ARM: tegra: Don't enable unused PLLs on resume from suspend

PLLC and PLLM are usually disabled on system suspend because all devices
which use these PLLs are either suspended or switched away to other clock
source. Don't enable unused PLLs on resume from suspend by keeping track
of the enable-state of the PLLs across suspend-resume.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Tested-by: Matt Merhar <mattmerhar@protonmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 74 insertions, 20 deletions

diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 2667bcdb5dc6..0cc40b6b2ba3 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -71,6 +71,13 @@
 
 #define TEGRA30_POWER_HOTPLUG_SHUTDOWN	(1 << 27) /* Hotplug shutdown */
 
+#define PLLA_STORE_MASK			(1 << 0)
+#define PLLC_STORE_MASK			(1 << 1)
+#define PLLM_STORE_MASK			(1 << 2)
+#define PLLP_STORE_MASK			(1 << 3)
+#define PLLX_STORE_MASK			(1 << 4)
+#define PLLM_PMC_STORE_MASK		(1 << 5)
+
 .macro emc_device_mask, rd, base
 	ldr	\rd, [\base, #EMC_ADR_CFG]
 	tst	\rd, #0x1
@@ -87,7 +94,43 @@
 	bne	1001b
 .endm
 
-.macro pll_enable, rd, r_car_base, pll_base, pll_misc
+.macro test_pll_state, rd, test_mask
+	ldr	\rd, tegra_pll_state
+	tst	\rd, #\test_mask
+.endm
+
+.macro store_pll_state, rd, tmp, r_car_base, pll_base, pll_mask
+	ldr	\rd, [\r_car_base, #\pll_base]
+	tst	\rd, #(1 << 30)
+	ldr	\rd, tegra_pll_state
+	biceq	\rd, \rd, #\pll_mask
+	orrne	\rd, \rd, #\pll_mask
+	adr	\tmp, tegra_pll_state
+	str	\rd, [\tmp]
+.endm
+
+.macro store_pllm_pmc_state, rd, tmp, pmc_base
+	ldr	\rd, [\pmc_base, #PMC_PLLP_WB0_OVERRIDE]
+	tst	\rd, #(1 << 12)
+	ldr	\rd, tegra_pll_state
+	biceq	\rd, \rd, #PLLM_PMC_STORE_MASK
+	orrne	\rd, \rd, #PLLM_PMC_STORE_MASK
+	adr	\tmp, tegra_pll_state
+	str	\rd, [\tmp]
+.endm
+
+.macro pllm_pmc_enable, rd, pmc_base
+	test_pll_state \rd, PLLM_PMC_STORE_MASK
+
+	ldrne	\rd, [\pmc_base, #PMC_PLLP_WB0_OVERRIDE]
+	orrne	\rd, \rd, #(1 << 12)
+	strne	\rd, [\pmc_base, #PMC_PLLP_WB0_OVERRIDE]
+.endm
+
+.macro pll_enable, rd, r_car_base, pll_base, pll_misc, test_mask
+	test_pll_state \rd, \test_mask
+	beq	1f
+
 	ldr	\rd, [\r_car_base, #\pll_base]
 	tst	\rd, #(1 << 30)
 	orreq	\rd, \rd, #(1 << 30)
@@ -102,13 +145,17 @@
 	orr	\rd, \rd, #(1 << 18)
 	str	\rd, [\r_car_base, #\pll_misc]
 	.endif
+1:
 .endm
 
-.macro pll_locked, rd, r_car_base, pll_base
+.macro pll_locked, rd, r_car_base, pll_base, test_mask
+	test_pll_state \rd, \test_mask
+	beq	2f
 1:
 	ldr	\rd, [\r_car_base, #\pll_base]
 	tst	\rd, #(1 << 27)
 	beq	1b
+2:
 .endm
 
 .macro pll_iddq_exit, rd, car, iddq, iddq_bit
@@ -342,34 +389,30 @@ ENTRY(tegra30_lp1_reset)
 
 	/* enable PLLM via PMC */
 	mov32	r2, TEGRA_PMC_BASE
-	ldr	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
-	orr	r1, r1, #(1 << 12)
-	str	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
+	pllm_pmc_enable r1, r2
 
-	pll_enable r1, r0, CLK_RESET_PLLM_BASE, 0
-	pll_enable r1, r0, CLK_RESET_PLLC_BASE, 0
-	pll_enable r1, r0, CLK_RESET_PLLX_BASE, 0
+	pll_enable r1, r0, CLK_RESET_PLLM_BASE, 0, PLLM_STORE_MASK
+	pll_enable r1, r0, CLK_RESET_PLLC_BASE, 0, PLLC_STORE_MASK
+	pll_enable r1, r0, CLK_RESET_PLLX_BASE, 0, PLLX_STORE_MASK
 
 	b	_pll_m_c_x_done
 
 _no_pll_iddq_exit:
 	/* enable PLLM via PMC */
 	mov32	r2, TEGRA_PMC_BASE
-	ldr	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
-	orr	r1, r1, #(1 << 12)
-	str	r1, [r2, #PMC_PLLP_WB0_OVERRIDE]
+	pllm_pmc_enable r1, r2
 
-	pll_enable r1, r0, CLK_RESET_PLLM_BASE, CLK_RESET_PLLM_MISC
-	pll_enable r1, r0, CLK_RESET_PLLC_BASE, CLK_RESET_PLLC_MISC
+	pll_enable r1, r0, CLK_RESET_PLLM_BASE, CLK_RESET_PLLM_MISC, PLLM_STORE_MASK
+	pll_enable r1, r0, CLK_RESET_PLLC_BASE, CLK_RESET_PLLC_MISC, PLLC_STORE_MASK
 
 _pll_m_c_x_done:
-	pll_enable r1, r0, CLK_RESET_PLLP_BASE, CLK_RESET_PLLP_MISC
-	pll_enable r1, r0, CLK_RESET_PLLA_BASE, CLK_RESET_PLLA_MISC
+	pll_enable r1, r0, CLK_RESET_PLLP_BASE, CLK_RESET_PLLP_MISC, PLLP_STORE_MASK
+	pll_enable r1, r0, CLK_RESET_PLLA_BASE, CLK_RESET_PLLA_MISC, PLLA_STORE_MASK
 
-	pll_locked r1, r0, CLK_RESET_PLLM_BASE
-	pll_locked r1, r0, CLK_RESET_PLLP_BASE
-	pll_locked r1, r0, CLK_RESET_PLLA_BASE
-	pll_locked r1, r0, CLK_RESET_PLLC_BASE
+	pll_locked r1, r0, CLK_RESET_PLLM_BASE, PLLM_STORE_MASK
+	pll_locked r1, r0, CLK_RESET_PLLP_BASE, PLLP_STORE_MASK
+	pll_locked r1, r0, CLK_RESET_PLLA_BASE, PLLA_STORE_MASK
+	pll_locked r1, r0, CLK_RESET_PLLC_BASE, PLLC_STORE_MASK
 
 	/*
 	 * CPUFreq driver could select other PLL for CPU. PLLX will be
@@ -380,7 +423,7 @@ _pll_m_c_x_done:
 	cmp	r1, #TEGRA30
 	beq	1f
 
-	pll_locked r1, r0, CLK_RESET_PLLX_BASE
+	pll_locked r1, r0, CLK_RESET_PLLX_BASE, PLLX_STORE_MASK
 
 	ldr	r1, [r0, #CLK_RESET_PLLP_BASE]
 	bic	r1, r1, #(1<<31)	@ disable PllP bypass
@@ -593,6 +636,9 @@ tegra_sdram_pad_save:
 	.long	0
 	.endr
 
+tegra_pll_state:
+	.word	0x0
+
 /*
  * tegra30_tear_down_core
  *
@@ -641,6 +687,14 @@ tegra30_switch_cpu_to_clk32k:
 	add	r1, r1, #2
 	wait_until r1, r7, r9
 
+	/* store enable-state of PLLs */
+	store_pll_state r0, r1, r5, CLK_RESET_PLLA_BASE, PLLA_STORE_MASK
+	store_pll_state r0, r1, r5, CLK_RESET_PLLC_BASE, PLLC_STORE_MASK
+	store_pll_state r0, r1, r5, CLK_RESET_PLLM_BASE, PLLM_STORE_MASK
+	store_pll_state r0, r1, r5, CLK_RESET_PLLP_BASE, PLLP_STORE_MASK
+	store_pll_state r0, r1, r5, CLK_RESET_PLLX_BASE, PLLX_STORE_MASK
+	store_pllm_pmc_state r0, r1, r4
+
 	/* disable PLLM via PMC in LP1 */
 	ldr	r0, [r4, #PMC_PLLP_WB0_OVERRIDE]
 	bic	r0, r0, #(1 << 12)