ARM: am33xx: Inhibit re-initialization of DDR during RTC-only

This inhibits the re-inititialization of DDR during an RTC-only resume. If
this is not done, an L3 NOC error is produced as the DDR gets accessed
before the re-init has time to complete. Tested on AM437x GP EVM.

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
[j-keerthy@ti.com Ported to Latest Master branch]
Signed-off-by: Keerthy <j-keerthy@ti.com>
This commit is contained in:
Russ Dill 2018-03-20 12:23:00 +05:30 committed by Tom Rini
parent e18945ad22
commit 025a0d40e1
2 changed files with 30 additions and 2 deletions

View file

@ -68,6 +68,9 @@
#define PRM_RSTCTRL_RESET 0x01
#define PRM_RSTST_WARM_RESET_MASK 0x232
/* EMIF Control register bits */
#define EMIF_CTRL_DEVOFF BIT(0)
#ifndef __KERNEL_STRICT_NAMES
#ifndef __ASSEMBLY__
#include <asm/ti-common/omap_wdt.h>
@ -386,8 +389,19 @@ struct cm_device_inst {
};
struct prm_device_inst {
unsigned int prm_rstctrl;
unsigned int prm_rstst;
unsigned int rstctrl;
unsigned int rstst;
unsigned int rsttime;
unsigned int sram_count;
unsigned int ldo_sram_core_set; /* offset 0x10 */
unsigned int ldo_sram_core_ctr;
unsigned int ldo_sram_mpu_setu;
unsigned int ldo_sram_mpu_ctrl;
unsigned int io_count; /* offset 0x20 */
unsigned int io_pmctrl;
unsigned int vc_val_bypass;
unsigned int resv1;
unsigned int emif_ctrl; /* offset 0x30 */
};
struct cm_dpll {

View file

@ -376,6 +376,9 @@ static void watchdog_disable(void)
static void rtc_only(void)
{
struct davinci_rtc *rtc = (struct davinci_rtc *)RTC_BASE;
struct prm_device_inst *prm_device =
(struct prm_device_inst *)PRM_DEVICE_INST;
u32 scratch1;
void (*resume_func)(void);
@ -403,9 +406,20 @@ static void rtc_only(void)
*/
rtc_only_update_board_type(scratch1 >> RTC_BOARD_TYPE_SHIFT);
/*
* Enable EMIF_DEVOFF in PRCM_PRM_EMIF_CTRL to indicate to EMIF we
* are resuming from self-refresh. This avoids an unnecessary re-init
* of the DDR. The re-init takes time and we would need to wait for
* it to complete before accessing DDR to avoid L3 NOC errors.
*/
writel(EMIF_CTRL_DEVOFF, &prm_device->emif_ctrl);
rtc_only_prcm_init();
sdram_init();
/* Disable EMIF_DEVOFF for normal operation and to exit self-refresh */
writel(0, &prm_device->emif_ctrl);
resume_func = (void *)readl(&rtc->scratch0);
if (resume_func)
resume_func();