From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 4/8] mfd: stm32-timers: add support for dmas Date: Tue, 23 Jan 2018 13:32:34 +0000 Message-ID: <20180123133234.xmep76cgdremnj47@dell> References: <1516106631-18722-1-git-send-email-fabrice.gasnier@st.com> <1516106631-18722-5-git-send-email-fabrice.gasnier@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <1516106631-18722-5-git-send-email-fabrice.gasnier-qxv4g6HH51o@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Fabrice Gasnier Cc: thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, alexandre.torgue-qxv4g6HH51o@public.gmane.org, benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, mcoquelin.stm32-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, benjamin.gaignard-qxv4g6HH51o@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pwm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Tue, 16 Jan 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, keep reference of device's bus address to allow child drivers to > transfer data from/to device by using dma. > > Signed-off-by: Fabrice Gasnier > --- > drivers/mfd/stm32-timers.c | 37 ++++++++++++++++++++++++++++++++++++- > include/linux/mfd/stm32-timers.h | 14 ++++++++++++++ > 2 files changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/mfd/stm32-timers.c b/drivers/mfd/stm32-timers.c > index a6675a4..372b51e 100644 > --- a/drivers/mfd/stm32-timers.c > +++ b/drivers/mfd/stm32-timers.c > @@ -29,6 +29,23 @@ static void stm32_timers_get_arr_size(struct stm32_timers *ddata) > regmap_write(ddata->regmap, TIM_ARR, 0x0); > } > > +static void stm32_timers_dma_probe(struct device *dev, > + struct stm32_timers *ddata) > +{ > + int i; > + char name[4]; > + > + for (i = STM32_TIMERS_DMA_CH1; i <= STM32_TIMERS_DMA_CH4; i++) { > + snprintf(name, ARRAY_SIZE(name), "ch%1d", i + 1); > + ddata->dmas[i] = dma_request_slave_channel(dev, name); And if any of them fail? > + } > + ddata->dmas[STM32_TIMERS_DMA_UP] = dma_request_slave_channel(dev, "up"); > + ddata->dmas[STM32_TIMERS_DMA_TRIG] = > + dma_request_slave_channel(dev, "trig"); > + ddata->dmas[STM32_TIMERS_DMA_COM] = > + dma_request_slave_channel(dev, "com"); Can you format these in the same why. This hurts my eyes. > +} > + > static int stm32_timers_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -44,6 +61,7 @@ static int stm32_timers_probe(struct platform_device *pdev) > mmio = devm_ioremap_resource(dev, res); > if (IS_ERR(mmio)) > return PTR_ERR(mmio); > + ddata->phys_base = res->start; What do you use this for? > ddata->regmap = devm_regmap_init_mmio_clk(dev, "int", mmio, > &stm32_timers_regmap_cfg); > @@ -56,9 +74,25 @@ static int stm32_timers_probe(struct platform_device *pdev) > > stm32_timers_get_arr_size(ddata); > > + stm32_timers_dma_probe(dev, ddata); > + Surely this can fail? > platform_set_drvdata(pdev, ddata); > > - return devm_of_platform_populate(&pdev->dev); > + return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); > +} > + > +static int stm32_timers_remove(struct platform_device *pdev) > +{ > + struct stm32_timers *ddata = platform_get_drvdata(pdev); > + int i; > + > + of_platform_depopulate(&pdev->dev); > + > + for (i = 0; i < STM32_TIMERS_MAX_DMAS; i++) > + if (ddata->dmas[i]) > + dma_release_channel(ddata->dmas[i]); > + > + return 0; > } > > static const struct of_device_id stm32_timers_of_match[] = { > @@ -69,6 +103,7 @@ static int stm32_timers_probe(struct platform_device *pdev) > > static struct platform_driver stm32_timers_driver = { > .probe = stm32_timers_probe, > + .remove = stm32_timers_remove, > .driver = { > .name = "stm32-timers", > .of_match_table = stm32_timers_of_match, > diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h > index ce7346e..2b4ffb9 100644 > --- a/include/linux/mfd/stm32-timers.h > +++ b/include/linux/mfd/stm32-timers.h > @@ -10,6 +10,7 @@ > #define _LINUX_STM32_GPTIMER_H_ > > #include > +#include > #include > > #define TIM_CR1 0x00 /* Control Register 1 */ > @@ -67,9 +68,22 @@ > #define TIM_BDTR_BKF_SHIFT 16 > #define TIM_BDTR_BK2F_SHIFT 20 > > +enum stm32_timers_dmas { > + STM32_TIMERS_DMA_CH1, > + STM32_TIMERS_DMA_CH2, > + STM32_TIMERS_DMA_CH3, > + STM32_TIMERS_DMA_CH4, > + STM32_TIMERS_DMA_UP, > + STM32_TIMERS_DMA_TRIG, > + STM32_TIMERS_DMA_COM, > + STM32_TIMERS_MAX_DMAS, > +}; > + > struct stm32_timers { > struct clk *clk; > struct regmap *regmap; > + phys_addr_t phys_base; > u32 max_arr; > + struct dma_chan *dmas[STM32_TIMERS_MAX_DMAS]; > }; > #endif -- Lee Jones Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html