The i.MX driver currently uses a shortcut and doesn't write all of the
state through to the hardware when the PWM is disabled. This causes an
inconsistent state to be read back by consumers with the result of them
malfunctioning.
Fix this by always writing the full state through to the hardware
registers so that the correct state can always be read back.
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
The hardware register containing the duty cycle value cannot be accessed
when the PWM is disabled. This causes the ->get_state() callback to read
back a duty cycle value of 0, which can confuse consumer drivers.
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:
#define PERIOD 5000000
#define DUTY_LITTLE 10
...
struct pwm_state state = {
.period = PERIOD,
.duty_cycle = DUTY_LITTLE,
.polarity = PWM_POLARITY_NORMAL,
.enabled = true,
};
pwm_apply_state(mypwm, &state);
...
state.duty_cycle = PERIOD / 2;
pwm_apply_state(mypwm, &state);
For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.
So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Use the new helper devm_platform_ioremap_resource() which wraps the
platform_get_resource() and devm_ioremap_resource() together, to
simplify the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Currently the function pwm_imx27_get_state() of enables the clocks once
unconditionally at the start, a second time if the PWM is enabled and
disables unconditionally at the end.
Simplify that to enable once at the start and disable conditionally at
the end.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
"ret" only holds zero and negative error codes. It needs to be signed
for the error handling to work.
Fixes: 9f4c8f9607 ("pwm: imx: Add ipg clock operation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
The two PWM implementations called v1 (for i.MX1 and i.MX21) and v2 (for
i.MX27 and later) have nothing in common apart from needing two clocks
named "per" and "ipg" and being integrated in a SoC named i.MX.
So split the file containing the two disjunct drivers into two files and
two complete separate drivers.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix a modular build issue]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Thierry Reding