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authorClaudiu Beznea <claudiu.beznea@microchip.com>2020-01-20 13:10:02 +0100
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2020-02-18 21:47:53 +0100
commitc4cae59d80f07f086967b1a67d287832e7fc281e (patch)
treef877876f74e68df1a5188b07809a128f455b8f2b /arch/arm/mach-at91
parentARM: at91: pm: use proper master clock register offset (diff)
downloadlinux-c4cae59d80f07f086967b1a67d287832e7fc281e.tar.xz
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ARM: at91: pm: revert do not disable/enable PLLA for ULP modes
This reverts commit 2725d70aa5138284ba2cebf0ef51dd23e0c9ea21 ("ARM: at91: pm: do not disable/enable PLLA for ULP modes"). This is because PLLA is the clock source for CPU, PLLA should be disabled/enabled in the final/first phase of suspend/resume so that the power consumption in suspend/resume to be minimal and suspend/resume time to be minimized. Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/1579522208-19523-3-git-send-email-claudiu.beznea@microchip.com
Diffstat (limited to 'arch/arm/mach-at91')
-rw-r--r--arch/arm/mach-at91/pm_suspend.S31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index 52b262d56cfd..bfb3aab8859e 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -47,6 +47,15 @@ tmp2 .req r5
.endm
/*
+ * Wait until PLLA has locked.
+ */
+ .macro wait_pllalock
+1: ldr tmp1, [pmc, #AT91_PMC_SR]
+ tst tmp1, #AT91_PMC_LOCKA
+ beq 1b
+ .endm
+
+/*
* Put the processor to enter the idle state
*/
.macro at91_cpu_idle
@@ -343,6 +352,14 @@ ENTRY(at91_ulp_mode)
wait_mckrdy
+ /* Save PLLA setting and disable it */
+ ldr tmp1, [pmc, #AT91_CKGR_PLLAR]
+ str tmp1, .saved_pllar
+
+ mov tmp1, #AT91_PMC_PLLCOUNT
+ orr tmp1, tmp1, #(1 << 29) /* bit 29 always set */
+ str tmp1, [pmc, #AT91_CKGR_PLLAR]
+
ldr r0, .pm_mode
cmp r0, #AT91_PM_ULP1
beq ulp1_mode
@@ -357,6 +374,18 @@ ulp1_mode:
ulp_exit:
ldr pmc, .pmc_base
+ /* Restore PLLA setting */
+ ldr tmp1, .saved_pllar
+ str tmp1, [pmc, #AT91_CKGR_PLLAR]
+
+ tst tmp1, #(AT91_PMC_MUL & 0xff0000)
+ bne 3f
+ tst tmp1, #(AT91_PMC_MUL & ~0xff0000)
+ beq 4f
+3:
+ wait_pllalock
+4:
+
/*
* Restore master clock setting
*/
@@ -512,6 +541,8 @@ ENDPROC(at91_sramc_self_refresh)
.word 0
.saved_mckr:
.word 0
+.saved_pllar:
+ .word 0
.saved_sam9_lpr:
.word 0
.saved_sam9_lpr1: