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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-14 22:42:43 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-14 22:42:43 +0200 |
commit | 2cf4d4514d5b43c1f3b64bd0ec8b9853bde8f1dc (patch) | |
tree | e35a625496acc6ac852846d40b8851186b9d1ac4 /arch/arm/mach-kirkwood/cpuidle.c | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6 (diff) | |
parent | MAINTAINERS: EB110ATX is not ebsa110 (diff) | |
download | linux-2cf4d4514d5b43c1f3b64bd0ec8b9853bde8f1dc.tar.xz linux-2cf4d4514d5b43c1f3b64bd0ec8b9853bde8f1dc.zip |
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (417 commits)
MAINTAINERS: EB110ATX is not ebsa110
MAINTAINERS: update Eric Miao's email address and status
fb: add support of LCD display controller on pxa168/910 (base layer)
[ARM] 5552/1: ep93xx get_uart_rate(): use EP93XX_SYSCON_PWRCNT and EP93XX_SYSCON_PWRCN
[ARM] pxa/sharpsl_pm: zaurus needs generic pxa suspend/resume routines
[ARM] 5544/1: Trust PrimeCell resource sizes
[ARM] pxa/sharpsl_pm: cleanup of gpio-related code.
[ARM] pxa/sharpsl_pm: drop set_irq_type calls
[ARM] pxa/sharpsl_pm: merge pxa-specific code into generic one
[ARM] pxa/sharpsl_pm: merge the two sharpsl_pm.c since it's now pxa specific
[ARM] sa1100: remove unused collie_pm.c
[ARM] pxa: fix the conflicting non-static declarations of global_gpios[]
[ARM] 5550/1: Add default configure file for w90p910 platform
[ARM] 5549/1: Add clock api for w90p910 platform.
[ARM] 5548/1: Add gpio api for w90p910 platform
[ARM] 5551/1: Add multi-function pin api for w90p910 platform.
[ARM] Make ARM_VIC_NR depend on ARM_VIC
[ARM] 5546/1: ARM PL022 SSP/SPI driver v3
ARM: OMAP4: SMP: Update defconfig for OMAP4430
ARM: OMAP4: SMP: Enable SMP support for OMAP4430
...
Diffstat (limited to 'arch/arm/mach-kirkwood/cpuidle.c')
-rw-r--r-- | arch/arm/mach-kirkwood/cpuidle.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c new file mode 100644 index 000000000000..f68d33f1f396 --- /dev/null +++ b/arch/arm/mach-kirkwood/cpuidle.c @@ -0,0 +1,96 @@ +/* + * arch/arm/mach-kirkwood/cpuidle.c + * + * CPU idle Marvell Kirkwood SoCs + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * The cpu idle uses wait-for-interrupt and DDR self refresh in order + * to implement two idle states - + * #1 wait-for-interrupt + * #2 wait-for-interrupt and DDR self refresh + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/cpuidle.h> +#include <linux/io.h> +#include <asm/proc-fns.h> +#include <mach/kirkwood.h> + +#define KIRKWOOD_MAX_STATES 2 + +static struct cpuidle_driver kirkwood_idle_driver = { + .name = "kirkwood_idle", + .owner = THIS_MODULE, +}; + +static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device); + +/* Actual code that puts the SoC in different idle states */ +static int kirkwood_enter_idle(struct cpuidle_device *dev, + struct cpuidle_state *state) +{ + struct timeval before, after; + int idle_time; + + local_irq_disable(); + do_gettimeofday(&before); + if (state == &dev->states[0]) + /* Wait for interrupt state */ + cpu_do_idle(); + else if (state == &dev->states[1]) { + /* + * Following write will put DDR in self refresh. + * Note that we have 256 cycles before DDR puts it + * self in self-refresh, so the wait-for-interrupt + * call afterwards won't get the DDR from self refresh + * mode. + */ + writel(0x7, DDR_OPERATION_BASE); + cpu_do_idle(); + } + do_gettimeofday(&after); + local_irq_enable(); + idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC + + (after.tv_usec - before.tv_usec); + return idle_time; +} + +/* Initialize CPU idle by registering the idle states */ +static int kirkwood_init_cpuidle(void) +{ + struct cpuidle_device *device; + + cpuidle_register_driver(&kirkwood_idle_driver); + + device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id()); + device->state_count = KIRKWOOD_MAX_STATES; + + /* Wait for interrupt state */ + device->states[0].enter = kirkwood_enter_idle; + device->states[0].exit_latency = 1; + device->states[0].target_residency = 10000; + device->states[0].flags = CPUIDLE_FLAG_TIME_VALID; + strcpy(device->states[0].name, "WFI"); + strcpy(device->states[0].desc, "Wait for interrupt"); + + /* Wait for interrupt and DDR self refresh state */ + device->states[1].enter = kirkwood_enter_idle; + device->states[1].exit_latency = 10; + device->states[1].target_residency = 10000; + device->states[1].flags = CPUIDLE_FLAG_TIME_VALID; + strcpy(device->states[1].name, "DDR SR"); + strcpy(device->states[1].desc, "WFI and DDR Self Refresh"); + + if (cpuidle_register_device(device)) { + printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n"); + return -EIO; + } + return 0; +} + +device_initcall(kirkwood_init_cpuidle); |