From cf40b86b6ef6df5262ef5a8463b42524e6aa5590 Mon Sep 17 00:00:00 2001 From: John Youn Date: Mon, 14 Nov 2016 12:32:43 -0800 Subject: [PATCH] usb: dwc3: Implement interrupt moderation Implement interrupt moderation which allows the interrupt rate to be throttled. To enable this feature the dwc->imod_interval must be set to 1 or greater. This value specifies the minimum inter-interrupt interval, in 250 ns increments. A value of 0 disables interrupt moderation. This applies for DWC_usb3 version 3.00a and higher and for DWC_usb31 version 1.20a and higher. Signed-off-by: John Youn Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/core.c | 16 ++++++++++++++++ drivers/usb/dwc3/core.h | 15 +++++++++++++++ drivers/usb/dwc3/gadget.c | 16 ++++++++++++++++ 3 files changed, 47 insertions(+) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 87d0cfb7b29e..889dbabc7c2d 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -982,12 +982,28 @@ static void dwc3_get_properties(struct dwc3 *dwc) dwc->hird_threshold = hird_threshold | (dwc->is_utmi_l1_suspend << 4); + dwc->imod_interval = 0; +} + +/* check whether the core supports IMOD */ +bool dwc3_has_imod(struct dwc3 *dwc) +{ + return ((dwc3_is_usb3(dwc) && + dwc->revision >= DWC3_REVISION_300A) || + (dwc3_is_usb31(dwc) && + dwc->revision >= DWC3_USB31_REVISION_120A)); } static void dwc3_check_params(struct dwc3 *dwc) { struct device *dev = dwc->dev; + /* Check for proper value of imod_interval */ + if (dwc->imod_interval && !dwc3_has_imod(dwc)) { + dev_warn(dwc->dev, "Interrupt moderation not supported\n"); + dwc->imod_interval = 0; + } + /* Check the maximum_speed parameter */ switch (dwc->maximum_speed) { case USB_SPEED_LOW: diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index bf63756bc176..ef81fa5d0088 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -67,6 +67,7 @@ #define DWC3_DEVICE_EVENT_OVERFLOW 11 #define DWC3_GEVNTCOUNT_MASK 0xfffc +#define DWC3_GEVNTCOUNT_EHB (1 << 31) #define DWC3_GSNPSID_MASK 0xffff0000 #define DWC3_GSNPSREV_MASK 0xffff @@ -149,6 +150,8 @@ #define DWC3_DEPCMDPAR0 0x08 #define DWC3_DEPCMD 0x0c +#define DWC3_DEV_IMOD(n) (0xca00 + (n * 0x4)) + /* OTG Registers */ #define DWC3_OCFG 0xcc00 #define DWC3_OCTL 0xcc04 @@ -465,6 +468,11 @@ #define DWC3_DEPCMD_TYPE_BULK 2 #define DWC3_DEPCMD_TYPE_INTR 3 +#define DWC3_DEV_IMOD_COUNT_SHIFT 16 +#define DWC3_DEV_IMOD_COUNT_MASK (0xffff << 16) +#define DWC3_DEV_IMOD_INTERVAL_SHIFT 0 +#define DWC3_DEV_IMOD_INTERVAL_MASK (0xffff << 0) + /* Structures */ struct dwc3_trb; @@ -846,6 +854,8 @@ struct dwc3_scratchpad_array { * 1 - -3.5dB de-emphasis * 2 - No de-emphasis * 3 - Reserved + * @imod_interval: set the interrupt moderation interval in 250ns + * increments or 0 to disable. */ struct dwc3 { struct usb_ctrlrequest *ctrl_req; @@ -933,6 +943,7 @@ struct dwc3 { */ #define DWC3_REVISION_IS_DWC31 0x80000000 #define DWC3_USB31_REVISION_110A (0x3131302a | DWC3_REVISION_IS_DWC31) +#define DWC3_USB31_REVISION_120A (0x3132302a | DWC3_REVISION_IS_DWC31) enum dwc3_ep0_next ep0_next_event; enum dwc3_ep0_state ep0state; @@ -991,6 +1002,8 @@ struct dwc3 { unsigned tx_de_emphasis_quirk:1; unsigned tx_de_emphasis:2; + + u16 imod_interval; }; /* -------------------------------------------------------------------------- */ @@ -1162,6 +1175,8 @@ static inline bool dwc3_is_usb31(struct dwc3 *dwc) return !!(dwc->revision & DWC3_REVISION_IS_DWC31); } +bool dwc3_has_imod(struct dwc3 *dwc); + #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE) int dwc3_host_init(struct dwc3 *dwc); void dwc3_host_exit(struct dwc3 *dwc); diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 3d5ba4106979..e2416de36bb0 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1685,6 +1685,17 @@ static int __dwc3_gadget_start(struct dwc3 *dwc) int ret = 0; u32 reg; + /* + * Use IMOD if enabled via dwc->imod_interval. Otherwise, if + * the core supports IMOD, disable it. + */ + if (dwc->imod_interval) { + dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval); + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB); + } else if (dwc3_has_imod(dwc)) { + dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), 0); + } + reg = dwc3_readl(dwc->regs, DWC3_DCFG); reg &= ~(DWC3_DCFG_SPEED_MASK); @@ -2847,6 +2858,11 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) reg &= ~DWC3_GEVNTSIZ_INTMASK; dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg); + if (dwc->imod_interval) { + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB); + dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval); + } + return ret; } -- 2.45.2