OMAP3: PM: Program SDRC to send self refresh on timeout of AUTO_CNT

Due to an OMAP3 errata (1.142), on HS/EMU devices SDRC should be
programed to issue automatic self refresh on timeout
of AUTO_CNT = 1 prior to any transition to OFF mode.
This is needed only on sil rev's ES3.0 and above.

This patch enables the above needed WA in the SDRC power register
value stored in scratchpad, so that ROM code restores this value
in SDRC POWER on the wakeup path.
The original SDRC POWER register value is stored and restored back
in omap_sram_idle() function.

This fixes some random crashes observed while stressing suspend
on HS/EMU devices.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@digia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 2ff8d7cc60a2..cdd1f35636dd 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -265,7 +265,21 @@ void omap3_save_scratchpad_contents(void)
                         (sdrc_read_reg(SDRC_ERR_TYPE) & 0xFFFF);
         sdrc_block_contents.dll_a_ctrl = sdrc_read_reg(SDRC_DLLA_CTRL);
         sdrc_block_contents.dll_b_ctrl = 0x0;
-        sdrc_block_contents.power = sdrc_read_reg(SDRC_POWER);
+        /*
+         * Due to a OMAP3 errata (1.142), on EMU/HS devices SRDC should
+         * be programed to issue automatic self refresh on timeout
+         * of AUTO_CNT = 1 prior to any transition to OFF mode.
+         */
+        if ((omap_type() != OMAP2_DEVICE_TYPE_GP)
+                        && (omap_rev() >= OMAP3430_REV_ES3_0))
+                sdrc_block_contents.power = (sdrc_read_reg(SDRC_POWER) &
+                                ~(SDRC_POWER_AUTOCOUNT_MASK|
+                                SDRC_POWER_CLKCTRL_MASK)) |
+                                (1 << SDRC_POWER_AUTOCOUNT_SHIFT) |
+                                SDRC_SELF_REFRESH_ON_AUTOCOUNT;
+        else
+                sdrc_block_contents.power = sdrc_read_reg(SDRC_POWER);
+
         sdrc_block_contents.cs_0 = 0x0;
         sdrc_block_contents.mcfg_0 = sdrc_read_reg(SDRC_MCFG_0);
         sdrc_block_contents.mr_0 = (sdrc_read_reg(SDRC_MR_0) & 0xFFFF);