From: Peter 'p2' De Schrijver <peter.de-schrijver@xxxxxxxxx> Erratum i581 impacts OMAP3 platforms. PRCM DPLL control FSM removes SDRC_IDLEREQ before DPLL3 locks causing the DPLL not to be locked at times. IMPORTANT: *) This is not a complete workaround implementation as recommended by the silicon erratum. this is a support logic for detecting lockups and attempting to recover where possible and is known to provide stability in multiple platforms. *) This code is mostly important for inactive and retention. The ROM code waits for the maximum dll lock time when resuming from off mode. So for off mode this code isn't really needed. This should eventually get refactored as part of cleanups to sleep34xx.S Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> Cc: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@xxxxxxxxx> --- (no change done, posting for completeness of the series) v2: https://patchwork.kernel.org/patch/365252/ typo correction- erratum, support, added comment from Peter from the thread to commit message v1: http://marc.info/?l=linux-omap&m=129013172525234&w=2 arch/arm/mach-omap2/sleep34xx.S | 52 +++++++++++++++++++++++++++++++++++--- 1 files changed, 47 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S index 2c20fcf..3fbd1e5 100644 --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -42,6 +42,7 @@ OMAP3430_PM_PREPWSTST) #define PM_PWSTCTRL_MPU_P OMAP3430_PRM_BASE + MPU_MOD + OMAP2_PM_PWSTCTRL #define CM_IDLEST1_CORE_V OMAP34XX_CM_REGADDR(CORE_MOD, CM_IDLEST1) +#define CM_IDLEST_CKGEN_V OMAP34XX_CM_REGADDR(PLL_MOD, CM_IDLEST) #define SRAM_BASE_P 0x40200000 #define CONTROL_STAT 0x480022F0 #define SCRATCHPAD_MEM_OFFS 0x310 /* Move this as correct place is @@ -554,31 +555,67 @@ skip_l2_inval: /* Make sure SDRC accesses are ok */ wait_sdrc_ok: + +/* DPLL3 must be locked before accessing the SDRC. Maybe the HW ensures this. */ + ldr r4, cm_idlest_ckgen +wait_dpll3_lock: + ldr r5, [r4] + tst r5, #1 + beq wait_dpll3_lock + ldr r4, cm_idlest1_core +wait_sdrc_ready: ldr r5, [r4] - and r5, r5, #0x2 - cmp r5, #0 - bne wait_sdrc_ok + tst r5, #0x2 + bne wait_sdrc_ready + /* allow DLL powerdown upon hw idle req */ ldr r4, sdrc_power ldr r5, [r4] bic r5, r5, #0x40 str r5, [r4] -wait_dll_lock: +is_dll_in_lock_mode: + /* Is dll in lock mode? */ ldr r4, sdrc_dlla_ctrl ldr r5, [r4] tst r5, #0x4 bxne lr /* wait till dll locks */ - ldr r4, sdrc_dlla_status +wait_dll_lock_timed: + ldr r4, wait_dll_lock_counter + add r4, r4, #1 + str r4, wait_dll_lock_counter + ldr r4, sdrc_dlla_status + mov r6, #8 /* Wait 20uS for lock */ +wait_dll_lock: + subs r6, r6, #0x1 + beq kick_dll ldr r5, [r4] and r5, r5, #0x4 cmp r5, #0x4 bne wait_dll_lock bx lr + /* disable/reenable DLL if not locked */ +kick_dll: + ldr r4, sdrc_dlla_ctrl + ldr r5, [r4] + mov r6, r5 + bic r6, #(1<<3) /* disable dll */ + str r6, [r4] + dsb + orr r6, r6, #(1<<3) /* enable dll */ + str r6, [r4] + dsb + ldr r4, kick_counter + add r4, r4, #1 + str r4, kick_counter + b wait_dll_lock_timed + cm_idlest1_core: .word CM_IDLEST1_CORE_V +cm_idlest_ckgen: + .word CM_IDLEST_CKGEN_V sdrc_dlla_status: .word SDRC_DLLA_STATUS_V sdrc_dlla_ctrl: @@ -615,5 +652,10 @@ control_stat: .word CONTROL_STAT kernel_flush: .word v7_flush_dcache_all + /* these 2 words need to be at the end !!! */ +kick_counter: + .word 0 +wait_dll_lock_counter: + .word 0 ENTRY(omap34xx_cpu_suspend_sz) .word . - omap34xx_cpu_suspend -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
