[PATCH 0/3] clk: ux500: Set sdmmc clock to 100MHz

[PATCH 0/3] clk: ux500: Set sdmmc clock to 100MHz

[Ulf Hansson]

From: Ulf Hansson <ulf.hansson@linaro.org>

The reason behind this change is that we would like to enable all
the mmc/sd/sdio features from a hardware perspective (ARM PL18x).
It is then required that the frequency must be 100MHz.

Ulf Hansson (3):
  mfd: dbx500: Export prmcu_request_ape_opp_100_voltage
  clk: ux500: Support prcmu ape opp voltage clock
  clk: ux500: Update sdmmc clock to 100MHz for u8500

 drivers/clk/ux500/clk-prcmu.c    |   55 ++++++++++++++++++++++++++++++++++++++
 drivers/clk/ux500/clk.h          |    6 +++++
 drivers/clk/ux500/u8500_clk.c    |    5 ++--
 drivers/mfd/db8500-prcmu.c       |    4 +--
 include/linux/mfd/db8500-prcmu.h |    4 +--
 include/linux/mfd/dbx500-prcmu.h |   10 +++++++
 6 files changed, 78 insertions(+), 6 deletions(-)

-- 
1.7.10

[PATCH 1/3] mfd: dbx500: Export prmcu_request_ape_opp_100_voltage

[Ulf Hansson]

From: Ulf Hansson <ulf.hansson@linaro.org>

This function needs to be exported to let clients be able to
request the ape opp 100 voltage.

Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/mfd/db8500-prcmu.c       |    4 ++--
 include/linux/mfd/db8500-prcmu.h |    4 ++--
 include/linux/mfd/dbx500-prcmu.h |   10 ++++++++++
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index e7f9539..0b8e0a0 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -1167,12 +1167,12 @@ int db8500_prcmu_get_ape_opp(void)
 }
 
 /**
- * prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
+ * db8500_prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
  * @enable: true to request the higher voltage, false to drop a request.
  *
  * Calls to this function to enable and disable requests must be balanced.
  */
-int prcmu_request_ape_opp_100_voltage(bool enable)
+int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
 {
 	int r = 0;
 	u8 header;
diff --git a/include/linux/mfd/db8500-prcmu.h b/include/linux/mfd/db8500-prcmu.h
index b82f6ee..6ee4247 100644
--- a/include/linux/mfd/db8500-prcmu.h
+++ b/include/linux/mfd/db8500-prcmu.h
@@ -515,7 +515,6 @@ enum romcode_read prcmu_get_rc_p2a(void);
 enum ap_pwrst prcmu_get_xp70_current_state(void);
 bool prcmu_has_arm_maxopp(void);
 struct prcmu_fw_version *prcmu_get_fw_version(void);
-int prcmu_request_ape_opp_100_voltage(bool enable);
 int prcmu_release_usb_wakeup_state(void);
 void prcmu_configure_auto_pm(struct prcmu_auto_pm_config *sleep,
 	struct prcmu_auto_pm_config *idle);
@@ -564,6 +563,7 @@ int db8500_prcmu_set_arm_opp(u8 opp);
 int db8500_prcmu_get_arm_opp(void);
 int db8500_prcmu_set_ape_opp(u8 opp);
 int db8500_prcmu_get_ape_opp(void);
+int db8500_prcmu_request_ape_opp_100_voltage(bool enable);
 int db8500_prcmu_set_ddr_opp(u8 opp);
 int db8500_prcmu_get_ddr_opp(void);
 
@@ -610,7 +610,7 @@ static inline int db8500_prcmu_get_ape_opp(void)
 	return APE_100_OPP;
 }
 
-static inline int prcmu_request_ape_opp_100_voltage(bool enable)
+static inline int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
 {
 	return 0;
 }
diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
index c410d99..c202d6c 100644
--- a/include/linux/mfd/dbx500-prcmu.h
+++ b/include/linux/mfd/dbx500-prcmu.h
@@ -336,6 +336,11 @@ static inline int prcmu_get_ape_opp(void)
 	return db8500_prcmu_get_ape_opp();
 }
 
+static inline int prcmu_request_ape_opp_100_voltage(bool enable)
+{
+	return db8500_prcmu_request_ape_opp_100_voltage(enable);
+}
+
 static inline void prcmu_system_reset(u16 reset_code)
 {
 	return db8500_prcmu_system_reset(reset_code);
@@ -507,6 +512,11 @@ static inline int prcmu_get_ape_opp(void)
 	return APE_100_OPP;
 }
 
+static inline int prcmu_request_ape_opp_100_voltage(bool enable)
+{
+	return 0;
+}
+
 static inline int prcmu_set_arm_opp(u8 opp)
 {
 	return 0;
-- 
1.7.10

[PATCH 2/3] clk: ux500: Support prcmu ape opp voltage clock

[Ulf Hansson]

From: Ulf Hansson <ulf.hansson@linaro.org>

Some scalable prcmu clocks needs to be handled in conjuction with the
ape opp 100 voltage. A new prcmu clock type clk_prcmu_opp_volt_scalable
is implemented to handle this.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/clk/ux500/clk-prcmu.c |   55 +++++++++++++++++++++++++++++++++++++++++
 drivers/clk/ux500/clk.h       |    6 +++++
 2 files changed, 61 insertions(+)

diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
index 930cdfe..04577ca 100644
--- a/drivers/clk/ux500/clk-prcmu.c
+++ b/drivers/clk/ux500/clk-prcmu.c
@@ -133,6 +133,40 @@ out_error:
 		hw->init->name);
 }
 
+static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
+{
+	int err;
+	struct clk_prcmu *clk = to_clk_prcmu(hw);
+
+	err = prcmu_request_ape_opp_100_voltage(true);
+	if (err) {
+		pr_err("clk_prcmu: %s failed to request APE OPP VOLT for %s.\n",
+			__func__, hw->init->name);
+		return err;
+	}
+
+	err = prcmu_request_clock(clk->cg_sel, true);
+	if (err)
+		prcmu_request_ape_opp_100_voltage(false);
+
+	return err;
+}
+
+static void clk_prcmu_opp_volt_unprepare(struct clk_hw *hw)
+{
+	struct clk_prcmu *clk = to_clk_prcmu(hw);
+
+	if (prcmu_request_clock(clk->cg_sel, false))
+		goto out_error;
+	if (prcmu_request_ape_opp_100_voltage(false))
+		goto out_error;
+	return;
+
+out_error:
+	pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
+		hw->init->name);
+}
+
 static struct clk_ops clk_prcmu_scalable_ops = {
 	.prepare = clk_prcmu_prepare,
 	.unprepare = clk_prcmu_unprepare,
@@ -167,6 +201,17 @@ static struct clk_ops clk_prcmu_opp_gate_ops = {
 	.recalc_rate = clk_prcmu_recalc_rate,
 };
 
+static struct clk_ops clk_prcmu_opp_volt_scalable_ops = {
+	.prepare = clk_prcmu_opp_volt_prepare,
+	.unprepare = clk_prcmu_opp_volt_unprepare,
+	.enable = clk_prcmu_enable,
+	.disable = clk_prcmu_disable,
+	.is_enabled = clk_prcmu_is_enabled,
+	.recalc_rate = clk_prcmu_recalc_rate,
+	.round_rate = clk_prcmu_round_rate,
+	.set_rate = clk_prcmu_set_rate,
+};
+
 static struct clk *clk_reg_prcmu(const char *name,
 				 const char *parent_name,
 				 u8 cg_sel,
@@ -250,3 +295,13 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
 	return clk_reg_prcmu(name, parent_name, cg_sel, 0, flags,
 			&clk_prcmu_opp_gate_ops);
 }
+
+struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
+					    const char *parent_name,
+					    u8 cg_sel,
+					    unsigned long rate,
+					    unsigned long flags)
+{
+	return clk_reg_prcmu(name, parent_name, cg_sel, rate, flags,
+			&clk_prcmu_opp_volt_scalable_ops);
+}
diff --git a/drivers/clk/ux500/clk.h b/drivers/clk/ux500/clk.h
index 836d7d1..f36eeed 100644
--- a/drivers/clk/ux500/clk.h
+++ b/drivers/clk/ux500/clk.h
@@ -45,4 +45,10 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
 				   u8 cg_sel,
 				   unsigned long flags);
 
+struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
+					    const char *parent_name,
+					    u8 cg_sel,
+					    unsigned long rate,
+					    unsigned long flags);
+
 #endif /* __UX500_CLK_H */
-- 
1.7.10

[PATCH 3/3] clk: ux500: Update sdmmc clock to 100MHz for u8500

[Ulf Hansson]

From: Ulf Hansson <ulf.hansson@linaro.org>

For u8500 and using 100MHz as the frequency also requires the ape opp 100
voltage, thus use the prcmu_opp_volt_scalable clock type.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/clk/ux500/u8500_clk.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/ux500/u8500_clk.c b/drivers/clk/ux500/u8500_clk.c
index ca4a25e..7bebf1f 100644
--- a/drivers/clk/ux500/u8500_clk.c
+++ b/drivers/clk/ux500/u8500_clk.c
@@ -170,10 +170,11 @@ void u8500_clk_init(void)
 	clk_register_clkdev(clk, NULL, "mtu0");
 	clk_register_clkdev(clk, NULL, "mtu1");
 
-	clk = clk_reg_prcmu_gate("sdmmcclk", NULL, PRCMU_SDMMCCLK, CLK_IS_ROOT);
+	clk = clk_reg_prcmu_opp_volt_scalable("sdmmcclk", NULL, PRCMU_SDMMCCLK,
+					100000000,
+					CLK_IS_ROOT|CLK_SET_RATE_GATE);
 	clk_register_clkdev(clk, NULL, "sdmmc");
 
-
 	clk = clk_reg_prcmu_scalable("dsi_pll", "hdmiclk",
 				PRCMU_PLLDSI, 0, CLK_SET_RATE_GATE);
 	clk_register_clkdev(clk, "dsihs2", "mcde");
-- 
1.7.10

Re: [PATCH 2/3] clk: ux500: Support prcmu ape opp voltage clock

[Mike Turquette]

Quoting Ulf Hansson (2012-09-24 07:43:18)
> From: Ulf Hansson <ulf.hansson@linaro.org>
> 
> Some scalable prcmu clocks needs to be handled in conjuction with the
> ape opp 100 voltage. A new prcmu clock type clk_prcmu_opp_volt_scalable
> is implemented to handle this.
> 
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/clk/ux500/clk-prcmu.c |   55 +++++++++++++++++++++++++++++++++++++++++
>  drivers/clk/ux500/clk.h       |    6 +++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
> index 930cdfe..04577ca 100644
> --- a/drivers/clk/ux500/clk-prcmu.c
> +++ b/drivers/clk/ux500/clk-prcmu.c
> @@ -133,6 +133,40 @@ out_error:
>                 hw->init->name);
>  }
>  
> +static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
> +{
> +       int err;
> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
> +
> +       err = prcmu_request_ape_opp_100_voltage(true);
> +       if (err) {
> +               pr_err("clk_prcmu: %s failed to request APE OPP VOLT for %s.\n",
> +                       __func__, hw->init->name);
> +               return err;
> +       }
> +
> +       err = prcmu_request_clock(clk->cg_sel, true);
> +       if (err)
> +               prcmu_request_ape_opp_100_voltage(false);
> +
> +       return err;
> +}
> +
> +static void clk_prcmu_opp_volt_unprepare(struct clk_hw *hw)
> +{
> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
> +
> +       if (prcmu_request_clock(clk->cg_sel, false))
> +               goto out_error;
> +       if (prcmu_request_ape_opp_100_voltage(false))
> +               goto out_error;
> +       return;
> +
> +out_error:
> +       pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
> +               hw->init->name);
> +}

Hello Ulf,

I was hoping to use the rate-change notifiers for voltage scaling, as in
my clk reentrancy/dvfs RFCs.  Using prepare/unprepare to set voltage for
non-scalable clocks is probably OK; do you plan to scale voltage when
your clocks change rate?  If so then you will need more than just
prepare/unprepare.

Regards,
Mike

> +
>  static struct clk_ops clk_prcmu_scalable_ops = {
>         .prepare = clk_prcmu_prepare,
>         .unprepare = clk_prcmu_unprepare,
> @@ -167,6 +201,17 @@ static struct clk_ops clk_prcmu_opp_gate_ops = {
>         .recalc_rate = clk_prcmu_recalc_rate,
>  };
>  
> +static struct clk_ops clk_prcmu_opp_volt_scalable_ops = {
> +       .prepare = clk_prcmu_opp_volt_prepare,
> +       .unprepare = clk_prcmu_opp_volt_unprepare,
> +       .enable = clk_prcmu_enable,
> +       .disable = clk_prcmu_disable,
> +       .is_enabled = clk_prcmu_is_enabled,
> +       .recalc_rate = clk_prcmu_recalc_rate,
> +       .round_rate = clk_prcmu_round_rate,
> +       .set_rate = clk_prcmu_set_rate,
> +};
> +
>  static struct clk *clk_reg_prcmu(const char *name,
>                                  const char *parent_name,
>                                  u8 cg_sel,
> @@ -250,3 +295,13 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
>         return clk_reg_prcmu(name, parent_name, cg_sel, 0, flags,
>                         &clk_prcmu_opp_gate_ops);
>  }
> +
> +struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
> +                                           const char *parent_name,
> +                                           u8 cg_sel,
> +                                           unsigned long rate,
> +                                           unsigned long flags)
> +{
> +       return clk_reg_prcmu(name, parent_name, cg_sel, rate, flags,
> +                       &clk_prcmu_opp_volt_scalable_ops);
> +}
> diff --git a/drivers/clk/ux500/clk.h b/drivers/clk/ux500/clk.h
> index 836d7d1..f36eeed 100644
> --- a/drivers/clk/ux500/clk.h
> +++ b/drivers/clk/ux500/clk.h
> @@ -45,4 +45,10 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
>                                    u8 cg_sel,
>                                    unsigned long flags);
>  
> +struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
> +                                           const char *parent_name,
> +                                           u8 cg_sel,
> +                                           unsigned long rate,
> +                                           unsigned long flags);
> +
>  #endif /* __UX500_CLK_H */
> -- 
> 1.7.10

Re: [PATCH 2/3] clk: ux500: Support prcmu ape opp voltage clock

[Ulf Hansson]

Hi Mike,

Thanks for your input!

On 24 September 2012 17:35, Mike Turquette <mturquette@ti.com> wrote:
> Quoting Ulf Hansson (2012-09-24 07:43:18)
>> From: Ulf Hansson <ulf.hansson@linaro.org>
>>
>> Some scalable prcmu clocks needs to be handled in conjuction with the
>> ape opp 100 voltage. A new prcmu clock type clk_prcmu_opp_volt_scalable
>> is implemented to handle this.
>>
>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> ---
>>  drivers/clk/ux500/clk-prcmu.c |   55 +++++++++++++++++++++++++++++++++++++++++
>>  drivers/clk/ux500/clk.h       |    6 +++++
>>  2 files changed, 61 insertions(+)
>>
>> diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
>> index 930cdfe..04577ca 100644
>> --- a/drivers/clk/ux500/clk-prcmu.c
>> +++ b/drivers/clk/ux500/clk-prcmu.c
>> @@ -133,6 +133,40 @@ out_error:
>>                 hw->init->name);
>>  }
>>
>> +static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
>> +{
>> +       int err;
>> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
>> +
>> +       err = prcmu_request_ape_opp_100_voltage(true);
>> +       if (err) {
>> +               pr_err("clk_prcmu: %s failed to request APE OPP VOLT for %s.\n",
>> +                       __func__, hw->init->name);
>> +               return err;
>> +       }
>> +
>> +       err = prcmu_request_clock(clk->cg_sel, true);
>> +       if (err)
>> +               prcmu_request_ape_opp_100_voltage(false);
>> +
>> +       return err;
>> +}
>> +
>> +static void clk_prcmu_opp_volt_unprepare(struct clk_hw *hw)
>> +{
>> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
>> +
>> +       if (prcmu_request_clock(clk->cg_sel, false))
>> +               goto out_error;
>> +       if (prcmu_request_ape_opp_100_voltage(false))
>> +               goto out_error;
>> +       return;
>> +
>> +out_error:
>> +       pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
>> +               hw->init->name);
>> +}
>
> Hello Ulf,
>
> I was hoping to use the rate-change notifiers for voltage scaling, as in
> my clk reentrancy/dvfs RFCs.  Using prepare/unprepare to set voltage for
> non-scalable clocks is probably OK; do you plan to scale voltage when
> your clocks change rate?  If so then you will need more than just
> prepare/unprepare.

I see, you have a good point here. Although right now this clock will
never change rate except during "init". Prepare/unprepare is thus
enough.

For the u8500 platform the sdmmc clock is the parent for all the
mmc/sd/sdio controllers. So, to no introduce a very complex
clockhandling mechanism (using rate-change notifiers would help a bit,
but is not enough), the clock is not supposed to be changed after
init. Proper dividing of the clock is handled internally by each
controller instead.


>
> Regards,
> Mike
>
>> +
>>  static struct clk_ops clk_prcmu_scalable_ops = {
>>         .prepare = clk_prcmu_prepare,
>>         .unprepare = clk_prcmu_unprepare,
>> @@ -167,6 +201,17 @@ static struct clk_ops clk_prcmu_opp_gate_ops = {
>>         .recalc_rate = clk_prcmu_recalc_rate,
>>  };
>>
>> +static struct clk_ops clk_prcmu_opp_volt_scalable_ops = {
>> +       .prepare = clk_prcmu_opp_volt_prepare,
>> +       .unprepare = clk_prcmu_opp_volt_unprepare,
>> +       .enable = clk_prcmu_enable,
>> +       .disable = clk_prcmu_disable,
>> +       .is_enabled = clk_prcmu_is_enabled,
>> +       .recalc_rate = clk_prcmu_recalc_rate,
>> +       .round_rate = clk_prcmu_round_rate,
>> +       .set_rate = clk_prcmu_set_rate,
>> +};
>> +
>>  static struct clk *clk_reg_prcmu(const char *name,
>>                                  const char *parent_name,
>>                                  u8 cg_sel,
>> @@ -250,3 +295,13 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
>>         return clk_reg_prcmu(name, parent_name, cg_sel, 0, flags,
>>                         &clk_prcmu_opp_gate_ops);
>>  }
>> +
>> +struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
>> +                                           const char *parent_name,
>> +                                           u8 cg_sel,
>> +                                           unsigned long rate,
>> +                                           unsigned long flags)
>> +{
>> +       return clk_reg_prcmu(name, parent_name, cg_sel, rate, flags,
>> +                       &clk_prcmu_opp_volt_scalable_ops);
>> +}
>> diff --git a/drivers/clk/ux500/clk.h b/drivers/clk/ux500/clk.h
>> index 836d7d1..f36eeed 100644
>> --- a/drivers/clk/ux500/clk.h
>> +++ b/drivers/clk/ux500/clk.h
>> @@ -45,4 +45,10 @@ struct clk *clk_reg_prcmu_opp_gate(const char *name,
>>                                    u8 cg_sel,
>>                                    unsigned long flags);
>>
>> +struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
>> +                                           const char *parent_name,
>> +                                           u8 cg_sel,
>> +                                           unsigned long rate,
>> +                                           unsigned long flags);
>> +
>>  #endif /* __UX500_CLK_H */
>> --
>> 1.7.10

Kind regards
Ulf Hansson

Re: [PATCH 2/3] clk: ux500: Support prcmu ape opp voltage clock

[Ulf Hansson]

Hi Mike,

On 26 September 2012 21:25, Mike Turquette <mturquette@ti.com> wrote:
> Quoting Ulf Hansson (2012-09-25 00:56:56)
>> Hi Mike,
>>
>> Thanks for your input!
>>
>> On 24 September 2012 17:35, Mike Turquette <mturquette@ti.com> wrote:
>> > Quoting Ulf Hansson (2012-09-24 07:43:18)
>> >> From: Ulf Hansson <ulf.hansson@linaro.org>
>> >>
>> >> Some scalable prcmu clocks needs to be handled in conjuction with the
>> >> ape opp 100 voltage. A new prcmu clock type clk_prcmu_opp_volt_scalable
>> >> is implemented to handle this.
>> >>
>> >> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> >> ---
>> >>  drivers/clk/ux500/clk-prcmu.c |   55 +++++++++++++++++++++++++++++++++++++++++
>> >>  drivers/clk/ux500/clk.h       |    6 +++++
>> >>  2 files changed, 61 insertions(+)
>> >>
>> >> diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
>> >> index 930cdfe..04577ca 100644
>> >> --- a/drivers/clk/ux500/clk-prcmu.c
>> >> +++ b/drivers/clk/ux500/clk-prcmu.c
>> >> @@ -133,6 +133,40 @@ out_error:
>> >>                 hw->init->name);
>> >>  }
>> >>
>> >> +static int clk_prcmu_opp_volt_prepare(struct clk_hw *hw)
>> >> +{
>> >> +       int err;
>> >> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
>> >> +
>> >> +       err = prcmu_request_ape_opp_100_voltage(true);
>> >> +       if (err) {
>> >> +               pr_err("clk_prcmu: %s failed to request APE OPP VOLT for %s.\n",
>> >> +                       __func__, hw->init->name);
>> >> +               return err;
>> >> +       }
>> >> +
>> >> +       err = prcmu_request_clock(clk->cg_sel, true);
>> >> +       if (err)
>> >> +               prcmu_request_ape_opp_100_voltage(false);
>> >> +
>> >> +       return err;
>> >> +}
>> >> +
>> >> +static void clk_prcmu_opp_volt_unprepare(struct clk_hw *hw)
>> >> +{
>> >> +       struct clk_prcmu *clk = to_clk_prcmu(hw);
>> >> +
>> >> +       if (prcmu_request_clock(clk->cg_sel, false))
>> >> +               goto out_error;
>> >> +       if (prcmu_request_ape_opp_100_voltage(false))
>> >> +               goto out_error;
>> >> +       return;
>> >> +
>> >> +out_error:
>> >> +       pr_err("clk_prcmu: %s failed to disable %s.\n", __func__,
>> >> +               hw->init->name);
>> >> +}
>> >
>> > Hello Ulf,
>> >
>> > I was hoping to use the rate-change notifiers for voltage scaling, as in
>> > my clk reentrancy/dvfs RFCs.  Using prepare/unprepare to set voltage for
>> > non-scalable clocks is probably OK; do you plan to scale voltage when
>> > your clocks change rate?  If so then you will need more than just
>> > prepare/unprepare.
>>
>> I see, you have a good point here. Although right now this clock will
>> never change rate except during "init". Prepare/unprepare is thus
>> enough.
>>
>> For the u8500 platform the sdmmc clock is the parent for all the
>> mmc/sd/sdio controllers. So, to no introduce a very complex
>> clockhandling mechanism (using rate-change notifiers would help a bit,
>> but is not enough), the clock is not supposed to be changed after
>> init. Proper dividing of the clock is handled internally by each
>> controller instead.
>>
>
> The internal dividers could be modeled as clk nodes, which themselves
> could have notifier handlers that scale voltage.  So perhaps the MMC
> controller driver for your platform should define the appropriate leaf
> clks?

I am not sure I completely follow you here, but let me try to answer
your suggestions.
The internal dividers are supposed to be handled only by the mmc host
driver since it is IP specific. I don't think it is viable to add
another clock type/node for this, but maybe that is not what you are
suggesting either. :-)

In my case for ux500 we use the mmci host driver. It is an ARM cross
SoC device driver, and I believe adding clock notifiers in the driver
to handle the voltage scale would complicate things quite a bit. It
seems a lot easier to let the clock driver handle this, especially
since the frequency will remain fixed after initialization. So in the
end I see now need and benefit for adding the clock notifiers in the
mmci host driver.

Kind regards
Ulf Hansson

Re: [PATCH 2/3] clk: ux500: Support prcmu ape opp voltage clock

[Linus Walleij]

On Thu, Sep 27, 2012 at 9:43 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:

> In my case for ux500 we use the mmci host driver. It is an ARM cross
> SoC device driver, and I believe adding clock notifiers in the driver
> to handle the voltage scale would complicate things quite a bit. It
> seems a lot easier to let the clock driver handle this, especially
> since the frequency will remain fixed after initialization. So in the
> end I see now need and benefit for adding the clock notifiers in the
> mmci host driver.

Right now it certainly cannot be done anyway, because some of the
clients to this driver does not implement the generic clock framework,
and thus it just won't compile anymore for them if we introduce that.

The patch does raise the issue of how to handle OPP requests
though.

Yours,
Linus Walleij

Re: [PATCH 1/3] mfd: dbx500: Export prmcu_request_ape_opp_100_voltage

[Ulf Hansson]

Hi Sam and Linus,

Do you see any issues with this patch? Can we advise Mike to merge it
though his clock tree?

Kind regards
Ulf Hansson

On 24 September 2012 16:43, Ulf Hansson <ulf.hansson@stericsson.com> wrote:
> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> This function needs to be exported to let clients be able to
> request the ape opp 100 voltage.
>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/mfd/db8500-prcmu.c       |    4 ++--
>  include/linux/mfd/db8500-prcmu.h |    4 ++--
>  include/linux/mfd/dbx500-prcmu.h |   10 ++++++++++
>  3 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> index e7f9539..0b8e0a0 100644
> --- a/drivers/mfd/db8500-prcmu.c
> +++ b/drivers/mfd/db8500-prcmu.c
> @@ -1167,12 +1167,12 @@ int db8500_prcmu_get_ape_opp(void)
>  }
>
>  /**
> - * prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
> + * db8500_prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
>   * @enable: true to request the higher voltage, false to drop a request.
>   *
>   * Calls to this function to enable and disable requests must be balanced.
>   */
> -int prcmu_request_ape_opp_100_voltage(bool enable)
> +int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
>  {
>         int r = 0;
>         u8 header;
> diff --git a/include/linux/mfd/db8500-prcmu.h b/include/linux/mfd/db8500-prcmu.h
> index b82f6ee..6ee4247 100644
> --- a/include/linux/mfd/db8500-prcmu.h
> +++ b/include/linux/mfd/db8500-prcmu.h
> @@ -515,7 +515,6 @@ enum romcode_read prcmu_get_rc_p2a(void);
>  enum ap_pwrst prcmu_get_xp70_current_state(void);
>  bool prcmu_has_arm_maxopp(void);
>  struct prcmu_fw_version *prcmu_get_fw_version(void);
> -int prcmu_request_ape_opp_100_voltage(bool enable);
>  int prcmu_release_usb_wakeup_state(void);
>  void prcmu_configure_auto_pm(struct prcmu_auto_pm_config *sleep,
>         struct prcmu_auto_pm_config *idle);
> @@ -564,6 +563,7 @@ int db8500_prcmu_set_arm_opp(u8 opp);
>  int db8500_prcmu_get_arm_opp(void);
>  int db8500_prcmu_set_ape_opp(u8 opp);
>  int db8500_prcmu_get_ape_opp(void);
> +int db8500_prcmu_request_ape_opp_100_voltage(bool enable);
>  int db8500_prcmu_set_ddr_opp(u8 opp);
>  int db8500_prcmu_get_ddr_opp(void);
>
> @@ -610,7 +610,7 @@ static inline int db8500_prcmu_get_ape_opp(void)
>         return APE_100_OPP;
>  }
>
> -static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> +static inline int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
>  {
>         return 0;
>  }
> diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
> index c410d99..c202d6c 100644
> --- a/include/linux/mfd/dbx500-prcmu.h
> +++ b/include/linux/mfd/dbx500-prcmu.h
> @@ -336,6 +336,11 @@ static inline int prcmu_get_ape_opp(void)
>         return db8500_prcmu_get_ape_opp();
>  }
>
> +static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> +{
> +       return db8500_prcmu_request_ape_opp_100_voltage(enable);
> +}
> +
>  static inline void prcmu_system_reset(u16 reset_code)
>  {
>         return db8500_prcmu_system_reset(reset_code);
> @@ -507,6 +512,11 @@ static inline int prcmu_get_ape_opp(void)
>         return APE_100_OPP;
>  }
>
> +static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> +{
> +       return 0;
> +}
> +
>  static inline int prcmu_set_arm_opp(u8 opp)
>  {
>         return 0;
> --
> 1.7.10
>

Re: [PATCH 1/3] mfd: dbx500: Export prmcu_request_ape_opp_100_voltage

[Samuel Ortiz]

Hi Ulf,

On Mon, Sep 24, 2012 at 04:43:17PM +0200, Ulf Hansson wrote:
> From: Ulf Hansson <ulf.hansson@linaro.org>
> 
> This function needs to be exported to let clients be able to
> request the ape opp 100 voltage.
> 
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>

Cheers,
Samuel.

-- 
Intel Open Source Technology Centre
http://oss.intel.com/

Re: [PATCH 1/3] mfd: dbx500: Export prmcu_request_ape_opp_100_voltage

[Linus Walleij]

On Mon, Sep 24, 2012 at 4:43 PM, Ulf Hansson <ulf.hansson@stericsson.com> wrote:

> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> This function needs to be exported to let clients be able to
> request the ape opp 100 voltage.
>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH 1/3] mfd: dbx500: Export prmcu_request_ape_opp_100_voltage

[Mike Turquette]

Quoting Ulf Hansson (2012-10-04 05:03:05)
> Hi Sam and Linus,
> 
> Do you see any issues with this patch? Can we advise Mike to merge it
> though his clock tree?
> 

Thanks for the re-ping and gathering Ack's.  I'll pull into my clk-next
as soon as I push out a new branch towards 3.8.

Regards,
Mike

> Kind regards
> Ulf Hansson
> 
> On 24 September 2012 16:43, Ulf Hansson <ulf.hansson@stericsson.com> wrote:
> > From: Ulf Hansson <ulf.hansson@linaro.org>
> >
> > This function needs to be exported to let clients be able to
> > request the ape opp 100 voltage.
> >
> > Cc: Samuel Ortiz <sameo@linux.intel.com>
> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > ---
> >  drivers/mfd/db8500-prcmu.c       |    4 ++--
> >  include/linux/mfd/db8500-prcmu.h |    4 ++--
> >  include/linux/mfd/dbx500-prcmu.h |   10 ++++++++++
> >  3 files changed, 14 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> > index e7f9539..0b8e0a0 100644
> > --- a/drivers/mfd/db8500-prcmu.c
> > +++ b/drivers/mfd/db8500-prcmu.c
> > @@ -1167,12 +1167,12 @@ int db8500_prcmu_get_ape_opp(void)
> >  }
> >
> >  /**
> > - * prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
> > + * db8500_prcmu_request_ape_opp_100_voltage - Request APE OPP 100% voltage
> >   * @enable: true to request the higher voltage, false to drop a request.
> >   *
> >   * Calls to this function to enable and disable requests must be balanced.
> >   */
> > -int prcmu_request_ape_opp_100_voltage(bool enable)
> > +int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
> >  {
> >         int r = 0;
> >         u8 header;
> > diff --git a/include/linux/mfd/db8500-prcmu.h b/include/linux/mfd/db8500-prcmu.h
> > index b82f6ee..6ee4247 100644
> > --- a/include/linux/mfd/db8500-prcmu.h
> > +++ b/include/linux/mfd/db8500-prcmu.h
> > @@ -515,7 +515,6 @@ enum romcode_read prcmu_get_rc_p2a(void);
> >  enum ap_pwrst prcmu_get_xp70_current_state(void);
> >  bool prcmu_has_arm_maxopp(void);
> >  struct prcmu_fw_version *prcmu_get_fw_version(void);
> > -int prcmu_request_ape_opp_100_voltage(bool enable);
> >  int prcmu_release_usb_wakeup_state(void);
> >  void prcmu_configure_auto_pm(struct prcmu_auto_pm_config *sleep,
> >         struct prcmu_auto_pm_config *idle);
> > @@ -564,6 +563,7 @@ int db8500_prcmu_set_arm_opp(u8 opp);
> >  int db8500_prcmu_get_arm_opp(void);
> >  int db8500_prcmu_set_ape_opp(u8 opp);
> >  int db8500_prcmu_get_ape_opp(void);
> > +int db8500_prcmu_request_ape_opp_100_voltage(bool enable);
> >  int db8500_prcmu_set_ddr_opp(u8 opp);
> >  int db8500_prcmu_get_ddr_opp(void);
> >
> > @@ -610,7 +610,7 @@ static inline int db8500_prcmu_get_ape_opp(void)
> >         return APE_100_OPP;
> >  }
> >
> > -static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> > +static inline int db8500_prcmu_request_ape_opp_100_voltage(bool enable)
> >  {
> >         return 0;
> >  }
> > diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
> > index c410d99..c202d6c 100644
> > --- a/include/linux/mfd/dbx500-prcmu.h
> > +++ b/include/linux/mfd/dbx500-prcmu.h
> > @@ -336,6 +336,11 @@ static inline int prcmu_get_ape_opp(void)
> >         return db8500_prcmu_get_ape_opp();
> >  }
> >
> > +static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> > +{
> > +       return db8500_prcmu_request_ape_opp_100_voltage(enable);
> > +}
> > +
> >  static inline void prcmu_system_reset(u16 reset_code)
> >  {
> >         return db8500_prcmu_system_reset(reset_code);
> > @@ -507,6 +512,11 @@ static inline int prcmu_get_ape_opp(void)
> >         return APE_100_OPP;
> >  }
> >
> > +static inline int prcmu_request_ape_opp_100_voltage(bool enable)
> > +{
> > +       return 0;
> > +}
> > +
> >  static inline int prcmu_set_arm_opp(u8 opp)
> >  {
> >         return 0;
> > --
> > 1.7.10
> >