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/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         }
 111         return 0;
 112 }
 113
 114 static int pnx4008_pm_valid(suspend_state_t state)
 115 {
 116         return (state == PM_SUSPEND_STANDBY) ||
 117                (state == PM_SUSPEND_MEM);
 118 }
 119
 120 static struct platform_suspend_ops pnx4008_pm_ops = {
 121         .enter = pnx4008_pm_enter,
 122         .valid = pnx4008_pm_valid,
 123 };
 124
 125 static int __init pnx4008_pm_init(void)
 126 {
 127         u32 sram_size_to_allocate;
 128
 129         pll4_clk = clk_get(0, "ck_pll4");
 130         if (IS_ERR(pll4_clk)) {
 131                 printk(KERN_ERR
 132                        "PM Suspend cannot acquire ARM(PLL4) clock control\n");
 133                 return PTR_ERR(pll4_clk);
 134         }
 135
 136         if (pnx4008_cpu_standby_sz > pnx4008_cpu_suspend_sz)
 137                 sram_size_to_allocate = pnx4008_cpu_standby_sz;
 138         else
 139                 sram_size_to_allocate = pnx4008_cpu_suspend_sz;
 140
 141         saved_sram = kmalloc(sram_size_to_allocate, GFP_ATOMIC);
 142         if (!saved_sram) {
 143                 printk(KERN_ERR
 144                        "PM Suspend: cannot allocate memory to save portion of SRAM\n");
 145                 clk_put(pll4_clk);
 146                 return -ENOMEM;
 147         }
 148
 149         suspend_set_ops(&pnx4008_pm_ops);
 150         return 0;
 151 }
 152
 153 late_initcall(pnx4008_pm_init);