Re: [PATCH 1/2] usb: cdns3: Add quirk flag to enable suspend residency

From: Peter Chen
Date: Tue May 14 2024 - 21:38:55 EST


On 24-05-14 14:54:20, Ravi Gunasekaran wrote:
> From: Roger Quadros <rogerq@xxxxxxxxxx>
>
> Some platforms (e.g. ti,j721e-usb, ti,am64-usb) require
> this bit to be set to workaround a lockup issue with PHY
> short suspend intervals [1]. Add a platform quirk flag
> to indicate if Suspend Residency should be enabled.
>
> [1] - https://www.ti.com/lit/er/sprz457h/sprz457h.pdf
> i2409 - USB: USB2 PHY locks up due to short suspend
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxxxxxx>
> Signed-off-by: Ravi Gunasekaran <r-gunasekaran@xxxxxx>
> ---
> drivers/usb/cdns3/core.h | 1 +
> drivers/usb/cdns3/drd.c | 9 ++++++++-
> drivers/usb/cdns3/drd.h | 3 +++
> 3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h
> index 81a9c9d6be08..57d47348dc19 100644
> --- a/drivers/usb/cdns3/core.h
> +++ b/drivers/usb/cdns3/core.h
> @@ -44,6 +44,7 @@ struct cdns3_platform_data {
> bool suspend, bool wakeup);
> unsigned long quirks;
> #define CDNS3_DEFAULT_PM_RUNTIME_ALLOW BIT(0)
> +#define CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE BIT(1)
> };
>
> /**
> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
> index 8b936a2e93a0..de0d25a072b4 100644
> --- a/drivers/usb/cdns3/drd.c
> +++ b/drivers/usb/cdns3/drd.c
> @@ -389,7 +389,7 @@ static irqreturn_t cdns_drd_irq(int irq, void *data)
> int cdns_drd_init(struct cdns *cdns)
> {
> void __iomem *regs;
> - u32 state;
> + u32 state, reg;
> int ret;
>
> regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
> @@ -439,6 +439,13 @@ int cdns_drd_init(struct cdns *cdns)
> return -EINVAL;
> }
>
> + if (cdns->pdata &&
> + (cdns->pdata->quirks & CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE)) {
> + reg = readl(&cdns->otg_v1_regs->susp_ctrl);
> + reg |= SUSP_CTRL_SUSPEND_RESIDENCY_ENABLE;
> + writel(reg, &cdns->otg_v1_regs->susp_ctrl);
> + }
> +

It is better put this above (just above code cdns->version =
CDNS3_CONTROLLER_V1;)

Peter
> dev_dbg(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
> readl(&cdns->otg_v1_regs->did),
> readl(&cdns->otg_v1_regs->rid));
> diff --git a/drivers/usb/cdns3/drd.h b/drivers/usb/cdns3/drd.h
> index d72370c321d3..1e2aee14d629 100644
> --- a/drivers/usb/cdns3/drd.h
> +++ b/drivers/usb/cdns3/drd.h
> @@ -193,6 +193,9 @@ struct cdns_otg_irq_regs {
> /* OTGREFCLK - bitmasks */
> #define OTGREFCLK_STB_CLK_SWITCH_EN BIT(31)
>
> +/* SUPS_CTRL - bitmasks */
> +#define SUSP_CTRL_SUSPEND_RESIDENCY_ENABLE BIT(17)
> +
> /* OVERRIDE - bitmasks */
> #define OVERRIDE_IDPULLUP BIT(0)
> /* Only for CDNS3_CONTROLLER_V0 version */
> --
> 2.17.1
>

--

Thanks,
Peter Chen