On Thu, 2012-03-01 at 12:19 +0530, Rajendra Nayak wrote:

On Wednesday 29 February 2012 07:56 PM, Tero Kristo wrote:

quoted

From: Vishwanath BS<redacted>

Since IO Daisychain modifies only PRM registers, it makes sense to move
it to PRM File.

Signed-off-by: Vishwanath BS<redacted>
Tested-by: Govindraj.R<redacted>
Signed-off-by: Tero Kristo<redacted>
---
  arch/arm/mach-omap2/pm34xx.c       |   30 +-----------------------------
  arch/arm/mach-omap2/prm2xxx_3xxx.c |   32 ++++++++++++++++++++++++++++++++
  arch/arm/mach-omap2/prm2xxx_3xxx.h |   14 ++++++++++++++
  3 files changed, 47 insertions(+), 29 deletions(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index b0821a8..e97ec3f 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c

@@ -85,34 +85,6 @@ static inline void omap3_per_restore_context(void)
  	omap_gpio_restore_context();
  }

-static void omap3_enable_io_chain(void)
-{
-	int timeout = 0;
-
-	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-				   PM_WKEN);
-	/* Do a readback to assure write has been done */
-	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
-
-	while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
-		 OMAP3430_ST_IO_CHAIN_MASK)) {
-		timeout++;
-		if (timeout>  1000) {
-			pr_err("Wake up daisy chain activation failed.\n");
-			return;
-		}
-	}
-	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-			PM_WKEN);
-
-}
-
-static void omap3_disable_io_chain(void)
-{
-	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-				     PM_WKEN);
-}
-
  static void omap3_core_save_context(void)
  {
  	omap3_ctrl_save_padconf();

@@ -324,7 +296,7 @@ void omap_sram_idle(void)
  	     core_next_state<  PWRDM_POWER_ON)) {
  		omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD, PM_WKEN);
  		if (omap3_has_io_chain_ctrl())
-			omap3_enable_io_chain();
+			omap3_trigger_io_chain();
  	}

  	pwrdm_pre_transition();

diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index 9ce7654..fc98781 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c

@@ -301,6 +301,38 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
  				OMAP3_PRM_IRQENABLE_MPU_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

Since we are changing the implementation to use omap_test_timeout()
in this patch, it makes sense to make this 100 so we have a max 100us
delay, similar to what we did on OMAP4.

I didn't change this timeout as I wasn't quite sure what is a safe value
for it. Do you know if 100us is safe for omap3 also in all possible
scenarios?

quoted

+
+/* OMAP3 Daisychain enable sequence */
+void omap3_trigger_io_chain(void)
+{
+	int i = 0;
+
+	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+				   PM_WKEN);
+	/* Do a readback to assure write has been done */
+	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
+
+	omap_test_timeout(((omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
+			    OMAP3430_ST_IO_CHAIN_MASK) == 1),
+			  MAX_IOPAD_LATCH_TIME, i);
+
+	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+				     PM_WKEN);

The comment from Djamil should hold good here too. We should wait for
IO chain status to show 0 here.

Hmm okay, I'll address this also for next version.

-Tero

quoted

+}
+

regards,
Rajendra