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* [PATCH 0/4] clk: Support for smp_twd clock for ux500
@ 2012-08-31 12:21 Ulf Hansson
  2012-08-31 12:21 ` [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate Ulf Hansson
                   ` (4 more replies)
  0 siblings, 5 replies; 15+ messages in thread
From: Ulf Hansson @ 2012-08-31 12:21 UTC (permalink / raw)
  To: linux-arm-kernel, Mike Turquette, Mike Turquette, Samuel Ortiz,
	linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

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

To implement support for the smp_twd clock for ux500 several steps
was needed. This patchseries has also proposed some new changes in the
common clock core, which the ux500 smp_twd clock definition are
relying on.

Moreover some crossdepency exist to the ux500 prcmu mfd driver.
My idea is that the corresponding maintainers may be able to ack these
changes, if they like them of course, so we can merge this through
Mike Turquette's clk git tree. Otherwise I can happily set up some other
way forward, if that suits better.

Patches is based upon Linux 3.6 rc2. The clock patches specific for ux500,
is based upon the series [PATCH V2 0/4] clk: Convert ARM ux500 to common
clock.

Michel Jaouen (1):
  mfd: dbx500: Provide a more accurate smp_twd clock

Ulf Hansson (3):
  clk: Provide option for clk_get_rate to issue hw for new rate
  clk: ux500: Support for prmcu_rate clock
  clk: ux500: Define smp_twd clock for u8500

 drivers/clk/clk.c                |   43 +++++++++++++++++++++-----------------
 drivers/clk/ux500/clk-prcmu.c    |   14 +++++++++++++
 drivers/clk/ux500/clk.h          |    5 +++++
 drivers/clk/ux500/u8500_clk.c    |   12 +++++++----
 drivers/mfd/db8500-prcmu.c       |   42 +++++++++++++++++++++++++++++++++++++
 drivers/mfd/dbx500-prcmu-regs.h  |    4 +++-
 include/linux/clk-provider.h     |    1 +
 include/linux/mfd/dbx500-prcmu.h |    1 +
 8 files changed, 98 insertions(+), 24 deletions(-)

-- 
1.7.10


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
@ 2012-08-31 12:21 ` Ulf Hansson
  2012-08-31 19:29   ` Mike Turquette
  2012-08-31 12:21 ` [PATCH 2/4] clk: ux500: Support for prmcu_rate clock Ulf Hansson
                   ` (3 subsequent siblings)
  4 siblings, 1 reply; 15+ messages in thread
From: Ulf Hansson @ 2012-08-31 12:21 UTC (permalink / raw)
  To: linux-arm-kernel, Mike Turquette, Mike Turquette, Samuel Ortiz,
	linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

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

By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
issue the hw for an updated clock rate. This can be used for a clock
which rate may be updated without a client necessary modifying it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/clk/clk.c            |   43 +++++++++++++++++++++++-------------------
 include/linux/clk-provider.h |    1 +
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index efdfd00..d9cbae0 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -558,25 +558,6 @@ int clk_enable(struct clk *clk)
 EXPORT_SYMBOL_GPL(clk_enable);
 
 /**
- * clk_get_rate - return the rate of clk
- * @clk: the clk whose rate is being returned
- *
- * Simply returns the cached rate of the clk.  Does not query the hardware.  If
- * clk is NULL then returns 0.
- */
-unsigned long clk_get_rate(struct clk *clk)
-{
-	unsigned long rate;
-
-	mutex_lock(&prepare_lock);
-	rate = __clk_get_rate(clk);
-	mutex_unlock(&prepare_lock);
-
-	return rate;
-}
-EXPORT_SYMBOL_GPL(clk_get_rate);
-
-/**
  * __clk_round_rate - round the given rate for a clk
  * @clk: round the rate of this clock
  *
@@ -702,6 +683,30 @@ static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
 }
 
 /**
+ * clk_get_rate - return the rate of clk
+ * @clk: the clk whose rate is being returned
+ *
+ * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
+ * is set, which means a recalc_rate will be issued.
+ * If clk is NULL then returns 0.
+ */
+unsigned long clk_get_rate(struct clk *clk)
+{
+	unsigned long rate;
+
+	mutex_lock(&prepare_lock);
+
+	if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
+		__clk_recalc_rates(clk, 0);
+
+	rate = __clk_get_rate(clk);
+	mutex_unlock(&prepare_lock);
+
+	return rate;
+}
+EXPORT_SYMBOL_GPL(clk_get_rate);
+
+/**
  * __clk_speculate_rates
  * @clk: first clk in the subtree
  * @parent_rate: the "future" rate of clk's parent
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 77335fa..1b15307 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -26,6 +26,7 @@
 #define CLK_IGNORE_UNUSED	BIT(3) /* do not gate even if unused */
 #define CLK_IS_ROOT		BIT(4) /* root clk, has no parent */
 #define CLK_IS_BASIC		BIT(5) /* Basic clk, can't do a to_clk_foo() */
+#define CLK_GET_RATE_NOCACHE	BIT(6) /* do not use the cached clk rate */
 
 struct clk_hw;
 
-- 
1.7.10


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 2/4] clk: ux500: Support for prmcu_rate clock
  2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
  2012-08-31 12:21 ` [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate Ulf Hansson
@ 2012-08-31 12:21 ` Ulf Hansson
  2012-08-31 12:21 ` [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock Ulf Hansson
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2012-08-31 12:21 UTC (permalink / raw)
  To: linux-arm-kernel, Mike Turquette, Mike Turquette, Samuel Ortiz,
	linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

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

The prmcu_rate clock is not gateable and has a rate which
only can be fetched.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/clk/ux500/clk-prcmu.c |   14 ++++++++++++++
 drivers/clk/ux500/clk.h       |    5 +++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c
index 1d779ad..930cdfe 100644
--- a/drivers/clk/ux500/clk-prcmu.c
+++ b/drivers/clk/ux500/clk-prcmu.c
@@ -153,6 +153,11 @@ static struct clk_ops clk_prcmu_gate_ops = {
 	.recalc_rate = clk_prcmu_recalc_rate,
 };
 
+static struct clk_ops clk_prcmu_rate_ops = {
+	.is_enabled = clk_prcmu_is_enabled,
+	.recalc_rate = clk_prcmu_recalc_rate,
+};
+
 static struct clk_ops clk_prcmu_opp_gate_ops = {
 	.prepare = clk_prcmu_opp_prepare,
 	.unprepare = clk_prcmu_opp_unprepare,
@@ -228,6 +233,15 @@ struct clk *clk_reg_prcmu_gate(const char *name,
 			&clk_prcmu_gate_ops);
 }
 
+struct clk *clk_reg_prcmu_rate(const char *name,
+			       const char *parent_name,
+			       u8 cg_sel,
+			       unsigned long flags)
+{
+	return clk_reg_prcmu(name, parent_name, cg_sel, 0, flags,
+			&clk_prcmu_rate_ops);
+}
+
 struct clk *clk_reg_prcmu_opp_gate(const char *name,
 				   const char *parent_name,
 				   u8 cg_sel,
diff --git a/drivers/clk/ux500/clk.h b/drivers/clk/ux500/clk.h
index 32085aa..836d7d1 100644
--- a/drivers/clk/ux500/clk.h
+++ b/drivers/clk/ux500/clk.h
@@ -35,6 +35,11 @@ struct clk *clk_reg_prcmu_gate(const char *name,
 			       u8 cg_sel,
 			       unsigned long flags);
 
+struct clk *clk_reg_prcmu_rate(const char *name,
+			       const char *parent_name,
+			       u8 cg_sel,
+			       unsigned long flags);
+
 struct clk *clk_reg_prcmu_opp_gate(const char *name,
 				   const char *parent_name,
 				   u8 cg_sel,
-- 
1.7.10


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock
  2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
  2012-08-31 12:21 ` [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate Ulf Hansson
  2012-08-31 12:21 ` [PATCH 2/4] clk: ux500: Support for prmcu_rate clock Ulf Hansson
@ 2012-08-31 12:21 ` Ulf Hansson
  2012-09-19 16:02   ` Samuel Ortiz
  2012-08-31 12:21 ` [PATCH 4/4] clk: ux500: Define smp_twd clock for u8500 Ulf Hansson
  2012-08-31 23:32 ` [PATCH 0/4] clk: Support for smp_twd clock for ux500 Linus Walleij
  4 siblings, 1 reply; 15+ messages in thread
From: Ulf Hansson @ 2012-08-31 12:21 UTC (permalink / raw)
  To: linux-arm-kernel, Mike Turquette, Mike Turquette, Samuel Ortiz,
	linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar,
	Michel Jaouen, Ulf Hansson, Rickard Andersson

From: Michel Jaouen <michel.jaouen@stericsson.com>

The local timer clock is based on ARM subsystem clock. This patch
obtains a more exact value of that clock by reading PRCMU registers.
Using this increases the accuracy of the local timer events.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
---
 drivers/mfd/db8500-prcmu.c       |   42 ++++++++++++++++++++++++++++++++++++++
 drivers/mfd/dbx500-prcmu-regs.h  |    4 +++-
 include/linux/mfd/dbx500-prcmu.h |    1 +
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 4f74529..e7f9539 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -418,6 +418,9 @@ static struct {
 
 static atomic_t ac_wake_req_state = ATOMIC_INIT(0);
 
+/* Functions definition */
+static void compute_armss_rate(void);
+
 /* Spinlocks */
 static DEFINE_SPINLOCK(prcmu_lock);
 static DEFINE_SPINLOCK(clkout_lock);
@@ -517,6 +520,7 @@ static struct dsiescclk dsiescclk[3] = {
 	}
 };
 
+
 /*
 * Used by MCDE to setup all necessary PRCMU registers
 */
@@ -1013,6 +1017,7 @@ int db8500_prcmu_set_arm_opp(u8 opp)
 		(mb1_transfer.ack.arm_opp != opp))
 		r = -EIO;
 
+	compute_armss_rate();
 	mutex_unlock(&mb1_transfer.lock);
 
 	return r;
@@ -1612,6 +1617,7 @@ static unsigned long pll_rate(void __iomem *reg, unsigned long src_rate,
 	if ((branch == PLL_FIX) || ((branch == PLL_DIV) &&
 		(val & PRCM_PLL_FREQ_DIV2EN) &&
 		((reg == PRCM_PLLSOC0_FREQ) ||
+		 (reg == PRCM_PLLARM_FREQ) ||
 		 (reg == PRCM_PLLDDR_FREQ))))
 		div *= 2;
 
@@ -1661,6 +1667,39 @@ static unsigned long clock_rate(u8 clock)
 	else
 		return 0;
 }
+static unsigned long latest_armss_rate;
+static unsigned long armss_rate(void)
+{
+	return latest_armss_rate;
+}
+
+static void compute_armss_rate(void)
+{
+	u32 r;
+	unsigned long rate;
+
+	r = readl(PRCM_ARM_CHGCLKREQ);
+
+	if (r & PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ) {
+		/* External ARMCLKFIX clock */
+
+		rate = pll_rate(PRCM_PLLDDR_FREQ, ROOT_CLOCK_RATE, PLL_FIX);
+
+		/* Check PRCM_ARM_CHGCLKREQ divider */
+		if (!(r & PRCM_ARM_CHGCLKREQ_PRCM_ARM_DIVSEL))
+			rate /= 2;
+
+		/* Check PRCM_ARMCLKFIX_MGT divider */
+		r = readl(PRCM_ARMCLKFIX_MGT);
+		r &= PRCM_CLK_MGT_CLKPLLDIV_MASK;
+		rate /= r;
+
+	} else {/* ARM PLL */
+		rate = pll_rate(PRCM_PLLARM_FREQ, ROOT_CLOCK_RATE, PLL_DIV);
+	}
+
+	latest_armss_rate = rate;
+}
 
 static unsigned long dsiclk_rate(u8 n)
 {
@@ -1707,6 +1746,8 @@ unsigned long prcmu_clock_rate(u8 clock)
 		return pll_rate(PRCM_PLLSOC0_FREQ, ROOT_CLOCK_RATE, PLL_RAW);
 	else if (clock == PRCMU_PLLSOC1)
 		return pll_rate(PRCM_PLLSOC1_FREQ, ROOT_CLOCK_RATE, PLL_RAW);
+	else if (clock == PRCMU_ARMSS)
+		return armss_rate();
 	else if (clock == PRCMU_PLLDDR)
 		return pll_rate(PRCM_PLLDDR_FREQ, ROOT_CLOCK_RATE, PLL_RAW);
 	else if (clock == PRCMU_PLLDSI)
@@ -2693,6 +2734,7 @@ void __init db8500_prcmu_early_init(void)
 					 handle_simple_irq);
 		set_irq_flags(irq, IRQF_VALID);
 	}
+	compute_armss_rate();
 }
 
 static void __init init_prcm_registers(void)
diff --git a/drivers/mfd/dbx500-prcmu-regs.h b/drivers/mfd/dbx500-prcmu-regs.h
index 23108a6..79c76eb 100644
--- a/drivers/mfd/dbx500-prcmu-regs.h
+++ b/drivers/mfd/dbx500-prcmu-regs.h
@@ -61,7 +61,8 @@
 #define PRCM_PLLARM_LOCKP_PRCM_PLLARM_LOCKP3	0x2
 
 #define PRCM_ARM_CHGCLKREQ	(_PRCMU_BASE + 0x114)
-#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ	0x1
+#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ	BIT(0)
+#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_DIVSEL	BIT(16)
 
 #define PRCM_PLLARM_ENABLE	(_PRCMU_BASE + 0x98)
 #define PRCM_PLLARM_ENABLE_PRCM_PLLARM_ENABLE	0x1
@@ -140,6 +141,7 @@
 /* PRCMU clock/PLL/reset registers */
 #define PRCM_PLLSOC0_FREQ	   (_PRCMU_BASE + 0x080)
 #define PRCM_PLLSOC1_FREQ	   (_PRCMU_BASE + 0x084)
+#define PRCM_PLLARM_FREQ	   (_PRCMU_BASE + 0x088)
 #define PRCM_PLLDDR_FREQ	   (_PRCMU_BASE + 0x08C)
 #define PRCM_PLL_FREQ_D_SHIFT	0
 #define PRCM_PLL_FREQ_D_MASK	BITS(0, 7)
diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
index 5b90e94..c410d99 100644
--- a/include/linux/mfd/dbx500-prcmu.h
+++ b/include/linux/mfd/dbx500-prcmu.h
@@ -136,6 +136,7 @@ enum prcmu_clock {
 	PRCMU_TIMCLK,
 	PRCMU_PLLSOC0,
 	PRCMU_PLLSOC1,
+	PRCMU_ARMSS,
 	PRCMU_PLLDDR,
 	PRCMU_PLLDSI,
 	PRCMU_DSI0CLK,
-- 
1.7.10


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 4/4] clk: ux500: Define smp_twd clock for u8500
  2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
                   ` (2 preceding siblings ...)
  2012-08-31 12:21 ` [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock Ulf Hansson
@ 2012-08-31 12:21 ` Ulf Hansson
  2012-08-31 23:32 ` [PATCH 0/4] clk: Support for smp_twd clock for ux500 Linus Walleij
  4 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2012-08-31 12:21 UTC (permalink / raw)
  To: linux-arm-kernel, Mike Turquette, Mike Turquette, Samuel Ortiz,
	linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

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

The smp_twd clock is based upon a prcmu_rate clock type
for the PRCMU_ARMSS clock.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/clk/ux500/u8500_clk.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/ux500/u8500_clk.c b/drivers/clk/ux500/u8500_clk.c
index 5c1fca1..ca4a25e 100644
--- a/drivers/clk/ux500/u8500_clk.c
+++ b/drivers/clk/ux500/u8500_clk.c
@@ -205,12 +205,16 @@ void u8500_clk_init(void)
 	clk_register_clkdev(clk, "dsilp2", "dsilink.2");
 	clk_register_clkdev(clk, "dsilp2", "mcde");
 
+	clk = clk_reg_prcmu_rate("smp_twd", NULL, PRCMU_ARMSS,
+				CLK_IS_ROOT|CLK_GET_RATE_NOCACHE|
+				CLK_IGNORE_UNUSED);
+	clk_register_clkdev(clk, NULL, "smp_twd");
+
 	/*
 	 * FIXME: Add special handled PRCMU clocks here:
-	 * 1. smp_twd, use PRCMU_ARMSS.
-	 * 2. clk_arm, use PRCMU_ARMCLK.
-	 * 3. clkout0yuv, use PRCMU as parent + need regulator + pinctrl.
-	 * 4. ab9540_clkout1yuv, see clkout0yuv
+	 * 1. clk_arm, use PRCMU_ARMCLK.
+	 * 2. clkout0yuv, use PRCMU as parent + need regulator + pinctrl.
+	 * 3. ab9540_clkout1yuv, see clkout0yuv
 	 */
 
 	/* PRCC P-clocks */
-- 
1.7.10


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-08-31 12:21 ` [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate Ulf Hansson
@ 2012-08-31 19:29   ` Mike Turquette
  2012-09-06  9:09     ` Ulf Hansson
  0 siblings, 1 reply; 15+ messages in thread
From: Mike Turquette @ 2012-08-31 19:29 UTC (permalink / raw)
  To: Ulf Hansson, linux-arm-kernel, Samuel Ortiz, linux-kernel
  Cc: Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

Quoting Ulf Hansson (2012-08-31 05:21:28)
> From: Ulf Hansson <ulf.hansson@linaro.org>
> 
> By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
> issue the hw for an updated clock rate. This can be used for a clock
> which rate may be updated without a client necessary modifying it.
> 

I'm glad to see this.  We discussed whether the default behavior should
be cached or from the hardware at length some time back, so having a
flag to support the non-default is great.

> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/clk/clk.c            |   43 +++++++++++++++++++++++-------------------
>  include/linux/clk-provider.h |    1 +
>  2 files changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index efdfd00..d9cbae0 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -558,25 +558,6 @@ int clk_enable(struct clk *clk)
>  EXPORT_SYMBOL_GPL(clk_enable);
>  
>  /**
> - * clk_get_rate - return the rate of clk
> - * @clk: the clk whose rate is being returned
> - *
> - * Simply returns the cached rate of the clk.  Does not query the hardware.  If
> - * clk is NULL then returns 0.
> - */
> -unsigned long clk_get_rate(struct clk *clk)
> -{
> -       unsigned long rate;
> -
> -       mutex_lock(&prepare_lock);
> -       rate = __clk_get_rate(clk);
> -       mutex_unlock(&prepare_lock);
> -
> -       return rate;
> -}
> -EXPORT_SYMBOL_GPL(clk_get_rate);
> -
> -/**
>   * __clk_round_rate - round the given rate for a clk
>   * @clk: round the rate of this clock
>   *
> @@ -702,6 +683,30 @@ static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
>  }
>  
>  /**
> + * clk_get_rate - return the rate of clk
> + * @clk: the clk whose rate is being returned
> + *
> + * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
> + * is set, which means a recalc_rate will be issued.
> + * If clk is NULL then returns 0.
> + */
> +unsigned long clk_get_rate(struct clk *clk)
> +{
> +       unsigned long rate;
> +
> +       mutex_lock(&prepare_lock);
> +
> +       if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
> +               __clk_recalc_rates(clk, 0);

This is a bit subtle.  Calling __clk_recalc_rates will walk the subtree
of children recalculating rates as well as firing off notifiers.  Is
this what you want?  If your clock changes rates behind your back AND
has chilren then this is probably the right thing to do.  However you
might be better off with:

	if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
		rate = clk->ops->recalc_rate(clk->hw, clk->parent->rate);

This doesn't update children or fire off notifiers.  What is best for
your platform?

Regards,
Mike

> +
> +       rate = __clk_get_rate(clk);
> +       mutex_unlock(&prepare_lock);
> +
> +       return rate;
> +}
> +EXPORT_SYMBOL_GPL(clk_get_rate);
> +
> +/**
>   * __clk_speculate_rates
>   * @clk: first clk in the subtree
>   * @parent_rate: the "future" rate of clk's parent
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index 77335fa..1b15307 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -26,6 +26,7 @@
>  #define CLK_IGNORE_UNUSED      BIT(3) /* do not gate even if unused */
>  #define CLK_IS_ROOT            BIT(4) /* root clk, has no parent */
>  #define CLK_IS_BASIC           BIT(5) /* Basic clk, can't do a to_clk_foo() */
> +#define CLK_GET_RATE_NOCACHE   BIT(6) /* do not use the cached clk rate */
>  
>  struct clk_hw;
>  
> -- 
> 1.7.10

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 0/4] clk: Support for smp_twd clock for ux500
  2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
                   ` (3 preceding siblings ...)
  2012-08-31 12:21 ` [PATCH 4/4] clk: ux500: Define smp_twd clock for u8500 Ulf Hansson
@ 2012-08-31 23:32 ` Linus Walleij
  4 siblings, 0 replies; 15+ messages in thread
From: Linus Walleij @ 2012-08-31 23:32 UTC (permalink / raw)
  To: Ulf Hansson, Mike Turquette, Mike Turquette
  Cc: linux-arm-kernel, Samuel Ortiz, linux-kernel, Lee Jones,
	Philippe Begnic, Srinidhi Kasagar, Ulf Hansson

On Fri, Aug 31, 2012 at 2:21 PM, Ulf Hansson <ulf.hansson@stericsson.com> wrote:

> From: Ulf Hansson <ulf.hansson@linaro.org>
>
> To implement support for the smp_twd clock for ux500 several steps
> was needed. This patchseries has also proposed some new changes in the
> common clock core, which the ux500 smp_twd clock definition are
> relying on.

This is a great series,
Acked-by: Linus Walleij <linus.walleij@linaro.org>
For the ux500 parts.

Mike it'd be great if you could merge this once you have the semantics
of [1/4] sorted out with Ulf.

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-08-31 19:29   ` Mike Turquette
@ 2012-09-06  9:09     ` Ulf Hansson
       [not found]       ` <20120907001927.20289.41627@nucleus>
  0 siblings, 1 reply; 15+ messages in thread
From: Ulf Hansson @ 2012-09-06  9:09 UTC (permalink / raw)
  To: Mike Turquette
  Cc: Ulf Hansson, linux-arm-kernel, Samuel Ortiz, linux-kernel,
	Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar

Hi Mike,

Thanks for your input, and sorry for my late reply!

On 31 August 2012 21:29, Mike Turquette <mturquette@ti.com> wrote:
> Quoting Ulf Hansson (2012-08-31 05:21:28)
>> From: Ulf Hansson <ulf.hansson@linaro.org>
>>
>> By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
>> issue the hw for an updated clock rate. This can be used for a clock
>> which rate may be updated without a client necessary modifying it.
>>
>
> I'm glad to see this.  We discussed whether the default behavior should
> be cached or from the hardware at length some time back, so having a
> flag to support the non-default is great.
>
>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> ---
>>  drivers/clk/clk.c            |   43 +++++++++++++++++++++++-------------------
>>  include/linux/clk-provider.h |    1 +
>>  2 files changed, 25 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index efdfd00..d9cbae0 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>> @@ -558,25 +558,6 @@ int clk_enable(struct clk *clk)
>>  EXPORT_SYMBOL_GPL(clk_enable);
>>
>>  /**
>> - * clk_get_rate - return the rate of clk
>> - * @clk: the clk whose rate is being returned
>> - *
>> - * Simply returns the cached rate of the clk.  Does not query the hardware.  If
>> - * clk is NULL then returns 0.
>> - */
>> -unsigned long clk_get_rate(struct clk *clk)
>> -{
>> -       unsigned long rate;
>> -
>> -       mutex_lock(&prepare_lock);
>> -       rate = __clk_get_rate(clk);
>> -       mutex_unlock(&prepare_lock);
>> -
>> -       return rate;
>> -}
>> -EXPORT_SYMBOL_GPL(clk_get_rate);
>> -
>> -/**
>>   * __clk_round_rate - round the given rate for a clk
>>   * @clk: round the rate of this clock
>>   *
>> @@ -702,6 +683,30 @@ static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
>>  }
>>
>>  /**
>> + * clk_get_rate - return the rate of clk
>> + * @clk: the clk whose rate is being returned
>> + *
>> + * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
>> + * is set, which means a recalc_rate will be issued.
>> + * If clk is NULL then returns 0.
>> + */
>> +unsigned long clk_get_rate(struct clk *clk)
>> +{
>> +       unsigned long rate;
>> +
>> +       mutex_lock(&prepare_lock);
>> +
>> +       if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
>> +               __clk_recalc_rates(clk, 0);
>
> This is a bit subtle.  Calling __clk_recalc_rates will walk the subtree
> of children recalculating rates as well as firing off notifiers.  Is
> this what you want?  If your clock changes rates behind your back AND
> has chilren then this is probably the right thing to do.  However you
> might be better off with:
>
>         if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
>                 rate = clk->ops->recalc_rate(clk->hw, clk->parent->rate);
>
> This doesn't update children or fire off notifiers.  What is best for
> your platform?

For my platform, ux500 and for the clock connected to this
patchseries, your suggesting above is enough. (Well some additional
error handling is needed in your code proposal though :-) )

The reason for why I used "__clk_recalc_rates" was because I think it
could make sense to have a more generic approach, not sure if it is
needed as you mention. Additionally, using  __clk_recalc_rates with
"0" as the notification argument, should prevent notifications from
happen, right?

So basically, I wanted the clock rates for the children to be updated
as well as the parent clock rate, but no notifications.

I can happily update the patch according to your proposal if you still
think it is the best way to do it, just tell me again then. :-)

Kind regards
Ulf Hansson

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
       [not found]       ` <20120907001927.20289.41627@nucleus>
@ 2012-09-07  1:00         ` Turquette, Mike
  2012-09-07  8:21           ` Linus Walleij
  0 siblings, 1 reply; 15+ messages in thread
From: Turquette, Mike @ 2012-09-07  1:00 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Ulf Hansson, linux-arm-kernel, Samuel Ortiz, linux-kernel,
	Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar

On Thu, Sep 6, 2012 at 5:19 PM, Mike Turquette <mturquette@ti.com> wrote:
> I'll take this series into clk-next.
>

Oops, I forgot to ask about patch #3.  Which tree do you want that to
go through?

Thanks,
Mike

> Regards,
> Mike
>
>> Kind regards
>> Ulf Hansson

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-09-07  1:00         ` Turquette, Mike
@ 2012-09-07  8:21           ` Linus Walleij
  2012-09-07 12:29             ` Ulf Hansson
  0 siblings, 1 reply; 15+ messages in thread
From: Linus Walleij @ 2012-09-07  8:21 UTC (permalink / raw)
  To: Turquette, Mike
  Cc: Ulf Hansson, Ulf Hansson, linux-arm-kernel, Samuel Ortiz,
	linux-kernel, Lee Jones, Philippe Begnic, Srinidhi Kasagar

On Fri, Sep 7, 2012 at 3:00 AM, Turquette, Mike <mturquette@ti.com> wrote:
> On Thu, Sep 6, 2012 at 5:19 PM, Mike Turquette <mturquette@ti.com> wrote:
>> I'll take this series into clk-next.
>
> Oops, I forgot to ask about patch #3.  Which tree do you want that to
> go through?

Just take it all through your tree if there are no major conflicts.
Acked-by etc.

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-09-07  8:21           ` Linus Walleij
@ 2012-09-07 12:29             ` Ulf Hansson
  2012-09-07 21:34               ` Linus Walleij
  0 siblings, 1 reply; 15+ messages in thread
From: Ulf Hansson @ 2012-09-07 12:29 UTC (permalink / raw)
  To: Linus Walleij
  Cc: Turquette, Mike, Ulf Hansson, linux-arm-kernel, Samuel Ortiz,
	linux-kernel, Lee Jones, Philippe Begnic, Srinidhi Kasagar

On 7 September 2012 10:21, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Fri, Sep 7, 2012 at 3:00 AM, Turquette, Mike <mturquette@ti.com> wrote:
>> On Thu, Sep 6, 2012 at 5:19 PM, Mike Turquette <mturquette@ti.com> wrote:
>>> I'll take this series into clk-next.
>>
>> Oops, I forgot to ask about patch #3.  Which tree do you want that to
>> go through?
>
> Just take it all through your tree if there are no major conflicts.
> Acked-by etc.

Agree, it makes it simpler to go through Mike's clock tree. At least
let's try it out.
I will likely have similar patch series with cross dependencies later
on, so this can be a good first test and hopefully it works.

Although, don't we need an ack by Samuel Ortiz for the patch on mfd?
"mfd: dbx500: Provide a more accurate smp_twd clock"

Or, is it enough with Linus ack since he is the maintainer of that
specific mfd file I have patched?

Kind regards
Ulf Hansson

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate
  2012-09-07 12:29             ` Ulf Hansson
@ 2012-09-07 21:34               ` Linus Walleij
  0 siblings, 0 replies; 15+ messages in thread
From: Linus Walleij @ 2012-09-07 21:34 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Turquette, Mike, Ulf Hansson, linux-arm-kernel, Samuel Ortiz,
	linux-kernel, Lee Jones, Philippe Begnic, Srinidhi Kasagar

On Fri, Sep 7, 2012 at 2:29 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> On 7 September 2012 10:21, Linus Walleij <linus.walleij@linaro.org> wrote:
>> On Fri, Sep 7, 2012 at 3:00 AM, Turquette, Mike <mturquette@ti.com> wrote:
>>> On Thu, Sep 6, 2012 at 5:19 PM, Mike Turquette <mturquette@ti.com> wrote:
>>>> I'll take this series into clk-next.
>>>
>>> Oops, I forgot to ask about patch #3.  Which tree do you want that to
>>> go through?
>>
>> Just take it all through your tree if there are no major conflicts.
>> Acked-by etc.
>
> Agree, it makes it simpler to go through Mike's clock tree. At least
> let's try it out.
> I will likely have similar patch series with cross dependencies later
> on, so this can be a good first test and hopefully it works.

That will probably hit the next merge window anyway - these
patches will go into v3.7 as it looks, then you can finalize the
next series for v3.8.

> Although, don't we need an ack by Samuel Ortiz for the patch on mfd?
> "mfd: dbx500: Provide a more accurate smp_twd clock"

Confused, isn't that patch part of the latter series, and not
part of what Mike merged?

> Or, is it enough with Linus ack since he is the maintainer of that
> specific mfd file I have patched?

That's up to Mike, but I hardly think Sam is going to get very
angry about this if we merge it.

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock
  2012-08-31 12:21 ` [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock Ulf Hansson
@ 2012-09-19 16:02   ` Samuel Ortiz
  2012-09-19 16:42     ` Mike Turquette
  0 siblings, 1 reply; 15+ messages in thread
From: Samuel Ortiz @ 2012-09-19 16:02 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: linux-arm-kernel, Mike Turquette, Mike Turquette, linux-kernel,
	Linus Walleij, Lee Jones, Philippe Begnic, Srinidhi Kasagar,
	Michel Jaouen, Ulf Hansson, Rickard Andersson

Hi Ulf,

On Fri, Aug 31, 2012 at 02:21:30PM +0200, Ulf Hansson wrote:
> From: Michel Jaouen <michel.jaouen@stericsson.com>
> 
> The local timer clock is based on ARM subsystem clock. This patch
> obtains a more exact value of that clock by reading PRCMU registers.
> Using this increases the accuracy of the local timer events.
> 
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
> Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
> ---
>  drivers/mfd/db8500-prcmu.c       |   42 ++++++++++++++++++++++++++++++++++++++
>  drivers/mfd/dbx500-prcmu-regs.h  |    4 +++-
>  include/linux/mfd/dbx500-prcmu.h |    1 +
>  3 files changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> index 4f74529..e7f9539 100644
> --- a/drivers/mfd/db8500-prcmu.c
> +++ b/drivers/mfd/db8500-prcmu.c
> @@ -418,6 +418,9 @@ static struct {
>  
>  static atomic_t ac_wake_req_state = ATOMIC_INIT(0);
>  
> +/* Functions definition */
> +static void compute_armss_rate(void);
> +
I'm not a big fan of forward declarations, but I still applied your patch to
my for-next branch. Thanks.

Cheers,
Samuel.

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

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock
  2012-09-19 16:02   ` Samuel Ortiz
@ 2012-09-19 16:42     ` Mike Turquette
  2012-09-19 16:56       ` Samuel Ortiz
  0 siblings, 1 reply; 15+ messages in thread
From: Mike Turquette @ 2012-09-19 16:42 UTC (permalink / raw)
  To: Samuel Ortiz, Ulf Hansson
  Cc: linux-arm-kernel, linux-kernel, Linus Walleij, Lee Jones,
	Philippe Begnic, Srinidhi Kasagar, Michel Jaouen, Ulf Hansson,
	Rickard Andersson

Quoting Samuel Ortiz (2012-09-19 09:02:51)
> Hi Ulf,
> 
> On Fri, Aug 31, 2012 at 02:21:30PM +0200, Ulf Hansson wrote:
> > From: Michel Jaouen <michel.jaouen@stericsson.com>
> > 
> > The local timer clock is based on ARM subsystem clock. This patch
> > obtains a more exact value of that clock by reading PRCMU registers.
> > Using this increases the accuracy of the local timer events.
> > 
> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
> > Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
> > ---
> >  drivers/mfd/db8500-prcmu.c       |   42 ++++++++++++++++++++++++++++++++++++++
> >  drivers/mfd/dbx500-prcmu-regs.h  |    4 +++-
> >  include/linux/mfd/dbx500-prcmu.h |    1 +
> >  3 files changed, 46 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> > index 4f74529..e7f9539 100644
> > --- a/drivers/mfd/db8500-prcmu.c
> > +++ b/drivers/mfd/db8500-prcmu.c
> > @@ -418,6 +418,9 @@ static struct {
> >  
> >  static atomic_t ac_wake_req_state = ATOMIC_INIT(0);
> >  
> > +/* Functions definition */
> > +static void compute_armss_rate(void);
> > +
> I'm not a big fan of forward declarations, but I still applied your patch to
> my for-next branch. Thanks.
> 

Samuel,

Not sure if you were Cc'd on the rest of the patches in this series but
after some discussion (see patch #1) I took all four patches into
clk-next, including the MFD change.  This was done first week of
September.  At this point those patches have shifted into my stable
branch that I have promised not to rebase (for arm-soc dependencies).

Are you OK with me taking this patch through the clk-next branch?

Regards,
Mike

> Cheers,
> Samuel.
> 
> -- 
> Intel Open Source Technology Centre
> http://oss.intel.com/

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock
  2012-09-19 16:42     ` Mike Turquette
@ 2012-09-19 16:56       ` Samuel Ortiz
  0 siblings, 0 replies; 15+ messages in thread
From: Samuel Ortiz @ 2012-09-19 16:56 UTC (permalink / raw)
  To: Mike Turquette
  Cc: Ulf Hansson, linux-arm-kernel, linux-kernel, Linus Walleij,
	Lee Jones, Philippe Begnic, Srinidhi Kasagar, Michel Jaouen,
	Ulf Hansson, Rickard Andersson

Hi Mike,

On Wed, Sep 19, 2012 at 09:42:31AM -0700, Mike Turquette wrote:
> Quoting Samuel Ortiz (2012-09-19 09:02:51)
> > Hi Ulf,
> > 
> > On Fri, Aug 31, 2012 at 02:21:30PM +0200, Ulf Hansson wrote:
> > > From: Michel Jaouen <michel.jaouen@stericsson.com>
> > > 
> > > The local timer clock is based on ARM subsystem clock. This patch
> > > obtains a more exact value of that clock by reading PRCMU registers.
> > > Using this increases the accuracy of the local timer events.
> > > 
> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > > Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
> > > Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
> > > ---
> > >  drivers/mfd/db8500-prcmu.c       |   42 ++++++++++++++++++++++++++++++++++++++
> > >  drivers/mfd/dbx500-prcmu-regs.h  |    4 +++-
> > >  include/linux/mfd/dbx500-prcmu.h |    1 +
> > >  3 files changed, 46 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> > > index 4f74529..e7f9539 100644
> > > --- a/drivers/mfd/db8500-prcmu.c
> > > +++ b/drivers/mfd/db8500-prcmu.c
> > > @@ -418,6 +418,9 @@ static struct {
> > >  
> > >  static atomic_t ac_wake_req_state = ATOMIC_INIT(0);
> > >  
> > > +/* Functions definition */
> > > +static void compute_armss_rate(void);
> > > +
> > I'm not a big fan of forward declarations, but I still applied your patch to
> > my for-next branch. Thanks.
> > 
> 
> Samuel,
> 
> Not sure if you were Cc'd on the rest of the patches in this series but
> after some discussion (see patch #1) I took all four patches into
> clk-next, including the MFD change.  This was done first week of
> September.  At this point those patches have shifted into my stable
> branch that I have promised not to rebase (for arm-soc dependencies).
> 
> Are you OK with me taking this patch through the clk-next branch?
Yes, I'm fine with it.

Cheers,
Samuel.

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

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2012-09-19 16:56 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-08-31 12:21 [PATCH 0/4] clk: Support for smp_twd clock for ux500 Ulf Hansson
2012-08-31 12:21 ` [PATCH 1/4] clk: Provide option for clk_get_rate to issue hw for new rate Ulf Hansson
2012-08-31 19:29   ` Mike Turquette
2012-09-06  9:09     ` Ulf Hansson
     [not found]       ` <20120907001927.20289.41627@nucleus>
2012-09-07  1:00         ` Turquette, Mike
2012-09-07  8:21           ` Linus Walleij
2012-09-07 12:29             ` Ulf Hansson
2012-09-07 21:34               ` Linus Walleij
2012-08-31 12:21 ` [PATCH 2/4] clk: ux500: Support for prmcu_rate clock Ulf Hansson
2012-08-31 12:21 ` [PATCH 3/4] mfd: dbx500: Provide a more accurate smp_twd clock Ulf Hansson
2012-09-19 16:02   ` Samuel Ortiz
2012-09-19 16:42     ` Mike Turquette
2012-09-19 16:56       ` Samuel Ortiz
2012-08-31 12:21 ` [PATCH 4/4] clk: ux500: Define smp_twd clock for u8500 Ulf Hansson
2012-08-31 23:32 ` [PATCH 0/4] clk: Support for smp_twd clock for ux500 Linus Walleij

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