Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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);
154 
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