1 files changed, 107 insertions, 81 deletions

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 0ff5a6c53aa0..89463190923a 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -51,97 +51,112 @@ static void (*_omap_sram_idle)(u32 *addr, int save_state);
 
 static struct powerdomain *mpu_pwrdm;
 
-/* PRCM Interrupt Handler for wakeups */
-static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id)
+/*
+ * PRCM Interrupt Handler Helper Function
+ *
+ * The purpose of this function is to clear any wake-up events latched
+ * in the PRCM PM_WKST_x registers. It is possible that a wake-up event
+ * may occur whilst attempting to clear a PM_WKST_x register and thus
+ * set another bit in this register. A while loop is used to ensure
+ * that any peripheral wake-up events occurring while attempting to
+ * clear the PM_WKST_x are detected and cleared.
+ */
+static int prcm_clear_mod_irqs(s16 module, u8 regs)
 {
-	u32 wkst, irqstatus_mpu;
-	u32 fclk, iclk;
-
-	/* WKUP */
-	wkst = prm_read_mod_reg(WKUP_MOD, PM_WKST);
+	u32 wkst, fclk, iclk, clken;
+	u16 wkst_off = (regs == 3) ? OMAP3430ES2_PM_WKST3 : PM_WKST1;
+	u16 fclk_off = (regs == 3) ? OMAP3430ES2_CM_FCLKEN3 : CM_FCLKEN1;
+	u16 iclk_off = (regs == 3) ? CM_ICLKEN3 : CM_ICLKEN1;
+	u16 grpsel_off = (regs == 3) ?
+		OMAP3430ES2_PM_MPUGRPSEL3 : OMAP3430_PM_MPUGRPSEL;
+	int c = 0;
+
+	wkst = prm_read_mod_reg(module, wkst_off);
+	wkst &= prm_read_mod_reg(module, grpsel_off);
 	if (wkst) {
-		iclk = cm_read_mod_reg(WKUP_MOD, CM_ICLKEN);
-		fclk = cm_read_mod_reg(WKUP_MOD, CM_FCLKEN);
-		cm_set_mod_reg_bits(wkst, WKUP_MOD, CM_ICLKEN);
-		cm_set_mod_reg_bits(wkst, WKUP_MOD, CM_FCLKEN);
-		prm_write_mod_reg(wkst, WKUP_MOD, PM_WKST);
-		while (prm_read_mod_reg(WKUP_MOD, PM_WKST))
-			cpu_relax();
-		cm_write_mod_reg(iclk, WKUP_MOD, CM_ICLKEN);
-		cm_write_mod_reg(fclk, WKUP_MOD, CM_FCLKEN);
+		iclk = cm_read_mod_reg(module, iclk_off);
+		fclk = cm_read_mod_reg(module, fclk_off);
+		while (wkst) {
+			clken = wkst;
+			cm_set_mod_reg_bits(clken, module, iclk_off);
+			/*
+			 * For USBHOST, we don't know whether HOST1 or
+			 * HOST2 woke us up, so enable both f-clocks
+			 */
+			if (module == OMAP3430ES2_USBHOST_MOD)
+				clken |= 1 << OMAP3430ES2_EN_USBHOST2_SHIFT;
+			cm_set_mod_reg_bits(clken, module, fclk_off);
+			prm_write_mod_reg(wkst, module, wkst_off);
+			wkst = prm_read_mod_reg(module, wkst_off);
+			c++;
+		}
+		cm_write_mod_reg(iclk, module, iclk_off);
+		cm_write_mod_reg(fclk, module, fclk_off);
 	}
 
-	/* CORE */
-	wkst = prm_read_mod_reg(CORE_MOD, PM_WKST1);
-	if (wkst) {
-		iclk = cm_read_mod_reg(CORE_MOD, CM_ICLKEN1);
-		fclk = cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
-		cm_set_mod_reg_bits(wkst, CORE_MOD, CM_ICLKEN1);
-		cm_set_mod_reg_bits(wkst, CORE_MOD, CM_FCLKEN1);
-		prm_write_mod_reg(wkst, CORE_MOD, PM_WKST1);
-		while (prm_read_mod_reg(CORE_MOD, PM_WKST1))
-			cpu_relax();
-		cm_write_mod_reg(iclk, CORE_MOD, CM_ICLKEN1);
-		cm_write_mod_reg(fclk, CORE_MOD, CM_FCLKEN1);
-	}
-	wkst = prm_read_mod_reg(CORE_MOD, OMAP3430ES2_PM_WKST3);
-	if (wkst) {
-		iclk = cm_read_mod_reg(CORE_MOD, CM_ICLKEN3);
-		fclk = cm_read_mod_reg(CORE_MOD, OMAP3430ES2_CM_FCLKEN3);
-		cm_set_mod_reg_bits(wkst, CORE_MOD, CM_ICLKEN3);
-		cm_set_mod_reg_bits(wkst, CORE_MOD, OMAP3430ES2_CM_FCLKEN3);
-		prm_write_mod_reg(wkst, CORE_MOD, OMAP3430ES2_PM_WKST3);
-		while (prm_read_mod_reg(CORE_MOD, OMAP3430ES2_PM_WKST3))
-			cpu_relax();
-		cm_write_mod_reg(iclk, CORE_MOD, CM_ICLKEN3);
-		cm_write_mod_reg(fclk, CORE_MOD, OMAP3430ES2_CM_FCLKEN3);
-	}
+	return c;
+}
 
-	/* PER */
-	wkst = prm_read_mod_reg(OMAP3430_PER_MOD, PM_WKST);
-	if (wkst) {
-		iclk = cm_read_mod_reg(OMAP3430_PER_MOD, CM_ICLKEN);
-		fclk = cm_read_mod_reg(OMAP3430_PER_MOD, CM_FCLKEN);
-		cm_set_mod_reg_bits(wkst, OMAP3430_PER_MOD, CM_ICLKEN);
-		cm_set_mod_reg_bits(wkst, OMAP3430_PER_MOD, CM_FCLKEN);
-		prm_write_mod_reg(wkst, OMAP3430_PER_MOD, PM_WKST);
-		while (prm_read_mod_reg(OMAP3430_PER_MOD, PM_WKST))
-			cpu_relax();
-		cm_write_mod_reg(iclk, OMAP3430_PER_MOD, CM_ICLKEN);
-		cm_write_mod_reg(fclk, OMAP3430_PER_MOD, CM_FCLKEN);
-	}
+static int _prcm_int_handle_wakeup(void)
+{
+	int c;
 
+	c = prcm_clear_mod_irqs(WKUP_MOD, 1);
+	c += prcm_clear_mod_irqs(CORE_MOD, 1);
+	c += prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1);
 	if (omap_rev() > OMAP3430_REV_ES1_0) {
-		/* USBHOST */
-		wkst = prm_read_mod_reg(OMAP3430ES2_USBHOST_MOD, PM_WKST);
-		if (wkst) {
-			iclk = cm_read_mod_reg(OMAP3430ES2_USBHOST_MOD,
-					       CM_ICLKEN);
-			fclk = cm_read_mod_reg(OMAP3430ES2_USBHOST_MOD,
-					       CM_FCLKEN);
-			cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD,
-					    CM_ICLKEN);
-			cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD,
-					    CM_FCLKEN);
-			prm_write_mod_reg(wkst, OMAP3430ES2_USBHOST_MOD,
-					  PM_WKST);
-			while (prm_read_mod_reg(OMAP3430ES2_USBHOST_MOD,
-						PM_WKST))
-				cpu_relax();
-			cm_write_mod_reg(iclk, OMAP3430ES2_USBHOST_MOD,
-					 CM_ICLKEN);
-			cm_write_mod_reg(fclk, OMAP3430ES2_USBHOST_MOD,
-					 CM_FCLKEN);
-		}
+		c += prcm_clear_mod_irqs(CORE_MOD, 3);
+		c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1);
 	}
 
-	irqstatus_mpu = prm_read_mod_reg(OCP_MOD,
-					 OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-	prm_write_mod_reg(irqstatus_mpu, OCP_MOD,
-			  OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
+	return c;
+}
+
+/*
+ * PRCM Interrupt Handler
+ *
+ * The PRM_IRQSTATUS_MPU register indicates if there are any pending
+ * interrupts from the PRCM for the MPU. These bits must be cleared in
+ * order to clear the PRCM interrupt. The PRCM interrupt handler is
+ * implemented to simply clear the PRM_IRQSTATUS_MPU in order to clear
+ * the PRCM interrupt. Please note that bit 0 of the PRM_IRQSTATUS_MPU
+ * register indicates that a wake-up event is pending for the MPU and
+ * this bit can only be cleared if the all the wake-up events latched
+ * in the various PM_WKST_x registers have been cleared. The interrupt
+ * handler is implemented using a do-while loop so that if a wake-up
+ * event occurred during the processing of the prcm interrupt handler
+ * (setting a bit in the corresponding PM_WKST_x register and thus
+ * preventing us from clearing bit 0 of the PRM_IRQSTATUS_MPU register)
+ * this would be handled.
+ */
+static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id)
+{
+	u32 irqstatus_mpu;
+	int c = 0;
+
+	do {
+		irqstatus_mpu = prm_read_mod_reg(OCP_MOD,
+					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
+
+		if (irqstatus_mpu & (OMAP3430_WKUP_ST | OMAP3430_IO_ST)) {
+			c = _prcm_int_handle_wakeup();
+
+			/*
+			 * Is the MPU PRCM interrupt handler racing with the
+			 * IVA2 PRCM interrupt handler ?
+			 */
+			WARN(c == 0, "prcm: WARNING: PRCM indicated MPU wakeup "
+			     "but no wakeup sources are marked\n");
+		} else {
+			/* XXX we need to expand our PRCM interrupt handler */
+			WARN(1, "prcm: WARNING: PRCM interrupt received, but "
+			     "no code to handle it (%08x)\n", irqstatus_mpu);
+		}
+
+		prm_write_mod_reg(irqstatus_mpu, OCP_MOD,
+					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
 
-	while (prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET))
-		cpu_relax();
+	} while (prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET));
 
 	return IRQ_HANDLED;
 }
@@ -624,6 +639,17 @@ static void __init prcm_setup_regs(void)
 	prm_write_mod_reg(OMAP3430_IO_EN | OMAP3430_WKUP_EN,
 			  OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 
+	/* Enable wakeups in PER */
+	prm_write_mod_reg(OMAP3430_EN_GPIO2 | OMAP3430_EN_GPIO3 |
+			  OMAP3430_EN_GPIO4 | OMAP3430_EN_GPIO5 |
+			  OMAP3430_EN_GPIO6 | OMAP3430_EN_UART3,
+			  OMAP3430_PER_MOD, PM_WKEN);
+	/* and allow them to wake up MPU */
+	prm_write_mod_reg(OMAP3430_GRPSEL_GPIO2 | OMAP3430_EN_GPIO3 |
+			  OMAP3430_GRPSEL_GPIO4 | OMAP3430_EN_GPIO5 |
+			  OMAP3430_GRPSEL_GPIO6 | OMAP3430_EN_UART3,
+			  OMAP3430_PER_MOD, OMAP3430_PM_MPUGRPSEL);
+
 	/* Don't attach IVA interrupts */
 	prm_write_mod_reg(0, WKUP_MOD, OMAP3430_PM_IVAGRPSEL);
 	prm_write_mod_reg(0, CORE_MOD, OMAP3430_PM_IVAGRPSEL1);