| 1 | From: Rabeeh Khoury <rabeeh@marvell.com> |
| 2 | Date: Tue, 24 Mar 2009 14:10:15 +0000 (+0200) |
| 3 | Subject: [ARM] Kirkwood: CPU idle driver |
| 4 | X-Git-Url: http://git.marvell.com/?p=orion.git;a=commitdiff_plain;h=039b97666e1335eac517c7d35a0fa1143af689f0;hp=56a50adda49b2020156616c4eb15353e0f9ad7de |
| 5 | |
| 6 | [ARM] Kirkwood: CPU idle driver |
| 7 | |
| 8 | The patch adds support for Kirkwood cpu idle. |
| 9 | Two idle states are defined: |
| 10 | 1. Wait-for-interrupt (replacing default kirkwood wfi) |
| 11 | 2. Wait-for-interrupt and DDR self refresh |
| 12 | |
| 13 | Signed-off-by: Rabeeh Khoury <rabeeh@marvell.com> |
| 14 | Signed-off-by: Nicolas Pitre <nico@marvell.com> |
| 15 | --- |
| 16 | |
| 17 | --- a/arch/arm/configs/kirkwood_defconfig |
| 18 | +++ b/arch/arm/configs/kirkwood_defconfig |
| 19 | @@ -270,7 +270,9 @@ CONFIG_CMDLINE="" |
| 20 | # |
| 21 | # CPU Power Management |
| 22 | # |
| 23 | -# CONFIG_CPU_IDLE is not set |
| 24 | +CONFIG_CPU_IDLE=y |
| 25 | +CONFIG_CPU_IDLE_GOV_LADDER=y |
| 26 | +CONFIG_CPU_IDLE_GOV_MENU=y |
| 27 | |
| 28 | # |
| 29 | # Floating point emulation |
| 30 | --- a/arch/arm/mach-kirkwood/Makefile |
| 31 | +++ b/arch/arm/mach-kirkwood/Makefile |
| 32 | @@ -5,3 +5,5 @@ obj-$(CONFIG_MACH_RD88F6192_NAS) += rd88 |
| 33 | obj-$(CONFIG_MACH_RD88F6281) += rd88f6281-setup.o |
| 34 | obj-$(CONFIG_MACH_SHEEVAPLUG) += sheevaplug-setup.o |
| 35 | obj-$(CONFIG_MACH_TS219) += ts219-setup.o |
| 36 | + |
| 37 | +obj-$(CONFIG_CPU_IDLE) += cpuidle.o |
| 38 | --- /dev/null |
| 39 | +++ b/arch/arm/mach-kirkwood/cpuidle.c |
| 40 | @@ -0,0 +1,96 @@ |
| 41 | +/* |
| 42 | + * arch/arm/mach-kirkwood/cpuidle.c |
| 43 | + * |
| 44 | + * CPU idle Marvell Kirkwood SoCs |
| 45 | + * |
| 46 | + * This file is licensed under the terms of the GNU General Public |
| 47 | + * License version 2. This program is licensed "as is" without any |
| 48 | + * warranty of any kind, whether express or implied. |
| 49 | + * |
| 50 | + * The cpu idle uses wait-for-interrupt and DDR self refresh in order |
| 51 | + * to implement two idle states - |
| 52 | + * #1 wait-for-interrupt |
| 53 | + * #2 wait-for-interrupt and DDR self refresh |
| 54 | + */ |
| 55 | + |
| 56 | +#include <linux/kernel.h> |
| 57 | +#include <linux/init.h> |
| 58 | +#include <linux/platform_device.h> |
| 59 | +#include <linux/cpuidle.h> |
| 60 | +#include <asm/io.h> |
| 61 | +#include <asm/proc-fns.h> |
| 62 | +#include <mach/kirkwood.h> |
| 63 | + |
| 64 | +#define KIRKWOOD_MAX_STATES 2 |
| 65 | + |
| 66 | +static struct cpuidle_driver kirkwood_idle_driver = { |
| 67 | + .name = "kirkwood_idle", |
| 68 | + .owner = THIS_MODULE, |
| 69 | +}; |
| 70 | + |
| 71 | +static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device); |
| 72 | + |
| 73 | +/* Actual code that puts the SoC in different idle states */ |
| 74 | +static int kirkwood_enter_idle(struct cpuidle_device *dev, |
| 75 | + struct cpuidle_state *state) |
| 76 | +{ |
| 77 | + struct timeval before, after; |
| 78 | + int idle_time; |
| 79 | + |
| 80 | + local_irq_disable(); |
| 81 | + do_gettimeofday(&before); |
| 82 | + if (state == &dev->states[0]) |
| 83 | + /* Wait for interrupt state */ |
| 84 | + cpu_do_idle(); |
| 85 | + else if (state == &dev->states[1]) { |
| 86 | + /* |
| 87 | + * Following write will put DDR in self refresh. |
| 88 | + * Note that we have 256 cycles before DDR puts it |
| 89 | + * self in self-refresh, so the wait-for-interrupt |
| 90 | + * call afterwards won't get the DDR from self refresh |
| 91 | + * mode. |
| 92 | + */ |
| 93 | + writel(0x7, DDR_OPERATION_BASE); |
| 94 | + cpu_do_idle(); |
| 95 | + } |
| 96 | + do_gettimeofday(&after); |
| 97 | + local_irq_enable(); |
| 98 | + idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC + |
| 99 | + (after.tv_usec - before.tv_usec); |
| 100 | + return idle_time; |
| 101 | +} |
| 102 | + |
| 103 | +/* Initialize CPU idle by registering the idle states */ |
| 104 | +static int kirkwood_init_cpuidle(void) |
| 105 | +{ |
| 106 | + struct cpuidle_device *device; |
| 107 | + |
| 108 | + cpuidle_register_driver(&kirkwood_idle_driver); |
| 109 | + |
| 110 | + device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id()); |
| 111 | + device->state_count = KIRKWOOD_MAX_STATES; |
| 112 | + |
| 113 | + /* Wait for interrupt state */ |
| 114 | + device->states[0].enter = kirkwood_enter_idle; |
| 115 | + device->states[0].exit_latency = 1; |
| 116 | + device->states[0].target_residency = 10000; |
| 117 | + device->states[0].flags = CPUIDLE_FLAG_TIME_VALID; |
| 118 | + strcpy(device->states[0].name, "WFI"); |
| 119 | + strcpy(device->states[0].desc, "Wait for interrupt"); |
| 120 | + |
| 121 | + /* Wait for interrupt and DDR self refresh state */ |
| 122 | + device->states[1].enter = kirkwood_enter_idle; |
| 123 | + device->states[1].exit_latency = 10; |
| 124 | + device->states[1].target_residency = 10000; |
| 125 | + device->states[1].flags = CPUIDLE_FLAG_TIME_VALID; |
| 126 | + strcpy(device->states[1].name, "DDR SR"); |
| 127 | + strcpy(device->states[1].desc, "WFI and DDR Self Refresh"); |
| 128 | + |
| 129 | + if (cpuidle_register_device(device)) { |
| 130 | + printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n"); |
| 131 | + return -EIO; |
| 132 | + } |
| 133 | + return 0; |
| 134 | +} |
| 135 | + |
| 136 | +device_initcall(kirkwood_init_cpuidle); |
| 137 | --- a/arch/arm/mach-kirkwood/include/mach/kirkwood.h |
| 138 | +++ b/arch/arm/mach-kirkwood/include/mach/kirkwood.h |
| 139 | @@ -48,6 +48,7 @@ |
| 140 | */ |
| 141 | #define DDR_VIRT_BASE (KIRKWOOD_REGS_VIRT_BASE | 0x00000) |
| 142 | #define DDR_WINDOW_CPU_BASE (DDR_VIRT_BASE | 0x1500) |
| 143 | +#define DDR_OPERATION_BASE (DDR_VIRT_BASE | 0x1418) |
| 144 | |
| 145 | #define DEV_BUS_PHYS_BASE (KIRKWOOD_REGS_PHYS_BASE | 0x10000) |
| 146 | #define DEV_BUS_VIRT_BASE (KIRKWOOD_REGS_VIRT_BASE | 0x10000) |
| 147 | |
