Re: [PATCH V3 2/3] usb: dwc3: qcom: Add interconnect support in dwc3 driver

[Evan Green <evgreen@chromium.org>]

On Tue, Sep 17, 2019 at 4:11 AM Chandana Kishori Chiluveru
<cchiluve@codeaurora.org> wrote:
>
> Add interconnect support in dwc3-qcom driver to vote for bus
> bandwidth.
>
> This requires for two different paths - from USB master to
> DDR slave. The other is from APPS master to USB slave.
>
> Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 145 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 143 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 184df4d..2a2f5af 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -12,6 +12,7 @@
>  #include <linux/module.h>
>  #include <linux/kernel.h>
>  #include <linux/extcon.h>
> +#include <linux/interconnect.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/phy/phy.h>
> @@ -59,8 +60,13 @@ struct dwc3_qcom {
>         enum usb_dr_mode        mode;
>         bool                    is_suspended;
>         bool                    pm_suspended;
> +       struct icc_path         *usb_ddr_icc_path;
> +       struct icc_path         *apps_usb_icc_path;
>  };
>
> +static int dwc3_qcom_interconnect_enable(struct dwc3_qcom *qcom);
> +static int dwc3_qcom_interconnect_disable(struct dwc3_qcom *qcom);
> +
>  static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
>  {
>         u32 reg;
> @@ -222,7 +228,7 @@ static void dwc3_qcom_enable_interrupts(struct dwc3_qcom *qcom)
>  static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
>  {
>         u32 val;
> -       int i;
> +       int i, ret;
>
>         if (qcom->is_suspended)
>                 return 0;
> @@ -234,6 +240,10 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
>         for (i = qcom->num_clocks - 1; i >= 0; i--)
>                 clk_disable_unprepare(qcom->clks[i]);
>
> +       ret = dwc3_qcom_interconnect_disable(qcom);
> +       if (ret)
> +               dev_warn(qcom->dev, "failed to disable interconnect %d\n", ret);
> +
>         qcom->is_suspended = true;
>         dwc3_qcom_enable_interrupts(qcom);
>
> @@ -259,6 +269,10 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
>                 }
>         }
>
> +       ret = dwc3_qcom_interconnect_enable(qcom);
> +       if (ret)
> +               dev_warn(qcom->dev, "failed to enable interconnect %d\n", ret);
> +
>         /* Clear existing events from PHY related to L2 in/out */
>         dwc3_qcom_setbits(qcom->qscratch_base, PWR_EVNT_IRQ_STAT_REG,
>                           PWR_EVNT_LPM_IN_L2_MASK | PWR_EVNT_LPM_OUT_L2_MASK);
> @@ -268,6 +282,124 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
>         return 0;
>  }
>
> +/* Interconnect path bandwidths in MBps */
> +#define USB_MEMORY_AVG_HS_BW MBps_to_icc(240)
> +#define USB_MEMORY_PEAK_HS_BW MBps_to_icc(700)
> +#define USB_MEMORY_AVG_SS_BW  MBps_to_icc(1000)
> +#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(2500)
> +#define APPS_USB_AVG_BW 0
> +#define APPS_USB_PEAK_BW MBps_to_icc(40)
> +
> +/**
> + * dwc3_qcom_interconnect_init() - Get interconnect path handles
> + * @qcom:                      Pointer to the concerned usb core.
> + *
> + */
> +static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
> +{
> +       struct device *dev = qcom->dev;

I'm not subscribed to linux-usb, so I don't have the V4 edition. So
I'm commenting here. In the v4 version there's a line:
 struct dwc3 *dwc;

that results in an unused local variable compiler warning.
-Evan