diff mbox

[v10,25/27] ARM: davinci: add device tree support to timer

Message ID 20180509172606.29387-26-david@lechnology.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

David Lechner May 9, 2018, 5:26 p.m. UTC
This adds device tree support to the davinci timer so that when clocks
are moved to device tree, the timer will still work.

Signed-off-by: David Lechner <david@lechnology.com>
---

v10 changes:
- change compatible to "ti,da830-timer"
- remove comment clocks as platform devices

v9 changes:
- none (there were supposed to be changed, but apparently they got squashed
  into the next commit - will fix on the next round)

v8 changes:
- none

v7 changes:
- rebased
- add davinci prefix to commit message

v6 changes:
- rebased


 arch/arm/mach-davinci/Kconfig |  1 +
 arch/arm/mach-davinci/time.c  | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

Comments

Sekhar Nori May 17, 2018, 2:35 p.m. UTC | #1
Hi David,

On Wednesday 09 May 2018 10:56 PM, David Lechner wrote:
> This adds device tree support to the davinci timer so that when clocks
> are moved to device tree, the timer will still work.
> 
> Signed-off-by: David Lechner <david@lechnology.com>
> ---

> +static int __init of_davinci_timer_init(struct device_node *np)
> +{
> +	struct clk *clk;
> +
> +	clk = of_clk_get(np, 0);
> +	if (IS_ERR(clk)) {
> +		struct of_phandle_args clkspec;
> +
> +		/*
> +		 * Fall back to using ref_clk if the actual clock is not
> +		 * available. There will be problems later if the real clock
> +		 * source is disabled.
> +		 */
> +
> +		pr_warn("%s: falling back to ref_clk\n", __func__);
> +
> +		clkspec.np = of_find_node_by_name(NULL, "ref_clk");
> +		if (IS_ERR(clkspec.np)) {
> +			pr_err("%s: No clock available for timer!\n", __func__);
> +			return PTR_ERR(clkspec.np);
> +		}
> +		clk = of_clk_get_from_provider(&clkspec);
> +		of_node_put(clkspec.np);
> +	}

Do we need this error path now?

Thanks,
Sekhar
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David Lechner May 17, 2018, 3:09 p.m. UTC | #2
On 05/17/2018 09:35 AM, Sekhar Nori wrote:
> Hi David,
> 
> On Wednesday 09 May 2018 10:56 PM, David Lechner wrote:
>> This adds device tree support to the davinci timer so that when clocks
>> are moved to device tree, the timer will still work.
>>
>> Signed-off-by: David Lechner <david@lechnology.com>
>> ---
> 
>> +static int __init of_davinci_timer_init(struct device_node *np)
>> +{
>> +	struct clk *clk;
>> +
>> +	clk = of_clk_get(np, 0);
>> +	if (IS_ERR(clk)) {
>> +		struct of_phandle_args clkspec;
>> +
>> +		/*
>> +		 * Fall back to using ref_clk if the actual clock is not
>> +		 * available. There will be problems later if the real clock
>> +		 * source is disabled.
>> +		 */
>> +
>> +		pr_warn("%s: falling back to ref_clk\n", __func__);
>> +
>> +		clkspec.np = of_find_node_by_name(NULL, "ref_clk");
>> +		if (IS_ERR(clkspec.np)) {
>> +			pr_err("%s: No clock available for timer!\n", __func__);
>> +			return PTR_ERR(clkspec.np);
>> +		}
>> +		clk = of_clk_get_from_provider(&clkspec);
>> +		of_node_put(clkspec.np);
>> +	}
> 
> Do we need this error path now?
> 
> Thanks,
> Sekhar
> 

No, not really.
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Sekhar Nori May 18, 2018, 6:05 a.m. UTC | #3
On Thursday 17 May 2018 08:39 PM, David Lechner wrote:
> On 05/17/2018 09:35 AM, Sekhar Nori wrote:
>> Hi David,
>>
>> On Wednesday 09 May 2018 10:56 PM, David Lechner wrote:
>>> This adds device tree support to the davinci timer so that when clocks
>>> are moved to device tree, the timer will still work.
>>>
>>> Signed-off-by: David Lechner <david@lechnology.com>
>>> ---
>>
>>> +static int __init of_davinci_timer_init(struct device_node *np)
>>> +{
>>> +    struct clk *clk;
>>> +
>>> +    clk = of_clk_get(np, 0);
>>> +    if (IS_ERR(clk)) {
>>> +        struct of_phandle_args clkspec;
>>> +
>>> +        /*
>>> +         * Fall back to using ref_clk if the actual clock is not
>>> +         * available. There will be problems later if the real clock
>>> +         * source is disabled.
>>> +         */
>>> +
>>> +        pr_warn("%s: falling back to ref_clk\n", __func__);
>>> +
>>> +        clkspec.np = of_find_node_by_name(NULL, "ref_clk");
>>> +        if (IS_ERR(clkspec.np)) {
>>> +            pr_err("%s: No clock available for timer!\n", __func__);
>>> +            return PTR_ERR(clkspec.np);
>>> +        }
>>> +        clk = of_clk_get_from_provider(&clkspec);
>>> +        of_node_put(clkspec.np);
>>> +    }
>>
>> Do we need this error path now?
>>
>> Thanks,
>> Sekhar
>>
> 
> No, not really.

Then lets just print an error and return the error number.

Thanks,
Sekhar
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David Lechner May 18, 2018, 3:35 p.m. UTC | #4
On 05/18/2018 01:05 AM, Sekhar Nori wrote:
> On Thursday 17 May 2018 08:39 PM, David Lechner wrote:
>> On 05/17/2018 09:35 AM, Sekhar Nori wrote:
>>> Hi David,
>>>
>>> On Wednesday 09 May 2018 10:56 PM, David Lechner wrote:
>>>> This adds device tree support to the davinci timer so that when clocks
>>>> are moved to device tree, the timer will still work.
>>>>
>>>> Signed-off-by: David Lechner <david@lechnology.com>
>>>> ---
>>>
>>>> +static int __init of_davinci_timer_init(struct device_node *np)
>>>> +{
>>>> +    struct clk *clk;
>>>> +
>>>> +    clk = of_clk_get(np, 0);
>>>> +    if (IS_ERR(clk)) {
>>>> +        struct of_phandle_args clkspec;
>>>> +
>>>> +        /*
>>>> +         * Fall back to using ref_clk if the actual clock is not
>>>> +         * available. There will be problems later if the real clock
>>>> +         * source is disabled.
>>>> +         */
>>>> +
>>>> +        pr_warn("%s: falling back to ref_clk\n", __func__);
>>>> +
>>>> +        clkspec.np = of_find_node_by_name(NULL, "ref_clk");
>>>> +        if (IS_ERR(clkspec.np)) {
>>>> +            pr_err("%s: No clock available for timer!\n", __func__);
>>>> +            return PTR_ERR(clkspec.np);
>>>> +        }
>>>> +        clk = of_clk_get_from_provider(&clkspec);
>>>> +        of_node_put(clkspec.np);
>>>> +    }
>>>
>>> Do we need this error path now?
>>>
>>> Thanks,
>>> Sekhar
>>>
>>
>> No, not really.
> 
> Then lets just print an error and return the error number.
> 

OK. FYI, timer_probe() prints the error if we return and error, so
I will just return the error.

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diff mbox

Patch

diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index ba9912b4dfab..da8a039d65f9 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -59,6 +59,7 @@  config MACH_DA8XX_DT
 	default y
 	depends on ARCH_DAVINCI_DA850
 	select PINCTRL
+	select TIMER_OF
 	help
 	  Say y here to include support for TI DaVinci DA850 based using
 	  Flattened Device Tree. More information at Documentation/devicetree
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index 7ea3db0ff062..184e72922cc1 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -17,6 +17,7 @@ 
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/sched_clock.h>
 
@@ -397,3 +398,34 @@  void __init davinci_timer_init(struct clk *timer_clk)
 	for (i=0; i< ARRAY_SIZE(timers); i++)
 		timer32_config(&timers[i]);
 }
+
+static int __init of_davinci_timer_init(struct device_node *np)
+{
+	struct clk *clk;
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		struct of_phandle_args clkspec;
+
+		/*
+		 * Fall back to using ref_clk if the actual clock is not
+		 * available. There will be problems later if the real clock
+		 * source is disabled.
+		 */
+
+		pr_warn("%s: falling back to ref_clk\n", __func__);
+
+		clkspec.np = of_find_node_by_name(NULL, "ref_clk");
+		if (IS_ERR(clkspec.np)) {
+			pr_err("%s: No clock available for timer!\n", __func__);
+			return PTR_ERR(clkspec.np);
+		}
+		clk = of_clk_get_from_provider(&clkspec);
+		of_node_put(clkspec.np);
+	}
+
+	davinci_timer_init(clk);
+
+	return 0;
+}
+TIMER_OF_DECLARE(davinci_timer, "ti,da830-timer", of_davinci_timer_init);