Re: [PATCH 2/2] ARM: OMAP4+: Add a timer attribute for timers that can interrupt IPU

[Jon Hunter <jon-hunter@ti.com>]

On 04/17/2013 07:04 PM, Jon Hunter wrote:
> 
> On 04/17/2013 06:23 PM, Suman Anna wrote:
>> Some instances of the DMTIMER peripheral on OMAP4+ devices have the
>> ability to interrupt the on-chip image processor unit (IPU) subsystem
>> (a common name for the dual Cortex-M3 subsystem on OMAP4 or the dual
>> Cortex-M4 subsystem on OMAP5) in addition to the ARM CPU. Add a
>> DMTIMER attribute to indicate which timers can interrupt the IPU.
>>
>> This patch is similar to the patch, 5c3e4ec (ARM: OMAP: Add a timer
>> attribute for timers that can interrupt the DSP) that adds a similar
>> capability for DSP.
>>
>> DMTIMERs that have the ability to interrupt the IPU on OMAP devices
>> are as follows:
>>     OMAP1/2/3 devices : not applicable
>>     OMAP4/5 devices   : DMTIMERs 3,4,9 & 11
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  Documentation/devicetree/bindings/arm/omap/timer.txt |  3 +++
>>  arch/arm/boot/dts/omap4.dtsi                         |  4 ++++
>>  arch/arm/boot/dts/omap5.dtsi                         |  4 ++++
>>  arch/arm/mach-omap2/omap_hwmod_44xx_data.c           | 16 ++++++++++++++--
>>  arch/arm/plat-omap/dmtimer.c                         |  2 ++
>>  arch/arm/plat-omap/include/plat/dmtimer.h            |  1 +
>>  6 files changed, 28 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/omap/timer.txt b/Documentation/devicetree/bindings/arm/omap/timer.txt
>> index 8732d4d..edaf664 100644
>> --- a/Documentation/devicetree/bindings/arm/omap/timer.txt
>> +++ b/Documentation/devicetree/bindings/arm/omap/timer.txt
>> @@ -15,6 +15,9 @@ Optional properties:
>>  - ti,timer-alwon:	Indicates the timer is in an alway-on power domain.
>>  - ti,timer-dsp:		Indicates the timer can interrupt the on-chip DSP in
>>  			addition to the ARM CPU.
>> +- ti,timer-ipu:		Indicates the timer can interrupt the on-chip IPU (the
>> +			dual Cortex-M3/Cortex-M4 subsystem on OMAP4/OMAP5) in
>> +			addition to the ARM CPU.
> 
> I am ok with adding a new property. However, reading the omap5 reference
> manual I see that the timers can interrupt the dsp, c2c and ipu.
> Therefore, I am not sure if we should consider making this a property
> with a value that is a mask of all other devices that can be
> interrupted. For example, "ti,timer-irqs".
> 
>>  - ti,timer-pwm: 	Indicates the timer can generate a PWM output.
>>  - ti,timer-secure: 	Indicates the timer is reserved on a secure OMAP device
>>  			and therefore cannot be used by the kernel.
>> diff --git a/arch/arm/boot/dts/omap4.dtsi b/arch/arm/boot/dts/omap4.dtsi
>> index 739bb79..55c633a 100644
>> --- a/arch/arm/boot/dts/omap4.dtsi
>> +++ b/arch/arm/boot/dts/omap4.dtsi
>> @@ -460,6 +460,7 @@
>>  			reg = <0x48034000 0x80>;
>>  			interrupts = <0 39 0x4>;
>>  			ti,hwmods = "timer3";
>> +			ti,timer-ipu;
>>  		};
>>  
>>  		timer4: timer@48036000 {
>> @@ -467,6 +468,7 @@
>>  			reg = <0x48036000 0x80>;
>>  			interrupts = <0 40 0x4>;
>>  			ti,hwmods = "timer4";
>> +			ti,timer-ipu;
>>  		};
>>  
>>  		timer5: timer@40138000 {
>> @@ -511,6 +513,7 @@
>>  			reg = <0x4803e000 0x80>;
>>  			interrupts = <0 45 0x4>;
>>  			ti,hwmods = "timer9";
>> +			ti,timer-ipu;
>>  			ti,timer-pwm;
>>  		};
>>  
>> @@ -527,6 +530,7 @@
>>  			reg = <0x48088000 0x80>;
>>  			interrupts = <0 47 0x4>;
>>  			ti,hwmods = "timer11";
>> +			ti,timer-ipu;
>>  			ti,timer-pwm;
>>  		};
>>  	};
>> diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
>> index 0d155f5..c9ecdbe 100644
>> --- a/arch/arm/boot/dts/omap5.dtsi
>> +++ b/arch/arm/boot/dts/omap5.dtsi
>> @@ -406,6 +406,7 @@
>>  			reg = <0x48034000 0x80>;
>>  			interrupts = <0 39 0x4>;
>>  			ti,hwmods = "timer3";
>> +			ti,timer-ipu;
>>  		};
>>  
>>  		timer4: timer@48036000 {
>> @@ -413,6 +414,7 @@
>>  			reg = <0x48036000 0x80>;
>>  			interrupts = <0 40 0x4>;
>>  			ti,hwmods = "timer4";
>> +			ti,timer-ipu;
>>  		};
>>  
>>  		timer5: timer@40138000 {
>> @@ -459,6 +461,7 @@
>>  			reg = <0x4803e000 0x80>;
>>  			interrupts = <0 45 0x4>;
>>  			ti,hwmods = "timer9";
>> +			ti,timer-ipu;
>>  			ti,timer-pwm;
>>  		};
>>  
>> @@ -475,6 +478,7 @@
>>  			reg = <0x48088000 0x80>;
>>  			interrupts = <0 47 0x4>;
>>  			ti,hwmods = "timer11";
>> +			ti,timer-ipu;
>>  			ti,timer-pwm;
>>  		};
>>  
>> diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> index 9e05765..f57796b 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> @@ -3150,6 +3150,16 @@ static struct omap_timer_capability_dev_attr capability_dsp_pwm_dev_attr = {
>>  	.timer_capability       = OMAP_TIMER_HAS_DSP_IRQ | OMAP_TIMER_HAS_PWM,
>>  };
>>  
>> +/* timers with IPU interrupt dev attribute */
>> +static struct omap_timer_capability_dev_attr capability_ipu_dev_attr = {
>> +	.timer_capability       = OMAP_TIMER_HAS_IPU_IRQ,
>> +};
>> +
>> +/* pwm timers with IPU interrupt dev attribute */
>> +static struct omap_timer_capability_dev_attr capability_ipu_pwm_dev_attr = {
>> +	.timer_capability       = OMAP_TIMER_HAS_IPU_IRQ | OMAP_TIMER_HAS_PWM,
>> +};
>> +
>>  /* timer1 */
>>  static struct omap_hwmod_irq_info omap44xx_timer1_irqs[] = {
>>  	{ .irq = 37 + OMAP44XX_IRQ_GIC_START },
>> @@ -3214,6 +3224,7 @@ static struct omap_hwmod omap44xx_timer3_hwmod = {
>>  			.modulemode   = MODULEMODE_SWCTRL,
>>  		},
>>  	},
>> +	.dev_attr	= &capability_ipu_dev_attr,
>>  };
>>  
>>  /* timer4 */
>> @@ -3235,6 +3246,7 @@ static struct omap_hwmod omap44xx_timer4_hwmod = {
>>  			.modulemode   = MODULEMODE_SWCTRL,
>>  		},
>>  	},
>> +	.dev_attr	= &capability_ipu_dev_attr,
>>  };
>>  
>>  /* timer5 */
>> @@ -3344,7 +3356,7 @@ static struct omap_hwmod omap44xx_timer9_hwmod = {
>>  			.modulemode   = MODULEMODE_SWCTRL,
>>  		},
>>  	},
>> -	.dev_attr	= &capability_pwm_dev_attr,
>> +	.dev_attr	= &capability_ipu_pwm_dev_attr,
>>  };
>>  
>>  /* timer10 */
>> @@ -3389,7 +3401,7 @@ static struct omap_hwmod omap44xx_timer11_hwmod = {
>>  			.modulemode   = MODULEMODE_SWCTRL,
>>  		},
>>  	},
>> -	.dev_attr	= &capability_pwm_dev_attr,
>> +	.dev_attr	= &capability_ipu_pwm_dev_attr,
>>  };
>>  
>>  /*
>> diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
>> index a0daa2f..b97bd6a 100644
>> --- a/arch/arm/plat-omap/dmtimer.c
>> +++ b/arch/arm/plat-omap/dmtimer.c
>> @@ -817,6 +817,8 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
>>  			timer->capability |= OMAP_TIMER_ALWON;
>>  		if (of_find_property(dev->of_node, "ti,timer-dsp", NULL))
>>  			timer->capability |= OMAP_TIMER_HAS_DSP_IRQ;
>> +		if (of_find_property(dev->of_node, "ti,timer-ipu", NULL))
>> +			timer->capability |= OMAP_TIMER_HAS_IPU_IRQ;
>>  		if (of_find_property(dev->of_node, "ti,timer-pwm", NULL))
>>  			timer->capability |= OMAP_TIMER_HAS_PWM;
>>  		if (of_find_property(dev->of_node, "ti,timer-secure", NULL))
>> diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h
>> index a3fbc48..4bbc72d 100644
>> --- a/arch/arm/plat-omap/include/plat/dmtimer.h
>> +++ b/arch/arm/plat-omap/include/plat/dmtimer.h
>> @@ -64,6 +64,7 @@
>>  #define OMAP_TIMER_HAS_PWM				0x20000000
>>  #define OMAP_TIMER_NEEDS_RESET				0x10000000
>>  #define OMAP_TIMER_HAS_DSP_IRQ				0x08000000
>> +#define OMAP_TIMER_HAS_IPU_IRQ				0x04000000
>>  
>>  /*
>>   * timer errata flags
> 
> You also need to update arch/arm/mach-omap2/timer.c if you are adding a
> new property. See [1].
> 
> [1]
> http://git.kernel.org/cgit/linux/kernel/git/tmlind/linux-omap.git/commit/?h=omap-for-v3.10/timer&id=2eb03937df3ebc822dab413bd69533dcd66afd48

Thinking about this some more, I should have added a
omap_dmtimer_get_properties_dt() that returns the timer properties from
device-tree and then there would be a single place for adding new
properties. So if we add another property probably a good time to add
such a helper function.

Cheers
Jon