From mboxrd@z Thu Jan 1 00:00:00 1970 From: pierre-yves.mordret@st.com (Pierre Yves MORDRET) Date: Wed, 26 Jul 2017 07:38:02 +0000 Subject: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver In-Reply-To: <20170726052930.GF3053@localhost> References: <1499343623-5964-1-git-send-email-pierre-yves.mordret@st.com> <1499343623-5964-3-git-send-email-pierre-yves.mordret@st.com> <20170722065133.GT3053@localhost> <2b916330-9b65-f4d5-817f-79b66cc236b3@st.com> <20170726052930.GF3053@localhost> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/26/2017 07:29 AM, Vinod Koul wrote: > On Mon, Jul 24, 2017 at 01:55:10PM +0000, Pierre Yves MORDRET wrote: > >>>> + >>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >>>> + if (!res) >>>> + return -ENODEV; >>>> + >>>> + iomem = devm_ioremap_resource(&pdev->dev, res); >>>> + if (!iomem) >>>> + return -ENOMEM; >>>> + >>>> + spin_lock_init(&stm32_dmamux->lock); >>>> + >>>> + stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL); >>>> + if (IS_ERR(stm32_dmamux->clk)) { >>>> + dev_info(&pdev->dev, "Missing controller clock\n"); >>> >>> Can you check for EPROBE_DEFER and print only for if that is not the error >>> otherwise we end up sapmming with defered probe issues >>> >> >> This is what you meant ? >> if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) { >> dev_info(&pdev->dev, "Missing controller clock\n"); >> return PTR_ERR(stm32_dmamux->clk); >> } >> >> OR >> >> if (IS_ERR(stm32_dmamux->clk)) { >> if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) >> dev_info(&pdev->dev, "Missing controller clock\n"); >> return PTR_ERR(stm32_dmamux->clk); >> } > > This one please > ok >> >>>> + >>>> +#ifndef __DMA_STM32_DMAMUX_H >>>> +#define __DMA_STM32_DMAMUX_H >>>> + >>>> +#if defined(CONFIG_STM32_DMAMUX) >>>> +int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id); >>> >>> Why do we need a custom API in this case? >>> >> >> This API is called by DMA when a slave is requested by client. DMA can work >> without DMAMUX this API has been put in place to configure DMAMUX whether client >> is requesting a DMAMUX Channel instead of a DMA one. > > You mean the dmaengine driver right? > Yes. The API is mainly called by "device_config" through out STM32 DMA Driver when a router is in place for client. Please refer to Patch 4/5 on this set. Thanks Py