From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751297AbeDQHM5 (ORCPT ); Tue, 17 Apr 2018 03:12:57 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:40940 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbeDQHMz (ORCPT ); Tue, 17 Apr 2018 03:12:55 -0400 X-Google-Smtp-Source: AIpwx4/PRZelIwFnLEjfH8aBfSyOQG5gXg26Shz526jg3T8ar4jLHn5vvAr75dTZrIamW2fUr5cIgw== Date: Tue, 17 Apr 2018 08:12:50 +0100 From: Lee Jones To: Fabrice Gasnier Cc: alexandre.torgue@st.com, thierry.reding@gmail.com, benjamin.gaignard@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, mcoquelin.stm32@gmail.com, benjamin.gaignard@st.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org Subject: Re: [PATCH v4 2/6] mfd: stm32-timers: add support for dmas Message-ID: <20180417071250.yhgl7c7apn7w53xf@dell> References: <1523895561-4073-1-git-send-email-fabrice.gasnier@st.com> <1523895561-4073-3-git-send-email-fabrice.gasnier@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1523895561-4073-3-git-send-email-fabrice.gasnier@st.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Apr 2018, Fabrice Gasnier wrote: > STM32 Timers can support up to 7 DMA requests: > - 4 channels, update, compare and trigger. > Optionally request part, or all DMAs from stm32-timers MFD core. > > Also add routine to implement burst reads using DMA from timer registers. > This is exported. So, it can be used by child drivers, PWM capture > for instance (but not limited to). > > Signed-off-by: Fabrice Gasnier > Reviewed-by: Benjamin Gaignard > --- > Changes in v4: > - Lee's comments: Add kerneldoc header, better format comments. > Changes in v3: > - Basically Lee's comments: > - rather create a struct stm32_timers_dma, and place a reference to it > in existing ddata (instead of adding priv struct). > - rather use a struct device in exported routine prototype, and use > standard helpers instead of ddata. Get rid of to_stm32_timers_priv(). > - simplify error handling in probe (remove a goto) > - comment on devm_of_platform_*populate() usage. > > Changes in v2: > - Abstract DMA handling from child driver: move it to MFD core > - Add comments on optional dma support > --- > drivers/mfd/stm32-timers.c | 227 ++++++++++++++++++++++++++++++++++++++- > include/linux/mfd/stm32-timers.h | 32 ++++++ > 2 files changed, 257 insertions(+), 2 deletions(-) [...] > diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h > index 2aadab6..a04d7a1 100644 > --- a/include/linux/mfd/stm32-timers.h > +++ b/include/linux/mfd/stm32-timers.h > @@ -8,6 +8,8 @@ > #define _LINUX_STM32_GPTIMER_H_ > > #include > +#include > +#include > #include [...] > +struct stm32_timers_dma; > + > struct stm32_timers { > struct clk *clk; > struct regmap *regmap; > u32 max_arr; > + struct stm32_timers_dma *dma; /* Only to be used by the parent */ I'm confused. I thought the point of putting this comment in was so that you could place the definition of 'stm32_timers_dma' and remove the forward declaration? > }; > + > +int stm32_timers_dma_burst_read(struct device *dev, u32 *buf, > + enum stm32_timers_dmas id, u32 reg, > + unsigned int num_reg, unsigned int bursts, > + unsigned long tmo_ms); > #endif -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog