[PATCH v4 0/7] cleanup imx5 idle, add imx5/6 cpuidle

[PATCH v4 0/7] cleanup imx5 idle, add imx5/6 cpuidle

[Robert Lee]

Cleanup up imx5 idle code and enable imx5 low powe idle for imx53.

Add common imx cpuidle initialization functionality and add a i.MX5 and i.MX6Q
platform cpuidle implementation.

Based on v3.4-rc7 plus recently submitted/accepted MACHINE_INIT late_initcall
 patch: http://www.spinics.net/lists/arm-kernel/msg171620.html

v4 changes:
 * Added several imx5 idle cleanups to series.
 * Modified imx_io_p2v function to allow common imx5 AIPS2 bus virutal address
 * Added comment to tzic_wakeup_enable().
 * Movied imx5 idle code from mm-imx5.c to pm-imx5.c.
 * Removed unnecessary time consuming code execution that ran on each idle
   instance.
 * modified imx5_pm_init to be a late_initcall
 * added late_initcall to all imx53 MACHINE_START entries.
 * enabled imx5 low power idle for imx53
 * rebased cpuidle driver on top of imx5 cleanup changes.
 * modified cpuidle driver exit time to reflect removal of unnecessary code
   

v3 changes:
 * removed file introduced in v1 no longer needed after v2 [per Shawn Guo]
 * re-ordered added #includes in alphabetical order [per Shawn Guo]
 * Remove if(!drv) check to allow handling by stack trace [per Sascha Hauer]
 * Added missing return value in error meesage [per Shawn Guo]
 * fixed (void *) casting problem pointed out Sasha Hauer.  Used a different
   type of casting to properly give warning on improper casting:
   	arm_pm_idle = (void (*)(void))imx5_idle;
   Used this casting instead of adding a dummy caller function because
   adding the dummy function appears to unnecessarily introduce the following
   additional operations:
	static void imx5_pm_idle(void)
	{
	  a0:	e1a0c00d 	mov	ip, sp
	  a4:	e92dd800 	push	{fp, ip, lr, pc}
	  a8:	e24cb004 	sub	fp, ip, #4
		imx5_idle();
	  ac:	ebffffd3 	bl	0 <imx5_idle>
	}
	  b0:	e89da800 	ldm	sp, {fp, sp, pc}

http://permalink.gmane.org/gmane.linux.linaro.devel/11653

v2 changes:
 * Removed some unnecessary  spaces [per Jess Juhl]
 * Added return value for an error message [per Sascha Hauer]
 * Reworked init scheme to use device tree late_initcall [per Sascha and Shawn]
 * Moved imx6q and imx5 cpuidle functionality to existing files.

https://lkml.org/lkml/2012/5/1/363

v1 initial submission:

https://lkml.org/lkml/2012/4/16/644

Robert Lee (7):
  ARM: imx: Modify IMX_IO_P2V macro
  ARM: imx: Add comments to tzic_enable_waker()
  ARM: imx: clean and consolidate imx5 suspend and idle code
  ARM: imx: Enable imx53 low power idle
  ARM: imx: Add common imx cpuidle init functionality.
  ARM: imx: Add imx5 cpuidle
  ARM: imx: Add imx6q cpuidle driver

 arch/arm/mach-imx/clock-mx51-mx53.c       |    1 +
 arch/arm/mach-imx/imx53-dt.c              |    1 +
 arch/arm/mach-imx/mach-imx6q.c            |   19 ++++++
 arch/arm/mach-imx/mach-mx53_ard.c         |    1 +
 arch/arm/mach-imx/mach-mx53_evk.c         |    1 +
 arch/arm/mach-imx/mach-mx53_loco.c        |    1 +
 arch/arm/mach-imx/mach-mx53_smd.c         |    1 +
 arch/arm/mach-imx/mm-imx5.c               |   25 ++-----
 arch/arm/mach-imx/pm-imx5.c               |  103 +++++++++++++++++++++--------
 arch/arm/plat-mxc/Makefile                |    1 +
 arch/arm/plat-mxc/cpuidle.c               |   80 ++++++++++++++++++++++
 arch/arm/plat-mxc/include/mach/common.h   |    4 +-
 arch/arm/plat-mxc/include/mach/cpuidle.h  |   22 ++++++
 arch/arm/plat-mxc/include/mach/hardware.h |   25 ++++---
 arch/arm/plat-mxc/tzic.c                  |    4 ++
 15 files changed, 231 insertions(+), 58 deletions(-)
 create mode 100644 arch/arm/plat-mxc/cpuidle.c
 create mode 100644 arch/arm/plat-mxc/include/mach/cpuidle.h

-- 
1.7.10

[PATCH v4 1/7] ARM: imx: Modify IMX_IO_P2V macro

[Robert Lee]

A change is needed in the IMX_IO_P2V macro to allow all imx5 platforms
to use common definitions when accessing registers of peripherals on
the AIPS2 bus.  With this change, IMX_IO_P2V(MX50_AIPS2_BASE_ADDR) ==
IMX_IO_P2V(MX51_AIPS2_BASE_ADDR) == IMX_IO_P2V(MX53_AIPS2_BASE_ADDR).

This change was tested for mapping conflicts using the iop2v script
found at git://git.pengutronix.de/git/ukl/imx-iop2v.git and by
performing a bootup of a default build using imx_v6_v7_defconfig
on a imx51 babbage board and imx53 loco board.  The comments were
modified to reflect the output given by the script which shows the
virtual address mappings.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/plat-mxc/include/mach/hardware.h |   25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/arm/plat-mxc/include/mach/hardware.h b/arch/arm/plat-mxc/include/mach/hardware.h
index 0630513..071afd0 100644
--- a/arch/arm/plat-mxc/include/mach/hardware.h
+++ b/arch/arm/plat-mxc/include/mach/hardware.h
@@ -50,7 +50,7 @@
  *	IO	0x00200000+0x100000	->	0xf4000000+0x100000
  * mx21:
  *	AIPI	0x10000000+0x100000	->	0xf4400000+0x100000
- *	SAHB1	0x80000000+0x100000	->	0xf4000000+0x100000
+ *	SAHB1	0x80000000+0x100000	->	0xf5000000+0x100000
  *	X_MEMC	0xdf000000+0x004000	->	0xf5f00000+0x004000
  * mx25:
  *	AIPS1	0x43f00000+0x100000	->	0xf5300000+0x100000
@@ -58,47 +58,50 @@
  *	AVIC	0x68000000+0x100000	->	0xf5800000+0x100000
  * mx27:
  *	AIPI	0x10000000+0x100000	->	0xf4400000+0x100000
- *	SAHB1	0x80000000+0x100000	->	0xf4000000+0x100000
+ *	SAHB1	0x80000000+0x100000	->	0xf5000000+0x100000
  *	X_MEMC	0xd8000000+0x100000	->	0xf5c00000+0x100000
  * mx31:
  *	AIPS1	0x43f00000+0x100000	->	0xf5300000+0x100000
  *	AIPS2	0x53f00000+0x100000	->	0xf5700000+0x100000
  *	AVIC	0x68000000+0x100000	->	0xf5800000+0x100000
- *	X_MEMC	0xb8000000+0x010000	->	0xf4c00000+0x010000
+ *	X_MEMC	0xb8000000+0x010000	->	0xf5c00000+0x010000
  *	SPBA0	0x50000000+0x100000	->	0xf5400000+0x100000
  * mx35:
  *	AIPS1	0x43f00000+0x100000	->	0xf5300000+0x100000
  *	AIPS2	0x53f00000+0x100000	->	0xf5700000+0x100000
  *	AVIC	0x68000000+0x100000	->	0xf5800000+0x100000
- *	X_MEMC	0xb8000000+0x010000	->	0xf4c00000+0x010000
+ *	X_MEMC	0xb8000000+0x010000	->	0xf5c00000+0x010000
  *	SPBA0	0x50000000+0x100000	->	0xf5400000+0x100000
  * mx50:
  *	TZIC	0x0fffc000+0x004000	->	0xf4bfc000+0x004000
- *	SPBA0	0x50000000+0x100000	->	0xf5400000+0x100000
  *	AIPS1	0x53f00000+0x100000	->	0xf5700000+0x100000
+ *	SPBA0	0x50000000+0x100000	->	0xf5400000+0x100000
  *	AIPS2	0x63f00000+0x100000	->	0xf5300000+0x100000
  * mx51:
- *	TZIC	0xe0000000+0x004000	->	0xf5000000+0x004000
+ *	TZIC	0x0fffc000+0x004000	->	0xf4bfc000+0x004000
  *	IRAM	0x1ffe0000+0x020000	->	0xf4fe0000+0x020000
+ *	DEBUG	0x60000000+0x100000	->	0xf5000000+0x100000
  *	SPBA0	0x70000000+0x100000	->	0xf5400000+0x100000
  *	AIPS1	0x73f00000+0x100000	->	0xf5700000+0x100000
- *	AIPS2	0x83f00000+0x100000	->	0xf4300000+0x100000
+ *	AIPS2	0x83f00000+0x100000	->	0xf5300000+0x100000
  * mx53:
  *	TZIC	0x0fffc000+0x004000	->	0xf4bfc000+0x004000
+ *	DEBUG	0x40000000+0x100000	->	0xf5000000+0x100000
  *	SPBA0	0x50000000+0x100000	->	0xf5400000+0x100000
  *	AIPS1	0x53f00000+0x100000	->	0xf5700000+0x100000
  *	AIPS2	0x63f00000+0x100000	->	0xf5300000+0x100000
  * mx6q:
- *	SCU	0x00a00000+0x001000	->	0xf4000000+0x001000
+ *	SCU	0x00a00000+0x004000	->	0xf4000000+0x004000
  *	CCM	0x020c4000+0x004000	->	0xf42c4000+0x004000
- *	ANATOP	0x020c8000+0x001000	->	0xf42c8000+0x001000
+ *	ANATOP	0x020c8000+0x004000	->	0xf42c8000+0x004000
  *	UART4	0x021f0000+0x004000	->	0xf42f0000+0x004000
  */
 #define IMX_IO_P2V(x)	(						\
-			0xf4000000 +					\
+			(((x) & 0x80000000) >> 7) |			\
+			(0xf4000000 +					\
 			(((x) & 0x50000000) >> 6) +			\
 			(((x) & 0x0b000000) >> 4) +			\
-			(((x) & 0x000fffff)))
+			(((x) & 0x000fffff))))
 
 #define IMX_IO_ADDRESS(x)	IOMEM(IMX_IO_P2V(x))
 
-- 
1.7.10

[PATCH v4 2/7] ARM: imx: Add comments to tzic_enable_waker()

[Robert Lee]

Add additional comments to the tzic_enable_wake() funciton to
clarify its intended usage.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/plat-mxc/tzic.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/plat-mxc/tzic.c b/arch/arm/plat-mxc/tzic.c
index 98308ec..a45dbea 100644
--- a/arch/arm/plat-mxc/tzic.c
+++ b/arch/arm/plat-mxc/tzic.c
@@ -190,6 +190,10 @@ void __init tzic_init_irq(void __iomem *irqbase)
  * tzic_enable_wake() - enable wakeup interrupt
  *
  * @return			0 if successful; non-zero otherwise
+ *
+ * This function provides an interrupt synchronization point that is required
+ * by tzic enabled platforms before entering imx specific low power modes (ie,
+ * those low power modes beyond the WAIT_CLOCKED basic ARM WFI only mode).
  */
 int tzic_enable_wake(void)
 {
-- 
1.7.10

[PATCH v4 3/7] ARM: imx: clean and consolidate imx5 suspend and idle code

[Robert Lee]

The imx5 idle code that existed in mm-imx5.c is moved to pm-imx5.c.
The imx5_pm_init call is now exported and called during the
MACHINE_START late_init in supported imx5 platforms.

Remove various enabling/disabling of the gpc_dvfs clock and
enable it once during initialization.  This is a very low
power clock that must be enabled during low power operations.

There are only two "suspend_state_t" imx5 low power modes ever
used.  STOP_POWER_OFF for suspend to mem and
WAIT_UNCLOCKED_POWER_OFF for idle and suspend to standby.  The
latter mode only requires 500 nanoseconds of extra hardware
exit time beyond a basic WFI operation (WAIT_CLOCKED mode) so
no other idle mode is necessary.  Given this information, it
is more efficient to keep the registers in the often used
WAIT_UNCLOCKED_POWER_OFF state and only to and from the
STOP_POWER_OFF register state as needed when suspend to
mem is required.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/mach-imx/mm-imx5.c             |   20 +---------
 arch/arm/mach-imx/pm-imx5.c             |   63 ++++++++++++++++++-------------
 arch/arm/plat-mxc/include/mach/common.h |    3 +-
 3 files changed, 40 insertions(+), 46 deletions(-)

diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
index d6b7e9f..bb38747 100644
--- a/arch/arm/mach-imx/mm-imx5.c
+++ b/arch/arm/mach-imx/mm-imx5.c
@@ -15,7 +15,6 @@
 #include <linux/init.h>
 #include <linux/clk.h>
 
-#include <asm/system_misc.h>
 #include <asm/mach/map.h>
 
 #include <mach/hardware.h>
@@ -23,23 +22,6 @@
 #include <mach/devices-common.h>
 #include <mach/iomux-v3.h>
 
-static struct clk *gpc_dvfs_clk;
-
-static void imx5_idle(void)
-{
-	/* gpc clock is needed for SRPG */
-	if (gpc_dvfs_clk == NULL) {
-		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
-		if (IS_ERR(gpc_dvfs_clk))
-			return;
-	}
-	clk_enable(gpc_dvfs_clk);
-	mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
-	if (!tzic_enable_wake())
-		cpu_do_idle();
-	clk_disable(gpc_dvfs_clk);
-}
-
 /*
  * Define the MX50 memory map.
  */
@@ -103,7 +85,6 @@ void __init imx51_init_early(void)
 	mxc_set_cpu_type(MXC_CPU_MX51);
 	mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));
 	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
-	arm_pm_idle = imx5_idle;
 }
 
 void __init imx53_init_early(void)
@@ -238,4 +219,5 @@ void __init imx53_soc_init(void)
 void __init imx51_init_late(void)
 {
 	mx51_neon_fixup();
+	imx5_pm_init();
 }
diff --git a/arch/arm/mach-imx/pm-imx5.c b/arch/arm/mach-imx/pm-imx5.c
index e26a9cb..6e62d79 100644
--- a/arch/arm/mach-imx/pm-imx5.c
+++ b/arch/arm/mach-imx/pm-imx5.c
@@ -13,18 +13,27 @@
 #include <linux/io.h>
 #include <linux/err.h>
 #include <asm/cacheflush.h>
+#include <asm/system_misc.h>
 #include <asm/tlbflush.h>
 #include <mach/common.h>
 #include <mach/hardware.h>
 #include "crm-regs-imx5.h"
 
-static struct clk *gpc_dvfs_clk;
+/*
+ * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
+ * This is also the lowest power state possible without affecting
+ * non-cpu parts of the system.  For these reasons, imx5 should default
+ * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
+ * uses this state and needs to take no action when registers remain confgiured
+ * for this state.
+ */
+#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
 
 /*
  * set cpu low power mode before WFI instruction. This function is called
  * mx5 because it can be used for mx50, mx51, and mx53.
  */
-void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
+static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
 {
 	u32 plat_lpc, arm_srpgcr, ccm_clpcr;
 	u32 empgc0, empgc1;
@@ -87,11 +96,6 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
 	}
 }
 
-static int mx5_suspend_prepare(void)
-{
-	return clk_prepare_enable(gpc_dvfs_clk);
-}
-
 static int mx5_suspend_enter(suspend_state_t state)
 {
 	switch (state) {
@@ -99,7 +103,7 @@ static int mx5_suspend_enter(suspend_state_t state)
 		mx5_cpu_lp_set(STOP_POWER_OFF);
 		break;
 	case PM_SUSPEND_STANDBY:
-		mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
+		/* DEFAULT_IDLE_STATE already configured */
 		break;
 	default:
 		return -EINVAL;
@@ -114,12 +118,10 @@ static int mx5_suspend_enter(suspend_state_t state)
 		__raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
 	}
 	cpu_do_idle();
-	return 0;
-}
 
-static void mx5_suspend_finish(void)
-{
-	clk_disable_unprepare(gpc_dvfs_clk);
+	/* return registers to default idle state */
+	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
+	return 0;
 }
 
 static int mx5_pm_valid(suspend_state_t state)
@@ -129,25 +131,34 @@ static int mx5_pm_valid(suspend_state_t state)
 
 static const struct platform_suspend_ops mx5_suspend_ops = {
 	.valid = mx5_pm_valid,
-	.prepare = mx5_suspend_prepare,
 	.enter = mx5_suspend_enter,
-	.finish = mx5_suspend_finish,
 };
 
-static int __init mx5_pm_init(void)
+static void imx5_pm_idle(void)
+{
+	if (likely(!tzic_enable_wake()))
+		cpu_do_idle();
+}
+
+int __init imx5_pm_init(void)
 {
-	if (!cpu_is_mx51() && !cpu_is_mx53())
-		return 0;
+	int ret;
+	struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
+
+	if (IS_ERR(gpc_dvfs_clk))
+		return (int)gpc_dvfs_clk;
+
+	ret = clk_enable(gpc_dvfs_clk);
+	if (ret)
+		return ret;
+
+	if (cpu_is_mx51())
+		suspend_set_ops(&mx5_suspend_ops);
 
-	if (gpc_dvfs_clk == NULL)
-		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
+	arm_pm_idle = imx5_pm_idle;
 
-	if (!IS_ERR(gpc_dvfs_clk)) {
-		if (cpu_is_mx51())
-			suspend_set_ops(&mx5_suspend_ops);
-	} else
-		return -EPERM;
+	/* Set the registers to the default cpu idle state. */
+	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 
 	return 0;
 }
-device_initcall(mx5_pm_init);
diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
index cf663d8..5660e1e 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -95,7 +95,6 @@ enum mx3_cpu_pwr_mode {
 };
 
 extern void mx3_cpu_lp_set(enum mx3_cpu_pwr_mode mode);
-extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode);
 extern void imx_print_silicon_rev(const char *cpu, int srev);
 
 void avic_handle_irq(struct pt_regs *);
@@ -146,8 +145,10 @@ extern void imx6q_clock_map_io(void);
 
 #ifdef CONFIG_PM
 extern void imx6q_pm_init(void);
+extern int imx5_pm_init(void);
 #else
 static inline void imx6q_pm_init(void) {}
+static inline int imx5_pm_init(void) { return -ENODEV; }
 #endif
 
 #ifdef CONFIG_NEON
-- 
1.7.10

[PATCH v4 4/7] ARM: imx: Enable imx53 low power idle

[Robert Lee]

Add various functionality needed to enable a imx53 low power idle
state.  This includes adding the imx53 gpc_dvfs clock and making a
common imx5_late_init function and initializing all imx53
 MACHINE_STATE late_init calls to imx5_late_init.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/mach-imx/clock-mx51-mx53.c     |    1 +
 arch/arm/mach-imx/imx53-dt.c            |    1 +
 arch/arm/mach-imx/mach-mx53_ard.c       |    1 +
 arch/arm/mach-imx/mach-mx53_evk.c       |    1 +
 arch/arm/mach-imx/mach-mx53_loco.c      |    1 +
 arch/arm/mach-imx/mach-mx53_smd.c       |    1 +
 arch/arm/mach-imx/mm-imx5.c             |    7 ++++++-
 arch/arm/plat-mxc/include/mach/common.h |    1 +
 8 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/clock-mx51-mx53.c b/arch/arm/mach-imx/clock-mx51-mx53.c
index 0847050..decedc6 100644
--- a/arch/arm/mach-imx/clock-mx51-mx53.c
+++ b/arch/arm/mach-imx/clock-mx51-mx53.c
@@ -1529,6 +1529,7 @@ static struct clk_lookup mx53_lookups[] = {
 	_REGISTER_CLOCK("imx-ssi.1", NULL, ssi2_clk)
 	_REGISTER_CLOCK("imx-ssi.2", NULL, ssi3_clk)
 	_REGISTER_CLOCK("imx-keypad", NULL, dummy_clk)
+	_REGISTER_CLOCK(NULL, "gpc_dvfs", gpc_dvfs_clk)
 	_REGISTER_CLOCK("pata_imx", NULL, pata_clk)
 	_REGISTER_CLOCK("imx53-ahci.0", "ahci", sata_clk)
 	_REGISTER_CLOCK("imx53-ahci.0", "ahci_phy", ahci_phy_clk)
diff --git a/arch/arm/mach-imx/imx53-dt.c b/arch/arm/mach-imx/imx53-dt.c
index 4172279..39d2ca7 100644
--- a/arch/arm/mach-imx/imx53-dt.c
+++ b/arch/arm/mach-imx/imx53-dt.c
@@ -125,6 +125,7 @@ DT_MACHINE_START(IMX53_DT, "Freescale i.MX53 (Device Tree Support)")
 	.handle_irq	= imx53_handle_irq,
 	.timer		= &imx53_timer,
 	.init_machine	= imx53_dt_init,
+	.init_late	= imx5_init_late,
 	.dt_compat	= imx53_dt_board_compat,
 	.restart	= mxc_restart,
 MACHINE_END
diff --git a/arch/arm/mach-imx/mach-mx53_ard.c b/arch/arm/mach-imx/mach-mx53_ard.c
index 0564198..afb3d14 100644
--- a/arch/arm/mach-imx/mach-mx53_ard.c
+++ b/arch/arm/mach-imx/mach-mx53_ard.c
@@ -266,5 +266,6 @@ MACHINE_START(MX53_ARD, "Freescale MX53 ARD Board")
 	.handle_irq = imx53_handle_irq,
 	.timer = &mx53_ard_timer,
 	.init_machine = mx53_ard_board_init,
+	.init_late	= imx5_init_late,
 	.restart	= mxc_restart,
 MACHINE_END
diff --git a/arch/arm/mach-imx/mach-mx53_evk.c b/arch/arm/mach-imx/mach-mx53_evk.c
index 5a72188..929969f 100644
--- a/arch/arm/mach-imx/mach-mx53_evk.c
+++ b/arch/arm/mach-imx/mach-mx53_evk.c
@@ -174,5 +174,6 @@ MACHINE_START(MX53_EVK, "Freescale MX53 EVK Board")
 	.handle_irq = imx53_handle_irq,
 	.timer = &mx53_evk_timer,
 	.init_machine = mx53_evk_board_init,
+	.init_late	= imx5_init_late,
 	.restart	= mxc_restart,
 MACHINE_END
diff --git a/arch/arm/mach-imx/mach-mx53_loco.c b/arch/arm/mach-imx/mach-mx53_loco.c
index 37f67ca..bc5012b 100644
--- a/arch/arm/mach-imx/mach-mx53_loco.c
+++ b/arch/arm/mach-imx/mach-mx53_loco.c
@@ -316,5 +316,6 @@ MACHINE_START(MX53_LOCO, "Freescale MX53 LOCO Board")
 	.handle_irq = imx53_handle_irq,
 	.timer = &mx53_loco_timer,
 	.init_machine = mx53_loco_board_init,
+	.init_late	= imx5_init_late,
 	.restart	= mxc_restart,
 MACHINE_END
diff --git a/arch/arm/mach-imx/mach-mx53_smd.c b/arch/arm/mach-imx/mach-mx53_smd.c
index 8e972c5..568190b 100644
--- a/arch/arm/mach-imx/mach-mx53_smd.c
+++ b/arch/arm/mach-imx/mach-mx53_smd.c
@@ -163,5 +163,6 @@ MACHINE_START(MX53_SMD, "Freescale MX53 SMD Board")
 	.handle_irq = imx53_handle_irq,
 	.timer = &mx53_smd_timer,
 	.init_machine = mx53_smd_board_init,
+	.init_late	= imx5_init_late,
 	.restart	= mxc_restart,
 MACHINE_END
diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
index bb38747..7740739 100644
--- a/arch/arm/mach-imx/mm-imx5.c
+++ b/arch/arm/mach-imx/mm-imx5.c
@@ -216,8 +216,13 @@ void __init imx53_soc_init(void)
 					ARRAY_SIZE(imx53_audmux_res));
 }
 
+void __init imx5_init_late(void)
+{
+	imx5_pm_init();
+}
+
 void __init imx51_init_late(void)
 {
 	mx51_neon_fixup();
-	imx5_pm_init();
+	imx5_init_late();
 }
diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
index 5660e1e..6d2e910 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -54,6 +54,7 @@ extern void imx50_soc_init(void);
 extern void imx51_soc_init(void);
 extern void imx53_soc_init(void);
 extern void imx51_init_late(void);
+extern void imx5_init_late(void);
 extern void epit_timer_init(struct clk *timer_clk, void __iomem *base, int irq);
 extern void mxc_timer_init(struct clk *timer_clk, void __iomem *, int);
 extern int mx1_clocks_init(unsigned long fref);
-- 
1.7.10

[PATCH v4 5/7] ARM: imx: Add common imx cpuidle init functionality.

[Robert Lee]

Add common cpuidle init functionality that can be used by various
imx platforms.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/plat-mxc/Makefile               |    1 +
 arch/arm/plat-mxc/cpuidle.c              |   80 ++++++++++++++++++++++++++++++
 arch/arm/plat-mxc/include/mach/cpuidle.h |   22 ++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 arch/arm/plat-mxc/cpuidle.c
 create mode 100644 arch/arm/plat-mxc/include/mach/cpuidle.h

diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index e81290c..63b064b 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_MXC_ULPI) += ulpi.o
 obj-$(CONFIG_MXC_USE_EPIT) += epit.o
 obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o
 obj-$(CONFIG_CPU_FREQ_IMX)    += cpufreq.o
+obj-$(CONFIG_CPU_IDLE) += cpuidle.o
 ifdef CONFIG_SND_IMX_SOC
 obj-y += ssi-fiq.o
 obj-y += ssi-fiq-ksym.o
diff --git a/arch/arm/plat-mxc/cpuidle.c b/arch/arm/plat-mxc/cpuidle.c
new file mode 100644
index 0000000..d4cb511
--- /dev/null
+++ b/arch/arm/plat-mxc/cpuidle.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+static struct cpuidle_device __percpu * imx_cpuidle_devices;
+
+static void __init imx_cpuidle_devices_uninit(void)
+{
+	int cpu_id;
+	struct cpuidle_device *dev;
+
+	for_each_possible_cpu(cpu_id) {
+		dev = per_cpu_ptr(imx_cpuidle_devices, cpu_id);
+		cpuidle_unregister_device(dev);
+	}
+
+	free_percpu(imx_cpuidle_devices);
+}
+
+int __init imx_cpuidle_init(struct cpuidle_driver *drv)
+{
+	struct cpuidle_device *dev;
+	int cpu_id, ret;
+
+	if (drv->state_count > CPUIDLE_STATE_MAX) {
+		pr_err("%s: state_count exceeds maximum\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = cpuidle_register_driver(drv);
+	if (ret) {
+		pr_err("%s: Failed to register cpuidle driver with error: %d\n",
+			 __func__, ret);
+		return ret;
+	}
+
+	imx_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (imx_cpuidle_devices == NULL) {
+		ret = -ENOMEM;
+		goto unregister_drv;
+	}
+
+	/* initialize state data for each cpuidle_device */
+	for_each_possible_cpu(cpu_id) {
+		dev = per_cpu_ptr(imx_cpuidle_devices, cpu_id);
+		dev->cpu = cpu_id;
+		dev->state_count = drv->state_count;
+
+		ret = cpuidle_register_device(dev);
+		if (ret) {
+			pr_err("%s: Failed to register cpu %u, error: %d\n",
+				__func__, cpu_id, ret);
+			goto uninit;
+		}
+	}
+
+	return 0;
+
+uninit:
+	imx_cpuidle_devices_uninit();
+
+unregister_drv:
+	cpuidle_unregister_driver(drv);
+	return ret;
+}
diff --git a/arch/arm/plat-mxc/include/mach/cpuidle.h b/arch/arm/plat-mxc/include/mach/cpuidle.h
new file mode 100644
index 0000000..bc932d1
--- /dev/null
+++ b/arch/arm/plat-mxc/include/mach/cpuidle.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/cpuidle.h>
+
+#ifdef CONFIG_CPU_IDLE
+extern int imx_cpuidle_init(struct cpuidle_driver *drv);
+#else
+static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
+{
+	return -ENODEV;
+}
+#endif
-- 
1.7.10

[PATCH v4 6/7] ARM: imx: Add imx5 cpuidle

[Robert Lee]

Add cpuidle driver for imx5 platform.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/mach-imx/pm-imx5.c |   44 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-imx/pm-imx5.c b/arch/arm/mach-imx/pm-imx5.c
index 6e62d79..966c71b 100644
--- a/arch/arm/mach-imx/pm-imx5.c
+++ b/arch/arm/mach-imx/pm-imx5.c
@@ -12,10 +12,12 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <asm/cacheflush.h>
 #include <asm/system_misc.h>
 #include <asm/tlbflush.h>
 #include <mach/common.h>
+#include <mach/cpuidle.h>
 #include <mach/hardware.h>
 #include "crm-regs-imx5.h"
 
@@ -134,12 +136,48 @@ static const struct platform_suspend_ops mx5_suspend_ops = {
 	.enter = mx5_suspend_enter,
 };
 
-static void imx5_pm_idle(void)
+static inline int imx5_cpu_do_idle(void)
 {
-	if (likely(!tzic_enable_wake()))
+	int ret = tzic_enable_wake();
+
+	if (likely(!ret))
 		cpu_do_idle();
+
+	return ret;
 }
 
+static void imx5_pm_idle(void)
+{
+	imx5_cpu_do_idle();
+}
+
+static int imx5_cpuidle_enter(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int idx)
+{
+	int ret;
+
+	ret = imx5_cpu_do_idle();
+	if (ret < 0)
+		return ret;
+
+	return idx;
+}
+
+static struct cpuidle_driver imx5_cpuidle_driver = {
+	.name			= "imx5_cpuidle",
+	.owner			= THIS_MODULE,
+	.en_core_tk_irqen	= 1,
+	.states[0]	= {
+		.enter			= imx5_cpuidle_enter,
+		.exit_latency		= 2,
+		.target_residency	= 1,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "IMX5 SRPG",
+		.desc			= "CPU state retained,powered off",
+	},
+	.state_count		= 1,
+};
+
 int __init imx5_pm_init(void)
 {
 	int ret;
@@ -160,5 +198,5 @@ int __init imx5_pm_init(void)
 	/* Set the registers to the default cpu idle state. */
 	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
 
-	return 0;
+	return imx_cpuidle_init(&imx5_cpuidle_driver);
 }
-- 
1.7.10

[PATCH v4 7/7] ARM: imx: Add imx6q cpuidle driver

[Robert Lee]

Add basic imx6q cpuidle driver.  For now, only basic WFI state is
supported.  Deeper idle states will be added in the future.

Signed-off-by: Robert Lee <rob.lee@linaro.org>
---
 arch/arm/mach-imx/mach-imx6q.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index da6c1d9..4fc1fe7 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -10,7 +10,9 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/cpuidle.h>
 #include <linux/delay.h>
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -21,6 +23,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy.h>
 #include <linux/micrel_phy.h>
+#include <asm/cpuidle.h>
 #include <asm/smp_twd.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/hardware/gic.h>
@@ -28,8 +31,10 @@
 #include <asm/mach/time.h>
 #include <asm/system_misc.h>
 #include <mach/common.h>
+#include <mach/cpuidle.h>
 #include <mach/hardware.h>
 
+
 void imx6q_restart(char mode, const char *cmd)
 {
 	struct device_node *np;
@@ -86,6 +91,19 @@ static void __init imx6q_init_machine(void)
 	imx6q_pm_init();
 }
 
+static struct cpuidle_driver imx6q_cpuidle_driver = {
+	.name			= "imx6q_cpuidle",
+	.owner			= THIS_MODULE,
+	.en_core_tk_irqen	= 1,
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.state_count		= 1,
+};
+
+static void __init imx6q_init_late(void)
+{
+	imx_cpuidle_init(&imx6q_cpuidle_driver);
+}
+
 static void __init imx6q_map_io(void)
 {
 	imx_lluart_map_io();
@@ -142,6 +160,7 @@ DT_MACHINE_START(IMX6Q, "Freescale i.MX6 Quad (Device Tree)")
 	.handle_irq	= imx6q_handle_irq,
 	.timer		= &imx6q_timer,
 	.init_machine	= imx6q_init_machine,
+	.init_late      = imx6q_init_late,
 	.dt_compat	= imx6q_dt_compat,
 	.restart	= imx6q_restart,
 MACHINE_END
-- 
1.7.10

Re: [PATCH v4 3/7] ARM: imx: clean and consolidate imx5 suspend and idle code

[Sascha Hauer]

Hi Robert,

Overall this looks ok now, some comments inline.

Sascha

On Tue, May 15, 2012 at 09:33:32PM -0500, Robert Lee wrote:
> The imx5 idle code that existed in mm-imx5.c is moved to pm-imx5.c.
> The imx5_pm_init call is now exported and called during the
> MACHINE_START late_init in supported imx5 platforms.
> 
> Remove various enabling/disabling of the gpc_dvfs clock and
> enable it once during initialization.  This is a very low
> power clock that must be enabled during low power operations.
> 
> There are only two "suspend_state_t" imx5 low power modes ever
> used.  STOP_POWER_OFF for suspend to mem and
> WAIT_UNCLOCKED_POWER_OFF for idle and suspend to standby.  The
> latter mode only requires 500 nanoseconds of extra hardware
> exit time beyond a basic WFI operation (WAIT_CLOCKED mode) so
> no other idle mode is necessary.  Given this information, it
> is more efficient to keep the registers in the often used
> WAIT_UNCLOCKED_POWER_OFF state and only to and from the
> STOP_POWER_OFF register state as needed when suspend to
> mem is required.
> 
> Signed-off-by: Robert Lee <rob.lee@linaro.org>
> ---
>  arch/arm/mach-imx/mm-imx5.c             |   20 +---------
>  arch/arm/mach-imx/pm-imx5.c             |   63 ++++++++++++++++++-------------
>  arch/arm/plat-mxc/include/mach/common.h |    3 +-
>  3 files changed, 40 insertions(+), 46 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
> index d6b7e9f..bb38747 100644
> --- a/arch/arm/mach-imx/mm-imx5.c
> +++ b/arch/arm/mach-imx/mm-imx5.c
> @@ -15,7 +15,6 @@
>  #include <linux/init.h>
>  #include <linux/clk.h>
>  
> -#include <asm/system_misc.h>
>  #include <asm/mach/map.h>
>  
>  #include <mach/hardware.h>
> @@ -23,23 +22,6 @@
>  #include <mach/devices-common.h>
>  #include <mach/iomux-v3.h>
>  
> -static struct clk *gpc_dvfs_clk;
> -
> -static void imx5_idle(void)
> -{
> -	/* gpc clock is needed for SRPG */
> -	if (gpc_dvfs_clk == NULL) {
> -		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
> -		if (IS_ERR(gpc_dvfs_clk))
> -			return;
> -	}
> -	clk_enable(gpc_dvfs_clk);
> -	mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
> -	if (!tzic_enable_wake())
> -		cpu_do_idle();
> -	clk_disable(gpc_dvfs_clk);
> -}
> -
>  /*
>   * Define the MX50 memory map.
>   */
> @@ -103,7 +85,6 @@ void __init imx51_init_early(void)
>  	mxc_set_cpu_type(MXC_CPU_MX51);
>  	mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));
>  	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
> -	arm_pm_idle = imx5_idle;
>  }
>  
>  void __init imx53_init_early(void)
> @@ -238,4 +219,5 @@ void __init imx53_soc_init(void)
>  void __init imx51_init_late(void)
>  {
>  	mx51_neon_fixup();
> +	imx5_pm_init();
>  }
> diff --git a/arch/arm/mach-imx/pm-imx5.c b/arch/arm/mach-imx/pm-imx5.c
> index e26a9cb..6e62d79 100644
> --- a/arch/arm/mach-imx/pm-imx5.c
> +++ b/arch/arm/mach-imx/pm-imx5.c
> @@ -13,18 +13,27 @@
>  #include <linux/io.h>
>  #include <linux/err.h>
>  #include <asm/cacheflush.h>
> +#include <asm/system_misc.h>
>  #include <asm/tlbflush.h>
>  #include <mach/common.h>
>  #include <mach/hardware.h>
>  #include "crm-regs-imx5.h"
>  
> -static struct clk *gpc_dvfs_clk;
> +/*
> + * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
> + * This is also the lowest power state possible without affecting
> + * non-cpu parts of the system.  For these reasons, imx5 should default
> + * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
> + * uses this state and needs to take no action when registers remain confgiured
> + * for this state.
> + */
> +#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
>  
>  /*
>   * set cpu low power mode before WFI instruction. This function is called
>   * mx5 because it can be used for mx50, mx51, and mx53.
>   */
> -void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
> +static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>  {
>  	u32 plat_lpc, arm_srpgcr, ccm_clpcr;
>  	u32 empgc0, empgc1;
> @@ -87,11 +96,6 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>  	}
>  }
>  
> -static int mx5_suspend_prepare(void)
> -{
> -	return clk_prepare_enable(gpc_dvfs_clk);
> -}
> -
>  static int mx5_suspend_enter(suspend_state_t state)
>  {
>  	switch (state) {
> @@ -99,7 +103,7 @@ static int mx5_suspend_enter(suspend_state_t state)
>  		mx5_cpu_lp_set(STOP_POWER_OFF);
>  		break;
>  	case PM_SUSPEND_STANDBY:
> -		mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
> +		/* DEFAULT_IDLE_STATE already configured */
>  		break;
>  	default:
>  		return -EINVAL;
> @@ -114,12 +118,10 @@ static int mx5_suspend_enter(suspend_state_t state)
>  		__raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
>  	}
>  	cpu_do_idle();
> -	return 0;
> -}
>  
> -static void mx5_suspend_finish(void)
> -{
> -	clk_disable_unprepare(gpc_dvfs_clk);
> +	/* return registers to default idle state */
> +	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
> +	return 0;
>  }
>  
>  static int mx5_pm_valid(suspend_state_t state)
> @@ -129,25 +131,34 @@ static int mx5_pm_valid(suspend_state_t state)
>  
>  static const struct platform_suspend_ops mx5_suspend_ops = {
>  	.valid = mx5_pm_valid,
> -	.prepare = mx5_suspend_prepare,
>  	.enter = mx5_suspend_enter,
> -	.finish = mx5_suspend_finish,
>  };
>  
> -static int __init mx5_pm_init(void)
> +static void imx5_pm_idle(void)
> +{
> +	if (likely(!tzic_enable_wake()))
> +		cpu_do_idle();
> +}
> +
> +int __init imx5_pm_init(void)
>  {
> -	if (!cpu_is_mx51() && !cpu_is_mx53())
> -		return 0;
> +	int ret;
> +	struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
> +
> +	if (IS_ERR(gpc_dvfs_clk))
> +		return (int)gpc_dvfs_clk;

PTR_ERR please

> +
> +	ret = clk_enable(gpc_dvfs_clk);

clk_prepare_enable

> +	if (ret)
> +		return ret;
> +
> +	if (cpu_is_mx51())
> +		suspend_set_ops(&mx5_suspend_ops);

Now this is called only in i.MX51 context, so you can skip the cpu_is

>  
> -	if (gpc_dvfs_clk == NULL)
> -		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
> +	arm_pm_idle = imx5_pm_idle;
>  
> -	if (!IS_ERR(gpc_dvfs_clk)) {
> -		if (cpu_is_mx51())
> -			suspend_set_ops(&mx5_suspend_ops);
> -	} else
> -		return -EPERM;
> +	/* Set the registers to the default cpu idle state. */
> +	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
>  
>  	return 0;
>  }
> -device_initcall(mx5_pm_init);
> diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
> index cf663d8..5660e1e 100644
> --- a/arch/arm/plat-mxc/include/mach/common.h
> +++ b/arch/arm/plat-mxc/include/mach/common.h
> @@ -95,7 +95,6 @@ enum mx3_cpu_pwr_mode {
>  };
>  
>  extern void mx3_cpu_lp_set(enum mx3_cpu_pwr_mode mode);
> -extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode);
>  extern void imx_print_silicon_rev(const char *cpu, int srev);
>  
>  void avic_handle_irq(struct pt_regs *);
> @@ -146,8 +145,10 @@ extern void imx6q_clock_map_io(void);
>  
>  #ifdef CONFIG_PM
>  extern void imx6q_pm_init(void);
> +extern int imx5_pm_init(void);
>  #else
>  static inline void imx6q_pm_init(void) {}
> +static inline int imx5_pm_init(void) { return -ENODEV; }

Why not make it return void like imx6? We do not check the return value
anyway.

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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Re: [PATCH v4 4/7] ARM: imx: Enable imx53 low power idle

[Sascha Hauer]

On Tue, May 15, 2012 at 09:33:33PM -0500, Robert Lee wrote:
> Add various functionality needed to enable a imx53 low power idle
> state.  This includes adding the imx53 gpc_dvfs clock and making a
> common imx5_late_init function and initializing all imx53
>  MACHINE_STATE late_init calls to imx5_late_init.
> 
> Signed-off-by: Robert Lee <rob.lee@linaro.org>
> ---
>  arch/arm/mach-imx/clock-mx51-mx53.c     |    1 +
>  arch/arm/mach-imx/imx53-dt.c            |    1 +
>  arch/arm/mach-imx/mach-mx53_ard.c       |    1 +
>  arch/arm/mach-imx/mach-mx53_evk.c       |    1 +
>  arch/arm/mach-imx/mach-mx53_loco.c      |    1 +
>  arch/arm/mach-imx/mach-mx53_smd.c       |    1 +
>  arch/arm/mach-imx/mm-imx5.c             |    7 ++++++-
>  arch/arm/plat-mxc/include/mach/common.h |    1 +
>  8 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-imx/clock-mx51-mx53.c b/arch/arm/mach-imx/clock-mx51-mx53.c
> index 0847050..decedc6 100644
> --- a/arch/arm/mach-imx/clock-mx51-mx53.c
> +++ b/arch/arm/mach-imx/clock-mx51-mx53.c
> @@ -1529,6 +1529,7 @@ static struct clk_lookup mx53_lookups[] = {
>  	_REGISTER_CLOCK("imx-ssi.1", NULL, ssi2_clk)
>  	_REGISTER_CLOCK("imx-ssi.2", NULL, ssi3_clk)
>  	_REGISTER_CLOCK("imx-keypad", NULL, dummy_clk)
> +	_REGISTER_CLOCK(NULL, "gpc_dvfs", gpc_dvfs_clk)

This has to be rebased against the common clock patches.

>  	.timer = &mx53_smd_timer,
>  	.init_machine = mx53_smd_board_init,
> +	.init_late	= imx5_init_late,
>  	.restart	= mxc_restart,
>  MACHINE_END
> diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
> index bb38747..7740739 100644
> --- a/arch/arm/mach-imx/mm-imx5.c
> +++ b/arch/arm/mach-imx/mm-imx5.c
> @@ -216,8 +216,13 @@ void __init imx53_soc_init(void)
>  					ARRAY_SIZE(imx53_audmux_res));
>  }
>  
> +void __init imx5_init_late(void)
> +{
> +	imx5_pm_init();
> +}
> +
>  void __init imx51_init_late(void)
>  {
>  	mx51_neon_fixup();
> -	imx5_pm_init();
> +	imx5_init_late();
>  }

Where would you add i.MX53 specific code above? Hint: imx5_init_late is
the wrong function name.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v4 5/7] ARM: imx: Add common imx cpuidle init functionality.

[Sascha Hauer]

On Tue, May 15, 2012 at 09:33:34PM -0500, Robert Lee wrote:
> Add common cpuidle init functionality that can be used by various
> imx platforms.
> 
> Signed-off-by: Robert Lee <rob.lee@linaro.org>
> ---
> +
> +#ifdef CONFIG_CPU_IDLE
> +extern int imx_cpuidle_init(struct cpuidle_driver *drv);
> +#else
> +static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
> +{
> +	return -ENODEV;
> +}
> +#endif

You should return succesfully here. Think about it, if imx_cpuidle_init
fails you basically do nothing except maybe printing an error message
which will be irritating when it appears on a kernel with cpuidle
disabled.

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v4 3/7] ARM: imx: clean and consolidate imx5 suspend and idle code

[Rob Lee]

On Wed, May 16, 2012 at 12:38 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> Hi Robert,
>
> Overall this looks ok now, some comments inline.
>
> Sascha
>
> On Tue, May 15, 2012 at 09:33:32PM -0500, Robert Lee wrote:
>> The imx5 idle code that existed in mm-imx5.c is moved to pm-imx5.c.
>> The imx5_pm_init call is now exported and called during the
>> MACHINE_START late_init in supported imx5 platforms.
>>
>> Remove various enabling/disabling of the gpc_dvfs clock and
>> enable it once during initialization.  This is a very low
>> power clock that must be enabled during low power operations.
>>
>> There are only two "suspend_state_t" imx5 low power modes ever
>> used.  STOP_POWER_OFF for suspend to mem and
>> WAIT_UNCLOCKED_POWER_OFF for idle and suspend to standby.  The
>> latter mode only requires 500 nanoseconds of extra hardware
>> exit time beyond a basic WFI operation (WAIT_CLOCKED mode) so
>> no other idle mode is necessary.  Given this information, it
>> is more efficient to keep the registers in the often used
>> WAIT_UNCLOCKED_POWER_OFF state and only to and from the
>> STOP_POWER_OFF register state as needed when suspend to
>> mem is required.
>>
>> Signed-off-by: Robert Lee <rob.lee@linaro.org>
>> ---
>>  arch/arm/mach-imx/mm-imx5.c             |   20 +---------
>>  arch/arm/mach-imx/pm-imx5.c             |   63 ++++++++++++++++++-------------
>>  arch/arm/plat-mxc/include/mach/common.h |    3 +-
>>  3 files changed, 40 insertions(+), 46 deletions(-)
>>
>> diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
>> index d6b7e9f..bb38747 100644
>> --- a/arch/arm/mach-imx/mm-imx5.c
>> +++ b/arch/arm/mach-imx/mm-imx5.c
>> @@ -15,7 +15,6 @@
>>  #include <linux/init.h>
>>  #include <linux/clk.h>
>>
>> -#include <asm/system_misc.h>
>>  #include <asm/mach/map.h>
>>
>>  #include <mach/hardware.h>
>> @@ -23,23 +22,6 @@
>>  #include <mach/devices-common.h>
>>  #include <mach/iomux-v3.h>
>>
>> -static struct clk *gpc_dvfs_clk;
>> -
>> -static void imx5_idle(void)
>> -{
>> -     /* gpc clock is needed for SRPG */
>> -     if (gpc_dvfs_clk == NULL) {
>> -             gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
>> -             if (IS_ERR(gpc_dvfs_clk))
>> -                     return;
>> -     }
>> -     clk_enable(gpc_dvfs_clk);
>> -     mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
>> -     if (!tzic_enable_wake())
>> -             cpu_do_idle();
>> -     clk_disable(gpc_dvfs_clk);
>> -}
>> -
>>  /*
>>   * Define the MX50 memory map.
>>   */
>> @@ -103,7 +85,6 @@ void __init imx51_init_early(void)
>>       mxc_set_cpu_type(MXC_CPU_MX51);
>>       mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));
>>       mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
>> -     arm_pm_idle = imx5_idle;
>>  }
>>
>>  void __init imx53_init_early(void)
>> @@ -238,4 +219,5 @@ void __init imx53_soc_init(void)
>>  void __init imx51_init_late(void)
>>  {
>>       mx51_neon_fixup();
>> +     imx5_pm_init();
>>  }
>> diff --git a/arch/arm/mach-imx/pm-imx5.c b/arch/arm/mach-imx/pm-imx5.c
>> index e26a9cb..6e62d79 100644
>> --- a/arch/arm/mach-imx/pm-imx5.c
>> +++ b/arch/arm/mach-imx/pm-imx5.c
>> @@ -13,18 +13,27 @@
>>  #include <linux/io.h>
>>  #include <linux/err.h>
>>  #include <asm/cacheflush.h>
>> +#include <asm/system_misc.h>
>>  #include <asm/tlbflush.h>
>>  #include <mach/common.h>
>>  #include <mach/hardware.h>
>>  #include "crm-regs-imx5.h"
>>
>> -static struct clk *gpc_dvfs_clk;
>> +/*
>> + * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
>> + * This is also the lowest power state possible without affecting
>> + * non-cpu parts of the system.  For these reasons, imx5 should default
>> + * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
>> + * uses this state and needs to take no action when registers remain confgiured
>> + * for this state.
>> + */
>> +#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
>>
>>  /*
>>   * set cpu low power mode before WFI instruction. This function is called
>>   * mx5 because it can be used for mx50, mx51, and mx53.
>>   */
>> -void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>> +static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>>  {
>>       u32 plat_lpc, arm_srpgcr, ccm_clpcr;
>>       u32 empgc0, empgc1;
>> @@ -87,11 +96,6 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>>       }
>>  }
>>
>> -static int mx5_suspend_prepare(void)
>> -{
>> -     return clk_prepare_enable(gpc_dvfs_clk);
>> -}
>> -
>>  static int mx5_suspend_enter(suspend_state_t state)
>>  {
>>       switch (state) {
>> @@ -99,7 +103,7 @@ static int mx5_suspend_enter(suspend_state_t state)
>>               mx5_cpu_lp_set(STOP_POWER_OFF);
>>               break;
>>       case PM_SUSPEND_STANDBY:
>> -             mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
>> +             /* DEFAULT_IDLE_STATE already configured */
>>               break;
>>       default:
>>               return -EINVAL;
>> @@ -114,12 +118,10 @@ static int mx5_suspend_enter(suspend_state_t state)
>>               __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
>>       }
>>       cpu_do_idle();
>> -     return 0;
>> -}
>>
>> -static void mx5_suspend_finish(void)
>> -{
>> -     clk_disable_unprepare(gpc_dvfs_clk);
>> +     /* return registers to default idle state */
>> +     mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
>> +     return 0;
>>  }
>>
>>  static int mx5_pm_valid(suspend_state_t state)
>> @@ -129,25 +131,34 @@ static int mx5_pm_valid(suspend_state_t state)
>>
>>  static const struct platform_suspend_ops mx5_suspend_ops = {
>>       .valid = mx5_pm_valid,
>> -     .prepare = mx5_suspend_prepare,
>>       .enter = mx5_suspend_enter,
>> -     .finish = mx5_suspend_finish,
>>  };
>>
>> -static int __init mx5_pm_init(void)
>> +static void imx5_pm_idle(void)
>> +{
>> +     if (likely(!tzic_enable_wake()))
>> +             cpu_do_idle();
>> +}
>> +
>> +int __init imx5_pm_init(void)
>>  {
>> -     if (!cpu_is_mx51() && !cpu_is_mx53())
>> -             return 0;
>> +     int ret;
>> +     struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
>> +
>> +     if (IS_ERR(gpc_dvfs_clk))
>> +             return (int)gpc_dvfs_clk;
>
> PTR_ERR please
>

Thanks.  Will fix in v5.

>> +
>> +     ret = clk_enable(gpc_dvfs_clk);
>
> clk_prepare_enable
>

Thanks.  Will fix in v5.

>> +     if (ret)
>> +             return ret;
>> +
>> +     if (cpu_is_mx51())
>> +             suspend_set_ops(&mx5_suspend_ops);
>
> Now this is called only in i.MX51 context, so you can skip the cpu_is
>

After this patch series this is also called in i.MX53 context.  I'm
not confident about the i.MX53 suspend/resume and would prefer to
perform further testing and address issues with it in a separate patch
series.

>>
>> -     if (gpc_dvfs_clk == NULL)
>> -             gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
>> +     arm_pm_idle = imx5_pm_idle;
>>
>> -     if (!IS_ERR(gpc_dvfs_clk)) {
>> -             if (cpu_is_mx51())
>> -                     suspend_set_ops(&mx5_suspend_ops);
>> -     } else
>> -             return -EPERM;
>> +     /* Set the registers to the default cpu idle state. */
>> +     mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
>>
>>       return 0;
>>  }
>> -device_initcall(mx5_pm_init);
>> diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
>> index cf663d8..5660e1e 100644
>> --- a/arch/arm/plat-mxc/include/mach/common.h
>> +++ b/arch/arm/plat-mxc/include/mach/common.h
>> @@ -95,7 +95,6 @@ enum mx3_cpu_pwr_mode {
>>  };
>>
>>  extern void mx3_cpu_lp_set(enum mx3_cpu_pwr_mode mode);
>> -extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode);
>>  extern void imx_print_silicon_rev(const char *cpu, int srev);
>>
>>  void avic_handle_irq(struct pt_regs *);
>> @@ -146,8 +145,10 @@ extern void imx6q_clock_map_io(void);
>>
>>  #ifdef CONFIG_PM
>>  extern void imx6q_pm_init(void);
>> +extern int imx5_pm_init(void);
>>  #else
>>  static inline void imx6q_pm_init(void) {}
>> +static inline int imx5_pm_init(void) { return -ENODEV; }
>
> Why not make it return void like imx6? We do not check the return value
> anyway.

Will change in v5.

Thanks,
Rob

>
> Sascha
>
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v4 4/7] ARM: imx: Enable imx53 low power idle

[Rob Lee]

On Wed, May 16, 2012 at 12:47 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Tue, May 15, 2012 at 09:33:33PM -0500, Robert Lee wrote:
>> Add various functionality needed to enable a imx53 low power idle
>> state.  This includes adding the imx53 gpc_dvfs clock and making a
>> common imx5_late_init function and initializing all imx53
>>  MACHINE_STATE late_init calls to imx5_late_init.
>>
>> Signed-off-by: Robert Lee <rob.lee@linaro.org>
>> ---
>>  arch/arm/mach-imx/clock-mx51-mx53.c     |    1 +
>>  arch/arm/mach-imx/imx53-dt.c            |    1 +
>>  arch/arm/mach-imx/mach-mx53_ard.c       |    1 +
>>  arch/arm/mach-imx/mach-mx53_evk.c       |    1 +
>>  arch/arm/mach-imx/mach-mx53_loco.c      |    1 +
>>  arch/arm/mach-imx/mach-mx53_smd.c       |    1 +
>>  arch/arm/mach-imx/mm-imx5.c             |    7 ++++++-
>>  arch/arm/plat-mxc/include/mach/common.h |    1 +
>>  8 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-imx/clock-mx51-mx53.c b/arch/arm/mach-imx/clock-mx51-mx53.c
>> index 0847050..decedc6 100644
>> --- a/arch/arm/mach-imx/clock-mx51-mx53.c
>> +++ b/arch/arm/mach-imx/clock-mx51-mx53.c
>> @@ -1529,6 +1529,7 @@ static struct clk_lookup mx53_lookups[] = {
>>       _REGISTER_CLOCK("imx-ssi.1", NULL, ssi2_clk)
>>       _REGISTER_CLOCK("imx-ssi.2", NULL, ssi3_clk)
>>       _REGISTER_CLOCK("imx-keypad", NULL, dummy_clk)
>> +     _REGISTER_CLOCK(NULL, "gpc_dvfs", gpc_dvfs_clk)
>
> This has to be rebased against the common clock patches.
>

Ok.

>>       .timer = &mx53_smd_timer,
>>       .init_machine = mx53_smd_board_init,
>> +     .init_late      = imx5_init_late,
>>       .restart        = mxc_restart,
>>  MACHINE_END
>> diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
>> index bb38747..7740739 100644
>> --- a/arch/arm/mach-imx/mm-imx5.c
>> +++ b/arch/arm/mach-imx/mm-imx5.c
>> @@ -216,8 +216,13 @@ void __init imx53_soc_init(void)
>>                                       ARRAY_SIZE(imx53_audmux_res));
>>  }
>>
>> +void __init imx5_init_late(void)
>> +{
>> +     imx5_pm_init();
>> +}
>> +
>>  void __init imx51_init_late(void)
>>  {
>>       mx51_neon_fixup();
>> -     imx5_pm_init();
>> +     imx5_init_late();
>>  }
>
> Where would you add i.MX53 specific code above? Hint: imx5_init_late is
> the wrong function name.

I added imx5_init_late for late_init functionality that is common
among all imx5.  For example, in the future imx50 may use it as well.
But I can remove this and repeat the imx5_pm_init() calls for each
platform if you prefer that.

Thanks,
Rob

>
> Sascha
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v4 5/7] ARM: imx: Add common imx cpuidle init functionality.

[Rob Lee]

On Wed, May 16, 2012 at 12:55 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Tue, May 15, 2012 at 09:33:34PM -0500, Robert Lee wrote:
>> Add common cpuidle init functionality that can be used by various
>> imx platforms.
>>
>> Signed-off-by: Robert Lee <rob.lee@linaro.org>
>> ---
>> +
>> +#ifdef CONFIG_CPU_IDLE
>> +extern int imx_cpuidle_init(struct cpuidle_driver *drv);
>> +#else
>> +static inline int imx_cpuidle_init(struct cpuidle_driver *drv)
>> +{
>> +     return -ENODEV;
>> +}
>> +#endif
>
> You should return succesfully here. Think about it, if imx_cpuidle_init
> fails you basically do nothing except maybe printing an error message
> which will be irritating when it appears on a kernel with cpuidle
> disabled.

Oops, yeah, I missed that.  Will fix in v5.

Thanks,
Rob

>
> Sascha
>
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v4 4/7] ARM: imx: Enable imx53 low power idle

[Sascha Hauer]

On Thu, May 17, 2012 at 09:46:21AM -0500, Rob Lee wrote:
> On Wed, May 16, 2012 at 12:47 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> >>
> >> +void __init imx5_init_late(void)
> >> +{
> >> +     imx5_pm_init();
> >> +}
> >> +
> >>  void __init imx51_init_late(void)
> >>  {
> >>       mx51_neon_fixup();
> >> -     imx5_pm_init();
> >> +     imx5_init_late();
> >>  }
> >
> > Where would you add i.MX53 specific code above? Hint: imx5_init_late is
> > the wrong function name.
> 
> I added imx5_init_late for late_init functionality that is common
> among all imx5.  For example, in the future imx50 may use it as well.
> But I can remove this and repeat the imx5_pm_init() calls for each
> platform if you prefer that.

The point is that the init_late callback should have a imx53_* name,
otherwise if you call it imx5_* there is no place to add imx53 only
functionality. You can always call imx5 specific things from imx53
context, but not the other way round.

Sascha


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Re: [PATCH v4 3/7] ARM: imx: clean and consolidate imx5 suspend and idle code

[Sascha Hauer]

On Thu, May 17, 2012 at 09:34:26AM -0500, Rob Lee wrote:
> On Wed, May 16, 2012 at 12:38 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > Hi Robert,
> >
> > Overall this looks ok now, some comments inline.
> >
> >> +             return ret;
> >> +
> >> +     if (cpu_is_mx51())
> >> +             suspend_set_ops(&mx5_suspend_ops);
> >
> > Now this is called only in i.MX51 context, so you can skip the cpu_is
> >
> 
> After this patch series this is also called in i.MX53 context.  I'm
> not confident about the i.MX53 suspend/resume and would prefer to
> perform further testing and address issues with it in a separate patch
> series.

In this case there is also the possibility that you add a imx51_pm_init
in which you set the suspend_ops and call imx5_pm_init afterwards. The
cpu_is_macros a kind of deprecated. Instead we settled on calling
functions with the exact SoC name from the (dt-) board files and call
the more generic function from the SoC specific ones.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |