xref: /linux/arch/arm/mach-pxa/smemc.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Static Memory Controller
4  */
5 
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/io.h>
10 #include <linux/syscore_ops.h>
11 
12 #include <mach/hardware.h>
13 #include <mach/smemc.h>
14 
15 #ifdef CONFIG_PM
16 static unsigned long msc[2];
17 static unsigned long sxcnfg, memclkcfg;
18 static unsigned long csadrcfg[4];
19 
20 static int pxa3xx_smemc_suspend(void)
21 {
22 	msc[0] = __raw_readl(MSC0);
23 	msc[1] = __raw_readl(MSC1);
24 	sxcnfg = __raw_readl(SXCNFG);
25 	memclkcfg = __raw_readl(MEMCLKCFG);
26 	csadrcfg[0] = __raw_readl(CSADRCFG0);
27 	csadrcfg[1] = __raw_readl(CSADRCFG1);
28 	csadrcfg[2] = __raw_readl(CSADRCFG2);
29 	csadrcfg[3] = __raw_readl(CSADRCFG3);
30 
31 	return 0;
32 }
33 
34 static void pxa3xx_smemc_resume(void)
35 {
36 	__raw_writel(msc[0], MSC0);
37 	__raw_writel(msc[1], MSC1);
38 	__raw_writel(sxcnfg, SXCNFG);
39 	__raw_writel(memclkcfg, MEMCLKCFG);
40 	__raw_writel(csadrcfg[0], CSADRCFG0);
41 	__raw_writel(csadrcfg[1], CSADRCFG1);
42 	__raw_writel(csadrcfg[2], CSADRCFG2);
43 	__raw_writel(csadrcfg[3], CSADRCFG3);
44 	/* CSMSADRCFG wakes up in its default state (0), so we need to set it */
45 	__raw_writel(0x2, CSMSADRCFG);
46 }
47 
48 static struct syscore_ops smemc_syscore_ops = {
49 	.suspend	= pxa3xx_smemc_suspend,
50 	.resume		= pxa3xx_smemc_resume,
51 };
52 
53 static int __init smemc_init(void)
54 {
55 	if (cpu_is_pxa3xx()) {
56 		/*
57 		 * The only documentation we have on the
58 		 * Chip Select Configuration Register (CSMSADRCFG) is that
59 		 * it must be programmed to 0x2.
60 		 * Moreover, in the bit definitions, the second bit
61 		 * (CSMSADRCFG[1]) is called "SETALWAYS".
62 		 * Other bits are reserved in this register.
63 		 */
64 		__raw_writel(0x2, CSMSADRCFG);
65 
66 		register_syscore_ops(&smemc_syscore_ops);
67 	}
68 
69 	return 0;
70 }
71 subsys_initcall(smemc_init);
72 #endif
73