diff mbox

[v2,06/18] ARM: OMAP5: PM: Enable Mercury retention mode on CPUx powerdomains

Message ID 1364205910-32392-7-git-send-email-santosh.shilimkar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar March 25, 2013, 10:04 a.m. UTC
In addition to the standard power-management technique, the OMAP5
MPU subsystem also employs an SR3-APG (mercury) power management
technology to reduce leakage.

It allows for full logic and memories retention on MPU_C0 and MPU_C1 and
is controlled by the PRCM_MPU.

Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
 arch/arm/mach-omap2/omap-mpuss-lowpower.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

Comments

Kevin Hilman April 3, 2013, 8:31 p.m. UTC | #1
Santosh Shilimkar <santosh.shilimkar@ti.com> writes:

> In addition to the standard power-management technique, the OMAP5
> MPU subsystem also employs an SR3-APG (mercury) power management
> technology to reduce leakage.
>
> It allows for full logic and memories retention on MPU_C0 and MPU_C1 and
> is controlled by the PRCM_MPU.
>
> Acked-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> ---
>  arch/arm/mach-omap2/omap-mpuss-lowpower.c |   27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
> index b1441b1..d390d18 100644
> --- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
> +++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
> @@ -62,6 +62,10 @@
>  #include "prm44xx.h"
>  #include "prm-regbits-44xx.h"
>  
> +/* Add defines needed for mercury mode. Refer MPU's PRM_PSCON_COUNT */
> +#define PRM_PSCON_HG_EN		(1 << 24)
> +#define PRM_PSCON_HG_RAMPUP	(1 << 25)

nit: use BIT()

>  #ifdef CONFIG_SMP
>  
>  struct omap4_cpu_pm_info {
> @@ -337,6 +341,28 @@ int __cpuinit omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
>  	return 0;
>  }
>  
> +/**
> + * enable_mercury_retention_mode: Enable OMAP5 mercury retention feature
> + *
> + * OMAP5 devices supports  SR3-APG (mercury) power management technology to
> + * reduce leakage. It allows for full logic and memories retention on
> + * MPU_C0 and MPU_C1 and is controlled by the PRCM_MPU. The function enable
> + * the mercury retention feature.
> + */
> +static void enable_mercury_retention_mode(void)

__init ?

This is very OMAP5 specific (unless you generalize the offsets used) so
should this have omap5_ prefix?

Kevin

> +{
> +	u32 reg;
> +
> +	/*
> +	 * To enable mercury mode, both HG_EN and HG_RAMPUP needs to be
> +	 * enabled from PRM_PSCON_COUNT register.
> +	 */
> +	reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST,
> +			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
> +	reg |= PRM_PSCON_HG_EN | PRM_PSCON_HG_RAMPUP;
> +	omap4_prcm_mpu_write_inst_reg(reg, OMAP54XX_PRCM_MPU_DEVICE_INST,
> +			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);

nit: when I see 'reg', I expect it to be a register/offset.  But this is
a register value.  Maybe use 'val' instead as you've done elsewhere in
this series.

Kevin

> +}
>  
>  /*
>   * Initialise OMAP4 MPUSS
> @@ -415,6 +441,7 @@ int __init omap4_mpuss_init(void)
>  		cpu_context_offset = OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET;
>  	} else if (soc_is_omap54xx()) {
>  		cpu_context_offset = OMAP54XX_RM_CPU0_CPU0_CONTEXT_OFFSET;
> +		enable_mercury_retention_mode();
>  	}
>  
>  	return 0;
Santosh Shilimkar April 4, 2013, 12:08 p.m. UTC | #2
On Thursday 04 April 2013 02:01 AM, Kevin Hilman wrote:
> Santosh Shilimkar <santosh.shilimkar@ti.com> writes:
> 
>> In addition to the standard power-management technique, the OMAP5
>> MPU subsystem also employs an SR3-APG (mercury) power management
>> technology to reduce leakage.
>>
>> It allows for full logic and memories retention on MPU_C0 and MPU_C1 and
>> is controlled by the PRCM_MPU.
>>
>> Acked-by: Nishanth Menon <nm@ti.com>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> ---
>>  arch/arm/mach-omap2/omap-mpuss-lowpower.c |   27 +++++++++++++++++++++++++++
>>  1 file changed, 27 insertions(+)
>>
>> diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> index b1441b1..d390d18 100644
>> --- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> +++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
>> @@ -62,6 +62,10 @@
>>  #include "prm44xx.h"
>>  #include "prm-regbits-44xx.h"
>>  
>> +/* Add defines needed for mercury mode. Refer MPU's PRM_PSCON_COUNT */
>> +#define PRM_PSCON_HG_EN		(1 << 24)
>> +#define PRM_PSCON_HG_RAMPUP	(1 << 25)
> 
> nit: use BIT()
> 
ok

>>  #ifdef CONFIG_SMP
>>  
>>  struct omap4_cpu_pm_info {
>> @@ -337,6 +341,28 @@ int __cpuinit omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
>>  	return 0;
>>  }
>>  
>> +/**
>> + * enable_mercury_retention_mode: Enable OMAP5 mercury retention feature
>> + *
>> + * OMAP5 devices supports  SR3-APG (mercury) power management technology to
>> + * reduce leakage. It allows for full logic and memories retention on
>> + * MPU_C0 and MPU_C1 and is controlled by the PRCM_MPU. The function enable
>> + * the mercury retention feature.
>> + */
>> +static void enable_mercury_retention_mode(void)
> 
> __init ?
> 
yep.

> This is very OMAP5 specific (unless you generalize the offsets used) so
> should this have omap5_ prefix?
> 
Agree.

> 
>> +{
>> +	u32 reg;
>> +
>> +	/*
>> +	 * To enable mercury mode, both HG_EN and HG_RAMPUP needs to be
>> +	 * enabled from PRM_PSCON_COUNT register.
>> +	 */
>> +	reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST,
>> +			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
>> +	reg |= PRM_PSCON_HG_EN | PRM_PSCON_HG_RAMPUP;
>> +	omap4_prcm_mpu_write_inst_reg(reg, OMAP54XX_PRCM_MPU_DEVICE_INST,
>> +			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
> 
> nit: when I see 'reg', I expect it to be a register/offset.  But this is
> a register value.  Maybe use 'val' instead as you've done elsewhere in
> this series.
> 
I generally use 'offset' if it is offset and 'reg' for actual register read.
Anyways, I have changed it to 'val' now.

Regards,
Santosh
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
index b1441b1..d390d18 100644
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -62,6 +62,10 @@ 
 #include "prm44xx.h"
 #include "prm-regbits-44xx.h"
 
+/* Add defines needed for mercury mode. Refer MPU's PRM_PSCON_COUNT */
+#define PRM_PSCON_HG_EN		(1 << 24)
+#define PRM_PSCON_HG_RAMPUP	(1 << 25)
+
 #ifdef CONFIG_SMP
 
 struct omap4_cpu_pm_info {
@@ -337,6 +341,28 @@  int __cpuinit omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
 	return 0;
 }
 
+/**
+ * enable_mercury_retention_mode: Enable OMAP5 mercury retention feature
+ *
+ * OMAP5 devices supports  SR3-APG (mercury) power management technology to
+ * reduce leakage. It allows for full logic and memories retention on
+ * MPU_C0 and MPU_C1 and is controlled by the PRCM_MPU. The function enable
+ * the mercury retention feature.
+ */
+static void enable_mercury_retention_mode(void)
+{
+	u32 reg;
+
+	/*
+	 * To enable mercury mode, both HG_EN and HG_RAMPUP needs to be
+	 * enabled from PRM_PSCON_COUNT register.
+	 */
+	reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST,
+			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
+	reg |= PRM_PSCON_HG_EN | PRM_PSCON_HG_RAMPUP;
+	omap4_prcm_mpu_write_inst_reg(reg, OMAP54XX_PRCM_MPU_DEVICE_INST,
+			OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
+}
 
 /*
  * Initialise OMAP4 MPUSS
@@ -415,6 +441,7 @@  int __init omap4_mpuss_init(void)
 		cpu_context_offset = OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET;
 	} else if (soc_is_omap54xx()) {
 		cpu_context_offset = OMAP54XX_RM_CPU0_CPU0_CONTEXT_OFFSET;
+		enable_mercury_retention_mode();
 	}
 
 	return 0;