subject:"\[PATCH\] cpufreq\: OMAP\: specify range for voltage scaling"

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-03-02 Thread Tero Kristo

On Thu, 2012-03-01 at 14:07 -0800, Kevin Hilman wrote:
 +Tero
 
 Kevin Hilman khil...@ti.com writes:
 
  Afzal Mohammed af...@ti.com writes:
 
  Specify voltage in ranges for regulator. Range
  used is tolerance specified for OPP.
 
  This helps to achieve DVFS with a wider range of
  regulators.
 
  Cc: Kevin Hilman khil...@ti.com
  Cc: Sekhar Nori nsek...@ti.com
  Signed-off-by: Afzal Mohammed af...@ti.com
 
  Thanks, will queue this with the CPUfreq changes for MPU DVFS.
 
 Actually, not quite yet...
 
 After some testing with the SMPS regulators, this won't quite work with
 the current SMPS regulators.  Does this actually work with the
 regulators you're using?
 
 For OMAPs using VC/VP for voltage scaling, the TWL regulator passes on
 the voltage requested directly to the voltage layer.  When using voltage
 - tolerance, this results in voltages that the voltage layer doesn't
 know about because they do not match any of the voltages from the known
 OPPs.
 
 The problem that we have is that while the regulators can support a
 broad range of voltages (from min to max with a some step), the on-chip
 voltage domains cannot, which is why we have defined the OPPs which are
 known to work.
 
 Tero, for the SMPS regulators, would it be possible to configure the
 regulators so that only a discrete set voltages are availble to pick
 from?  These should be initialied from the OPP layer.

I guess this would be possible. Looking at this patch, I guess what we
want to do is that we just use the current API we have at the SMPS
regulator layer to pass the min_uV as target_uV for the regulator, and
just get the next opp voltage that is = than the target_uV.

Here is an inline patch that does this (also attached), this applies on
top of my SMPS regulator changes:

diff --git a/arch/arm/mach-omap2/twl-common.c
b/arch/arm/mach-omap2/twl-common.c
index f19793e..7dc891f 100644
--- a/arch/arm/mach-omap2/twl-common.c
+++ b/arch/arm/mach-omap2/twl-common.c
@@ -41,7 +41,16 @@ static struct i2c_board_info __initdata
pmic_i2c_board_info = {
 static int twl_set_voltage(void *data, int target_uV)
 {
struct voltagedomain *voltdm = (struct voltagedomain *)data;
-   return voltdm_scale(voltdm, target_uV);
+   struct omap_volt_data *volt_data = voltdm-volt_data;
+   
+   while (1) {
+   if (!volt_data-volt_nominal)
+   return -EINVAL;
+   if (volt_data-volt_nominal = target_uV)
+   break;
+   volt_data++;
+   }
+   return voltdm_scale(voltdm, volt_data-volt_nominal);
 }
 
 static int twl_get_voltage(void *data)


Do you want a new version of the whole set or just this as a separate
one?

-Tero

 
 Somehow we need to support something like $SUBJECT patch in order to
 support a broad range of regulators.   The OMAP voltagedomain
 limitations need to configured in platform specific way such that the
 CPUfreq driver can remain generic.
 
 Kevin
 

From 8b4c16fdfee63a414ebee52e674b6d9fbc16e7c9 Mon Sep 17 00:00:00 2001
From: Tero Kristo t-kri...@ti.com
Date: Fri, 2 Mar 2012 12:14:57 +0200
Subject: [PATCH] ARM: OMAP3+: smps regulator: match target_uV against OPP definitions

Scans through the nominal voltage for OPPs until a voltage is found
that is greater than equal to the one requested. This allows the
target_uV to have some error margin in it, and we will always scale
to the next closest OPP voltage.

Signed-off-by: Tero Kristo t-kri...@ti.com
---
 arch/arm/mach-omap2/twl-common.c |   11 ++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/twl-common.c b/arch/arm/mach-omap2/twl-common.c
index f19793e..7dc891f 100644
--- a/arch/arm/mach-omap2/twl-common.c
+++ b/arch/arm/mach-omap2/twl-common.c
@@ -41,7 +41,16 @@ static struct i2c_board_info __initdata pmic_i2c_board_info = {
 static int twl_set_voltage(void *data, int target_uV)
 {
 	struct voltagedomain *voltdm = (struct voltagedomain *)data;
-	return voltdm_scale(voltdm, target_uV);
+	struct omap_volt_data *volt_data = voltdm-volt_data;
+	
+	while (1) {
+		if (!volt_data-volt_nominal)
+			return -EINVAL;
+		if (volt_data-volt_nominal = target_uV)
+			break;
+		volt_data++;
+	}
+	return voltdm_scale(voltdm, volt_data-volt_nominal);
 }
 
 static int twl_get_voltage(void *data)
-- 
1.7.4.1

RE: [PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-03-02 Thread Mohammed, Afzal

Hi Kevin,

On Fri, Mar 02, 2012 at 03:37:51, Hilman, Kevin wrote:
  Thanks, will queue this with the CPUfreq changes for MPU DVFS.
 
 Actually, not quite yet...
 
 After some testing with the SMPS regulators, this won't quite work with
 the current SMPS regulators.  Does this actually work with the
 regulators you're using?

Yes, it works on AM335X (doesn't have VC/VP) using TPS65910, it always
sets voltage to lowest step possible within minus OPP tolerance range.

Regards
Afzal
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-03-02 Thread Kevin Hilman

+Nishanth

Tero Kristo t-kri...@ti.com writes:

 On Thu, 2012-03-01 at 14:07 -0800, Kevin Hilman wrote:
 +Tero
 
 Kevin Hilman khil...@ti.com writes:
 
  Afzal Mohammed af...@ti.com writes:
 
  Specify voltage in ranges for regulator. Range
  used is tolerance specified for OPP.
 
  This helps to achieve DVFS with a wider range of
  regulators.
 
  Cc: Kevin Hilman khil...@ti.com
  Cc: Sekhar Nori nsek...@ti.com
  Signed-off-by: Afzal Mohammed af...@ti.com
 
  Thanks, will queue this with the CPUfreq changes for MPU DVFS.
 
 Actually, not quite yet...
 
 After some testing with the SMPS regulators, this won't quite work with
 the current SMPS regulators.  Does this actually work with the
 regulators you're using?
 
 For OMAPs using VC/VP for voltage scaling, the TWL regulator passes on
 the voltage requested directly to the voltage layer.  When using voltage
 - tolerance, this results in voltages that the voltage layer doesn't
 know about because they do not match any of the voltages from the known
 OPPs.
 
 The problem that we have is that while the regulators can support a
 broad range of voltages (from min to max with a some step), the on-chip
 voltage domains cannot, which is why we have defined the OPPs which are
 known to work.
 
 Tero, for the SMPS regulators, would it be possible to configure the
 regulators so that only a discrete set voltages are availble to pick
 from?  These should be initialied from the OPP layer.

 I guess this would be possible. Looking at this patch, I guess what we
 want to do is that we just use the current API we have at the SMPS
 regulator layer to pass the min_uV as target_uV for the regulator, and
 just get the next opp voltage that is = than the target_uV.

Yeah, this should work.

However, after discussing this on IRC with Nishanth, instead of enforcing
this in the TWL glue layer, I think we need to enforce using OPP
voltages in the voltage layer itself.  Patch below[1].

I've now added that patch to my for_3.4/pm/smps-regulator branch (and
will post to the list shortly.)

I've also added $SUBJECT patch (back) to my for_3.4/cpufreq branch. 

I'd appreciate some testing of these two branches together.  With those
two, I've tested MPU DVFS on 3530/Overo, 3630/Zoom3 and 4430/Panda, but
would appreciate any additional testing.

Kevin


From 212024af641266c3de8b55764f84d923f238315c Mon Sep 17 00:00:00 2001
From: Kevin Hilman khil...@ti.com
Date: Fri, 2 Mar 2012 14:08:57 -0800
Subject: [PATCH] ARM: OMAP2+: voltage: ensure voltage used is exact voltage
 from OPP table

When using the SMPS regulators to scale voltages, the regulator
framework may pass a minimum voltage that is not an exact OPP voltage.
For the VC/VP controlled voltage domains, we must ensure that the
voltage requested is the exact voltage from the OPP table.  This is
especially critical when using SR.

To fix, voltdm_scale() uses the target voltage passed to walk through
the OPP voltages until it finds a voltage that is = one of the OPP
voltages.

Cc: Tero Kristo t-kri...@ti.com
Cc: Nishanth Menon n...@ti.com
Signed-off-by: Kevin Hilman khil...@ti.com
---
 arch/arm/mach-omap2/voltage.c |   21 ++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
index 8a36342..4dc60e8 100644
--- a/arch/arm/mach-omap2/voltage.c
+++ b/arch/arm/mach-omap2/voltage.c
@@ -73,7 +73,8 @@ unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
 int voltdm_scale(struct voltagedomain *voltdm,
 unsigned long target_volt)
 {
-   int ret;
+   int ret, i;
+   unsigned long volt = 0;
 
if (!voltdm || IS_ERR(voltdm)) {
pr_warning(%s: VDD specified does not exist!\n, __func__);
@@ -86,9 +87,23 @@ int voltdm_scale(struct voltagedomain *voltdm,
return -ENODATA;
}
 
-   ret = voltdm-scale(voltdm, target_volt);
+   /* Adjust voltage to the exact voltage from the OPP table */
+   for (i = 0; voltdm-volt_data[i].volt_nominal != 0; i++) {
+   if (voltdm-volt_data[i].volt_nominal = target_volt) {
+   volt = voltdm-volt_data[i].volt_nominal;
+   break;
+   }
+   }
+
+   if (!volt) {
+   pr_warning(%s: not scaling. OPP voltage for %lu, not found.\n,
+  __func__, target_volt);
+   return -EINVAL;
+   }
+
+   ret = voltdm-scale(voltdm, volt);
if (!ret)
-   voltdm-nominal_volt = target_volt;
+   voltdm-nominal_volt = volt;
 
return ret;
 }
-- 
1.7.9.2

--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-03-01 Thread Kevin Hilman

Afzal Mohammed af...@ti.com writes:

 Specify voltage in ranges for regulator. Range
 used is tolerance specified for OPP.

 This helps to achieve DVFS with a wider range of
 regulators.

 Cc: Kevin Hilman khil...@ti.com
 Cc: Sekhar Nori nsek...@ti.com
 Signed-off-by: Afzal Mohammed af...@ti.com

Thanks, will queue this with the CPUfreq changes for MPU DVFS.

Kevin

 ---
 Hi,

 Tolerance specified here is that of AM335X, least value
 of tolerance that I could find so far for OMAP family

 This applies on top of Kevin Hilman's patch (v2),
 cpufreq: OMAP: scale voltage along with frequency
 http://www.spinics.net/lists/linux-omap/msg65002.html

 Regards
 Afzal

  drivers/cpufreq/omap-cpufreq.c |   10 +++---
  1 files changed, 7 insertions(+), 3 deletions(-)

 diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
 index 10b8e23..3cea51b 100644
 --- a/drivers/cpufreq/omap-cpufreq.c
 +++ b/drivers/cpufreq/omap-cpufreq.c
 @@ -38,6 +38,9 @@
  
  #include mach/hardware.h
  
 +/* OPP tolerance in percentage */
 +#define  OPP_TOLERANCE   4
 +
  #ifdef CONFIG_SMP
  struct lpj_info {
   unsigned long   ref;
 @@ -81,7 +84,7 @@ static int omap_target(struct cpufreq_policy *policy,
   int r, ret = 0;
   struct cpufreq_freqs freqs;
   struct opp *opp;
 - unsigned long freq, volt = 0, volt_old = 0;
 + unsigned long freq, volt = 0, volt_old = 0, tol = 0;
  
   if (!freq_table) {
   dev_err(mpu_dev, %s: cpu%d: no freq table!\n, __func__,
 @@ -125,6 +128,7 @@ static int omap_target(struct cpufreq_policy *policy,
   return -EINVAL;
   }
   volt = opp_get_voltage(opp);
 + tol = volt * OPP_TOLERANCE / 100;
   volt_old = regulator_get_voltage(mpu_reg);
   }
  
 @@ -134,7 +138,7 @@ static int omap_target(struct cpufreq_policy *policy,
  
   /* scaling up?  scale voltage before frequency */
   if (mpu_reg  (freqs.new  freqs.old)) {
 - r = regulator_set_voltage(mpu_reg, volt, volt);
 + r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
   if (r  0) {
   dev_warn(mpu_dev, %s: unable to scale voltage up.\n,
__func__);
 @@ -147,7 +151,7 @@ static int omap_target(struct cpufreq_policy *policy,
  
   /* scaling down?  scale voltage after frequency */
   if (mpu_reg  (freqs.new  freqs.old)) {
 - r = regulator_set_voltage(mpu_reg, volt, volt);
 + r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
   if (r  0) {
   dev_warn(mpu_dev, %s: unable to scale voltage down.\n,
__func__);
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-03-01 Thread Kevin Hilman

+Tero

Kevin Hilman khil...@ti.com writes:

 Afzal Mohammed af...@ti.com writes:

 Specify voltage in ranges for regulator. Range
 used is tolerance specified for OPP.

 This helps to achieve DVFS with a wider range of
 regulators.

 Cc: Kevin Hilman khil...@ti.com
 Cc: Sekhar Nori nsek...@ti.com
 Signed-off-by: Afzal Mohammed af...@ti.com

 Thanks, will queue this with the CPUfreq changes for MPU DVFS.

Actually, not quite yet...

After some testing with the SMPS regulators, this won't quite work with
the current SMPS regulators.  Does this actually work with the
regulators you're using?

For OMAPs using VC/VP for voltage scaling, the TWL regulator passes on
the voltage requested directly to the voltage layer.  When using voltage
- tolerance, this results in voltages that the voltage layer doesn't
know about because they do not match any of the voltages from the known
OPPs.

The problem that we have is that while the regulators can support a
broad range of voltages (from min to max with a some step), the on-chip
voltage domains cannot, which is why we have defined the OPPs which are
known to work.

Tero, for the SMPS regulators, would it be possible to configure the
regulators so that only a discrete set voltages are availble to pick
from?  These should be initialied from the OPP layer.

Somehow we need to support something like $SUBJECT patch in order to
support a broad range of regulators.   The OMAP voltagedomain
limitations need to configured in platform specific way such that the
CPUfreq driver can remain generic.

Kevin

--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH] cpufreq: OMAP: specify range for voltage scaling

2012-02-23 Thread Afzal Mohammed

Specify voltage in ranges for regulator. Range
used is tolerance specified for OPP.

This helps to achieve DVFS with a wider range of
regulators.

Cc: Kevin Hilman khil...@ti.com
Cc: Sekhar Nori nsek...@ti.com
Signed-off-by: Afzal Mohammed af...@ti.com
---
Hi,

Tolerance specified here is that of AM335X, least value
of tolerance that I could find so far for OMAP family

This applies on top of Kevin Hilman's patch (v2),
cpufreq: OMAP: scale voltage along with frequency
http://www.spinics.net/lists/linux-omap/msg65002.html

Regards
Afzal

 drivers/cpufreq/omap-cpufreq.c |   10 +++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 10b8e23..3cea51b 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -38,6 +38,9 @@
 
 #include mach/hardware.h
 
+/* OPP tolerance in percentage */
+#defineOPP_TOLERANCE   4
+
 #ifdef CONFIG_SMP
 struct lpj_info {
unsigned long   ref;
@@ -81,7 +84,7 @@ static int omap_target(struct cpufreq_policy *policy,
int r, ret = 0;
struct cpufreq_freqs freqs;
struct opp *opp;
-   unsigned long freq, volt = 0, volt_old = 0;
+   unsigned long freq, volt = 0, volt_old = 0, tol = 0;
 
if (!freq_table) {
dev_err(mpu_dev, %s: cpu%d: no freq table!\n, __func__,
@@ -125,6 +128,7 @@ static int omap_target(struct cpufreq_policy *policy,
return -EINVAL;
}
volt = opp_get_voltage(opp);
+   tol = volt * OPP_TOLERANCE / 100;
volt_old = regulator_get_voltage(mpu_reg);
}
 
@@ -134,7 +138,7 @@ static int omap_target(struct cpufreq_policy *policy,
 
/* scaling up?  scale voltage before frequency */
if (mpu_reg  (freqs.new  freqs.old)) {
-   r = regulator_set_voltage(mpu_reg, volt, volt);
+   r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
if (r  0) {
dev_warn(mpu_dev, %s: unable to scale voltage up.\n,
 __func__);
@@ -147,7 +151,7 @@ static int omap_target(struct cpufreq_policy *policy,
 
/* scaling down?  scale voltage after frequency */
if (mpu_reg  (freqs.new  freqs.old)) {
-   r = regulator_set_voltage(mpu_reg, volt, volt);
+   r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
if (r  0) {
dev_warn(mpu_dev, %s: unable to scale voltage down.\n,
 __func__);
-- 
1.7.1

--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

RE: [PATCH] cpufreq: OMAP: specify range for voltage scaling

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

Re: [PATCH] cpufreq: OMAP: specify range for voltage scaling

[PATCH] cpufreq: OMAP: specify range for voltage scaling

6 matches

Site Navigation

Mail list logo

Footer information