Re: [PATCH 1/5] usb: dwc3-generic: implement Qualcomm wrapper

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

Hi Caleb,

Thank you for the patch.

On mer., janv. 31, 2024 at 14:57, Caleb Connolly <caleb.connolly@linaro.org> wrote:

> The Qualcomm specific dwc3 wrapper isn't hugely complicated, implemented
> the missing initialisation for host and gadget mode.
>
> Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
> ---
>  drivers/usb/dwc3/dwc3-generic.c | 99 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 98 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
> index 48da621ba966..1119cdecd26d 100644
> --- a/drivers/usb/dwc3/dwc3-generic.c
> +++ b/drivers/usb/dwc3/dwc3-generic.c
> @@ -419,6 +419,99 @@ struct dwc3_glue_ops ti_ops = {
>  	.glue_configure = dwc3_ti_glue_configure,
>  };
>  
> +/* USB QSCRATCH Hardware registers */
> +#define QSCRATCH_HS_PHY_CTRL 0x10
> +#define UTMI_OTG_VBUS_VALID BIT(20)
> +#define SW_SESSVLD_SEL BIT(28)
> +
> +#define QSCRATCH_SS_PHY_CTRL 0x30
> +#define LANE0_PWR_PRESENT BIT(24)
> +
> +#define QSCRATCH_GENERAL_CFG 0x08
> +#define PIPE_UTMI_CLK_SEL BIT(0)
> +#define PIPE3_PHYSTATUS_SW BIT(3)
> +#define PIPE_UTMI_CLK_DIS BIT(8)
> +
> +#define PWR_EVNT_IRQ_STAT_REG 0x58
> +#define PWR_EVNT_LPM_IN_L2_MASK BIT(4)
> +#define PWR_EVNT_LPM_OUT_L2_MASK BIT(5)
> +
> +#define SDM845_QSCRATCH_BASE_OFFSET 0xf8800
> +#define SDM845_QSCRATCH_SIZE 0x400
> +#define SDM845_DWC3_CORE_SIZE 0xcd00
> +static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
> +{
> +	u32 reg;
> +
> +	reg = readl(base + offset);
> +	reg |= val;
> +	writel(reg, base + offset);

Why can't we use the setbits() macro here?
see: arch/arm/include/asm/io.h

> +
> +	/* ensure that above write is through */
> +	readl(base + offset);
> +}
> +
> +static inline void dwc3_qcom_clrbits(void __iomem *base, u32 offset, u32 val)
> +{
> +	u32 reg;
> +
> +	reg = readl(base + offset);
> +	reg &= ~val;
> +	writel(reg, base + offset);

Same question for clrbits()

> +
> +	/* ensure that above write is through */
> +	readl(base + offset);
> +}
> +
> +static void dwc3_qcom_vbus_override_enable(void __iomem *qscratch_base, bool enable)
> +{
> +	if (enable) {
> +		dwc3_qcom_setbits(qscratch_base, QSCRATCH_SS_PHY_CTRL,
> +				  LANE0_PWR_PRESENT);
> +		dwc3_qcom_setbits(qscratch_base, QSCRATCH_HS_PHY_CTRL,
> +				  UTMI_OTG_VBUS_VALID | SW_SESSVLD_SEL);
> +	} else {
> +		dwc3_qcom_clrbits(qscratch_base, QSCRATCH_SS_PHY_CTRL,
> +				  LANE0_PWR_PRESENT);
> +		dwc3_qcom_clrbits(qscratch_base, QSCRATCH_HS_PHY_CTRL,
> +				  UTMI_OTG_VBUS_VALID | SW_SESSVLD_SEL);
> +	}
> +}
> +
> +/* For controllers running without superspeed PHYs */
> +static void dwc3_qcom_select_utmi_clk(void __iomem *qscratch_base)
> +{
> +	/* Configure dwc3 to use UTMI clock as PIPE clock not present */
> +	dwc3_qcom_setbits(qscratch_base, QSCRATCH_GENERAL_CFG,
> +			  PIPE_UTMI_CLK_DIS);
> +
> +	udelay(500);
> +
> +	dwc3_qcom_setbits(qscratch_base, QSCRATCH_GENERAL_CFG,
> +			  PIPE_UTMI_CLK_SEL | PIPE3_PHYSTATUS_SW);
> +
> +	udelay(500);
> +
> +	dwc3_qcom_clrbits(qscratch_base, QSCRATCH_GENERAL_CFG,
> +			  PIPE_UTMI_CLK_DIS);
> +}
> +
> +static void dwc3_qcom_glue_configure(struct udevice *dev, int index,
> +				     enum usb_dr_mode mode)
> +{
> +	void __iomem *qscratch_base = (void __iomem *)dev_read_addr(dev);
> +
> +	if (dev_read_bool(dev, "qcom,select-utmi-as-pipe-clk"))
> +		dwc3_qcom_select_utmi_clk(qscratch_base);
> +
> +	if (mode != USB_DR_MODE_HOST)
> +		dwc3_qcom_vbus_override_enable(qscratch_base, true);
> +}
> +
> +struct dwc3_glue_ops qcom_ops = {
> +	.glue_configure = dwc3_qcom_glue_configure,
> +};
> +
>  static int dwc3_rk_glue_get_ctrl_dev(struct udevice *dev, ofnode *node)
>  {
>  	*node = dev_ofnode(dev);
> @@ -506,6 +599,10 @@ static int dwc3_glue_reset_init(struct udevice *dev,
>  	else if (ret)
>  		return ret;
>  
> +	if (device_is_compatible(dev, "qcom,dwc3")) {
> +		reset_assert_bulk(&glue->resets);

Any reason for not doing error handling on reset_assert_bulk() like it's
done below ?

> +		udelay(500);
> +	}
>  	ret = reset_deassert_bulk(&glue->resets);
>  	if (ret) {
>  		reset_release_bulk(&glue->resets);
> @@ -623,7 +720,7 @@ static const struct udevice_id dwc3_glue_ids[] = {
>  	{ .compatible = "rockchip,rk3399-dwc3" },
>  	{ .compatible = "rockchip,rk3568-dwc3", .data = (ulong)&rk_ops },
>  	{ .compatible = "rockchip,rk3588-dwc3", .data = (ulong)&rk_ops },
> -	{ .compatible = "qcom,dwc3" },
> +	{ .compatible = "qcom,dwc3", .data = (ulong)&qcom_ops },
>  	{ .compatible = "fsl,imx8mp-dwc3", .data = (ulong)&imx8mp_ops },
>  	{ .compatible = "fsl,imx8mq-dwc3" },
>  	{ .compatible = "intel,tangier-dwc3" },
>
> -- 
> 2.43.0