Re: [PATCH v1] usb: dwc2: reset AHB hclk domain before init

[Felipe Balbi]

Hi,

On Tue, Aug 11, 2015 at 10:27:42AM +0800, Yunzhi Li wrote:
> We initiate dwc2 usb controller in BIOS, when kernel driver
> start-up we should reset AHB hclk domain to reset all AHB
> interface registers to default. Without this the FIFO value
> setting might be incorrect because calculating FIFO size need the
> power-on value of GRXFSIZ/GNPTXFSIZ/HPTXFSIZ registers.
> 
> This patch could avoid warnning massage like in rk3288 platform:
> [    2.074764] dwc2 ff580000.usb: 256 invalid for
> host_perio_tx_fifo_size. Check HW configuration.
> 
> Signed-off-by: Yunzhi Li <lyz@xxxxxxxxxxxxxx>
> 
> ---
> 
>  drivers/usb/dwc2/platform.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index 9093530..3da21ab 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -42,6 +42,7 @@
>  #include <linux/of_device.h>
>  #include <linux/mutex.h>
>  #include <linux/platform_device.h>
> +#include <linux/reset.h>
>  
>  #include <linux/usb/of.h>
>  
> @@ -165,6 +166,7 @@ static int dwc2_driver_probe(struct platform_device *dev)
>  	struct resource *res;
>  	struct phy *phy;
>  	struct usb_phy *uphy;
> +	struct reset_control *rst;
>  	int retval;
>  	int irq;
>  
> @@ -189,6 +191,16 @@ static int dwc2_driver_probe(struct platform_device *dev)
>  
>  	hsotg->dev = &dev->dev;
>  
> +	/* AHB hclk domain reset, set all AHB interface registers to default */
> +	rst = devm_reset_control_get_optional(&dev->dev, "ahb_reset");

why isn't this done in core so PCI systems can also make use of it ?

-- 
balbi

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