On Fri, Nov 20, 2015 at 09:06:33AM -0600, Felipe Balbi wrote:
>
> Hi,
>
> Andy Gross <agross@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>
>
> 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
The syscon is to set the mux selection for the phys. Our hardware has a
steering mux between hsic and dwc3 and setting this to 1 steers the phys to the
right controller.
It is optional because not all platforms appear to have this stupidity.
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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