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