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/suspend.h>
  19 #include <linux/delay.h>
  20 #include <linux/clk.h>
  21 #include <linux/io.h>
  22
  23 #include <asm/cacheflush.h>
  24
  25 #include <mach/hardware.h>
  26 #include <mach/pm.h>
  27 #include <mach/clock.h>
  28
  29 #define SRAM_VA IO_ADDRESS(PNX4008_IRAM_BASE)
  30
  31 static void *saved_sram;
  32
  33 static struct clk *pll4_clk;
  34
  35 static inline void pnx4008_standby(void)
  36 {
  37         void (*pnx4008_cpu_standby_ptr) (void);
  38
  39         local_irq_disable();
  40         local_fiq_disable();
  41
  42         clk_disable(pll4_clk);
  43
  44         /*saving portion of SRAM to be used by suspend function. */
  45         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_standby_sz);
  46
  47         /*make sure SRAM copy gets physically written into SDRAM.
  48            SDRAM will be placed into self-refresh during power down */
  49         flush_cache_all();
  50
  51         /*copy suspend function into SRAM */
  52         memcpy((void *)SRAM_VA, pnx4008_cpu_standby, pnx4008_cpu_standby_sz);
  53
  54         /*do suspend */
  55         pnx4008_cpu_standby_ptr = (void *)SRAM_VA;
  56         pnx4008_cpu_standby_ptr();
  57
  58         /*restoring portion of SRAM that was used by suspend function */
  59         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_standby_sz);
  60
  61         clk_enable(pll4_clk);
  62
  63         local_fiq_enable();
  64         local_irq_enable();
  65 }
  66
  67 static inline void pnx4008_suspend(void)
  68 {
  69         void (*pnx4008_cpu_suspend_ptr) (void);
  70
  71         local_irq_disable();
  72         local_fiq_disable();
  73
  74         clk_disable(pll4_clk);
  75
  76         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_PIN_BASE_INT));
  77         __raw_writel(0xffffffff, START_INT_RSR_REG(SE_INT_BASE_INT));
  78
  79         /*saving portion of SRAM to be used by suspend function. */
  80         memcpy(saved_sram, (void *)SRAM_VA, pnx4008_cpu_suspend_sz);
  81
  82         /*make sure SRAM copy gets physically written into SDRAM.
  83            SDRAM will be placed into self-refresh during power down */
  84         flush_cache_all();
  85
  86         /*copy suspend function into SRAM */
  87         memcpy((void *)SRAM_VA, pnx4008_cpu_suspend, pnx4008_cpu_suspend_sz);
  88
  89         /*do suspend */
  90         pnx4008_cpu_suspend_ptr = (void *)SRAM_VA;
  91         pnx4008_cpu_suspend_ptr();
  92
  93         /*restoring portion of SRAM that was used by suspend function */
  94         memcpy((void *)SRAM_VA, saved_sram, pnx4008_cpu_suspend_sz);
  95
  96         clk_enable(pll4_clk);
  97
  98         local_fiq_enable();
  99         local_irq_enable();
 100 }
 101
 102 static int pnx4008_pm_enter(suspend_state_t state)
 103 {
 104         switch (state) {
 105         case PM_SUSPEND_STANDBY:
 106                 pnx4008_standby();
 107                 break;
 108         case PM_SUSPEND_MEM:
 109                 pnx4008_suspend();
 110                 break;
 111         }
 112         return 0;
 113 }
 114
 115 static int pnx4008_pm_valid(suspend_state_t state)
 116 {
 117         return (state == PM_SUSPEND_STANDBY) ||
 118                (state == PM_SUSPEND_MEM);
 119 }
 120
 121 static struct platform_suspend_ops pnx4008_pm_ops = {
 122         .enter = pnx4008_pm_enter,
 123         .valid = pnx4008_pm_valid,
 124 };
 125
 126 static int __init pnx4008_pm_init(void)
 127 {
 128         u32 sram_size_to_allocate;
 129
 130         pll4_clk = clk_get(0, "ck_pll4");
 131         if (IS_ERR(pll4_clk)) {
 132                 printk(KERN_ERR
 133                        "PM Suspend cannot acquire ARM(PLL4) clock control\n");
 134                 return PTR_ERR(pll4_clk);
 135         }
 136
 137         if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
 138                 sram_size_to_allocate = pnx4008_cpu_standby_sz;
 139         else
 140                 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
 141
 142         saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
 143         if (!saved_sram) {
 144                 printk(KERN_ERR
 145                        "PM Suspend: cannot allocate memory to save portion of SRAM\n");
 146                 clk_put(pll4_clk);
 147                 return -ENOMEM;
 148         }
 149
 150         suspend_set_ops(&pnx4008_pm_ops);
 151         return 0;
 152 }
 153
 154 late_initcall(pnx4008_pm_init);