diff options
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
-rw-r--r-- | drivers/usb/dwc3/gadget.c | 54 |
1 files changed, 43 insertions, 11 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index bff2c35f37a8..eb28326a633d 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -485,17 +485,6 @@ static int dwc3_gadget_set_ep_config(struct dwc3 *dwc, struct dwc3_ep *dep, /* Burst size is only needed in SuperSpeed mode */ if (dwc->gadget.speed >= USB_SPEED_SUPER) { u32 burst = dep->endpoint.maxburst; - u32 nump; - u32 reg; - - /* update NumP */ - reg = dwc3_readl(dwc->regs, DWC3_DCFG); - nump = DWC3_DCFG_NUMP(reg); - nump = max(nump, burst); - reg &= ~DWC3_DCFG_NUMP_MASK; - reg |= nump << DWC3_DCFG_NUMP_SHIFT; - dwc3_writel(dwc->regs, DWC3_DCFG, reg); - params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst - 1); } @@ -1610,6 +1599,47 @@ static void dwc3_gadget_disable_irq(struct dwc3 *dwc) static irqreturn_t dwc3_interrupt(int irq, void *_dwc); static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc); +/** + * dwc3_gadget_setup_nump - Calculate and initialize NUMP field of DCFG + * dwc: pointer to our context structure + * + * The following looks like complex but it's actually very simple. In order to + * calculate the number of packets we can burst at once on OUT transfers, we're + * gonna use RxFIFO size. + * + * To calculate RxFIFO size we need two numbers: + * MDWIDTH = size, in bits, of the internal memory bus + * RAM2_DEPTH = depth, in MDWIDTH, of internal RAM2 (where RxFIFO sits) + * + * Given these two numbers, the formula is simple: + * + * RxFIFO Size = (RAM2_DEPTH * MDWIDTH / 8) - 24 - 16; + * + * 24 bytes is for 3x SETUP packets + * 16 bytes is a clock domain crossing tolerance + * + * Given RxFIFO Size, NUMP = RxFIFOSize / 1024; + */ +static void dwc3_gadget_setup_nump(struct dwc3 *dwc) +{ + u32 ram2_depth; + u32 mdwidth; + u32 nump; + u32 reg; + + ram2_depth = DWC3_GHWPARAMS7_RAM2_DEPTH(dwc->hwparams.hwparams7); + mdwidth = DWC3_GHWPARAMS0_MDWIDTH(dwc->hwparams.hwparams0); + + nump = ((ram2_depth * mdwidth / 8) - 24 - 16) / 1024; + nump = min_t(u32, nump, 16); + + /* update NumP */ + reg = dwc3_readl(dwc->regs, DWC3_DCFG); + reg &= ~DWC3_DCFG_NUMP_MASK; + reg |= nump << DWC3_DCFG_NUMP_SHIFT; + dwc3_writel(dwc->regs, DWC3_DCFG, reg); +} + static int __dwc3_gadget_start(struct dwc3 *dwc) { struct dwc3_ep *dep; @@ -1670,6 +1700,8 @@ static int __dwc3_gadget_start(struct dwc3 *dwc) reg &= ~DWC3_GRXTHRCFG_PKTCNTSEL; dwc3_writel(dwc->regs, DWC3_GRXTHRCFG, reg); + dwc3_gadget_setup_nump(dwc); + /* Start with SuperSpeed Default */ dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512); |