[PATCH 2/6] ARM: OMAP4 PM: Add IO Daisychain support

[Elaidi, Djamil]

Hi Kristo,

I think you must also add a omap_test_timeout() check after the Trigger WUCLKIN disable, to verify WUCLK_STATUS has come back to 0.
This is needed because the IO daisy chain will not be ready until the WUCLKIN falling edge has propagated.

+       /* Trigger WUCLKIN disable */
+       omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, 0x0,
+                       OMAP4430_PRM_DEVICE_INST, OMAP4_PRM_IO_PMCTRL_OFFSET);
+       return;
+       omap_test_timeout(
+               (((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+                       OMAP4_PRM_IO_PMCTRL_OFFSET) &
+                       OMAP4430_WUCLK_STATUS_MASK) >>
+                       OMAP4430_WUCLK_STATUS_SHIFT) == 0),
+               MAX_IOPAD_LATCH_TIME, i);


Best regards
Djamil ELAÏDI
+33 4 97 27 50 97
Software Systems Engineer
OMAP Platform Business Unit - PSI Modem Integration
Texas Instruments


Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve Loubet. 036 420 040 R.C.S Antibes. Capital de EUR 753.920

-----Original Message-----
From: linux-omap-owner at vger.kernel.org [mailto:linux-omap-owner at vger.kernel.org] On Behalf Of Kristo, Tero
Sent: jeudi 23 février 2012 14:22
To: linux-omap at vger.kernel.org; Hilman, Kevin
Cc: linux-arm-kernel at lists.infradead.org; Nayak, Rajendra; Sripathy, Vishwanath
Subject: [PATCH 2/6] ARM: OMAP4 PM: Add IO Daisychain support

From: Rajendra Nayak <rnayak at 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 at ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs at ti.com>
Signed-off-by: Tero Kristo <t-kristo at ti.com>
---
 arch/arm/mach-omap2/prm44xx.c |   32 ++++++++++++++++++++++++++++++++
 arch/arm/mach-omap2/prm44xx.h |    1 +
 2 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 33dd655..1557647 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -230,6 +230,41 @@ void omap44xx_prm_restore_irqen(u32 *saved_mask)
                                 OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
 }

+/**
+ * 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_MASK) >>
+                       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;
+}
+
 static int __init omap4xxx_prcm_init(void)
 {
        if (cpu_is_omap44xx())
diff --git a/arch/arm/mach-omap2/prm44xx.h b/arch/arm/mach-omap2/prm44xx.h
index 7978092..a840f0f 100644
--- a/arch/arm/mach-omap2/prm44xx.h
+++ b/arch/arm/mach-omap2/prm44xx.h
@@ -762,6 +762,7 @@ void omap4_prm_vp_clear_txdone(u8 vp_id);
 extern u32 omap4_prm_vcvp_read(u8 offset);
 extern void omap4_prm_vcvp_write(u32 val, u8 offset);
 extern u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset);
+extern void omap4_trigger_wuclk_ctrl(void);

 /* PRM interrupt-related functions */
 extern void omap44xx_prm_read_pending_irqs(unsigned long *events);
--
1.7.4.1

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