arch/arm/mach-pnx4008/pm.c

   1 /*
   2  * arch/arm/mach-pnx4008/pm.c
   3  *
   4  * Power Management driver for PNX4008
   5  *
   6  * Authors: Vitaly Wool, Dmitry Chigirev <source@mvista.com>
   7  *
   8  * 2005 (c) MontaVista Software, Inc. This file is licensed under
   9  * the terms of the GNU General Public License version 2. This program
  10  * is licensed "as is" without any warranty of any kind, whether express
  11  * or implied.
  12  */
  13
  14 #include <linux/pm.h>
  15 #include <linux/rtc.h>
  16 #include <linux/sched.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/pm.h>
  19 #include <linux/delay.h>
  20 #include <linux/clk.h>
  21
  22 #include <asm/io.h>
  23 #include <asm/mach-types.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/arch/pm.h>
  26 #include <asm/arch/clock.h>
  27
  28 #define SRAM_VA IO_ADDRESS(PNX4008_IRAM_BASE)
  29
  30 static void *saved_sram;
  31
  32 static struct clk *pll4_clk;
  33
  34 static inline void pnx4008_standby(void)
  35 {
  36         void (*pnx4008_cpu_standby_ptr) (void);
  37
  38         local_irq_disable();
  39         local_fiq_disable();
  40
  41         clk_disable(pll4_clk);
  42
  43         /*saving portion of SRAM to be used by suspend function. */
  44         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_standby_sz);
  45
  46         /*make sure SRAM copy gets physically written into SDRAM.
  47            SDRAM will be placed into self-refresh during power down */
  48         flush_cache_all();
  49
  50         /*copy suspend function into SRAM */
  51         memcpy((void *)SRAM_VA, pnx4008_cpu_standby, pnx4008_cpu_standby_sz);
  52
  53         /*do suspend */
  54         pnx4008_cpu_standby_ptr = (void *)SRAM_VA;
  55         pnx4008_cpu_standby_ptr();
  56
  57         /*restoring portion of SRAM that was used by suspend function */
  58         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_standby_sz);
  59
  60         clk_enable(pll4_clk);
  61
  62         local_fiq_enable();
  63         local_irq_enable();
  64 }
  65
  66 static inline void pnx4008_suspend(void)
  67 {
  68         void (*pnx4008_cpu_suspend_ptr) (void);
  69
  70         local_irq_disable();
  71         local_fiq_disable();
  72
  73         clk_disable(pll4_clk);
  74
  75         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_PIN_BASE_INT));
  76         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_INT_BASE_INT));
  77
  78         /*saving portion of SRAM to be used by suspend function. */
  79         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_suspend_sz);
  80
  81         /*make sure SRAM copy gets physically written into SDRAM.
  82            SDRAM will be placed into self-refresh during power down */
  83         flush_cache_all();
  84
  85         /*copy suspend function into SRAM */
  86         memcpy((void *)SRAM_VA, pnx4008_cpu_suspend, pnx4008_cpu_suspend_sz);
  87
  88         /*do suspend */
  89         pnx4008_cpu_suspend_ptr = (void *)SRAM_VA;
  90         pnx4008_cpu_suspend_ptr();
  91
  92         /*restoring portion of SRAM that was used by suspend function */
  93         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_suspend_sz);
  94
  95         clk_enable(pll4_clk);
  96
  97         local_fiq_enable();
  98         local_irq_enable();
  99 }
 100
 101 static int pnx4008_pm_enter(suspend_state_t state)
 102 {
 103         switch (state) {
 104         case PM_SUSPEND_STANDBY:
 105                 pnx4008_standby();
 106                 break;
 107         case PM_SUSPEND_MEM:
 108                 pnx4008_suspend();
 109                 break;
 110         case PM_SUSPEND_DISK:
 111                 return -ENOTSUPP;
 112         default:
 113                 return -EINVAL;
 114         }
 115         return 0;
 116 }
 117
 118 /*
 119  * Called after processes are frozen, but before we shut down devices.
 120  */
 121 static int pnx4008_pm_prepare(suspend_state_t state)
 122 {
 123         switch (state) {
 124         case PM_SUSPEND_STANDBY:
 125         case PM_SUSPEND_MEM:
 126                 break;
 127
 128         case PM_SUSPEND_DISK:
 129                 return -ENOTSUPP;
 130                 break;
 131
 132         default:
 133                 return -EINVAL;
 134                 break;
 135         }
 136         return 0;
 137 }
 138
 139 /*
 140  * Called after devices are re-setup, but before processes are thawed.
 141  */
 142 static int pnx4008_pm_finish(suspend_state_t state)
 143 {
 144         return 0;
 145 }
 146
 147 /*
 148  * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
 149  */
 150 static struct pm_ops pnx4008_pm_ops = {
 151         .prepare = pnx4008_pm_prepare,
 152         .enter = pnx4008_pm_enter,
 153         .finish = pnx4008_pm_finish,
 154 };
 155
 156 static int __init pnx4008_pm_init(void)
 157 {
 158         u32 sram_size_to_allocate;
 159
 160         pll4_clk = clk_get(0, "ck_pll4");
 161         if (IS_ERR(pll4_clk)) {
 162                 printk(KERN_ERR
 163                        "PM Suspend cannot acquire ARM(PLL4) clock control\n");
 164                 return PTR_ERR(pll4_clk);
 165         }
 166
 167         if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
 168                 sram_size_to_allocate = pnx4008_cpu_standby_sz;
 169         else
 170                 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
 171
 172         saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
 173         if (!saved_sram) {
 174                 printk(KERN_ERR
 175                        "PM Suspend: cannot allocate memory to save portion of SRAM\n");
 176                 clk_put(pll4_clk);
 177                 return -ENOMEM;
 178         }
 179
 180         pm_set_ops(&pnx4008_pm_ops);
 181         return 0;
 182 }
 183
 184 late_initcall(pnx4008_pm_init);