Subject: [RFC PATCH 07/16] ARM: local timers: move OMAP4 to LOCAL_TIMER_DEVICES/ARM_SMP_TWD

From: [email-masked] (Marc Zyngier)
Date: Fri, 17 Jun 2011 09:39:24 +0100

Hi Santosh,

On 17/06/11 09:16, Santosh Shilimkar wrote:
> On 6/17/2011 12:36 AM, Marc Zyngier wrote:
>> Convert the OMAP4 platforms to use the new arm_smp_twd driver.
>> Add the platform device and register it as early platform device.
>>
>> Tested on a Pandaboard.
>>
>> Cc: Tony Lindgren<[email-masked]>
>> Cc: Santosh Shilimkar<[email-masked]>
>> Signed-off-by: Marc Zyngier<[email-masked]>
>> ---
>>   arch/arm/mach-omap2/Kconfig     |    3 +-
>>   arch/arm/mach-omap2/Makefile    |    1 -
>>   arch/arm/mach-omap2/timer-gp.c  |   40 ++++++++++++++++++++++++++++++++------
>>   arch/arm/mach-omap2/timer-mpu.c |   40 ---------------------------------------
>>   4 files changed, 35 insertions(+), 49 deletions(-)
>>   delete mode 100644 arch/arm/mach-omap2/timer-mpu.c
>>
>> diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
>> index 19d5891..805d7b9 100644
>> --- a/arch/arm/mach-omap2/Kconfig
>> +++ b/arch/arm/mach-omap2/Kconfig
>> @@ -44,7 +44,8 @@ config ARCH_OMAP4
>>   	depends on ARCH_OMAP2PLUS
>>   	select CPU_V7
>>   	select ARM_GIC
>> -	select LOCAL_TIMERS if SMP
>> +	select LOCAL_TIMER_DEVICES if SMP
>> +	select ARM_SMP_TWD
>>   	select PL310_ERRATA_588369
>>   	select PL310_ERRATA_727915
>>   	select ARM_ERRATA_720789
>> diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
>> index b148077..f48c989 100644
>> --- a/arch/arm/mach-omap2/Makefile
>> +++ b/arch/arm/mach-omap2/Makefile
>> @@ -22,7 +22,6 @@ obj-$(CONFIG_TWL4030_CORE) += omap_twl.o
>>
>>   # SMP support ONLY available for OMAP4
>>   obj-$(CONFIG_SMP)			+= omap-smp.o omap-headsmp.o
>> -obj-$(CONFIG_LOCAL_TIMERS)		+= timer-mpu.o
>>   obj-$(CONFIG_HOTPLUG_CPU)		+= omap-hotplug.o
>>   obj-$(CONFIG_ARCH_OMAP4)		+= omap44xx-smc.o omap4-common.o
>>
>> diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
>> index 3b9cf85..f2f0db6 100644
>> --- a/arch/arm/mach-omap2/timer-gp.c
>> +++ b/arch/arm/mach-omap2/timer-gp.c
>> @@ -35,10 +35,10 @@
>>   #include<linux/irq.h>
>>   #include<linux/clocksource.h>
>>   #include<linux/clockchips.h>
>> +#include<linux/platform_device.h>
>>
>>   #include<asm/mach/time.h>
>>   #include<plat/dmtimer.h>
>> -#include<asm/localtimer.h>
>>   #include<asm/sched_clock.h>
>>   #include<plat/common.h>
>>   #include<plat/omap_hwmod.h>
>> @@ -247,18 +247,44 @@ static void __init omap2_gp_clocksource_init(void)
>>   }
>>   #endif
>>
>> +#ifdef CONFIG_ARM_SMP_TWD
>> +static struct resource omap2_gp_twd_resources[] = {
>> +	{
>> +		.start	= OMAP44XX_LOCAL_TWD_BASE,
>> +		.end	= OMAP44XX_LOCAL_TWD_BASE + 0x10,
>> +		.flags	= IORESOURCE_MEM,
>> +	},
>> +	{
>> +		.start	= OMAP44XX_IRQ_LOCALTIMER,
>> +		.end	= OMAP44XX_IRQ_LOCALTIMER,
>> +		.flags	= IORESOURCE_IRQ,
>> +	},
>> +};
>> +
>> +static struct platform_device omap2_gp_twd_device = {
>> +	.name		= "arm_smp_twd",
>> +	.id		= -1,
> Why is the id set to -1 ?

This is the normal way of indicating that there is only one such device
in the system. The device ends being called "arm_smp_twd" instead of
"arm_smp_twd.0". See Documentation/driver-model/platform.txt for details.

>> +	.resource	= omap2_gp_twd_resources,
>> +	.num_resources	= ARRAY_SIZE(omap2_gp_twd_resources),
>> +};
>> +
>> +static struct platform_device *omap2_gp_early_devices[] = {
>> +	&omap2_gp_twd_device,
>> +};
>> +#endif
>> +
>>   static void __init omap2_gp_timer_init(void)
>>   {
>> -#ifdef CONFIG_LOCAL_TIMERS
>> -	if (cpu_is_omap44xx()) {
>> -		twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256);
>> -		BUG_ON(!twd_base);
>> -	}
>> -#endif
>>   	omap_dm_timer_init();
>>
>>   	omap2_gp_clockevent_init();
>>   	omap2_gp_clocksource_init();
>> +#ifdef CONFIG_ARM_SMP_TWD
>> +	/* Local timers are not supprted on OMAP4430 ES1.0 */
>> +	if (omap_rev() != OMAP4430_REV_ES1_0)
>> +		early_platform_add_devices(omap2_gp_early_devices,
>> +					   ARRAY_SIZE(omap2_gp_early_devices));
>> +#endif
>>   }
>>
> These changes looks good.
> 
>>   struct sys_timer omap_timer = {
>> diff --git a/arch/arm/mach-omap2/timer-mpu.c b/arch/arm/mach-omap2/timer-mpu.c
>> deleted file mode 100644
>> index 1fd5ca5..0000000
>> --- a/arch/arm/mach-omap2/timer-mpu.c
>> +++ /dev/null
>> @@ -1,40 +0,0 @@
>> -/*
>> - * The MPU local timer source file. In OMAP4, both cortex-a9 cores have
>> - * own timer in it's MPU domain. These timers will be driving the
>> - * linux kernel SMP tick framework when active. These timers are not
>> - * part of the wake up domain.
>> - *
>> - * Copyright (C) 2009 Texas Instruments, Inc.
>> - *
>> - * Author:
>> - *      Santosh Shilimkar<[email-masked]>
>> - *
>> - * This file is based on arm realview smp platform file.
>> - * Copyright (C) 2002 ARM Ltd.
>> - *
>> - * This program is free software; you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License version 2 as
>> - * published by the Free Software Foundation.
>> - */
>> -#include<linux/init.h>
>> -#include<linux/smp.h>
>> -#include<linux/clockchips.h>
>> -#include<asm/irq.h>
>> -#include<asm/smp_twd.h>
>> -#include<asm/localtimer.h>
>> -#include<asm/hardware/gic.h>
>> -
>> -/*
>> - * Setup the local clock events for a CPU.
>> - */
>> -int __cpuinit local_timer_setup(struct clock_event_device *evt)
>> -{
>> -	/* Local timers are not supprted on OMAP4430 ES1.0 */
>> -	if (omap_rev() == OMAP4430_REV_ES1_0)
>> -		return -ENXIO;
>> -
>> -	evt->irq = gic_ppi_to_vppi(OMAP44XX_IRQ_LOCALTIMER);
>> -	twd_timer_setup(evt);
>> -	return 0;
>> -}
>> -
> And this one is even better. -40 lines from arch/arm/*omap*/
> 
> I am fine with all changes except the id value. With that
> clarified,
> Reviewedd-by: Santosh Shilimkar <[email-masked]>

Thanks for reviewing.

	M.
-- 
Jazz is not dead. It just smells funny...