Re: [PATCH 9/9] usb: cdns3: Impovement: simplify *switch_gadet and *switch_host

From: Peter Chen
Date: Tue Jul 07 2020 - 02:41:13 EST


On 20-07-01 08:20:04, Pawel Laszczak wrote:
> Patch split function cdns3_drd_switch_gadget and
> cdns3_drd_switch_host into:
> - cdns3_drd_host_on
> - cdns3_drd_host_off
> - cdns3_drd_gadget_on
> - cdns3_drd_gadgett_off
>
> These functions don't have any shared code so it's better to
> have smaller, faster and easier functions.

Changes the patch title, otherwise:

Reviewed-by: Peter Chen <peter.chen@xxxxxxx>

Peter
>
> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> ---
> drivers/usb/cdns3/drd.c | 124 ++++++++++++++++++++-----------------
> drivers/usb/cdns3/drd.h | 6 +-
> drivers/usb/cdns3/gadget.c | 4 +-
> drivers/usb/cdns3/host.c | 4 +-
> 4 files changed, 76 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c
> index 8e7673da905e..6234bcd6158a 100644
> --- a/drivers/usb/cdns3/drd.c
> +++ b/drivers/usb/cdns3/drd.c
> @@ -124,85 +124,97 @@ static void cdns3_otg_enable_irq(struct cdns3 *cdns)
> }
>
> /**
> - * cdns3_drd_switch_host - start/stop host
> - * @cdns: Pointer to controller context structure
> - * @on: 1 for start, 0 for stop
> + * cdns3_drd_host_on - start host.
> + * @cdns: Pointer to controller context structure.
> *
> - * Returns 0 on success otherwise negative errno
> + * Returns 0 on success otherwise negative errno.
> */
> -int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
> +int cdns3_drd_host_on(struct cdns3 *cdns)
> {
> - int ret, val;
> + u32 val;
> + int ret;
>
> - /* switch OTG core */
> - if (on) {
> - writel(OTGCMD_HOST_BUS_REQ | OTGCMD_OTG_DIS,
> - &cdns->otg_regs->cmd);
> -
> - dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
> - ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
> - val & OTGSTS_XHCI_READY,
> - 1, 100000);
> - if (ret) {
> - dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
> - return ret;
> - }
> - } else {
> - writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
> - OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
> - &cdns->otg_regs->cmd);
> - /* Waiting till H_IDLE state.*/
> - readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
> - !(val & OTGSTATE_HOST_STATE_MASK),
> - 1, 2000000);
> - }
> + /* Enable host mode. */
> + writel(OTGCMD_HOST_BUS_REQ | OTGCMD_OTG_DIS,
> + &cdns->otg_regs->cmd);
>
> - return 0;
> + dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
> + ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
> + val & OTGSTS_XHCI_READY, 1, 100000);
> +
> + if (ret)
> + dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
> +
> + return ret;
> }
>
> /**
> - * cdns3_drd_switch_gadget - start/stop gadget
> - * @cdns: Pointer to controller context structure
> - * @on: 1 for start, 0 for stop
> + * cdns3_drd_host_off - stop host.
> + * @cdns: Pointer to controller context structure.
> + */
> +void cdns3_drd_host_off(struct cdns3 *cdns)
> +{
> + u32 val;
> +
> + writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
> + OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
> + &cdns->otg_regs->cmd);
> +
> + /* Waiting till H_IDLE state.*/
> + readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
> + !(val & OTGSTATE_HOST_STATE_MASK),
> + 1, 2000000);
> +}
> +
> +/**
> + * cdns3_drd_gadget_on - start gadget.
> + * @cdns: Pointer to controller context structure.
> *
> * Returns 0 on success otherwise negative errno
> */
> -int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
> +int cdns3_drd_gadget_on(struct cdns3 *cdns)
> {
> int ret, val;
> u32 reg = OTGCMD_OTG_DIS;
>
> /* switch OTG core */
> - if (on) {
> - writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
> + writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
>
> - dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
> + dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
>
> - ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
> - val & OTGSTS_DEV_READY,
> - 1, 100000);
> - if (ret) {
> - dev_err(cdns->dev, "timeout waiting for dev_ready\n");
> - return ret;
> - }
> - } else {
> - /*
> - * driver should wait at least 10us after disabling Device
> - * before turning-off Device (DEV_BUS_DROP)
> - */
> - usleep_range(20, 30);
> - writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
> - OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
> - &cdns->otg_regs->cmd);
> - /* Waiting till DEV_IDLE state.*/
> - readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
> - !(val & OTGSTATE_DEV_STATE_MASK),
> - 1, 2000000);
> + ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
> + val & OTGSTS_DEV_READY,
> + 1, 100000);
> + if (ret) {
> + dev_err(cdns->dev, "timeout waiting for dev_ready\n");
> + return ret;
> }
>
> return 0;
> }
>
> +/**
> + * cdns3_drd_gadget_off - stop gadget.
> + * @cdns: Pointer to controller context structure.
> + */
> +void cdns3_drd_gadget_off(struct cdns3 *cdns)
> +{
> + u32 val;
> +
> + /*
> + * Driver should wait at least 10us after disabling Device
> + * before turning-off Device (DEV_BUS_DROP).
> + */
> + usleep_range(20, 30);
> + writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
> + OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
> + &cdns->otg_regs->cmd);
> + /* Waiting till DEV_IDLE state.*/
> + readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
> + !(val & OTGSTATE_DEV_STATE_MASK),
> + 1, 2000000);
> +}
> +
> /**
> * cdns3_init_otg_mode - initialize drd controller
> * @cdns: Pointer to controller context structure
> diff --git a/drivers/usb/cdns3/drd.h b/drivers/usb/cdns3/drd.h
> index 3889fead9df1..7e7cf7fa2dd3 100644
> --- a/drivers/usb/cdns3/drd.h
> +++ b/drivers/usb/cdns3/drd.h
> @@ -163,8 +163,10 @@ int cdns3_get_vbus(struct cdns3 *cdns);
> int cdns3_drd_init(struct cdns3 *cdns);
> int cdns3_drd_exit(struct cdns3 *cdns);
> int cdns3_drd_update_mode(struct cdns3 *cdns);
> -int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on);
> -int cdns3_drd_switch_host(struct cdns3 *cdns, int on);
> +int cdns3_drd_gadget_on(struct cdns3 *cdns);
> +void cdns3_drd_gadget_off(struct cdns3 *cdns);
> +int cdns3_drd_host_on(struct cdns3 *cdns);
> +void cdns3_drd_host_off(struct cdns3 *cdns);
> int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode);
>
> #endif /* __LINUX_CDNS3_DRD */
> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
> index c303ab7c62d1..6ea6839a2a8c 100644
> --- a/drivers/usb/cdns3/gadget.c
> +++ b/drivers/usb/cdns3/gadget.c
> @@ -3014,7 +3014,7 @@ void cdns3_gadget_exit(struct cdns3 *cdns)
> kfree(priv_dev->zlp_buf);
> kfree(priv_dev);
> cdns->gadget_dev = NULL;
> - cdns3_drd_switch_gadget(cdns, 0);
> + cdns3_drd_gadget_off(cdns);
> }
>
> static int cdns3_gadget_start(struct cdns3 *cdns)
> @@ -3145,7 +3145,7 @@ static int __cdns3_gadget_init(struct cdns3 *cdns)
> return ret;
> }
>
> - cdns3_drd_switch_gadget(cdns, 1);
> + cdns3_drd_gadget_on(cdns);
> pm_runtime_get_sync(cdns->dev);
>
> ret = cdns3_gadget_start(cdns);
> diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c
> index ad788bf3fe4f..36c63d9ecd37 100644
> --- a/drivers/usb/cdns3/host.c
> +++ b/drivers/usb/cdns3/host.c
> @@ -19,7 +19,7 @@ static int __cdns3_host_init(struct cdns3 *cdns)
> struct platform_device *xhci;
> int ret;
>
> - cdns3_drd_switch_host(cdns, 1);
> + cdns3_drd_host_on(cdns);
>
> xhci = platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> if (!xhci) {
> @@ -53,7 +53,7 @@ static void cdns3_host_exit(struct cdns3 *cdns)
> {
> platform_device_unregister(cdns->host_dev);
> cdns->host_dev = NULL;
> - cdns3_drd_switch_host(cdns, 0);
> + cdns3_drd_host_off(cdns);
> }
>
> int cdns3_host_init(struct cdns3 *cdns)
> --
> 2.17.1
>

--

Thanks,
Peter Chen