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SubjectRe: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver
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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
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