diff mbox

[RFC/PATCH] OMAP3: run the ASM sleep code from DDR

Message ID 1294935563-14426-1-git-send-email-j-pihet@ti.com (mailing list archive)
State RFC
Delegated to: Paul Walmsley
Headers show

Commit Message

Jean Pihet Jan. 13, 2011, 4:19 p.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 1c1b0ab..ae9dec0 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -87,18 +87,29 @@  extern int pm_dbg_regset_init(int reg_set);
 #define pm_dbg_regset_init(reg_set) do {} while (0);
 #endif /* CONFIG_PM_DEBUG */
 
+/* 24xx */
 extern void omap24xx_idle_loop_suspend(void);
+extern unsigned int omap24xx_idle_loop_suspend_sz;
 
 extern void omap24xx_cpu_suspend(u32 dll_ctrl, void __iomem *sdrc_dlla_ctrl,
 					void __iomem *sdrc_power);
+extern unsigned int omap24xx_cpu_suspend_sz;
+
+/* 3xxx */
 extern void omap34xx_cpu_suspend(u32 *addr, int save_state);
+
+/* omap3_do_wfi function pointer and size, for copy to SRAM */
+extern void omap3_do_wfi(void);
+extern unsigned int omap3_do_wfi_sz;
+/* ... and its pointer from SRAM after copy */
+extern void (*omap3_do_wfi_sram)(void);
+
+/* save_secure_ram_context function pointer and size, for copy to SRAM */
 extern void save_secure_ram_context(u32 *addr);
-extern void omap3_save_scratchpad_contents(void);
 
-extern unsigned int omap24xx_idle_loop_suspend_sz;
 extern unsigned int save_secure_ram_context_sz;
-extern unsigned int omap24xx_cpu_suspend_sz;
-extern unsigned int omap34xx_cpu_suspend_sz;
+
+extern void omap3_save_scratchpad_contents(void);
 
 #define PM_RTA_ERRATUM_i608		(1 << 0)
 #define PM_SDRC_WAKEUP_ERRATUM_i583	(1 << 1)
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 5b323f2..56ca3cb 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -82,9 +82,8 @@  struct power_state {
 
 static LIST_HEAD(pwrst_list);
 
-static void (*_omap_sram_idle)(u32 *addr, int save_state);
-
 static int (*_omap_save_secure_sram)(u32 *addr);
+void (*omap3_do_wfi_sram)(void);
 
 static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
 static struct powerdomain *core_pwrdm, *per_pwrdm;
@@ -355,9 +354,6 @@  void omap_sram_idle(void)
 	int core_prev_state, per_prev_state;
 	u32 sdrc_pwr = 0;
 
-	if (!_omap_sram_idle)
-		return;
-
 	pwrdm_clear_all_prev_pwrst(mpu_pwrdm);
 	pwrdm_clear_all_prev_pwrst(neon_pwrdm);
 	pwrdm_clear_all_prev_pwrst(core_pwrdm);
@@ -439,7 +435,7 @@  void omap_sram_idle(void)
 	 * get saved. The restore path then reads from this
 	 * location and restores them back.
 	 */
-	_omap_sram_idle(omap3_arm_context, save_state);
+	omap34xx_cpu_suspend(omap3_arm_context, save_state);
 	cpu_init();
 
 	/* Restore normal SDRC POWER settings */
@@ -996,10 +992,17 @@  static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
 	return 0;
 }
 
+/*
+ * Push functions to SRAM
+ *
+ * The minimum set of functions is pushed to SRAM for execution:
+ * - omap3_do_wfi for erratum i581 WA,
+ * - save_secure_ram_context for security extensions.
+ */
 void omap_push_sram_idle(void)
 {
-	_omap_sram_idle = omap_sram_push(omap34xx_cpu_suspend,
-					omap34xx_cpu_suspend_sz);
+	omap3_do_wfi_sram = omap_sram_push(omap3_do_wfi, omap3_do_wfi_sz);
+
 	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
 		_omap_save_secure_sram = omap_sram_push(save_secure_ram_context,
 				save_secure_ram_context_sz);
diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index 98d8232..ced85b5 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -163,8 +163,10 @@  ENTRY(save_secure_ram_context_sz)
  *
  *
  * Notes:
- * - this code gets copied to internal SRAM at boot and after wake-up
- *   from OFF mode. The execution pointer in SRAM is _omap_sram_idle.
+ * - only the minimum set of functions gets copied to internal SRAM at boot
+ *   and after wake-up from OFF mode, cf. omap_push_sram_idle. The function
+ *   pointers in SDRAM or SRAM are called depending on the desired low power
+ *   target state.
  * - when the OMAP wakes up it continues at different execution points
  *   depending on the low power mode (non-OFF vs OFF modes),
  *   cf. 'Resume path for xxx mode' comments.
@@ -181,9 +183,15 @@  ENTRY(omap34xx_cpu_suspend)
 	 *   3 - Both L1 and L2 lost
 	 */
 
-	/* Directly jump to WFI is the context save is not required */
-	cmp	r1, #0x0
-	beq	omap3_do_wfi
+	/*
+	 * For OFF mode: save context and jump to WFI in SDRAM (omap3_do_wfi)
+	 * For non-OFF modes: jump to the WFI code in SRAM (omap3_do_wfi_sram)
+	 */
+	ldr	r4, omap3_do_wfi_sram_addr
+	ldr	r5, [r4]
+	cmp	r1, #0x0		@ If no context save required,
+	bxeq	r5			@  jump to the WFI code in SRAM
+
 
 	/* Otherwise fall through to the save context code */
 save_context_wfi:
@@ -282,7 +290,31 @@  clean_l2:
 	mov	lr, pc
 	bx	r1
 
-omap3_do_wfi:
+	b	omap3_do_wfi
+
+/*
+ * Local variables
+ */
+omap3_do_wfi_sram_addr:
+	.word omap3_do_wfi_sram
+kernel_flush:
+	.word v7_flush_dcache_all
+
+/* ===================================
+ * == WFI instruction => Enter idle ==
+ * ===================================
+ */
+
+/*
+ * Do WFI instruction
+ * Includes the resume path for non-OFF modes
+ *
+ * This code gets copied to internal SRAM and is accessible
+ * from both SDRAM and SRAM:
+ * - executed from SRAM for non-off modes (omap3_do_wfi_sram),
+ * - executed from SDRAM for OFF mode (omap3_do_wfi).
+ */
+ENTRY(omap3_do_wfi)
 	ldr	r4, sdrc_power		@ read the SDRC_POWER register
 	ldr	r5, [r4]		@ read the contents of SDRC_POWER
 	orr	r5, r5, #0x40		@ enable self refresh on idle req
@@ -315,15 +347,111 @@  omap3_do_wfi:
 	nop
 	nop
 	nop
-	bl wait_sdrc_ok
+
+/*
+ * wait_sdrc_ok implements the erratum ID i581 WA:
+ *  SDRC state restore before accessing the SDRAM
+ *
+ * Only used at return from non-OFF mode. For OFF
+ * mode the ROM code configures the SDRC and
+ * the DPLL before calling the restore code directly
+ * from SDRAM.
+ */
+
+/* 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]
+	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]
+
+is_dll_in_lock_mode:
+	/* Is dll in lock mode? */
+	ldr	r4, sdrc_dlla_ctrl
+	ldr	r5, [r4]
+	tst	r5, #0x4
+	bne	exit_nonoff_modes	@ Return if locked
+
+	/* wait till dll locks */
+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
+	/* Wait 20uS for lock */
+	mov	r6, #8
+wait_dll_lock:
+	subs	r6, r6, #0x1
+	beq	kick_dll
+	ldr	r5, [r4]
+	and	r5, r5, #0x4
+	cmp	r5, #0x4
+	bne	wait_dll_lock
+	b	exit_nonoff_modes	@ Return when locked
+
+	/* 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
 
 /*
  * ===================================
  * == Exit point from non-OFF modes ==
  * ===================================
  */
+exit_nonoff_modes:
 	ldmfd	sp!, {r0-r12, pc}	@ restore regs and return
 
+/*
+ * Local variables
+ */
+sdrc_power:
+	.word	SDRC_POWER_V
+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:
+	.word	SDRC_DLLA_CTRL_V
+	/*
+	 * When exporting to userspace while the counters are in SRAM,
+	 * these 2 words need to be at the end to facilitate retrival!
+	 */
+kick_counter:
+	.word	0
+wait_dll_lock_counter:
+	.word	0
+
+ENTRY(omap3_do_wfi_sz)
+	.word	. - omap3_do_wfi
+
 
 /*
  * ==============================
@@ -339,6 +467,10 @@  omap3_do_wfi:
  *  restore_es3: applies to 34xx >= ES3.0
  *  restore_3630: applies to 36xx
  *  restore: common code for 3xxx
+ *
+ * Note: when back from CORE and MPU OFF mode we are running
+ *  from SDRAM, without MMU, without the caches and prediction.
+ *  Also the SRAM content has been cleared.
  */
 restore_es3:
 	ldr	r5, pm_prepwstst_core_p
@@ -357,7 +489,8 @@  copy_to_sram:
 	bne	copy_to_sram
 	ldr	r1, sram_base
 	blx	r1
-	b	restore
+
+	b	restore		@ Fall through to common code
 
 restore_3630:
 	ldr	r1, pm_prepwstst_core_p
@@ -600,12 +733,41 @@  usettbr0:
  */
 	ldmfd	sp!, {r0-r12, pc}	@ restore regs and return
 
+/*
+ * Local variables
+ */
+pm_prepwstst_core_p:
+	.word	PM_PREPWSTST_CORE_P
+pm_pwstctrl_mpu:
+	.word	PM_PWSTCTRL_MPU_P
+scratchpad_base:
+	.word	SCRATCHPAD_BASE_P
+sram_base:
+	.word	SRAM_BASE_P + 0x8000
+ttbrbit_mask:
+	.word	0xFFFFC000
+table_index_mask:
+	.word	0xFFF00000
+table_entry:
+	.word	0x00000C02
+cache_pred_disable_mask:
+	.word	0xFFFFE7FB
+control_stat:
+	.word	CONTROL_STAT
+control_mem_rta:
+	.word	CONTROL_MEM_RTA_CTRL
+l2dis_3630:
+	.word	0
+
 
 /*
  * Internal functions
  */
 
-/* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0 */
+/* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0
+ *
+ * Copied and run from SRAM in order to reconfigure the SDRC parameters.
+ */
 	.text
 ENTRY(es3_sdrc_fix)
 	ldr	r4, sdrc_syscfg		@ get config addr
@@ -634,6 +796,9 @@  ENTRY(es3_sdrc_fix)
 	str	r5, [r4]		@ kick off refreshes
 	bx	lr
 
+/*
+ * Local variables
+ */
 sdrc_syscfg:
 	.word	SDRC_SYSCONFIG_P
 sdrc_mr_0:
@@ -650,119 +815,3 @@  sdrc_manual_1:
 	.word	SDRC_MANUAL_1_P
 ENTRY(es3_sdrc_fix_sz)
 	.word	. - es3_sdrc_fix
-
-/*
- * This function implements the erratum ID i581 WA:
- *  SDRC state restore before accessing the SDRAM
- *
- * Only used at return from non-OFF mode. For OFF
- * mode the ROM code configures the SDRC and
- * the DPLL before calling the restore code directly
- * from DDR.
- */
-
-/* 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]
-	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]
-
-is_dll_in_lock_mode:
-	/* Is dll in lock mode? */
-	ldr	r4, sdrc_dlla_ctrl
-	ldr	r5, [r4]
-	tst	r5, #0x4
-	bxne	lr			@ Return if locked
-	/* wait till dll locks */
-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
-	/* Wait 20uS for lock */
-	mov	r6, #8
-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			@ Return when locked
-
-	/* 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:
-	.word	SDRC_DLLA_CTRL_V
-pm_prepwstst_core_p:
-	.word	PM_PREPWSTST_CORE_P
-pm_pwstctrl_mpu:
-	.word	PM_PWSTCTRL_MPU_P
-scratchpad_base:
-	.word	SCRATCHPAD_BASE_P
-sram_base:
-	.word	SRAM_BASE_P + 0x8000
-sdrc_power:
-	.word	SDRC_POWER_V
-ttbrbit_mask:
-	.word	0xFFFFC000
-table_index_mask:
-	.word	0xFFF00000
-table_entry:
-	.word	0x00000C02
-cache_pred_disable_mask:
-	.word	0xFFFFE7FB
-control_stat:
-	.word	CONTROL_STAT
-control_mem_rta:
-	.word	CONTROL_MEM_RTA_CTRL
-kernel_flush:
-	.word	v7_flush_dcache_all
-l2dis_3630:
-	.word	0
-	/*
-	 * When exporting to userspace while the counters are in SRAM,
-	 * these 2 words need to be at the end to facilitate retrival!
-	 */
-kick_counter:
-	.word	0
-wait_dll_lock_counter:
-	.word	0
-
-ENTRY(omap34xx_cpu_suspend_sz)
-	.word	. - omap34xx_cpu_suspend