drivers: usb_device: smartbond: Add power management

Add support for automatic control of PLL for USB subsystem.

This utilized virtual USB clock present in clock control.
USB driver enables PLL when device is attached or USB
sends resume signaling.

PLL can be turned off (if application does not requested it)
when device is detached (application request)
or USB host sends suspend request.

When VBUS is not present or application did not started USB yet
PD_DOMAIN_SYS is also not acquired that allows for deep
sleep. When USB is active deep sleep will never be activated.

Signed-off-by: Jerzy Kasenberg <[email protected]>

Author: kasjer

drivers/usb/device/usb_dc_smartbond.c

@@ -22,9 +22,12 @@
 #include <DA1469xAB.h>
 #include <soc.h>
 #include <da1469x_clock.h>
+#include <da1469x_pd.h>
 
 #include <zephyr/logging/log.h>
 #include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/clock_control/smartbond_clock_control.h>
+#include <zephyr/pm/policy.h>
 
 LOG_MODULE_REGISTER(usb_dc_smartbond, CONFIG_USB_DRIVER_LOG_LEVEL);
 
@@ -128,6 +131,7 @@ struct smartbond_ep_state {
 struct usb_dc_state {
 	bool vbus_present;
 	bool attached;
+	atomic_t clk_requested;
 	uint8_t nfsr;
 	usb_dc_status_callback status_cb;
 	struct smartbond_ep_state ep_state[2][4];
@@ -684,6 +688,7 @@ static uint32_t check_reset_end(uint32_t alt_ev)
 			}
 			LOG_INF("Set operational %02x", USB->USB_MAMSK_REG);
 			set_nfsr(NFSR_NODE_OPERATIONAL);
+			dev_state.status_cb(USB_DC_CONNECTED, NULL);
 		}
 	}
 	return alt_ev;
@@ -723,11 +728,30 @@ static void handle_bus_reset(void)
 	check_reset_end(alt_ev);
 }
 
+static void usb_clock_on(void)
+{
+	if (atomic_cas(&dev_state.clk_requested, 0, 1)) {
+		clock_control_on(DEVICE_DT_GET(DT_NODELABEL(osc)),
+				 (clock_control_subsys_rate_t)SMARTBOND_CLK_USB);
+	}
+}
+
+static void usb_clock_off(void)
+{
+	if (atomic_cas(&dev_state.clk_requested, 1, 0)) {
+		clock_control_off(DEVICE_DT_GET(DT_NODELABEL(osc)),
+				  (clock_control_subsys_rate_t)SMARTBOND_CLK_USB);
+	}
+}
+
 static void handle_alt_ev(void)
 {
 	struct smartbond_ep_state *ep_state;
 	uint32_t alt_ev = USB->USB_ALTEV_REG;
 
+	if (USB->USB_NFSR_REG == NFSR_NODE_SUSPEND) {
+		usb_clock_on();
+	}
 	alt_ev = check_reset_end(alt_ev);
 	if (GET_BIT(alt_ev, USB_USB_ALTEV_REG_USB_RESET) &&
 	    dev_state.nfsr != NFSR_NODE_RESET) {
@@ -755,6 +779,7 @@ static void handle_alt_ev(void)
 		USB->USB_ALTMSK_REG =
 			USB_USB_ALTMSK_REG_USB_M_RESET_Msk |
 			USB_USB_ALTMSK_REG_USB_M_RESUME_Msk;
+		usb_clock_off();
 		dev_state.status_cb(USB_DC_SUSPEND, NULL);
 	}
 }
@@ -892,34 +917,76 @@ static void usb_dc_smartbond_isr(void)
 	}
 }
 
-static void usb_dc_smartbond_vbus_changed(bool present)
+/**
+ * USB functionality can be disabled from HOST and DEVICE side.
+ * Host side is indicated by VBUS line.
+ * Device side is decided by pair of calls usb_dc_attach()/usb_dc_detach,
+ * USB will only work when application calls usb_dc_attach() and VBUS is present.
+ * When both conditions are not met USB clock (PLL) is released, and peripheral
+ * remain in reset state.
+ */
+static void usb_change_state(bool attached, bool vbus_present)
 {
-	if (dev_state.vbus_present == present) {
+	if (dev_state.attached == attached && dev_state.vbus_present == vbus_present) {
 		return;
 	}
 
-	dev_state.vbus_present = present;
-
-	if (present) {
-		/* TODO: Add PD acquire when available */
-		/* If power event happened before USB started, delay dcd_connect
-		 * until dcd_init is called.
+	if (attached && vbus_present) {
+		dev_state.attached = true;
+		dev_state.vbus_present = true;
+		/*
+		 * Prevent transition to standby, this greatly reduces
+		 * IRQ response time
 		 */
+		pm_policy_state_lock_get(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
+		usb_clock_on();
 		dev_state.status_cb(USB_DC_CONNECTED, NULL);
-	} else {
+		USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk;
+		USB->USB_NFSR_REG = 0;
+		USB->USB_FAR_REG = 0x80;
+		USB->USB_TXMSK_REG = 0;
+		USB->USB_RXMSK_REG = 0;
+
+		USB->USB_MAMSK_REG = USB_USB_MAMSK_REG_USB_M_INTR_Msk |
+				     USB_USB_MAMSK_REG_USB_M_ALT_Msk |
+				     USB_USB_MAMSK_REG_USB_M_WARN_Msk;
+		USB->USB_ALTMSK_REG = USB_USB_ALTMSK_REG_USB_M_RESET_Msk |
+				      USB_USB_ALTEV_REG_USB_SD3_Msk;
+
+		USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk |
+				     USB_USB_MCTRL_REG_USB_NAT_Msk;
+
+		/* Select chosen DMA to be triggered by USB. */
+		DMA->DMA_REQ_MUX_REG =
+			(DMA->DMA_REQ_MUX_REG & ~DA146XX_DMA_USB_MUX_MASK) |
+			DA146XX_DMA_USB_MUX;
+	} else if (dev_state.attached && dev_state.vbus_present) {
+		/*
+		 * USB was previously in use now either VBUS is gone or application
+		 * requested detach, put it down
+		 */
+		dev_state.attached = attached;
+		dev_state.vbus_present = vbus_present;
 		USB->USB_MCTRL_REG = 0;
+		usb_clock_off();
 		dev_state.status_cb(USB_DC_DISCONNECTED, NULL);
-		/* TODO: Add PD release when available */
+		/* Allow standby USB not in use or not connected */
+		pm_policy_state_lock_put(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
+	} else {
+		/* USB still not activated, keep track of what's on and off */
+		dev_state.attached = attached;
+		dev_state.vbus_present = vbus_present;
 	}
 }
 
 static void usb_dc_smartbond_vbus_isr(void)
 {
-	bool vbus_present =
-		(CRG_TOP->ANA_STATUS_REG & CRG_TOP_ANA_STATUS_REG_VBUS_AVAILABLE_Msk) != 0;
+	LOG_DBG("VBUS_ISR");
 
 	CRG_TOP->VBUS_IRQ_CLEAR_REG = 1;
-	usb_dc_smartbond_vbus_changed(vbus_present);
+	usb_change_state(dev_state.attached,
+			 (CRG_TOP->ANA_STATUS_REG &
+			  CRG_TOP_ANA_STATUS_REG_VBUS_AVAILABLE_Msk) != 0);
 }
 
 static int usb_init(void)
@@ -1255,40 +1322,18 @@ int usb_dc_ep_configure(const struct usb_dc_ep_cfg_data *const ep_cfg)
 
 int usb_dc_detach(void)
 {
-	LOG_DBG("");
+	LOG_DBG("Detach");
 
-	REG_CLR_BIT(USB_MCTRL_REG, USB_NAT);
-
-	dev_state.attached = false;
+	usb_change_state(false, dev_state.vbus_present);
 
 	return 0;
 }
 
 int usb_dc_attach(void)
 {
-	LOG_DBG("");
-	if (GET_BIT(USB->USB_MCTRL_REG, USB_USB_MCTRL_REG_USB_NAT) == 0) {
-		USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk;
-		USB->USB_NFSR_REG = 0;
-		USB->USB_FAR_REG = 0x80;
-		USB->USB_TXMSK_REG = 0;
-		USB->USB_RXMSK_REG = 0;
+	LOG_INF("Attach");
 
-		USB->USB_MAMSK_REG = USB_USB_MAMSK_REG_USB_M_INTR_Msk |
-				     USB_USB_MAMSK_REG_USB_M_ALT_Msk |
-				     USB_USB_MAMSK_REG_USB_M_WARN_Msk;
-		USB->USB_ALTMSK_REG = USB_USB_ALTMSK_REG_USB_M_RESET_Msk |
-				      USB_USB_ALTEV_REG_USB_SD3_Msk;
-
-		USB->USB_MCTRL_REG = USB_USB_MCTRL_REG_USBEN_Msk |
-				     USB_USB_MCTRL_REG_USB_NAT_Msk;
-
-		/* Select chosen DMA to be triggered by USB. */
-		DMA->DMA_REQ_MUX_REG =
-			(DMA->DMA_REQ_MUX_REG & ~DA146XX_DMA_USB_MUX_MASK) |
-			DA146XX_DMA_USB_MUX;
-	}
-	dev_state.attached = true;
+	usb_change_state(true, dev_state.vbus_present);
 
 	return 0;
 }