recipes/linux/linux-kirkwood/0001--ARM-Kirkwood-CPU-idle-driver.patch

   1 From 286f96f0b2e1ee5a124effba59a01f8d4bf69ddf Mon Sep 17 00:00:00 2001
   2 From: Rabeeh Khoury <rabeeh@marvell.com>
   3 Date: Tue, 24 Mar 2009 16:10:15 +0200
   4 Subject: [PATCH] [ARM] Kirkwood: CPU idle driver
   5
   6 The patch adds support for Kirkwood cpu idle.
   7 Two idle states are defined:
   8 1. Wait-for-interrupt (replacing default kirkwood wfi)
   9 2. Wait-for-interrupt and DDR self refresh
  10
  11 Signed-off-by: Rabeeh Khoury <rabeeh@marvell.com>
  12 Signed-off-by: Nicolas Pitre <nico@marvell.com>
  13 ---
  14  arch/arm/configs/kirkwood_defconfig            |    4 +-
  15  arch/arm/mach-kirkwood/Makefile                |    2 +
  16  arch/arm/mach-kirkwood/cpuidle.c               |   96 ++++++++++++++++++++++++
  17  arch/arm/mach-kirkwood/include/mach/kirkwood.h |    1 +
  18  4 files changed, 102 insertions(+), 1 deletions(-)
  19  create mode 100644 arch/arm/mach-kirkwood/cpuidle.c
  20
  21 diff --git a/arch/arm/configs/kirkwood_defconfig b/arch/arm/configs/kirkwood_defconfig
  22 index c367ae4..a99b3eb 100644
  23 --- a/arch/arm/configs/kirkwood_defconfig
  24 +++ b/arch/arm/configs/kirkwood_defconfig
  25 @@ -263,7 +263,9 @@ CONFIG_CMDLINE=""
  26  #
  27  # CPU Power Management
  28  #
  29 -# CONFIG_CPU_IDLE is not set
  30 +CONFIG_CPU_IDLE=y
  31 +CONFIG_CPU_IDLE_GOV_LADDER=y
  32 +CONFIG_CPU_IDLE_GOV_MENU=y
  33
  34  #
  35  # Floating point emulation
  36 diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile
  37 index 8f03c9b..f21f35d 100644
  38 --- a/arch/arm/mach-kirkwood/Makefile
  39 +++ b/arch/arm/mach-kirkwood/Makefile
  40 @@ -5,3 +5,5 @@ obj-$(CONFIG_MACH_RD88F6192_NAS)        += rd88f6192-nas-setup.o
  41  obj-$(CONFIG_MACH_RD88F6281)           += rd88f6281-setup.o
  42  obj-$(CONFIG_MACH_SHEEVAPLUG)          += sheevaplug-setup.o
  43  obj-$(CONFIG_MACH_TS219)               += ts219-setup.o
  44 +
  45 +obj-$(CONFIG_CPU_IDLE)                 += cpuidle.o
  46 diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c
  47 new file mode 100644
  48 index 0000000..43052c7
  49 --- /dev/null
  50 +++ b/arch/arm/mach-kirkwood/cpuidle.c
  51 @@ -0,0 +1,96 @@
  52 +/*
  53 + * arch/arm/mach-kirkwood/cpuidle.c
  54 + *
  55 + * CPU idle Marvell Kirkwood SoCs
  56 + *
  57 + * This file is licensed under the terms of the GNU General Public
  58 + * License version 2.  This program is licensed "as is" without any
  59 + * warranty of any kind, whether express or implied.
  60 + *
  61 + * The cpu idle uses wait-for-interrupt and DDR self refresh in order
  62 + * to implement two idle states -
  63 + * #1 wait-for-interrupt
  64 + * #2 wait-for-interrupt and DDR self refresh
  65 + */
  66 +
  67 +#include <linux/kernel.h>
  68 +#include <linux/init.h>
  69 +#include <linux/platform_device.h>
  70 +#include <linux/cpuidle.h>
  71 +#include <asm/io.h>
  72 +#include <asm/proc-fns.h>
  73 +#include <mach/kirkwood.h>
  74 +
  75 +#define KIRKWOOD_MAX_STATES    2
  76 +
  77 +static struct cpuidle_driver kirkwood_idle_driver = {
  78 +       .name =         "kirkwood_idle",
  79 +       .owner =        THIS_MODULE,
  80 +};
  81 +
  82 +static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device);
  83 +
  84 +/* Actual code that puts the SoC in different idle states */
  85 +static int kirkwood_enter_idle(struct cpuidle_device *dev,
  86 +                              struct cpuidle_state *state)
  87 +{
  88 +       struct timeval before, after;
  89 +       int idle_time;
  90 +
  91 +       local_irq_disable();
  92 +       do_gettimeofday(&before);
  93 +       if (state == &dev->states[0])
  94 +               /* Wait for interrupt state */
  95 +               cpu_do_idle();
  96 +       else if (state == &dev->states[1]) {
  97 +               /*
  98 +                * Following write will put DDR in self refresh.
  99 +                * Note that we have 256 cycles before DDR puts it
 100 +                * self in self-refresh, so the wait-for-interrupt
 101 +                * call afterwards won't get the DDR from self refresh
 102 +                * mode.
 103 +                */
 104 +               writel(0x7, DDR_OPERATION_BASE);
 105 +               cpu_do_idle();
 106 +       }
 107 +       do_gettimeofday(&after);
 108 +       local_irq_enable();
 109 +       idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
 110 +                       (after.tv_usec - before.tv_usec);
 111 +       return idle_time;
 112 +}
 113 +
 114 +/* Initialize CPU idle by registering the idle states */
 115 +static int kirkwood_init_cpuidle(void)
 116 +{
 117 +       struct cpuidle_device *device;
 118 +
 119 +       cpuidle_register_driver(&kirkwood_idle_driver);
 120 +
 121 +       device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id());
 122 +       device->state_count = KIRKWOOD_MAX_STATES;
 123 +
 124 +       /* Wait for interrupt state */
 125 +       device->states[0].enter = kirkwood_enter_idle;
 126 +       device->states[0].exit_latency = 1;
 127 +       device->states[0].target_residency = 10000;
 128 +       device->states[0].flags = CPUIDLE_FLAG_TIME_VALID;
 129 +       strcpy(device->states[0].name, "WFI");
 130 +       strcpy(device->states[0].desc, "Wait for interrupt");
 131 +
 132 +       /* Wait for interrupt and DDR self refresh state */
 133 +       device->states[1].enter = kirkwood_enter_idle;
 134 +       device->states[1].exit_latency = 10;
 135 +       device->states[1].target_residency = 10000;
 136 +       device->states[1].flags = CPUIDLE_FLAG_TIME_VALID;
 137 +       strcpy(device->states[1].name, "DDR SR");
 138 +       strcpy(device->states[1].desc, "WFI and DDR Self Refresh");
 139 +
 140 +       if (cpuidle_register_device(device)) {
 141 +               printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n");
 142 +               return -EIO;
 143 +       }
 144 +       return 0;
 145 +}
 146 +
 147 +device_initcall(kirkwood_init_cpuidle);
 148 diff --git a/arch/arm/mach-kirkwood/include/mach/kirkwood.h b/arch/arm/mach-kirkwood/include/mach/kirkwood.h
 149 index 38c9868..e9ae73d 100644
 150 --- a/arch/arm/mach-kirkwood/include/mach/kirkwood.h
 151 +++ b/arch/arm/mach-kirkwood/include/mach/kirkwood.h
 152 @@ -86,6 +86,7 @@
 153   */
 154  #define DDR_VIRT_BASE          (KIRKWOOD_REGS_VIRT_BASE | 0x00000)
 155  #define  DDR_WINDOW_CPU_BASE   (DDR_VIRT_BASE | 0x1500)
 156 +#define DDR_OPERATION_BASE     (DDR_VIRT_BASE | 0x1418)
 157
 158  #define DEV_BUS_PHYS_BASE      (KIRKWOOD_REGS_PHYS_BASE | 0x10000)
 159  #define DEV_BUS_VIRT_BASE      (KIRKWOOD_REGS_VIRT_BASE | 0x10000)
 160 --
 161 1.6.0.4
 162