Commit Graph

17 Commits

Author SHA1 Message Date
Thierry Reding 8c0216f377 pwm: Remove .can_sleep from struct pwm_chip
All PWM devices have been marked as "might sleep" since v4.5, there is
no longer a need to differentiate on a per-chip basis.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-04 09:40:54 +01:00
Lee Jones 7d8a600c91 pwm: sti: Take the opportunity to conduct a little house keeping
This includes fixing some Coding Style issues and re-ordering and/or
simplifying a little code.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
[thierry.reding@gmail.com: applied some bikeshedding>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:12 +02:00
Lee Jones 85a834c42a pwm: sti: It's now valid for number of PWM channels to be zero
Setting up the STI PWM IP as capture only, with zero PWM output devices
is a perfectly valid configuration. It is no longer okay to assume that
there must be at least 1 PWM output device. In this patch we make the
default number of PWM output devices zero and only configure channels
explicitly requested.

Reported-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:11 +02:00
Lee Jones c97267ae83 pwm: sti: Add PWM capture callback
Once a PWM capture has been initiated, the capture call enables a rising
edge detection interrupt, then waits. Once each of the 3 phase changes
have been recorded the thread then wakes. The remaining part of the call
carries out the relevant calculations and returns a structure filled out
with the capture data.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:11 +02:00
Lee Jones 25eb538096 pwm: sti: Add support for PWM capture interrupts
Here we're requesting the PWM capture IRQ and supplying the handler that
will be called in the event of an interrupt to handle it.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:10 +02:00
Lee Jones 3f0925b5a8 pwm: sti: Initialise PWM capture device data
Each PWM capture device is allocated a structure to hold its own state.
During a capture the device may be partaking in one of 3 phases. Initial
(rising) phase change, a subsequent (falling) phase change indicating
end of the duty-cycle phase and finally a final (rising) phase change
indicating the end of the period. The timer value snapshot each event is
held in a variable of the same name, and the phase number (0, 1, 2) is
contained in the index variable. Other device specific information, such
as GPIO pin, the IRQ wait queue and locking is also contained in the
structure. This patch initialises this structure for each of the
available devices.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:09 +02:00
Lee Jones d66a928dc0 pwm: sti: Supply PWM Capture clock handling
ST's PWM IP is supplied by 2 different clocks. One for PWM output and
the other for capture. This patch provides clock handling for the
latter.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:09 +02:00
Lee Jones f66d78faf2 pwm: sti: Supply PWM capture register addresses and bit locations
This is in preparation for subsequent patches that add support for PWM
capture to this driver.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:08 +02:00
Lee Jones d81738b76f pwm: sti: Only request clock rate when needed
In the original code the clock rate was only obtained during
initialisation; however, the rate may change between then and
its use.  This patch ensures the correct rate is acquired just
before use.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:08 +02:00
Lee Jones c5f94ae639 pwm: sti: Reorganise register names in preparation for new functionality
Exciting functionality is on the way to this device.  But
before we can add it, we need to do some basic housekeeping
so the additions can be added cleanly.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:07 +02:00
Lee Jones 09022e61d5 pwm: sti: Rename channel => device
This is to bring the terminology used in the STi PWM driver more
into line with the PWM subsystem.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:07 +02:00
Ajit Pal Singh cd264b6a65 pwm: sti: Maintain a bitmap of configured devices
This patch introduces a bitmap which is used to keep track of the
pwm channels which have been configured in a pwm chip.

The method used earlier to find the number of configured channels,
was to count the pwmdevices with PWMF_REQUESTED field set
and period value configured. This was not correct and failed
when of_pwm_get()/pwm_get() and then pwm_config() was used.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30 12:16:03 +01:00
Ajit Pal Singh 3aacd3e187 pwm: sti: Remove PWM period table
Removes the PWM period table. Instead the prescaler is computed
from the period value passed in the config() function.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-08 13:12:46 +02:00
Ajit Pal Singh 6ad6b838e1 pwm: sti: Sync between enable/disable calls
ST PWM IP has a common enable/disable control for all the PWM
channels on a PWM cell. Disables PWM output on the PWM HW only
when disable is called for the last channel.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-08 13:12:45 +02:00
Ajit Pal Singh 5165166e8a pwm: sti: Ensure same period values for all channels
ST PWM IP shares the same clock prescaler across all the PWM
channels. Hence configuration requests which change the period
will affect all the channels. Do not allow period changes which
will stomp period settings of the already configured channels.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-08 13:12:45 +02:00
Ajit Pal Singh bf9cc80b6c pwm: sti: Fix PWM prescaler handling
This patch fixes the pwm driver to write the complete 8 bits of
the prescaler value to the PWM Control register.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-08 13:12:40 +02:00
Lee Jones 378fe115d1 pwm: sti: Add new driver for ST's PWM IP
This driver supports all current STi platforms' PWM IPs.

Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[thierry.reding: rename module to pwm-sti, fix build breakage]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-07 16:18:27 +02:00