[PATCHV2 REPOST 3/7] ARM: OMAP4 PM: Add IO Daisychain support

[vishwanath.bs@ti.com (Vishwanath BS)]

From: Rajendra Nayak <rnayak@ti.com>

patch adds IO Daisychain support for OMAP4 as per section 3.9.4 in OMAP4430
Public TRM.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Tested-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/mach-omap2/prm44xx.c |   30 ++++++++++++++++++++++++++++++
 arch/arm/mach-omap2/prm44xx.h |    1 +
 2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 67d8d74..4dc58f7 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -142,3 +142,33 @@ static int __init omap4xxx_prcm_init(void)
 		return omap_prcm_register_chain_handler(&omap4_prcm_irq_setup);
 	return 0;
 }
+
+/**
+ * Maximum time(us) it takes to output the signal WUCLKOUT of the last pad of
+ * the I/O ring after asserting WUCLKIN high
+ */
+#define MAX_IOPAD_LATCH_TIME 1000
+
+/* OMAP4 IO Daisychain trigger sequence */
+void omap4_trigger_wuclk_ctrl(void)
+{
+	int i = 0;
+
+	/* Enable GLOBAL_WUEN */
+	if (!(omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, OMAP4_PRM_IO_PMCTRL_OFFSET)
+				& OMAP4430_GLOBAL_WUEN_MASK))
+		omap4_prm_rmw_inst_reg_bits(OMAP4430_GLOBAL_WUEN_MASK,
+				OMAP4430_GLOBAL_WUEN_MASK, OMAP4430_PRM_DEVICE_INST,
+			OMAP4_PRM_IO_PMCTRL_OFFSET);
+
+	/* Trigger WUCLKIN enable */
+	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, OMAP4430_WUCLK_CTRL_MASK,
+			OMAP4430_PRM_DEVICE_INST, OMAP4_PRM_IO_PMCTRL_OFFSET);
+	omap_test_timeout(
+		((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, OMAP4_PRM_IO_PMCTRL_OFFSET)
+		>> OMAP4430_WUCLK_STATUS_SHIFT) == 1), MAX_IOPAD_LATCH_TIME, i);
+	/* Trigger WUCLKIN disable */
+	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, 0x0,
+			OMAP4430_PRM_DEVICE_INST, OMAP4_PRM_IO_PMCTRL_OFFSET);
+	return;
+}
diff --git a/arch/arm/mach-omap2/prm44xx.h b/arch/arm/mach-omap2/prm44xx.h
index 3d66ccd..a8678db 100644
--- a/arch/arm/mach-omap2/prm44xx.h
+++ b/arch/arm/mach-omap2/prm44xx.h
@@ -750,6 +750,7 @@
 extern u32 omap4_prm_read_inst_reg(s16 inst, u16 idx);
 extern void omap4_prm_write_inst_reg(u32 val, s16 inst, u16 idx);
 extern u32 omap4_prm_rmw_inst_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx);
+extern void omap4_trigger_wuclk_ctrl(void);
 
 /* OMAP4-specific VP functions */
 u32 omap4_prm_vp_check_txdone(u8 vp_id);
-- 
1.7.0.4