[PATCH 0/3] ARM: at91/tc/clocksource: various robustness improvements

[PATCH 0/3] ARM: at91/tc/clocksource: various robustness improvements

[Boris BREZILLON]

Hello,

This series include several improvements regarding the at91 tc clocksource
driver:
 - use clk_prepare/unprepare_enable/disable functions instead of the
   clk_enable/disable functions to prepare the transition to the common clk
   framework
 - check several function return values instead of considering these functions
   always suceed.
 - remove the deprecated IRQF_DISABLED flag

Best Regards,

Boris

Boris BREZILLON (3):
  ARM: at91/tc/clocksource: replace clk_enable/disable with
    clk_prepare_enable/disable_unprepare
  ARM: at91/tc/clocksource: improve driver robustness
  ARM: at91/tc/clocksource: remove IRQF_DISABLED

 drivers/clocksource/tcb_clksrc.c |   61 +++++++++++++++++++++++++++++++-------
 1 file changed, 50 insertions(+), 11 deletions(-)

-- 
1.7.9.5

[PATCH 1/3] ARM: at91/tc/clocksource: replace clk_enable/disable with clk_prepare_enable/disable_unprepare

[Boris BREZILLON]

Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/clocksource/tcb_clksrc.c |   26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..0481562 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -100,7 +100,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 			|| tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
 		__raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
 		__raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
-		clk_disable(tcd->clk);
+		clk_disable_unprepare(tcd->clk);
 	}
 
 	switch (m) {
@@ -109,7 +109,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 	 * of oneshot, we get lower overhead and improved accuracy.
 	 */
 	case CLOCK_EVT_MODE_PERIODIC:
-		clk_enable(tcd->clk);
+		clk_prepare_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and restart */
 		__raw_writel(timer_clock
@@ -126,7 +126,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:
-		clk_enable(tcd->clk);
+		clk_prepare_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and stop */
 		__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
@@ -265,6 +265,7 @@ static int __init tcb_clksrc_init(void)
 	int best_divisor_idx = -1;
 	int clk32k_divisor_idx = -1;
 	int i;
+	int ret;
 
 	tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, clksrc.name);
 	if (!tc) {
@@ -275,7 +276,11 @@ static int __init tcb_clksrc_init(void)
 	pdev = tc->pdev;
 
 	t0_clk = tc->clk[0];
-	clk_enable(t0_clk);
+	ret = clk_prepare_enable(t0_clk);
+	if (ret) {
+		pr_debug("can't enable T0 clk\n");
+		goto err_free_tc;
+	}
 
 	/* How fast will we be counting?  Pick something over 5 MHz.  */
 	rate = (u32) clk_get_rate(t0_clk);
@@ -313,7 +318,11 @@ static int __init tcb_clksrc_init(void)
 		/* tclib will give us three clocks no matter what the
 		 * underlying platform supports.
 		 */
-		clk_enable(tc->clk[1]);
+		ret = clk_prepare_enable(tc->clk[1]);
+		if (ret) {
+			pr_debug("can't enable T1 clk\n");
+			goto err_disable_t0;
+		}
 		/* setup both channel 0 & 1 */
 		tcb_setup_dual_chan(tc, best_divisor_idx);
 	}
@@ -325,5 +334,12 @@ static int __init tcb_clksrc_init(void)
 	setup_clkevents(tc, clk32k_divisor_idx);
 
 	return 0;
+
+err_disable_t0:
+	clk_disable_unprepare(t0_clk);
+
+err_free_tc:
+	atmel_tc_free(tc);
+	return ret;
 }
 arch_initcall(tcb_clksrc_init);
-- 
1.7.9.5

[PATCH 1/3] ARM: at91/tc/clocksource: replace clk_enable/disable with clk_prepare_enable/disable_unprepare

[Boris BREZILLON]

Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/clocksource/tcb_clksrc.c |   26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..0481562 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -100,7 +100,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 			|| tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
 		__raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
 		__raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
-		clk_disable(tcd->clk);
+		clk_disable_unprepare(tcd->clk);
 	}
 
 	switch (m) {
@@ -109,7 +109,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 	 * of oneshot, we get lower overhead and improved accuracy.
 	 */
 	case CLOCK_EVT_MODE_PERIODIC:
-		clk_enable(tcd->clk);
+		clk_prepare_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and restart */
 		__raw_writel(timer_clock
@@ -126,7 +126,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:
-		clk_enable(tcd->clk);
+		clk_prepare_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and stop */
 		__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
@@ -265,6 +265,7 @@ static int __init tcb_clksrc_init(void)
 	int best_divisor_idx = -1;
 	int clk32k_divisor_idx = -1;
 	int i;
+	int ret;
 
 	tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, clksrc.name);
 	if (!tc) {
@@ -275,7 +276,11 @@ static int __init tcb_clksrc_init(void)
 	pdev = tc->pdev;
 
 	t0_clk = tc->clk[0];
-	clk_enable(t0_clk);
+	ret = clk_prepare_enable(t0_clk);
+	if (ret) {
+		pr_debug("can't enable T0 clk\n");
+		goto err_free_tc;
+	}
 
 	/* How fast will we be counting?  Pick something over 5 MHz.  */
 	rate = (u32) clk_get_rate(t0_clk);
@@ -313,7 +318,11 @@ static int __init tcb_clksrc_init(void)
 		/* tclib will give us three clocks no matter what the
 		 * underlying platform supports.
 		 */
-		clk_enable(tc->clk[1]);
+		ret = clk_prepare_enable(tc->clk[1]);
+		if (ret) {
+			pr_debug("can't enable T1 clk\n");
+			goto err_disable_t0;
+		}
 		/* setup both channel 0 & 1 */
 		tcb_setup_dual_chan(tc, best_divisor_idx);
 	}
@@ -325,5 +334,12 @@ static int __init tcb_clksrc_init(void)
 	setup_clkevents(tc, clk32k_divisor_idx);
 
 	return 0;
+
+err_disable_t0:
+	clk_disable_unprepare(t0_clk);
+
+err_free_tc:
+	atmel_tc_free(tc);
+	return ret;
 }
 arch_initcall(tcb_clksrc_init);
-- 
1.7.9.5

[PATCH 2/3] ARM: at91/tc/clocksource: improve driver robustness

[Boris BREZILLON]

Check function return values to avoid false positive driver init.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
---
 drivers/clocksource/tcb_clksrc.c |   33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 0481562..10a5d9e 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -184,11 +184,18 @@ static struct irqaction tc_irqaction = {
 	.handler	= ch2_irq,
 };
 
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 {
+	int ret;
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
 
+	/* try to enable t2 clk to avoid future errors in mode change */
+	ret = clk_prepare_enable(t2_clk);
+	if (ret)
+		return ret;
+	clk_disable_unprepare(t2_clk);
+
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;
 	tc_irqaction.dev_id = &clkevt;
@@ -197,16 +204,21 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
+	ret = setup_irq(irq, &tc_irqaction);
+	if (ret)
+		return ret;
+
 	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
 
-	setup_irq(irq, &tc_irqaction);
+	return ret;
 }
 
 #else /* !CONFIG_GENERIC_CLOCKEVENTS */
 
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 {
 	/* NOTHING */
+	return 0;
 }
 
 #endif
@@ -328,13 +340,24 @@ static int __init tcb_clksrc_init(void)
 	}
 
 	/* and away we go! */
-	clocksource_register_hz(&clksrc, divided_rate);
+	ret = clocksource_register_hz(&clksrc, divided_rate);
+	if (ret)
+		goto err_disable_t1;
 
 	/* channel 2:  periodic and oneshot timer support */
-	setup_clkevents(tc, clk32k_divisor_idx);
+	ret = setup_clkevents(tc, clk32k_divisor_idx);
+	if (ret)
+		goto err_unregister_clksrc;
 
 	return 0;
 
+err_unregister_clksrc:
+	clocksource_unregister(&clksrc);
+
+err_disable_t1:
+	if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
+		clk_disable_unprepare(tc->clk[1]);
+
 err_disable_t0:
 	clk_disable_unprepare(t0_clk);
 
-- 
1.7.9.5

[PATCH 3/3] ARM: at91/tc/clocksource: remove IRQF_DISABLED

[Boris BREZILLON]

Remove the deprecated IRQF_DISABLED flag.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
---
 drivers/clocksource/tcb_clksrc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 10a5d9e..00fdd11 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -180,7 +180,7 @@ static irqreturn_t ch2_irq(int irq, void *handle)
 
 static struct irqaction tc_irqaction = {
 	.name		= "tc_clkevt",
-	.flags		= IRQF_TIMER | IRQF_DISABLED,
+	.flags		= IRQF_TIMER,
 	.handler	= ch2_irq,
 };
 
-- 
1.7.9.5

[PATCH 2/3] ARM: at91/tc/clocksource: improve driver robustness

[Nicolas Ferre]

On 02/10/2013 14:35, Boris BREZILLON :
> Check function return values to avoid false positive driver init.
>
> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

> ---
>   drivers/clocksource/tcb_clksrc.c |   33 ++++++++++++++++++++++++++++-----
>   1 file changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 0481562..10a5d9e 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -184,11 +184,18 @@ static struct irqaction tc_irqaction = {
>   	.handler	= ch2_irq,
>   };
>
> -static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
> +static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>   {
> +	int ret;
>   	struct clk *t2_clk = tc->clk[2];
>   	int irq = tc->irq[2];
>
> +	/* try to enable t2 clk to avoid future errors in mode change */
> +	ret = clk_prepare_enable(t2_clk);
> +	if (ret)
> +		return ret;
> +	clk_disable_unprepare(t2_clk);
> +
>   	clkevt.regs = tc->regs;
>   	clkevt.clk = t2_clk;
>   	tc_irqaction.dev_id = &clkevt;
> @@ -197,16 +204,21 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>
>   	clkevt.clkevt.cpumask = cpumask_of(0);
>
> +	ret = setup_irq(irq, &tc_irqaction);
> +	if (ret)
> +		return ret;
> +
>   	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
>
> -	setup_irq(irq, &tc_irqaction);
> +	return ret;
>   }
>
>   #else /* !CONFIG_GENERIC_CLOCKEVENTS */
>
> -static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
> +static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>   {
>   	/* NOTHING */
> +	return 0;
>   }
>
>   #endif
> @@ -328,13 +340,24 @@ static int __init tcb_clksrc_init(void)
>   	}
>
>   	/* and away we go! */
> -	clocksource_register_hz(&clksrc, divided_rate);
> +	ret = clocksource_register_hz(&clksrc, divided_rate);
> +	if (ret)
> +		goto err_disable_t1;
>
>   	/* channel 2:  periodic and oneshot timer support */
> -	setup_clkevents(tc, clk32k_divisor_idx);
> +	ret = setup_clkevents(tc, clk32k_divisor_idx);
> +	if (ret)
> +		goto err_unregister_clksrc;
>
>   	return 0;
>
> +err_unregister_clksrc:
> +	clocksource_unregister(&clksrc);
> +
> +err_disable_t1:
> +	if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
> +		clk_disable_unprepare(tc->clk[1]);
> +
>   err_disable_t0:
>   	clk_disable_unprepare(t0_clk);
>
>


-- 
Nicolas Ferre

[PATCH 3/3] ARM: at91/tc/clocksource: remove IRQF_DISABLED

[Nicolas Ferre]

On 02/10/2013 14:35, Boris BREZILLON :
> Remove the deprecated IRQF_DISABLED flag.
>
> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

> ---
>   drivers/clocksource/tcb_clksrc.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 10a5d9e..00fdd11 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -180,7 +180,7 @@ static irqreturn_t ch2_irq(int irq, void *handle)
>
>   static struct irqaction tc_irqaction = {
>   	.name		= "tc_clkevt",
> -	.flags		= IRQF_TIMER | IRQF_DISABLED,
> +	.flags		= IRQF_TIMER,
>   	.handler	= ch2_irq,
>   };
>
>


-- 
Nicolas Ferre

[PATCH 0/3] ARM: at91/tc/clocksource: various robustness improvements

[Daniel Lezcano]

On 10/02/2013 02:34 PM, Boris BREZILLON wrote:
> Hello,
>
> This series include several improvements regarding the at91 tc clocksource
> driver:
>   - use clk_prepare/unprepare_enable/disable functions instead of the
>     clk_enable/disable functions to prepare the transition to the common clk
>     framework
>   - check several function return values instead of considering these functions
>     always suceed.
>   - remove the deprecated IRQF_DISABLED flag
>
> Best Regards,
>
> Boris
>
> Boris BREZILLON (3):
>    ARM: at91/tc/clocksource: replace clk_enable/disable with
>      clk_prepare_enable/disable_unprepare
>    ARM: at91/tc/clocksource: improve driver robustness
>    ARM: at91/tc/clocksource: remove IRQF_DISABLED
>
>   drivers/clocksource/tcb_clksrc.c |   61 +++++++++++++++++++++++++++++++-------
>   1 file changed, 50 insertions(+), 11 deletions(-)
>

Applied to my tree for 3.13 with the subsystem name and first letter 
capitalized fixed:

clocksource: tcb_clksrc: [A-Z]*

Thanks !
   -- Daniel

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