[PATCH 16/28] OMAP3: PM: Enable SDRAM auto-refresh during sleep

Kevin Hilman
2009-10-01T23:59:24Z

From: Tero Kristo <tero.kristo@nokia.com>

Fix for ES3.0 bug: SDRC not sending auto-refresh when OMAP wakes-up from OFF
mode (warning for HS devices.)

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
---
arch/arm/mach-omap2/pm34xx.c | 29 +++++++++++++++++++++++++++++
1 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 8541512..5e24552 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -45,6 +45,13 @@

#include "prm.h"
#include "pm.h"
+#include "sdrc.h"
+
+#define SDRC_POWER_AUTOCOUNT_SHIFT 8
+#define SDRC_POWER_AUTOCOUNT_MASK (0xffff << SDRC_POWER_AUTOCOUNT_SHIFT)
+#define SDRC_POWER_CLKCTRL_SHIFT 4
+#define SDRC_POWER_CLKCTRL_MASK (0x3 << SDRC_POWER_CLKCTRL_SHIFT)
+#define SDRC_SELF_REFRESH_ON_AUTOCOUNT (0x2 << SDRC_POWER_CLKCTRL_SHIFT)

/* Scratchpad offsets */
#define OMAP343X_TABLE_ADDRESS_OFFSET 0x31
@@ -296,6 +303,7 @@ static void omap_sram_idle(void)
int per_next_state = PWRDM_POWER_ON;
int core_next_state = PWRDM_POWER_ON;
int core_prev_state, per_prev_state;
+ u32 sdrc_pwr = 0;

if (!_omap_sram_idle)
return;
@@ -348,6 +356,21 @@ static void omap_sram_idle(void)
}

/*
+ * Force SDRAM controller to self-refresh mode after timeout on
+ * autocount. This is needed on ES3.0 to avoid SDRAM controller
+ * hang-ups.
+ */
+ if (system_rev >= OMAP3430_REV_ES3_0 &&
+ omap_type() != OMAP2_DEVICE_TYPE_GP &&
+ core_next_state == PWRDM_POWER_OFF) {
+ sdrc_pwr = sdrc_read_reg(SDRC_POWER);
+ sdrc_write_reg((sdrc_pwr &
+ ~(SDRC_POWER_AUTOCOUNT_MASK|SDRC_POWER_CLKCTRL_MASK)) |
+ (1 << SDRC_POWER_AUTOCOUNT_SHIFT) |
+ SDRC_SELF_REFRESH_ON_AUTOCOUNT, SDRC_POWER);
+ }
+
+ /*
* omap3_arm_context is the location where ARM registers
* get saved. The restore path then reads from this
* location and restores them back.
@@ -355,6 +378,12 @@ static void omap_sram_idle(void)
_omap_sram_idle(omap3_arm_context, save_state);
cpu_init();

+ /* Restore normal SDRAM settings */
+ if (system_rev >= OMAP3430_REV_ES3_0 &&
+ omap_type() != OMAP2_DEVICE_TYPE_GP &&
+ core_next_state == PWRDM_POWER_OFF)
+ sdrc_write_reg(sdrc_pwr, SDRC_POWER);
+
/* Restore table entry modified during MMU restoration */
if (pwrdm_read_prev_pwrst(mpu_pwrdm) == PWRDM_POWER_OFF)
restore_table_entry();
--
1.6.4.3