[PATCH 0/3] cpufreq: dt: Allow platforms to provide suspend/resume hooks

[PATCH 0/3] cpufreq: dt: Allow platforms to provide suspend/resume hooks

[Viresh Kumar]

Hi Miquel,

This is in response to the patch[1] you sent.

I have updated the cpufreq-dt driver to allow platform specific
suspend/resume hooks and done some minor cleanup in the driver. I have
updated your patch and applied that on top of all this. I haven't tested
any of this and would need your help to get that done.

Thanks.

--
viresh

[1] https://lkml.kernel.org/r/20180421141943.25705-1-miquel.raynal@bootlin.com

Miquel Raynal (1):
  cpufreq: add suspend/resume support in Armada 37xx DVFS driver

Viresh Kumar (2):
  cpufreq: dt: Allow platform specific suspend/resume callbacks
  cpufreq: armada: Free resources on error paths

 drivers/cpufreq/armada-37xx-cpufreq.c | 107 +++++++++++++++++++++++++++++-----
 drivers/cpufreq/cpufreq-dt.c          |  10 +++-
 drivers/cpufreq/cpufreq-dt.h          |   5 ++
 3 files changed, 104 insertions(+), 18 deletions(-)

-- 
2.15.0.194.g9af6a3dea062

[PATCH 2/3] cpufreq: armada: Free resources on error paths

[Viresh Kumar]

The resources weren't freed on failures, free them properly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/armada-37xx-cpufreq.c | 40 +++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
index 72a2975499db..9dafb3bbc334 100644
--- a/drivers/cpufreq/armada-37xx-cpufreq.c
+++ b/drivers/cpufreq/armada-37xx-cpufreq.c
@@ -166,6 +166,7 @@ static int __init armada37xx_cpufreq_driver_init(void)
 {
 	struct armada_37xx_dvfs *dvfs;
 	struct platform_device *pdev;
+	unsigned long freq;
 	unsigned int cur_frequency;
 	struct regmap *nb_pm_base;
 	struct device *cpu_dev;
@@ -202,38 +203,49 @@ static int __init armada37xx_cpufreq_driver_init(void)
 	cur_frequency = clk_get_rate(clk);
 	if (!cur_frequency) {
 		dev_err(cpu_dev, "Failed to get clock rate for CPU\n");
-		clk_put(clk);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto put_clk;
 	}
 
 	dvfs = armada_37xx_cpu_freq_info_get(cur_frequency);
-	if (!dvfs)
-		return -EINVAL;
+	if (!dvfs) {
+		ret = -EINVAL;
+		goto put_clk;
+	}
 
 	armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
 	clk_put(clk);
 
 	for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
 	     load_lvl++) {
-		unsigned long freq = cur_frequency / dvfs->divider[load_lvl];
+		freq = cur_frequency / dvfs->divider[load_lvl];
 
 		ret = dev_pm_opp_add(cpu_dev, freq, 0);
-		if (ret) {
-			/* clean-up the already added opp before leaving */
-			while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
-				freq = cur_frequency / dvfs->divider[load_lvl];
-				dev_pm_opp_remove(cpu_dev, freq);
-			}
-			return ret;
-		}
+		if (ret)
+			goto remove_opp;
 	}
 
 	/* Now that everything is setup, enable the DVFS at hardware level */
 	armada37xx_cpufreq_enable_dvfs(nb_pm_base);
 
 	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
+	ret = PTR_ERR_OR_ZERO(pdev);
+	if (ret)
+		goto disable_dvfs;
+
+	return 0;
 
-	return PTR_ERR_OR_ZERO(pdev);
+disable_dvfs:
+	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
+remove_opp:
+	/* clean-up the already added opp before leaving */
+	while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
+		freq = cur_frequency / dvfs->divider[load_lvl];
+		dev_pm_opp_remove(cpu_dev, freq);
+	}
+put_clk:
+	clk_put(clk);
+	return ret;
 }
 /* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
 late_initcall(armada37xx_cpufreq_driver_init);
-- 
2.15.0.194.g9af6a3dea062

[PATCH V2 3/3] cpufreq: add suspend/resume support in Armada 37xx DVFS driver

[Viresh Kumar]

From: Miquel Raynal <miquel.raynal@bootlin.com>

Add suspend/resume hooks in Armada 37xx DVFS driver to handle S2RAM
operations. As there is currently no 'driver' structure, create one
to store both the regmap and the register values during suspend
operation.

A syscore_ops is used to export the suspend/resume hooks.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V1->V2:
- Updated patch based on cpufreq-dt suspend/resume hooks.

 drivers/cpufreq/armada-37xx-cpufreq.c | 67 +++++++++++++++++++++++++++++++++--
 1 file changed, 65 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
index 9dafb3bbc334..c827d2437246 100644
--- a/drivers/cpufreq/armada-37xx-cpufreq.c
+++ b/drivers/cpufreq/armada-37xx-cpufreq.c
@@ -23,6 +23,8 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
+#include "cpufreq-dt.h"
+
 /* Power management in North Bridge register set */
 #define ARMADA_37XX_NB_L0L1	0x18
 #define ARMADA_37XX_NB_L2L3	0x1C
@@ -56,6 +58,16 @@
  */
 #define LOAD_LEVEL_NR	4
 
+struct armada37xx_cpufreq_state {
+	struct regmap *regmap;
+	u32 nb_l0l1;
+	u32 nb_l2l3;
+	u32 nb_dyn_mod;
+	u32 nb_cpu_load;
+};
+
+static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state;
+
 struct armada_37xx_dvfs {
 	u32 cpu_freq_max;
 	u8 divider[LOAD_LEVEL_NR];
@@ -136,7 +148,7 @@ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
 	clk_set_parent(clk, parent);
 }
 
-static void __init armada37xx_cpufreq_disable_dvfs(struct regmap *base)
+static void armada37xx_cpufreq_disable_dvfs(struct regmap *base)
 {
 	unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
 		mask = ARMADA_37XX_NB_DFS_EN;
@@ -162,8 +174,44 @@ static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
 	regmap_update_bits(base, reg, mask, mask);
 }
 
+static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy)
+{
+	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
+
+	regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1);
+	regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3);
+	regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
+		    &state->nb_cpu_load);
+	regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod);
+
+	return 0;
+}
+
+static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy)
+{
+	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
+
+	/* Ensure DVFS is disabled otherwise the following registers are RO */
+	armada37xx_cpufreq_disable_dvfs(state->regmap);
+
+	regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1);
+	regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3);
+	regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
+		     state->nb_cpu_load);
+
+	/*
+	 * NB_DYN_MOD register is the one that actually enable back DVFS if it
+	 * was enabled before the suspend operation. This must be done last
+	 * otherwise other registers are not writable.
+	 */
+	regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod);
+
+	return 0;
+}
+
 static int __init armada37xx_cpufreq_driver_init(void)
 {
+	struct cpufreq_dt_platform_data pdata;
 	struct armada_37xx_dvfs *dvfs;
 	struct platform_device *pdev;
 	unsigned long freq;
@@ -213,6 +261,15 @@ static int __init armada37xx_cpufreq_driver_init(void)
 		goto put_clk;
 	}
 
+	armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state),
+					   GFP_KERNEL);
+	if (!armada37xx_cpufreq_state) {
+		ret = -ENOMEM;
+		goto put_clk;
+	}
+
+	armada37xx_cpufreq_state->regmap = nb_pm_base;
+
 	armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
 	clk_put(clk);
 
@@ -228,7 +285,11 @@ static int __init armada37xx_cpufreq_driver_init(void)
 	/* Now that everything is setup, enable the DVFS at hardware level */
 	armada37xx_cpufreq_enable_dvfs(nb_pm_base);
 
-	pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
+	pdata.suspend = armada37xx_cpufreq_suspend;
+	pdata.resume = armada37xx_cpufreq_resume;
+
+	pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata,
+					     sizeof(pdata));
 	ret = PTR_ERR_OR_ZERO(pdev);
 	if (ret)
 		goto disable_dvfs;
@@ -243,6 +304,8 @@ static int __init armada37xx_cpufreq_driver_init(void)
 		freq = cur_frequency / dvfs->divider[load_lvl];
 		dev_pm_opp_remove(cpu_dev, freq);
 	}
+
+	kfree(armada37xx_cpufreq_state);
 put_clk:
 	clk_put(clk);
 	return ret;
-- 
2.15.0.194.g9af6a3dea062

Re: [PATCH V2 3/3] cpufreq: add suspend/resume support in Armada 37xx DVFS driver

[Miquel Raynal]

Hi Viresh,

On Tue, 24 Apr 2018 11:37:36 +0530, Viresh Kumar
<viresh.kumar@linaro.org> wrote:

> From: Miquel Raynal <miquel.raynal@bootlin.com>
> 
> Add suspend/resume hooks in Armada 37xx DVFS driver to handle S2RAM
> operations. As there is currently no 'driver' structure, create one
> to store both the regmap and the register values during suspend
> operation.
> 
> A syscore_ops is used to export the suspend/resume hooks.

I think you can remove this line too since there is no more syscore_ops.

> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Regards,
Miquèl

-- 
Miquel Raynal, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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linux-arm-kernel mailing list
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Re: [PATCH V2 3/3] cpufreq: add suspend/resume support in Armada 37xx DVFS driver

[Viresh Kumar]

On 24-04-18, 11:10, Miquel Raynal wrote:
> Hi Viresh,
> 
> On Tue, 24 Apr 2018 11:37:36 +0530, Viresh Kumar
> <viresh.kumar@linaro.org> wrote:
> 
> > From: Miquel Raynal <miquel.raynal@bootlin.com>
> > 
> > Add suspend/resume hooks in Armada 37xx DVFS driver to handle S2RAM
> > operations. As there is currently no 'driver' structure, create one
> > to store both the regmap and the register values during suspend
> > operation.
> > 
> > A syscore_ops is used to export the suspend/resume hooks.
> 
> I think you can remove this line too since there is no more syscore_ops.

That was stupid of me.

-- 
viresh

Re: [PATCH 0/3] cpufreq: dt: Allow platforms to provide suspend/resume hooks

[Miquel Raynal]

Hi Viresh,

On Tue, 24 Apr 2018 11:37:33 +0530, Viresh Kumar
<viresh.kumar@linaro.org> wrote:

> Hi Miquel,
> 
> This is in response to the patch[1] you sent.

Thank you very much for taking the time to look into it.

> 
> I have updated the cpufreq-dt driver to allow platform specific
> suspend/resume hooks and done some minor cleanup in the driver. I have
> updated your patch and applied that on top of all this. I haven't tested
> any of this and would need your help to get that done.

I tested on an EspressoBin (Armada 3720), it works.

However, I first had a panic due to the clock being 'put' twice. I
suggest you to merge this [1] into the second patch. With this (or
something similar):

Tested-by: Miquel Raynal <miquel.raynal@bootlin.com>

And the path error was reached because I did not select the cpufreq-dt
driver in menuconfig, which I think should be selected by default when
enabling the armada37xx-cpufreq driver. I wrote a small patch for
that too, see [2]. Tell me if you want me to send it of if you want to
include it in the next version ?

[1] http://code.bulix.org/auzdqa-323646
[2] http://code.bulix.org/e1yk5h-323647

Thank you,
Miquèl


> 
> Thanks.
> 
> --
> viresh
> 
> [1] https://lkml.kernel.org/r/20180421141943.25705-1-miquel.raynal@bootlin.com
> 
> Miquel Raynal (1):
>   cpufreq: add suspend/resume support in Armada 37xx DVFS driver
> 
> Viresh Kumar (2):
>   cpufreq: dt: Allow platform specific suspend/resume callbacks
>   cpufreq: armada: Free resources on error paths
> 
>  drivers/cpufreq/armada-37xx-cpufreq.c | 107 +++++++++++++++++++++++++++++-----
>  drivers/cpufreq/cpufreq-dt.c          |  10 +++-
>  drivers/cpufreq/cpufreq-dt.h          |   5 ++
>  3 files changed, 104 insertions(+), 18 deletions(-)
> 



-- 
Miquel Raynal, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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linux-arm-kernel mailing list
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 0/3] cpufreq: dt: Allow platforms to provide suspend/resume hooks

[Viresh Kumar]

On 24-04-18, 11:08, Miquel Raynal wrote:
> I tested on an EspressoBin (Armada 3720), it works.

Great.

> However, I first had a panic due to the clock being 'put' twice. I
> suggest you to merge this [1] into the second patch. With this (or
> something similar):

NULL is a valid clock. I have fixed it now, a bit differently though.

> Tested-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks.

> And the path error was reached because I did not select the cpufreq-dt
> driver in menuconfig, which I think should be selected by default when
> enabling the armada37xx-cpufreq driver. I wrote a small patch for
> that too, see [2]. Tell me if you want me to send it of if you want to
> include it in the next version ?

Maybe just send that separately (and you don't need to resend any of
the patches which are part of this series).

-- 
viresh