Subject: [PATCH 8/9] ARM: OMAP3: pm: use prcm chain handler

From: [email-masked] (Paul Walmsley)
Date: Thu, 15 Dec 2011 14:36:23 -0700

From: Tero Kristo <[email-masked]>

PM interrupt handling is now done through the PRCM chain handler. The
interrupt handling logic is also split in two parts, to serve IO and
WKUP events separately. This allows us to handle IO chain events in a
clean way.

Core event code is also changed in accordance to this, as PRCM
interrupt handling is done by independent handlers, and the core
handler should not clear the IO events anymore.

Signed-off-by: Tero Kristo <[email-masked]>
Tested-by: Kevin Hilman <[email-masked]>
Reviewed-by: Kevin Hilman <[email-masked]>
[paul at pwsan.com: use pr_err(); combined with portions of earlier patches and
 the "do not enable PRCM MPU interrupts manually" patch]
Signed-off-by: Paul Walmsley <[email-masked]>
---
 arch/arm/mach-omap2/pm34xx.c       |  115 ++++++++++++++----------------------
 arch/arm/mach-omap2/prm2xxx_3xxx.c |   26 ++++++++
 2 files changed, 70 insertions(+), 71 deletions(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index efa6649..ba1692e 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -194,7 +194,7 @@ static void omap3_save_secure_ram_context(void)
  * 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)
+static int prcm_clear_mod_irqs(s16 module, u8 regs, u32 ignore_bits)
 {
 	u32 wkst, fclk, iclk, clken;
 	u16 wkst_off = (regs == 3) ? OMAP3430ES2_PM_WKST3 : PM_WKST1;
@@ -206,6 +206,7 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 
 	wkst = omap2_prm_read_mod_reg(module, wkst_off);
 	wkst &= omap2_prm_read_mod_reg(module, grpsel_off);
+	wkst &= ~ignore_bits;
 	if (wkst) {
 		iclk = omap2_cm_read_mod_reg(module, iclk_off);
 		fclk = omap2_cm_read_mod_reg(module, fclk_off);
@@ -221,6 +222,7 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 			omap2_cm_set_mod_reg_bits(clken, module, fclk_off);
 			omap2_prm_write_mod_reg(wkst, module, wkst_off);
 			wkst = omap2_prm_read_mod_reg(module, wkst_off);
+			wkst &= ~ignore_bits;
 			c++;
 		}
 		omap2_cm_write_mod_reg(iclk, module, iclk_off);
@@ -230,76 +232,35 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 	return c;
 }
 
-static int _prcm_int_handle_wakeup(void)
+static irqreturn_t _prcm_int_handle_io(int irq, void *unused)
 {
 	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) {
-		c += prcm_clear_mod_irqs(CORE_MOD, 3);
-		c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1);
-	}
+	c = prcm_clear_mod_irqs(WKUP_MOD, 1,
+		~(OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK));
 
-	return c;
+	return c ? IRQ_HANDLED : IRQ_NONE;
 }
 
-/*
- * 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)
+static irqreturn_t _prcm_int_handle_wakeup(int irq, void *unused)
 {
-	u32 irqenable_mpu, irqstatus_mpu;
-	int c = 0;
-
-	irqenable_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					 OMAP3_PRM_IRQENABLE_MPU_OFFSET);
-	irqstatus_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					 OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-	irqstatus_mpu &= irqenable_mpu;
-
-	do {
-		if (irqstatus_mpu & (OMAP3430_WKUP_ST_MASK |
-				     OMAP3430_IO_ST_MASK)) {
-			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);
-		}
-
-		omap2_prm_write_mod_reg(irqstatus_mpu, OCP_MOD,
-					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-
-		irqstatus_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-		irqstatus_mpu &= irqenable_mpu;
+	int c;
 
-	} while (irqstatus_mpu);
+	/*
+	 * Clear all except ST_IO and ST_IO_CHAIN for wkup module,
+	 * these are handled in a separate handler to avoid acking
+	 * IO events before parsing in mux code
+	 */
+	c = prcm_clear_mod_irqs(WKUP_MOD, 1,
+		OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK);
+	c += prcm_clear_mod_irqs(CORE_MOD, 1, 0);
+	c += prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1, 0);
+	if (omap_rev() > OMAP3430_REV_ES1_0) {
+		c += prcm_clear_mod_irqs(CORE_MOD, 3, 0);
+		c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1, 0);
+	}
 
-	return IRQ_HANDLED;
+	return c ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static void omap34xx_save_context(u32 *save)
@@ -580,6 +541,7 @@ static int omap3_pm_begin(suspend_state_t state)
 	disable_hlt();
 	suspend_state = state;
 	omap_uart_enable_irqs(0);
+	omap_prcm_irq_prepare();
 	return 0;
 }
 
@@ -591,10 +553,16 @@ static void omap3_pm_end(void)
 	return;
 }
 
+static void omap3_pm_finish(void)
+{
+	omap_prcm_irq_complete();
+}
+
 static const struct platform_suspend_ops omap_pm_ops = {
 	.begin		= omap3_pm_begin,
 	.end		= omap3_pm_end,
 	.enter		= omap3_pm_enter,
+	.finish		= omap3_pm_finish,
 	.valid		= suspend_valid_only_mem,
 };
 #endif /* CONFIG_SUSPEND */
@@ -700,10 +668,6 @@ static void __init prcm_setup_regs(void)
 			  OMAP3430_GRPSEL_GPT1_MASK |
 			  OMAP3430_GRPSEL_GPT12_MASK,
 			  WKUP_MOD, OMAP3430_PM_MPUGRPSEL);
-	/* For some reason IO doesn't generate wakeup event even if
-	 * it is selected to mpu wakeup goup */
-	omap2_prm_write_mod_reg(OMAP3430_IO_EN_MASK | OMAP3430_WKUP_EN_MASK,
-			  OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 
 	/* Enable PM_WKEN to support DSS LPR */
 	omap2_prm_write_mod_reg(OMAP3430_PM_WKEN_DSS_EN_DSS_MASK,
@@ -880,12 +844,21 @@ static int __init omap3_pm_init(void)
 	 * supervised mode for powerdomains */
 	prcm_setup_regs();
 
-	ret = request_irq(INT_34XX_PRCM_MPU_IRQ,
-			  (irq_handler_t)prcm_interrupt_handler,
-			  IRQF_DISABLED, "prcm", NULL);
+	ret = request_irq(omap_prcm_event_to_irq("wkup"),
+		_prcm_int_handle_wakeup, IRQF_NO_SUSPEND, "pm_wkup", NULL);
+
+	if (ret) {
+		pr_err("pm: Failed to request pm_wkup irq\n");
+		goto err1;
+	}
+
+	/* IO interrupt is shared with mux code */
+	ret = request_irq(omap_prcm_event_to_irq("io"),
+		_prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io",
+		omap3_pm_init);
+
 	if (ret) {
-		printk(KERN_ERR "request_irq failed to register for 0x%x\n",
-		       INT_34XX_PRCM_MPU_IRQ);
+		pr_err("pm: Failed to request pm_io irq\n");
 		goto err1;
 	}
 
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index 58d9ce70..3545c9a 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -27,6 +27,24 @@
 #include "prm-regbits-24xx.h"
 #include "prm-regbits-34xx.h"
 
+static const struct omap_prcm_irq omap3_prcm_irqs[] = {
+	OMAP_PRCM_IRQ("wkup",	0,	0),
+	OMAP_PRCM_IRQ("io",	9,	1),
+};
+
+static struct omap_prcm_irq_setup omap3_prcm_irq_setup = {
+	.ack			= OMAP3_PRM_IRQSTATUS_MPU_OFFSET,
+	.mask			= OMAP3_PRM_IRQENABLE_MPU_OFFSET,
+	.nr_regs		= 1,
+	.irqs			= omap3_prcm_irqs,
+	.nr_irqs		= ARRAY_SIZE(omap3_prcm_irqs),
+	.irq			= INT_34XX_PRCM_MPU_IRQ,
+	.read_pending_irqs	= &omap3xxx_prm_read_pending_irqs,
+	.ocp_barrier		= &omap3xxx_prm_ocp_barrier,
+	.save_and_clear_irqen	= &omap3xxx_prm_save_and_clear_irqen,
+	.restore_irqen		= &omap3xxx_prm_restore_irqen,
+};
+
 u32 omap2_prm_read_mod_reg(s16 module, u16 idx)
 {
 	return __raw_readl(prm_base + module + idx);
@@ -281,3 +299,11 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
 	omap2_prm_write_mod_reg(saved_mask[0], OCP_MOD,
 				OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 }
+
+static int __init omap3xxx_prcm_init(void)
+{
+	if (cpu_is_omap34xx())
+		return omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
+	return 0;
+}
+subsys_initcall(omap3xxx_prcm_init);