06-11iio: adc: stm32: make core adc clock optional by defaultFabrice Gasnier
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 <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-01-29iio: adc: stm32: add optional dma supportFabrice Gasnier
Add DMA optional support to STM32 ADC, as there is a limited number DMA channels (request lines) that can be assigned to ADC. This way, driver may fall back using interrupts when all DMA channels are in use for other IPs. Use dma cyclic mode with two periods. Allow to tune period length by using watermark. Coherent memory is used for dma (max buffer size is fixed to PAGE_SIZE). Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-11-19iio: adc: Add support for STM32 ADC coreFabrice Gasnier
Add core driver for STMicroelectronics STM32 ADC (Analog to Digital Converter). STM32 ADC can be composed of up to 3 ADCs with shared resources like clock prescaler, common interrupt line and analog reference voltage. This core driver basically manages shared resources. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>