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pwm fixes for 3.8

PATCH New Tony Prisk 2 participants 4 messages Nov 19, 2012 – Nov 20, 2012

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PWM Arm/VT8500 Arm architecture
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Tony Prisk

author
#0 lore raw

v3 cover pwm fixes for 3.8

Hi Theirry,

I felt the error message for clk_enable in vt8500_pwm_config() needed to somehow indicate that the clk_enable failed in this function otherwise if there is a problem, you can't tell which of the clk_enable's generated the fail message.
If there is a clock error - as you pointed out - it will probably fail elsewhere as well so I've changed it to match the other error messages.

These should be applied on top of the original patch.

v2: Add error checking for clk_enable()
v3: Remove superfluous ;'s. Error message style correction.

Tony Prisk (2):
Fix build error in pwm-vt8500.c
pwm: vt8500: Ensure pwm clock is enabled during pwm_config

 drivers/pwm/pwm-vt8500.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)
Signature · 1 line
1.7.9.5
author
#1 lore raw

PATCH v3 1/2 Fix build error in pwm-vt8500.c

A missing '{' causes a build error in pwm-vt8500.c

Signed-off-by Tony Prisk <[email protected]>
---
 drivers/pwm/pwm-vt8500.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/pwm/pwm-vt8500.c +1 -1
index 970b0c6..806f72c 100644
@@ -100,7 +100,7 @@ static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
 
 	err = clk_enable(vt8500->clk);
-	if (err < 0)
+	if (err < 0) {
 		dev_err(chip->dev, "failed to enable clock\n");
 		return err;
 	};
Signature · 1 line
1.7.9.5
author
#2 lore raw

PATCH v3 2/2 pwm: vt8500: Ensure pwm clock is enabled during pwm_config

In reply to Tony Prisk

This patch corrects a bug reported by Peter Vasil.

When all PWMs are disabled, PWM module may be disabled during calls to pwm_config. This patch enables/disables the clock in pwm_config to ensure the module is active before register read/ writes.

Signed-off-by Tony Prisk <[email protected]>
Tested-by Peter Vasil <[email protected]>
---
 drivers/pwm/pwm-vt8500.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
drivers/pwm/pwm-vt8500.c +12 -2
index 806f72c..b0ba2d4 100644
@@ -62,6 +62,13 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
 	unsigned long long c;
 	unsigned long period_cycles, prescale, pv, dc;
+	int err;
+
+	err = clk_enable(vt8500->clk);
+	if (err < 0) {
+		dev_err(chip->dev, "failed to enable clock\n");
+		return err;
+	}
 
 	c = clk_get_rate(vt8500->clk);
 	c = c * period_ns;

@@ -75,8 +82,10 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (pv > 4095)
 		pv = 4095;
 
-	if (prescale > 1023)
+	if (prescale > 1023) {
+		clk_disable(vt8500->clk);
 		return -EINVAL;
+	}
 
 	c = (unsigned long long)pv * duty_ns;
 	do_div(c, period_ns);

@@ -91,6 +100,7 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 3));
 	writel(dc, vt8500->base + 0xc + (pwm->hwpwm << 4));
 
+	clk_disable(vt8500->clk);
 	return 0;
 }
 

@@ -103,7 +113,7 @@ static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	if (err < 0) {
 		dev_err(chip->dev, "failed to enable clock\n");
 		return err;
-	};
+	}
 
 	pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0));
 	writel(5, vt8500->base + (pwm->hwpwm << 4));
Signature · 1 line
1.7.9.5
#3 lore raw

v3 cover pwm fixes for 3.8

In reply to Tony Prisk
Quoted 14 lines · Tony Prisk

Hi Theirry,

I felt the error message for clk_enable in vt8500_pwm_config() needed to somehow indicate that the clk_enable failed in this function otherwise if there is a problem, you can't tell which of the clk_enable's generated the fail message.
If there is a clock error - as you pointed out - it will probably fail elsewhere as well so I've changed it to match the other error messages.

These should be applied on top of the original patch.

v2: Add error checking for clk_enable()
v3: Remove superfluous ;'s. Error message style correction.

Quoted 6 lines

Tony Prisk (2):
Fix build error in pwm-vt8500.c
pwm: vt8500: Ensure pwm clock is enabled during pwm_config

 drivers/pwm/pwm-vt8500.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

Applied with minor stylistic fixups to the commit message, thanks.

Thierry
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