Re: [PATCH v6 6/8] IIO: add STM32 timer trigger driver

3 Jan 2017

On 3 January 2017 12:59:20 GMT+00:00, Benjamin Gaignard benjamin.gaignard@linaro.org wrote:
...
2017-01-03 10:23 GMT+01:00 Benjamin Gaignard
benjamin.gaignard@linaro.org:
...
2017-01-02 19:22 GMT+01:00 Jonathan Cameron jic23@kernel.org:
...
On 02/01/17 08:46, Benjamin Gaignard wrote:
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2016-12-30 22:12 GMT+01:00 Jonathan Cameron jic23@kernel.org:
...
On 09/12/16 14:15, Benjamin Gaignard wrote:
...
Timers IPs can be used to generate triggers for other IPs like
DAC, ADC or other timers.
Each trigger may result of timer internals signals like counter
enable,
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reset or edge, this configuration could be done through
"master_mode"
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device attribute.
A timer device could be triggered by other timers, we use the
trigger
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name and is_stm32_iio_timer_trigger() function to distinguish
them
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and configure IP input switch.
Timer may also decide on which event (edge, level) they could
be activated by a trigger, this configuration is done by writing
in
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"slave_mode" device attribute.
Since triggers could also be used by DAC or ADC their names are
defined
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in include/ nux/iio/timer/stm32-timer-trigger.h so those IPs will
be able
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to configure themselves in valid_trigger function
Trigger have a "sampling_frequency" attribute which allow to
configure
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timer sampling frequency without using PWM interface
version 5:

simplify tables of triggers
only create an IIO device when needed

version 4:

get triggers configuration from "reg" in DT
add tables of triggers
sampling frequency is enable/disable when writing in trigger
sampling_frequency attribute
no more use of interruptions

version 3:

change compatible to "st,stm32-timer-trigger"
fix attributes access right
use string instead of int for master_mode and slave_mode
document device attributes in sysfs-bus-iio-timer-stm32

version 2:

keep only one compatible
use st,input-triggers-names and st,output-triggers-names
to know which triggers are accepted and/or create by the device

Firstly, sorry it has taken me so long to get back to this.
I'm still not keen on this use of iio_device elements just to act
as
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glue between triggers.  I think we need to work out a more light
weight
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way to do this.  As you are only using them for validation and to
provide
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somewhere to hang the control attibutes off, there is nothing
stopping us
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moving that over to the iio_trigger instead which would avoid the
messy
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duality going on here.
I have add an iio_device because each hardware can generate
multiple
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triggers (up to 5: trgo, ch 1...4) and slave_mode attribute will
impact all the
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triggers of a device. For me it was making sense to centralize that
in an
...
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iio_device rather than having an attribute "shared" (from hardware
point of view)
on multiple triggers.
Since master_mode attribute is only used by trgo and not impact
ch1...4
...
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triggers I will move it to trigger instead of the iio_device.
I also wanted to be able to connect triggers on a iio_device as I
could do for an
ADC with a command like 'echo "tim1_trgo" >
iio_deviceX/trigger/current_trigger'
...
...
This is interesting, but with a bit of refactoring I would think it
would
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be possible to share some of that code thus allowing non IIO devices
to
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bind to triggers.  Ultimately I want to be able to bind a trigger to
a trigger - I appreciate here the topology is more limited than that
so some complexity comes in.
My gut feeling is that representing that topology explicitly is hard
to do in a remotely general way, but lets try it and see.
We run into this sort of interdependency issue between different
bits of
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the hardware all the time.  Setting a value somewhere effects the
configuration
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elsewhere - often the best plan is to just let that happen and leave
it up to
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userspace to check for changes if it cares.
okay
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If I change that to parent_trigger attribute it change this
behavior
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and I will have to
duplicated what is done in iio_trigger_write_current() to find and
validate triggers.
I get the reasoning, but we still end up with something represented
by an IIO device that isn't providing any channels at all. It's
simply
...
...
using some of the infrastructure.  To my mind it is 'something else'
and should be represented as such.  I have no problem at all with
you registering additional elements in /sysfs/bus/iio/ to represent
these shared elements - we already have drivers that do that to
provide some centralized infrastructure (e.g. the sysfs-trigger)
My hardware block are timers maybe I can add a channel type
"IIO_TIMER"
...
and declare a channel with info_mask_separate =
BIT(IIO_CHAN_INFO_SAMP_FREQ)
...
so I will be able to write/read sampling frequency on IIO device.
If it isn't possible to implement IIO_TIMER I will simply drop device
part of
my driver until we find a solution because I would like to upstream at
least what is
need to ADC/DAC.
Agreed. Let's move forward with the easy stuff.
I might get a chance to look at trigger trees later
this week depending on how some tedious time in a pharma clean room and on planes goes.
I think we can mock most of this up with software triggers and the dummy driver.
Perhaps a sysfs trigger driving a timer trigger will get us moving in the right direction API wise.
Might let us figure out something generic without needing hardware.
A few other bits of hardware can do similar to yours but I don't think I have any in my pile of boards.
J
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I'm worried about the scope spread we get for an IIO device
otherwise.
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They serve a well defined purpose at the moment, and that isn't what
is happening here.
So my gut feeling is we are better deliberately not representing the
inter dependence and claiming all triggers we are creating are
independent.  That way we can have a nice generic infrastructure
that will work in all cases (be it pushing the sanity checking to
userspace).
So each trigger has direct access to what controls it.  Changing
anything
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can effect other triggers in weird ways.
I'm finding it hard to see anything else generalizing sufficiently
as we'll always get cases where we can't represent the topology
without
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diving into the complexity of something like the media controller
framework.
Jonathan
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I might still be missing something though!
You would only I think need 3 attributes
parrent_trigger
and something like your master_mode and slave_mode attributes.
The parrent_trigger would need some validation etc, but if we keep
it
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within this driver initially that won't be hard to do. Checking
the device
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parent matches will do most of it.
Jonathan
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Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com
.../ABI/testing/sysfs-bus-iio-timer-stm32          |  55 +++
 drivers/iio/Kconfig                                |   2 +-
 drivers/iio/Makefile                               |   1 +
 drivers/iio/timer/Kconfig                          |  13 +
 drivers/iio/timer/Makefile                         |   1 +
 drivers/iio/timer/stm32-timer-trigger.c            | 466
+++++++++++++++++++++
...
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drivers/iio/trigger/Kconfig                        |   1 -
 include/linux/iio/timer/stm32-timer-trigger.h      |  62 +++
 8 files changed, 599 insertions(+), 2 deletions(-)
 create mode 100644
Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
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create mode 100644 drivers/iio/timer/Kconfig
 create mode 100644 drivers/iio/timer/Makefile
 create mode 100644 drivers/iio/timer/stm32-timer-trigger.c
 create mode 100644 include/linux/iio/timer/stm32-timer-trigger.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
...
...
...
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new file mode 100644
index 0000000..26583dd
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
@@ -0,0 +1,55 @@
+What:
/sys/bus/iio/devices/iio:deviceX/master_mode_available
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+KernelVersion:       4.10
+Contact:     benjamin.gaignard@st.com
+Description:

        Reading returns the list possible master modes



which are:
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        - "reset"     : The UG bit from the TIMx_EGR



register is used as trigger output (TRGO).
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        - "enable"    : The Counter Enable signal CNT_EN is



used as trigger output.
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        - "update"    : The update event is selected as



trigger output.
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                        For instance a master timer can



then be used as a prescaler for a slave timer.
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        - "compare_pulse" : The trigger output send a



positive pulse when the CC1IF flag is to be set.
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        - "OC1REF"    : OC1REF signal is used as trigger



output.
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        - "OC2REF"    : OC2REF signal is used as trigger



output.
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        - "OC3REF"    : OC3REF signal is used as trigger



output.
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        - "OC4REF"    : OC4REF signal is used as trigger



output.
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...



+What:
/sys/bus/iio/devices/iio:deviceX/master_mode
...
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+KernelVersion:       4.10
+Contact:     benjamin.gaignard@st.com
+Description:

        Reading returns the current master modes.


        Writing set the master mode




+What:
/sys/bus/iio/devices/iio:deviceX/slave_mode_available
...
...
...
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+KernelVersion:       4.10
+Contact:     benjamin.gaignard@st.com
+Description:

        Reading returns the list possible slave modes which



are:
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        - "disabled"  : The prescaler is clocked directly



by the internal clock.
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        - "encoder_1" : Counter counts up/down on TI2FP1



edge depending on TI1FP2 level.
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        - "encoder_2" : Counter counts up/down on TI1FP2



edge depending on TI2FP1 level.
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        - "encoder_3" : Counter counts up/down on both



TI1FP1 and TI2FP2 edges depending
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                        on the level of the other input.


        - "reset"     : Rising edge of the selected trigger



input reinitializes the counter
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                        and generates an update of the



registers.
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        - "gated"     : The counter clock is enabled when



the trigger input is high.
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                        The counter stops (but is not



reset) as soon as the trigger becomes low.
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                        Both start and stop of the counter



are controlled.
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        - "trigger"   : The counter starts at a rising edge



of the trigger TRGI (but it is not
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                        reset). Only the start of the



counter is controlled.
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        - "external_clock": Rising edges of the selected



trigger (TRGI) clock the counter.
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+What:                /sys/bus/iio/devices/iio:deviceX/slave_mode
+KernelVersion:       4.10
+Contact:     benjamin.gaignard@st.com
+Description:

        Reading returns the current slave mode.


        Writing set the slave mode




+What:
/sys/bus/iio/devices/triggerX/sampling_frequency
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+KernelVersion:       4.10
+Contact:     benjamin.gaignard@st.com
+Description:

        Reading returns the current sampling frequency.


        Writing an value different of 0 set and start



sampling.
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        Writing 0 stop sampling.



diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 6743b18..2de2a80 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -90,5 +90,5 @@ source "drivers/iio/potentiometer/Kconfig"
 source "drivers/iio/pressure/Kconfig"
 source "drivers/iio/proximity/Kconfig"
 source "drivers/iio/temperature/Kconfig"



+source "drivers/iio/timer/Kconfig"
 endif # IIO
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 87e4c43..b797c08 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -32,4 +32,5 @@ obj-y += potentiometer/
 obj-y += pressure/
 obj-y += proximity/
 obj-y += temperature/
+obj-y += timer/
 obj-y += trigger/
diff --git a/drivers/iio/timer/Kconfig
b/drivers/iio/timer/Kconfig
...
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new file mode 100644
index 0000000..e3c21f2
--- /dev/null
+++ b/drivers/iio/timer/Kconfig
@@ -0,0 +1,13 @@
+#
+# Timers drivers



+menu "Timers"



+config IIO_STM32_TIMER_TRIGGER

tristate "STM32 Timer Trigger"


depends on (ARCH_STM32 && OF && MFD_STM32_TIMERS) ||



COMPILE_TEST
...
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select IIO_TRIGGERED_EVENT


help


  Select this option to enable STM32 Timer Trigger




+endmenu
diff --git a/drivers/iio/timer/Makefile
b/drivers/iio/timer/Makefile
...
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new file mode 100644
index 0000000..4ad95ec9
--- /dev/null
+++ b/drivers/iio/timer/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o
diff --git a/drivers/iio/timer/stm32-timer-trigger.c
b/drivers/iio/timer/stm32-timer-trigger.c
...
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new file mode 100644
index 0000000..8d16e8f
--- /dev/null
+++ b/drivers/iio/timer/stm32-timer-trigger.c
@@ -0,0 +1,466 @@
+/*


Copyright (C) STMicroelectronics 2016







Author: Benjamin Gaignard benjamin.gaignard@st.com







License terms:  GNU General Public License (GPL), version 2


*/


+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/timer/stm32-timer-trigger.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_event.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/stm32-timers.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>



+#define MAX_TRIGGERS 6
+#define MAX_VALIDS 5



+/* List the triggers created by each timer */
+static const void *triggers_table[][MAX_TRIGGERS] = {

{ TIM1_TRGO, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4,},


{ TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4,},


{ TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4,},


{ TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4,},


{ TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4,},


{ TIM6_TRGO,},


{ TIM7_TRGO,},


{ TIM8_TRGO, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4,},


{ TIM9_TRGO, TIM9_CH1, TIM9_CH2,},


{ TIM12_TRGO, TIM12_CH1, TIM12_CH2,},



+};



+/* List the triggers accepted by each timer */
+static const void *valids_table[][MAX_VALIDS] = {

{ TIM5_TRGO, TIM2_TRGO, TIM4_TRGO, TIM3_TRGO,},


{ TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO,},


{ TIM1_TRGO, TIM8_TRGO, TIM5_TRGO, TIM4_TRGO,},


{ TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO,},


{ TIM2_TRGO, TIM3_TRGO, TIM4_TRGO, TIM8_TRGO,},


{ }, /* timer 6 */


{ }, /* timer 7 */


{ TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO,},


{ TIM2_TRGO, TIM3_TRGO,},


{ TIM4_TRGO, TIM5_TRGO,},



+};



+struct stm32_timer_trigger {

struct device *dev;


struct regmap *regmap;


struct clk *clk;


u32 max_arr;


const void *triggers;


const void *valids;



+};



+static int stm32_timer_start(struct stm32_timer_trigger *priv,

                     unsigned int frequency)



+{

unsigned long long prd, div;


int prescaler = 0;


u32 ccer, cr1;



/* Period and prescaler values depends of clock rate */


div = (unsigned long long)clk_get_rate(priv->clk);



do_div(div, frequency);



prd = div;



/*


 * Increase prescaler value until we get a result that fit


 * with auto reload register maximum value.


 */


while (div > priv->max_arr) {


        prescaler++;


        div = prd;


        do_div(div, (prescaler + 1));


}


prd = div;



if (prescaler > MAX_TIM_PSC) {


        dev_err(priv->dev, "prescaler exceeds the maximum



value\n");
...
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...
...
...

        return -EINVAL;


}



/* Check if nobody else use the timer */


regmap_read(priv->regmap, TIM_CCER, &ccer);


if (ccer & TIM_CCER_CCXE)


        return -EBUSY;



regmap_read(priv->regmap, TIM_CR1, &cr1);


if (!(cr1 & TIM_CR1_CEN))


        clk_enable(priv->clk);



regmap_write(priv->regmap, TIM_PSC, prescaler);


regmap_write(priv->regmap, TIM_ARR, prd - 1);


regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE,



TIM_CR1_ARPE);
...
...
...
...
...


/* Force master mode to update mode */


regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS,



0x20);
...
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...
...
...


/* Make sure that registers are updated */


regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG,



TIM_EGR_UG);
...
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...
...
...


/* Enable controller */


regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,



TIM_CR1_CEN);
...
...
...
...
...


return 0;



+}



+static void stm32_timer_stop(struct stm32_timer_trigger *priv)
+{

u32 ccer, cr1;



regmap_read(priv->regmap, TIM_CCER, &ccer);


if (ccer & TIM_CCER_CCXE)


        return;



regmap_read(priv->regmap, TIM_CR1, &cr1);


if (cr1 & TIM_CR1_CEN)


        clk_disable(priv->clk);



/* Stop timer */


regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);


regmap_write(priv->regmap, TIM_PSC, 0);


regmap_write(priv->regmap, TIM_ARR, 0);



+}



+static ssize_t stm32_tt_store_frequency(struct device *dev,

                                struct device_attribute



*attr,
...
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...
...
...

                                const char *buf, size_t



len)
...
...
...
...
...
+{

struct iio_trigger *trig = to_iio_trigger(dev);


struct stm32_timer_trigger *priv =



iio_trigger_get_drvdata(trig);
...
...
...
...
...

unsigned int freq;


int ret;



ret = kstrtouint(buf, 10, &freq);


if (ret)


        return ret;



if (freq == 0) {


        stm32_timer_stop(priv);


} else {


        ret = stm32_timer_start(priv, freq);


        if (ret)


                return ret;


}



return len;



+}



+static ssize_t stm32_tt_read_frequency(struct device *dev,

                               struct device_attribute



*attr, char *buf)
...
...
...
...
...
+{

struct iio_trigger *trig = to_iio_trigger(dev);


struct stm32_timer_trigger *priv =



iio_trigger_get_drvdata(trig);
...
...
...
...
...

u32 psc, arr, cr1;


unsigned long long freq = 0;



regmap_read(priv->regmap, TIM_CR1, &cr1);


regmap_read(priv->regmap, TIM_PSC, &psc);


regmap_read(priv->regmap, TIM_ARR, &arr);



if (psc && arr && (cr1 & TIM_CR1_CEN)) {


        freq = (unsigned long long)clk_get_rate(priv->clk);


        do_div(freq, psc);


        do_div(freq, arr);


}



return sprintf(buf, "%d\n", (unsigned int)freq);



+}



+static IIO_DEV_ATTR_SAMP_FREQ(0660,

                      stm32_tt_read_frequency,


                      stm32_tt_store_frequency);




+static struct attribute *stm32_trigger_attrs[] = {

&iio_dev_attr_sampling_frequency.dev_attr.attr,


NULL,



+};



+static const struct attribute_group stm32_trigger_attr_group = {

.attrs = stm32_trigger_attrs,



+};



+static const struct attribute_group *stm32_trigger_attr_groups[]
= {
...
...
...
...
...

&stm32_trigger_attr_group,


NULL,



+};



+static char *master_mode_table[] = {

"reset",


"enable",


"update",


"compare_pulse",


"OC1REF",


"OC2REF",


"OC3REF",


"OC4REF"



+};



+static ssize_t stm32_tt_show_master_mode(struct device *dev,

                                 struct device_attribute



*attr,
...
...
...
...
...

                                 char *buf)



+{

struct iio_dev *indio_dev = dev_to_iio_dev(dev);


struct stm32_timer_trigger *priv = iio_priv(indio_dev);


u32 cr2;



regmap_read(priv->regmap, TIM_CR2, &cr2);


cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT;



return snprintf(buf, PAGE_SIZE, "%s\n",



master_mode_table[cr2]);
...
...
...
...
...
+}



+static ssize_t stm32_tt_store_master_mode(struct device *dev,

                                  struct device_attribute



*attr,
...
...
...
...
...

                                  const char *buf, size_t



len)
...
...
...
...
...
+{

struct iio_dev *indio_dev = dev_to_iio_dev(dev);


struct stm32_timer_trigger *priv = iio_priv(indio_dev);


int i;



for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) {


        if (!strncmp(master_mode_table[i], buf,


                     strlen(master_mode_table[i]))) {


                regmap_update_bits(priv->regmap, TIM_CR2,


                                   TIM_CR2_MMS, i <<



TIM_CR2_MMS_SHIFT);
...
...
...
...
...

                return len;


        }


}



return -EINVAL;



+}



+static IIO_CONST_ATTR(master_mode_available,

"reset enable update compare_pulse OC1REF OC2REF OC3REF



OC4REF");
...
...
...
...
...



+static IIO_DEVICE_ATTR(master_mode, 0660,

               stm32_tt_show_master_mode,


               stm32_tt_store_master_mode,


               0);




+static char *slave_mode_table[] = {

"disabled",


"encoder_1",


"encoder_2",


"encoder_3",


"reset",


"gated",


"trigger",


"external_clock",



+};



+static ssize_t stm32_tt_show_slave_mode(struct device *dev,

                                struct device_attribute



*attr,
...
...
...
...
...

                                char *buf)



+{

struct iio_dev *indio_dev = dev_to_iio_dev(dev);


struct stm32_timer_trigger *priv = iio_priv(indio_dev);


u32 smcr;



regmap_read(priv->regmap, TIM_SMCR, &smcr);


smcr &= TIM_SMCR_SMS;



return snprintf(buf, PAGE_SIZE, "%s\n",



slave_mode_table[smcr]);
...
...
...
...
...
+}



+static ssize_t stm32_tt_store_slave_mode(struct device *dev,

                                 struct device_attribute



*attr,
...
...
...
...
...

                                 const char *buf, size_t



len)
...
...
...
...
...
+{

struct iio_dev *indio_dev = dev_to_iio_dev(dev);


struct stm32_timer_trigger *priv = iio_priv(indio_dev);


int i;



for (i = 0; i < ARRAY_SIZE(slave_mode_table); i++) {


        if (!strncmp(slave_mode_table[i], buf,


                     strlen(slave_mode_table[i]))) {


                regmap_update_bits(priv->regmap,


                                   TIM_SMCR, TIM_SMCR_SMS,



i);
...
...
...
...
...

                return len;


        }


}



return -EINVAL;



+}



+static IIO_CONST_ATTR(slave_mode_available,
+"disabled encoder_1 encoder_2 encoder_3 reset gated trigger
external_clock");
...
...
...
...
...



+static IIO_DEVICE_ATTR(slave_mode, 0660,

               stm32_tt_show_slave_mode,


               stm32_tt_store_slave_mode,


               0);




+static struct attribute *stm32_timer_attrs[] = {

&iio_dev_attr_master_mode.dev_attr.attr,


&iio_const_attr_master_mode_available.dev_attr.attr,


&iio_dev_attr_slave_mode.dev_attr.attr,


&iio_const_attr_slave_mode_available.dev_attr.attr,


NULL,



+};



+static const struct attribute_group stm32_timer_attr_group = {

.attrs = stm32_timer_attrs,



+};



+static const struct iio_trigger_ops timer_trigger_ops = {

.owner = THIS_MODULE,



+};



+static int stm32_setup_iio_triggers(struct stm32_timer_trigger
*priv)
...
...
...
...
...
+{

int ret;


const char * const *cur = priv->triggers;



while (cur && *cur) {


        struct iio_trigger *trig;



        trig = devm_iio_trigger_alloc(priv->dev, "%s",



*cur);
...
...
...
...
...

        if  (!trig)


                return -ENOMEM;



        trig->dev.parent = priv->dev->parent;


        trig->ops = &timer_trigger_ops;


        trig->dev.groups = stm32_trigger_attr_groups;


        iio_trigger_set_drvdata(trig, priv);



        ret = devm_iio_trigger_register(priv->dev, trig);


        if (ret)


                return ret;


        cur++;


}



return 0;



+}



+/**


is_stm32_timer_trigger



@trig: trigger to be checked







return true if the trigger is a valid stm32 iio timer trigger



either return false


*/

+bool is_stm32_timer_trigger(struct iio_trigger *trig)
+{

return (trig->ops == &timer_trigger_ops);



+}
+EXPORT_SYMBOL(is_stm32_timer_trigger);



+static int stm32_validate_trigger(struct iio_dev *indio_dev,

                          struct iio_trigger *trig)



+{

struct stm32_timer_trigger *priv = iio_priv(indio_dev);


const char * const *cur = priv->valids;


unsigned int i = 0;



if (!is_stm32_timer_trigger(trig))


        return -EINVAL;



while (cur && *cur) {


        if (!strncmp(trig->name, *cur, strlen(trig->name)))



{
...
...
...
...
...

                regmap_update_bits(priv->regmap,


                                   TIM_SMCR, TIM_SMCR_TS,


                                   i << TIM_SMCR_TS_SHIFT);


                return 0;


        }


        cur++;


        i++;


}



return -EINVAL;



+}



+static const struct iio_info stm32_trigger_info = {

.driver_module = THIS_MODULE,


.validate_trigger = stm32_validate_trigger,


.attrs = &stm32_timer_attr_group,



+};



+static struct stm32_timer_trigger *stm32_setup_iio_device(struct
device *dev)
...
...
...
...
...
+{

struct iio_dev *indio_dev;


int ret;



indio_dev = devm_iio_device_alloc(dev,


                                  sizeof(struct



stm32_timer_trigger));
...
...
...
...
...

if (!indio_dev)


        return NULL;



indio_dev->name = dev_name(dev);


indio_dev->dev.parent = dev;


indio_dev->info = &stm32_trigger_info;


indio_dev->modes = INDIO_EVENT_TRIGGERED;


indio_dev->num_channels = 0;


indio_dev->dev.of_node = dev->of_node;



ret = devm_iio_device_register(dev, indio_dev);


if (ret)


        return NULL;



return iio_priv(indio_dev);



+}



+static int stm32_timer_trigger_probe(struct platform_device
*pdev)
...
...
...
...
...
+{

struct device *dev = &pdev->dev;


struct stm32_timer_trigger *priv;


struct stm32_timers *ddata =



dev_get_drvdata(pdev->dev.parent);
...
...
...
...
...

unsigned int index;


int ret;



if (of_property_read_u32(dev->of_node, "reg", &index))


        return -EINVAL;



if (index >= ARRAY_SIZE(triggers_table))


        return -EINVAL;



/* Create an IIO device only if we have triggers to be



validated */
...
...
...
...
...

if (*valids_table[index])


        priv = stm32_setup_iio_device(dev);



I still don't like this. Really feels like we shouldn't be
creating an
...
...
...
...
iio device with all the bagage that carries just to allow us to do
the
...
...
...
...
trigger trees.  We ought to have a much more light weight solution
for this
...
...
...
...
functionality - we aren't typically even using the interrupt tree
stuff
...
...
...
...
that the triggers for devices are all really about.
A simpler approach of allowing each trigger the option of a parent
seems like
...
...
...
...
it would be cleaner.  Could be done entirely within this driver in
the first
...
...
...
...
instance.  Basically it would just look like your master and slave
attributes
...
...
...
...
but have those under triggerX not iio:deviceX.
We can work out how to make it more generic later - including
perhaps the
...
...
...
...
option to trigger from triggers outside this driver, using some
parallel
...
...
...
...
infrastructure to the device triggering.
...

else


        priv = devm_kzalloc(dev, sizeof(*priv),



GFP_KERNEL);
...
...
...
...
...


if (!priv)


        return -ENOMEM;



priv->dev = dev;


priv->regmap = ddata->regmap;


priv->clk = ddata->clk;


priv->max_arr = ddata->max_arr;


priv->triggers = triggers_table[index];


priv->valids = valids_table[index];



ret = stm32_setup_iio_triggers(priv);


if (ret)


        return ret;



platform_set_drvdata(pdev, priv);



return 0;



+}



+static const struct of_device_id stm32_trig_of_match[] = {

{ .compatible = "st,stm32-timer-trigger", },


{ /* end node */ },



+};
+MODULE_DEVICE_TABLE(of, stm32_trig_of_match);



+static struct platform_driver stm32_timer_trigger_driver = {

.probe = stm32_timer_trigger_probe,


.driver = {


        .name = "stm32-timer-trigger",


        .of_match_table = stm32_trig_of_match,


},



+};
+module_platform_driver(stm32_timer_trigger_driver);



+MODULE_ALIAS("platform: stm32-timer-trigger");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Timer Trigger
driver");
...
...
...
...
...
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/trigger/Kconfig
b/drivers/iio/trigger/Kconfig
...
...
...
...
...
index 809b2e7..f2af4fe 100644
--- a/drivers/iio/trigger/Kconfig
+++ b/drivers/iio/trigger/Kconfig
@@ -46,5 +46,4 @@ config IIO_SYSFS_TRIGGER
    To compile this driver as a module, choose M here: the
    module will be called iio-trig-sysfs.




Clean this up.
ok
...
...
endmenu
diff --git a/include/linux/iio/timer/stm32-timer-trigger.h
b/include/linux/iio/timer/stm32-timer-trigger.h
...
...
...
...
...
new file mode 100644
index 0000000..55535ae
--- /dev/null
+++ b/include/linux/iio/timer/stm32-timer-trigger.h
@@ -0,0 +1,62 @@
+/*


Copyright (C) STMicroelectronics 2016







Author: Benjamin Gaignard benjamin.gaignard@st.com







License terms:  GNU General Public License (GPL), version 2


*/


+#ifndef _STM32_TIMER_TRIGGER_H_
+#define _STM32_TIMER_TRIGGER_H_



+#define TIM1_TRGO    "tim1_trgo"
+#define TIM1_CH1     "tim1_ch1"
+#define TIM1_CH2     "tim1_ch2"
+#define TIM1_CH3     "tim1_ch3"
+#define TIM1_CH4     "tim1_ch4"



+#define TIM2_TRGO    "tim2_trgo"
+#define TIM2_CH1     "tim2_ch1"
+#define TIM2_CH2     "tim2_ch2"
+#define TIM2_CH3     "tim2_ch3"
+#define TIM2_CH4     "tim2_ch4"



+#define TIM3_TRGO    "tim3_trgo"
+#define TIM3_CH1     "tim3_ch1"
+#define TIM3_CH2     "tim3_ch2"
+#define TIM3_CH3     "tim3_ch3"
+#define TIM3_CH4     "tim3_ch4"



+#define TIM4_TRGO    "tim4_trgo"
+#define TIM4_CH1     "tim4_ch1"
+#define TIM4_CH2     "tim4_ch2"
+#define TIM4_CH3     "tim4_ch3"
+#define TIM4_CH4     "tim4_ch4"



+#define TIM5_TRGO    "tim5_trgo"
+#define TIM5_CH1     "tim5_ch1"
+#define TIM5_CH2     "tim5_ch2"
+#define TIM5_CH3     "tim5_ch3"
+#define TIM5_CH4     "tim5_ch4"



+#define TIM6_TRGO    "tim6_trgo"



+#define TIM7_TRGO    "tim7_trgo"



+#define TIM8_TRGO    "tim8_trgo"
+#define TIM8_CH1     "tim8_ch1"
+#define TIM8_CH2     "tim8_ch2"
+#define TIM8_CH3     "tim8_ch3"
+#define TIM8_CH4     "tim8_ch4"



+#define TIM9_TRGO    "tim9_trgo"
+#define TIM9_CH1     "tim9_ch1"
+#define TIM9_CH2     "tim9_ch2"



+#define TIM12_TRGO   "tim12_trgo"
+#define TIM12_CH1    "tim12_ch1"
+#define TIM12_CH2    "tim12_ch2"



+bool is_stm32_timer_trigger(struct iio_trigger *trig);



+#endif
--
Benjamin Gaignard
Graphic Study Group
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

    

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Re: [PATCH v6 6/8] IIO: add STM32 timer trigger driver

Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com