From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Mon, 16 Apr 2018 13:24:26 +0100 Subject: [PATCH v3 3/6] pwm: stm32: add capture support In-Reply-To: <1522404084-24903-4-git-send-email-fabrice.gasnier@st.com> References: <1522404084-24903-1-git-send-email-fabrice.gasnier@st.com> <1522404084-24903-4-git-send-email-fabrice.gasnier@st.com> Message-ID: <20180416122426.72lhi3hrk2g7y526@dell> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 30 Mar 2018, Fabrice Gasnier wrote: > Add support for PMW input mode on pwm-stm32. STM32 timers support > period and duty cycle capture as long as they have at least two PWM > channels. One capture channel is used for period (rising-edge), one > for duty-cycle (falling-edge). > When there's only one channel available, only period can be captured. > Duty-cycle is simply zero'ed in such a case. > > Capture requires exclusive access (e.g. no pwm output running at the > same time, to protect common prescaler). > Timer DMA burst mode (from MFD core) is being used, to take two > snapshots of capture registers (upon each period rising edge). > > Signed-off-by: Fabrice Gasnier > Reviewed-by: Benjamin Gaignard > Acked-by: Thierry Reding > --- > Changes in v3: > - update stm32_timers_dma_burst_read() call: don't pass ddata structure, > use MFD parent device structure instead since MFD core update. > > Changes in v2: > - DMA handling has been moved to MFD core. Rework capture routines to > use it. > --- > drivers/pwm/pwm-stm32.c | 176 +++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/stm32-timers.h | 11 +++ For my own reference: Acked-for-MFD-by: Lee Jones > 2 files changed, 187 insertions(+) -- Lee Jones [???] Linaro Services Technical Lead Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog