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path: root/drivers/pwm/pwm-sti.c
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2016-09-08pwm: sti: Take the opportunity to conduct a little house keepingLee Jones
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>
2016-09-08pwm: sti: It's now valid for number of PWM channels to be zeroLee Jones
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>
2016-09-08pwm: sti: Add PWM capture callbackLee Jones
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>
2016-09-08pwm: sti: Add support for PWM capture interruptsLee Jones
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>
2016-09-08pwm: sti: Initialise PWM capture device dataLee Jones
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>
2016-09-08pwm: sti: Supply PWM Capture clock handlingLee Jones
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>
2016-09-08pwm: sti: Supply PWM capture register addresses and bit locationsLee Jones
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>
2016-09-08pwm: sti: Only request clock rate when neededLee Jones
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>
2016-09-08pwm: sti: Reorganise register names in preparation for new functionalityLee Jones
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>
2016-09-08pwm: sti: Rename channel => deviceLee Jones
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>
2015-01-30pwm: sti: Maintain a bitmap of configured devicesAjit Pal Singh
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>
2014-08-08pwm: sti: Remove PWM period tableAjit Pal Singh
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>
2014-08-08pwm: sti: Sync between enable/disable callsAjit Pal Singh
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>
2014-08-08pwm: sti: Ensure same period values for all channelsAjit Pal Singh
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>
2014-08-08pwm: sti: Fix PWM prescaler handlingAjit Pal Singh
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>
2014-08-07pwm: sti: Add new driver for ST's PWM IPLee Jones
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>