bfin: pm: add deepsleep for bf60x

Add add deepsleep for bf60x.
1. Call DMC init functions to enter and exit DDR self refresh mode.
2. Wait till CGU PLL is locked after wake up and exit DDR self refresh mode.
3. Make asessembly function enter_deepsleep comply with C funtion ABI in
order to call other C functions.
4. Switch kernel stack by register EX_SCRATCH_REG.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

1 files changed, 155 insertions, 0 deletions

diff --git a/arch/blackfin/mach-bf609/dpm.S b/arch/blackfin/mach-bf609/dpm.S
new file mode 100644
index 000000000000..62cc31994298
--- /dev/null
+++ b/arch/blackfin/mach-bf609/dpm.S
@@ -0,0 +1,155 @@
+#include <linux/linkage.h>
+#include <asm/blackfin.h>
+#include <asm/dpmc.h>
+
+#include <asm/context.S>
+
+#define PM_STACK   (COREA_L1_SCRATCH_START + L1_SCRATCH_LENGTH - 12)
+
+.section .l1.text
+ENTRY(_enter_hibernate)
+	/* switch stack to L1 scratch, prepare for ddr srfr */
+	P0.H = HI(PM_STACK);
+	P0.L = LO(PM_STACK);
+	SP = P0;
+
+	call _bf609_ddr_sr;
+	call _bfin_hibernate_syscontrol;
+
+	P0.H = HI(DPM0_RESTORE4);
+	P0.L = LO(DPM0_RESTORE4);
+	P1.H = _bf609_pm_data;
+	P1.L = _bf609_pm_data;
+	[P0] = P1;
+
+	P0.H = HI(DPM0_CTL);
+	P0.L = LO(DPM0_CTL);
+	R3.H = HI(0x00000010);
+	R3.L = LO(0x00000010);
+
+	bfin_init_pm_bench_cycles;
+
+	[P0] = R3;
+
+	SSYNC;
+ENDPROC(_enter_hibernate)
+
+/* DPM wake up interrupt won't wake up core on bf60x if its core IMASK
+ * is disabled. This behavior differ from bf5xx serial processor.
+ */
+ENTRY(_dummy_deepsleep)
+	[--sp] = SYSCFG;
+	[--sp] = (R7:0,P5:0);
+	cli r0;
+
+	/* get wake up interrupt ID */
+	P0.l = LO(SEC_SCI_BASE + SEC_CSID);
+	P0.h = HI(SEC_SCI_BASE + SEC_CSID);
+	R0 = [P0];
+
+	/* ACK wake up interrupt in SEC */
+	P1.l = LO(SEC_END);
+	P1.h = HI(SEC_END);
+
+	[P1] = R0;
+	SSYNC;
+
+	/* restore EVT 11 entry */
+	p0.h = hi(EVT11);
+	p0.l = lo(EVT11);
+	p1.h = _evt_evt11;
+	p1.l = _evt_evt11;
+
+	[p0] = p1;
+	SSYNC;
+
+	(R7:0,P5:0) = [sp++];
+	SYSCFG = [sp++];
+	RTI;
+ENDPROC(_dummy_deepsleep)
+
+ENTRY(_enter_deepsleep)
+	LINK 0x0;
+	[--sp] = (R7:0,P5:0);
+
+	/* Change EVT 11 entry to dummy handler for wake up event */
+	p0.h = hi(EVT11);
+	p0.l = lo(EVT11);
+	p1.h = _dummy_deepsleep;
+	p1.l = _dummy_deepsleep;
+
+	[p0] = p1;
+
+	P0.H = HI(PM_STACK);
+	P0.L = LO(PM_STACK);
+
+	EX_SCRATCH_REG = SP;
+	SP = P0;
+
+	SSYNC;
+
+	/* should put ddr to self refresh mode before sleep */
+	call _bf609_ddr_sr;
+
+	/* Set DPM controller to deep sleep mode */
+	P0.H = HI(DPM0_CTL);
+	P0.L = LO(DPM0_CTL);
+	R3.H = HI(0x00000008);
+	R3.L = LO(0x00000008);
+	[P0] = R3;
+	CSYNC;
+
+	/* Enable evt 11 in IMASK before idle, otherwise core doesn't wake up. */
+	r0.l = 0x800;
+	r0.h = 0;
+	sti r0;
+	SSYNC;
+
+	/* Fall into deep sleep in idle*/
+	idle;
+	SSYNC;
+
+	/* Restore PLL after wake up from deep sleep */
+	call _bf609_resume_ccbuf;
+
+	/* turn ddr out of self refresh mode */
+	call _bf609_ddr_sr_exit;
+
+	SP = EX_SCRATCH_REG;
+
+	(R7:0,P5:0) = [SP++];
+	UNLINK;
+	RTS;
+ENDPROC(_enter_deepsleep)
+
+.section .text
+ENTRY(_bf609_hibernate)
+	bfin_cpu_reg_save;
+	bfin_core_mmr_save;
+
+	P0.H = _bf609_pm_data;
+	P0.L = _bf609_pm_data;
+	R1.H = 0xDEAD;
+	R1.L = 0xBEEF;
+	R2.H = .Lpm_resume_here;
+	R2.L = .Lpm_resume_here;
+	[P0++] = R1;
+	[P0++] = R2;
+	[P0++] = SP;
+
+	P1.H = _enter_hibernate;
+	P1.L = _enter_hibernate;
+
+	call (P1);
+.Lpm_resume_here:
+
+	bfin_core_mmr_restore;
+	bfin_cpu_reg_restore;
+
+	[--sp] = RETI;  /* Clear Global Interrupt Disable */
+	SP += 4;
+
+	RTS;
+
+ENDPROC(_bf609_hibernate)
+