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