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>
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>
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>
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>
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>
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: 1add698802 ("iio: adc: Add support for STM32 ADC core").
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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>
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>
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>
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: 95e339b6e8 ("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>
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>
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>
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>
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>
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>
