2021-04-13 12:52:13

by Artur Petrosyan

[permalink] [raw]
Subject: [PATCH v2 01/12] usb: dwc2: Add device clock gating support functions

Added device clock gating support functions according
programming guide.

Moved "bus_suspended" flag to "dwc2_hsotg" struct because
we need to set that flag while entering to clock gating
in case when the driver is built in peripheral mode.

Added function names:
dwc2_gadget_enter_clock_gating()
dwc2_gadget_exit_clock_gating()

Signed-off-by: Artur Petrosyan <[email protected]>
Acked-by: Minas Harutyunyan <[email protected]>
---
drivers/usb/dwc2/core.h | 10 ++++--
drivers/usb/dwc2/gadget.c | 71 +++++++++++++++++++++++++++++++++++++++
2 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 5a7850482e57..e5597796dca4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -866,6 +866,7 @@ struct dwc2_hregs_backup {
* @ll_hw_enabled: Status of low-level hardware resources.
* @hibernated: True if core is hibernated
* @in_ppd: True if core is partial power down mode.
+ * @bus_suspended: True if bus is suspended
* @reset_phy_on_wake: Quirk saying that we should assert PHY reset on a
* remote wakeup.
* @phy_off_for_suspend: Status of whether we turned the PHY off at suspend.
@@ -1023,7 +1024,6 @@ struct dwc2_hregs_backup {
* a pointer to an array of register definitions, the
* array size and the base address where the register bank
* is to be found.
- * @bus_suspended: True if bus is suspended
* @last_frame_num: Number of last frame. Range from 0 to 32768
* @frame_num_array: Used only if CONFIG_USB_DWC2_TRACK_MISSED_SOFS is
* defined, for missed SOFs tracking. Array holds that
@@ -1062,6 +1062,7 @@ struct dwc2_hsotg {
unsigned int ll_hw_enabled:1;
unsigned int hibernated:1;
unsigned int in_ppd:1;
+ bool bus_suspended;
unsigned int reset_phy_on_wake:1;
unsigned int need_phy_for_wake:1;
unsigned int phy_off_for_suspend:1;
@@ -1145,7 +1146,6 @@ struct dwc2_hsotg {
unsigned long hs_periodic_bitmap[
DIV_ROUND_UP(DWC2_HS_SCHEDULE_US, BITS_PER_LONG)];
u16 periodic_qh_count;
- bool bus_suspended;
bool new_connection;

u16 last_frame_num;
@@ -1415,6 +1415,9 @@ int dwc2_gadget_exit_hibernation(struct dwc2_hsotg *hsotg,
int dwc2_gadget_enter_partial_power_down(struct dwc2_hsotg *hsotg);
int dwc2_gadget_exit_partial_power_down(struct dwc2_hsotg *hsotg,
bool restore);
+void dwc2_gadget_enter_clock_gating(struct dwc2_hsotg *hsotg);
+void dwc2_gadget_exit_clock_gating(struct dwc2_hsotg *hsotg,
+ int rem_wakeup);
int dwc2_hsotg_tx_fifo_count(struct dwc2_hsotg *hsotg);
int dwc2_hsotg_tx_fifo_total_depth(struct dwc2_hsotg *hsotg);
int dwc2_hsotg_tx_fifo_average_depth(struct dwc2_hsotg *hsotg);
@@ -1453,6 +1456,9 @@ static inline int dwc2_gadget_enter_partial_power_down(struct dwc2_hsotg *hsotg)
static inline int dwc2_gadget_exit_partial_power_down(struct dwc2_hsotg *hsotg,
bool restore)
{ return 0; }
+static inline void dwc2_gadget_enter_clock_gating(struct dwc2_hsotg *hsotg) {}
+static inline void dwc2_gadget_exit_clock_gating(struct dwc2_hsotg *hsotg,
+ int rem_wakeup) {}
static inline int dwc2_hsotg_tx_fifo_count(struct dwc2_hsotg *hsotg)
{ return 0; }
static inline int dwc2_hsotg_tx_fifo_total_depth(struct dwc2_hsotg *hsotg)
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index e08baee4987b..2f50f3e62caa 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -5483,3 +5483,74 @@ int dwc2_gadget_exit_partial_power_down(struct dwc2_hsotg *hsotg,
dev_dbg(hsotg->dev, "Exiting device partial Power Down completed.\n");
return ret;
}
+
+/**
+ * dwc2_gadget_enter_clock_gating() - Put controller in clock gating.
+ *
+ * @hsotg: Programming view of the DWC_otg controller
+ *
+ * Return: non-zero if failed to enter device partial power down.
+ *
+ * This function is for entering device mode clock gating.
+ */
+void dwc2_gadget_enter_clock_gating(struct dwc2_hsotg *hsotg)
+{
+ u32 pcgctl;
+
+ dev_dbg(hsotg->dev, "Entering device clock gating.\n");
+
+ /* Set the Phy Clock bit as suspend is received. */
+ pcgctl = dwc2_readl(hsotg, PCGCTL);
+ pcgctl |= PCGCTL_STOPPCLK;
+ dwc2_writel(hsotg, pcgctl, PCGCTL);
+ udelay(5);
+
+ /* Set the Gate hclk as suspend is received. */
+ pcgctl = dwc2_readl(hsotg, PCGCTL);
+ pcgctl |= PCGCTL_GATEHCLK;
+ dwc2_writel(hsotg, pcgctl, PCGCTL);
+ udelay(5);
+
+ hsotg->lx_state = DWC2_L2;
+ hsotg->bus_suspended = true;
+}
+
+/*
+ * dwc2_gadget_exit_clock_gating() - Exit controller from device clock gating.
+ *
+ * @hsotg: Programming view of the DWC_otg controller
+ * @rem_wakeup: indicates whether remote wake up is enabled.
+ *
+ * This function is for exiting from device mode clock gating.
+ */
+void dwc2_gadget_exit_clock_gating(struct dwc2_hsotg *hsotg, int rem_wakeup)
+{
+ u32 pcgctl;
+ u32 dctl;
+
+ dev_dbg(hsotg->dev, "Exiting device clock gating.\n");
+
+ /* Clear the Gate hclk. */
+ pcgctl = dwc2_readl(hsotg, PCGCTL);
+ pcgctl &= ~PCGCTL_GATEHCLK;
+ dwc2_writel(hsotg, pcgctl, PCGCTL);
+ udelay(5);
+
+ /* Phy Clock bit. */
+ pcgctl = dwc2_readl(hsotg, PCGCTL);
+ pcgctl &= ~PCGCTL_STOPPCLK;
+ dwc2_writel(hsotg, pcgctl, PCGCTL);
+ udelay(5);
+
+ if (rem_wakeup) {
+ /* Set Remote Wakeup Signaling */
+ dctl = dwc2_readl(hsotg, DCTL);
+ dctl |= DCTL_RMTWKUPSIG;
+ dwc2_writel(hsotg, dctl, DCTL);
+ }
+
+ /* Change to L0 state */
+ call_gadget(hsotg, resume);
+ hsotg->lx_state = DWC2_L0;
+ hsotg->bus_suspended = false;
+}
--
2.25.1