This patch adds support for IIO buffer to the Vybrid ADC driver.
IIO triggered buffer infrastructure along with iio sysfs trigger
is used to leverage continuous sampling support provided by the
ADC block.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver has an OF id table but the .of_match_table is not set so
the SPI core can't do an OF style match and the table was unused.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NMichael Welling <mwelling@ieee.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The Documentation/devicetree/bindings/iio/adc/ti-adc128s052.txt DT binding
doc lists "ti,adc128s052" or "ti,adc122s021" as compatible strings but the
corresponding driver does not have an OF match table. Add the table to the
driver so the SPI core can do an OF style match.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver has an OF id table but the .of_match_table is not set so
the SPI core can't do an OF style match and the table was unused.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver currently registers a pair of irq handlers using
request_threaded_irq(), however the synchronization mechanism between the
hardirq and the threadedirq handler is a regular spinlock.

Unfortunately, this breaks PREEMPT_RT builds, where a spinlock can sleep,
and is thus not able to be acquired from a hardirq handler. This patch gets
rid of the threaded handler and pushes all interrupt handling into the
hardirq context, and uses request_irq().

To validate that this change has no impact on RT performance, here are
cyclictest values with no processes running:

$ sudo cyclictest -S -m -p 98
policy: fifo: loadavg: 0.00 0.01 0.05 1/174 2539
T: 0 ( 1405) P:98 I:1000 C:167010520 Min: 9 Act: 12 Avg: 12 Max: 75
T: 1 ( 1862) P:98 I:1500 C:111340339 Min: 9 Act: 12 Avg: 12 Max: 73

Then, all xadc raw handles were accessed in a continuous loop via
/sys/bus/iio/devices/iio:device0:

$ sudo cyclictest -S -m -p 98
policy: fifo: loadavg: 7.84 7.70 7.63 3/182 4260
T: 0 ( 2559) P:98 I:1000 C:241557018 Min: 11 Act: 18 Avg: 21 Max: 74
T: 1 ( 2560) P:98 I:1500 C:161038006 Min: 10 Act: 21 Avg: 20 Max: 73
Signed-off-by: NXander Huff <xander.huff@ni.com>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Move the entry for the CC 10001 ADC driver in Kconfig and Makefile up to
maintain alphabetic order.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Some adjustment of indentation to make checkpatch.pl happy in strict mode.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Move the call to enable channel interrupts into its _read() function to
have it protected by a mutex. This ensures that only one channel is
sampled at a time.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Make use of GENMASK for consecutive bitmasks and BIT for single bitmasks.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Active channel number is stored in BERLIN2_SM_CTRL as value, instead of a
bit map.
The masks for channel interrupts and data ready are a 16 bits wide bit
map each, instead of just 4 bits.

Also correct the data mask for the temperature sensor, which was
Reported-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Drop the otherwise unused definition of the channel-array size and use it
directly in _probe - makes it a bit more obvious.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Use augmented assignment to subtract the offset for negative temperature
values.
Specify the amount of private data to be allocated through
devm_iio_device_alloc() with sizeof(*priv), as it is shorter and common
practice in IIO.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Mark berlin2_adc_channels array as constant.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Pass up the real error code returned by platform_get_irq_byname().
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver currently does not take into account the minimum sample time
as per the Figure 6-8 Chapter 9.1.1 12-bit ADC electrical characteristics.
We set a static amount of cycles instead of considering the sample time
as a given value, which depends on hardware characteristics.

Determine sampling frequencies by first reading the device tree property
node and then calculating the required Long Sample Time Adder (LSTAdder)
value, based on the ADC clock frequency and sample time value obtained
from the device tree. This LSTAdder value is then used for calculating
the sampling frequencies possible.

In case the sample time property is not specified through the device
tree, a safe default value of 1000ns is assumed.
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Acked-by: NStefan Agner <stefan@agner.ch>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This adds support for Microchip's 13 bit 1 channel AD converter MCP3301
Signed-off-by: NAndrea Galbusera <gizero@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

On reading in_voltage_scale of we got an NULL pointer dereference Oops.

The reason for this is, that mcp320x_read_raw tries to access
chip_info->resolution from struct mcp320x, but chip_info is never set.

chip_info was never set since the driver was added, but there was no
acute problem, because it was not referenced.
The acute problem exists since
b12206e9
iio: adc: mcp320x. Add support for more ADCs

This patch fixes the issue by setting chip_info in mcp320x_probe.
Signed-off-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
Reviewed-by: NMichael Welling <mwelling@ieee.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Read the register only when the adc register address is 4 byte aligned.
(rather than the other way around).
Signed-off-by: NHaibo Chen <haibo.chen@freescale.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Cc: <Stable.vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The Cosmic Circuits 10001 ADC driver depends on HAS_IOMEM, HAVE_CLK and
REGULATOR together, not just any of these.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The DT-Property "atmel,adc-startup-time" is stored in an u8 for a microsecond
value. When trying to increase the value of STARTUP in Register AT91_ADC_MR
some higher values can't be reached.

Change the type in function parameter and private structure field from u8 to
u32.
Signed-off-by: NJan Leupold <leupold@rsi-elektrotechnik.de>
[nicolas.ferre@atmel.com: change commit message, increase u16 to u32 for startup time]
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Since commit 1c6c6952 ("genirq: Reject bogus threaded irq requests")
threaded IRQs without a primary handler need to be requested with
IRQF_ONESHOT, otherwise the request will fail.

So pass the IRQF_ONESHOT flag in this case.

The semantic patch that makes this change is available
in scripts/coccinelle/misc/irqf_oneshot.cocci.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The module-data is currently missing. This includes the license-information
which makes the driver taint the kernel and miss symbols when compiled as
module.

Fixes: 44d6f2ef ("iio: adc: add driver for Rockchip saradc")
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Rework the help text of several ADCs to make sure that:
  - the module name is mentioned, if the driver can be built as a module
  - "If unsure, say N" messages are dropped
  - right indentation is maintained
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The Cosmic Circuits 10001 ADC driver depends on HAS_IOMEM, HAVE_CLK and
REGULATOR together, not just any of these.
Signed-off-by: NHartmut Knaack <knaack.h@gmx.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The DT-Property "atmel,adc-startup-time" is stored in an u8 for a microsecond
value. When trying to increase the value of STARTUP in Register AT91_ADC_MR
some higher values can't be reached.

Change the type in function parameter and private structure field from u8 to
u32.
Signed-off-by: NJan Leupold <leupold@rsi-elektrotechnik.de>
[nicolas.ferre@atmel.com: change commit message, increase u16 to u32 for startup time]
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The ADC is typically shared with remote CPUs not running Linux.
However, there is only one register to power-up/power-down. Remote CPUs
aren't able to power-up the ADC, and rely in Linux doing it instead.

This commit uses the adc-reserved-channels devicetree property to
distinguish shared usage. In this case, the ADC is powered up at
probe time.

If the ADC is used only by the CPU running Linux, power-up/down
at runtime, only when neeeded.
Signed-off-by: NNaidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Support configurable conversion mode through sysfs. So far, the
mode used was low-power, which is enabled by default now. Beside
that, the modes normal and high-speed are selectable as well.

Use the new device tree property which specifies the maximum ADC
conversion clock frequencies. Depending on the mode used, the
available resulting conversion frequency are calculated
dynamically.
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Since commit 1c6c6952 ("genirq: Reject bogus threaded irq requests")
threaded IRQs without a primary handler need to be requested with
IRQF_ONESHOT, otherwise the request will fail.

So pass the IRQF_ONESHOT flag in this case.

The semantic patch that makes this change is available
in scripts/coccinelle/misc/irqf_oneshot.cocci.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The module-data is currently missing. This includes the license-information
which makes the driver taint the kernel and miss symbols when compiled as
module.

Fixes: 44d6f2ef ("iio: adc: add driver for Rockchip saradc")
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The @chan parameter can be 0 or 1 and not a bit mask. Fix wrong description.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NMarek Belisko <marek@goldelico.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The bit mask to read the setting of the constant current source
for measuring the NTC voltage was the wrong one. Since default
value is initialized to the lowest level (000 = 10uA) the difference
was probably never noticed in practice.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NMarek Belisko <marek@goldelico.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NUrs Fässler <urs.fassler@bytesatwork.ch>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Remove extra space between platform prefix and DRIVER_NAME in MODULE_ALIAS.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch adds the support of the Berlin ADC, available on Berlin SoCs.
This ADC has 8 channels available, with one connected to a temperature
sensor.

The particularity here, is that the temperature sensor connected to the
ADC has its own registers, and both the ADC and the temperature sensor
must be configured when using it.
Signed-off-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add optional DT properties to set open delay, sample delay and number
of averages per sample for each adc step. Open delay, sample delay
and averaging are some of the parameters that affect the sampling rate
and accuracy of the sample. Making these parameters configurable via
DT will help in balancing speed vs accuracy.
Signed-off-by: NVignesh R <vigneshr@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

According to hardware team there should be some delay after
setting channel number, start mode and before setting START.
Add a one microsecond delay for this purpose.

Fixes: 1664f6a5 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: NNaidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

regulator_get_voltage() returns a non-negative value in case of success,
and a negative error in case of error. Let's fix this.

Fixes: 1664f6a5 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: NNaidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

At present we are incorrectly setting the register to 0x1 to power up
the ADC. Since it is an active high power down register, we need to set
the register to 0x0 to actually power up. Conversely, writing 0x1 to the
register powers it down.

This commit adds a couple of helpers to make the code clearer and then
use them to do the power-up/power-down properly.

Fixes: 1664f6a5 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: NNaidu Tellapati <naidu.tellapati@imgtec.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>