xref: /openbmc/linux/arch/arm/mach-pxa/smemc.c (revision 588b48ca)
1 /*
2  * Static Memory Controller
3  */
4 
5 #include <linux/module.h>
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/io.h>
9 #include <linux/syscore_ops.h>
10 
11 #include <mach/hardware.h>
12 #include <mach/smemc.h>
13 
14 #ifdef CONFIG_PM
15 static unsigned long msc[2];
16 static unsigned long sxcnfg, memclkcfg;
17 static unsigned long csadrcfg[4];
18 
19 static int pxa3xx_smemc_suspend(void)
20 {
21 	msc[0] = __raw_readl(MSC0);
22 	msc[1] = __raw_readl(MSC1);
23 	sxcnfg = __raw_readl(SXCNFG);
24 	memclkcfg = __raw_readl(MEMCLKCFG);
25 	csadrcfg[0] = __raw_readl(CSADRCFG0);
26 	csadrcfg[1] = __raw_readl(CSADRCFG1);
27 	csadrcfg[2] = __raw_readl(CSADRCFG2);
28 	csadrcfg[3] = __raw_readl(CSADRCFG3);
29 
30 	return 0;
31 }
32 
33 static void pxa3xx_smemc_resume(void)
34 {
35 	__raw_writel(msc[0], MSC0);
36 	__raw_writel(msc[1], MSC1);
37 	__raw_writel(sxcnfg, SXCNFG);
38 	__raw_writel(memclkcfg, MEMCLKCFG);
39 	__raw_writel(csadrcfg[0], CSADRCFG0);
40 	__raw_writel(csadrcfg[1], CSADRCFG1);
41 	__raw_writel(csadrcfg[2], CSADRCFG2);
42 	__raw_writel(csadrcfg[3], CSADRCFG3);
43 	/* CSMSADRCFG wakes up in its default state (0), so we need to set it */
44 	__raw_writel(0x2, CSMSADRCFG);
45 }
46 
47 static struct syscore_ops smemc_syscore_ops = {
48 	.suspend	= pxa3xx_smemc_suspend,
49 	.resume		= pxa3xx_smemc_resume,
50 };
51 
52 static int __init smemc_init(void)
53 {
54 	if (cpu_is_pxa3xx()) {
55 		/*
56 		 * The only documentation we have on the
57 		 * Chip Select Configuration Register (CSMSADRCFG) is that
58 		 * it must be programmed to 0x2.
59 		 * Moreover, in the bit definitions, the second bit
60 		 * (CSMSADRCFG[1]) is called "SETALWAYS".
61 		 * Other bits are reserved in this register.
62 		 */
63 		__raw_writel(0x2, CSMSADRCFG);
64 
65 		register_syscore_ops(&smemc_syscore_ops);
66 	}
67 
68 	return 0;
69 }
70 subsys_initcall(smemc_init);
71 #endif
72