Re: [PATCH 2/4] usb: dwc3: qcom: Configure TCSR phy mux register

[Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>]

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Hi,

Andy Gross <agross-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> writes:
> This patch adds automatic configuration of the TCSR phy mux register based on
> the syscon-tcsr devicetree entry.  This configuration is optional, as some
> platforms may not require the mux selection.
>
> Signed-off-by: Andy Gross <agross-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

just when I find a way to make a generic dwc3-of-simple.c glue layer :-p

I can, certainly drop my patches but I need more details on the syscon
usage below.

> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 0880260..fcf264c 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -17,6 +17,8 @@
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>  
>  struct dwc3_qcom {
>  	struct device		*dev;
> @@ -30,6 +32,9 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  {
>  	struct device_node *node = pdev->dev.of_node;
>  	struct dwc3_qcom *qdwc;
> +	struct regmap *regmap;
> +	u32 mux_offset;
> +	u32 mux_bit;
>  	int ret;
>  
>  	qdwc = devm_kzalloc(&pdev->dev, sizeof(*qdwc), GFP_KERNEL);
> @@ -58,6 +63,26 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  		qdwc->sleep_clk = NULL;
>  	}
>  
> +	/* look for tcsr and if present, provision it */
> +	regmap = syscon_regmap_lookup_by_phandle(node, "syscon-tcsr");
> +	if (!IS_ERR(regmap)) {
> +		if (of_property_read_u32_index(node, "syscon-tcsr", 1,
> +					       &mux_offset)) {
> +			dev_err(qdwc->dev, "missing USB TCSR mux offset\n");
> +			return -EINVAL;
> +		}
> +		if (of_property_read_u32_index(node, "syscon-tcsr", 2,
> +					       &mux_bit)) {
> +			dev_err(qdwc->dev, "missing USB TCSR mux bit\n");
> +			return -EINVAL;
> +		}
> +
> +		regmap_update_bits(regmap, mux_offset, BIT(mux_bit),
> +				   BIT(mux_bit));

what is tcsr and what does it ? It also seems to be optional, why's that ?

-- 
balbi

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