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
 32static void *saved_sram;
 33
 34static struct clk *pll4_clk;
 35
 36static 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
 68static 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
103static 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
116static int pnx4008_pm_valid(suspend_state_t state)
117{
118	return (state == PM_SUSPEND_STANDBY) ||
119	       (state == PM_SUSPEND_MEM);
120}
121
122static const struct platform_suspend_ops pnx4008_pm_ops = {
123	.enter = pnx4008_pm_enter,
124	.valid = pnx4008_pm_valid,
125};
126
127static 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
155late_initcall(pnx4008_pm_init);