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>
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: 2763ea0585 ("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>
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: 2763ea0585 ("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>
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>
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>
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>
