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#include <linux/soc/pxa/cpu.h>
12
13#include "smemc.h"
14#include <linux/soc/pxa/smemc.h>
15
16#ifdef CONFIG_PM
17static unsigned long msc[2];
18static unsigned long sxcnfg, memclkcfg;
19static unsigned long csadrcfg[4];
20
21static int pxa3xx_smemc_suspend(void)
22{
23 msc[0] = __raw_readl(MSC0);
24 msc[1] = __raw_readl(MSC1);
25 sxcnfg = __raw_readl(SXCNFG);
26 memclkcfg = __raw_readl(MEMCLKCFG);
27 csadrcfg[0] = __raw_readl(CSADRCFG0);
28 csadrcfg[1] = __raw_readl(CSADRCFG1);
29 csadrcfg[2] = __raw_readl(CSADRCFG2);
30 csadrcfg[3] = __raw_readl(CSADRCFG3);
31
32 return 0;
33}
34
35static void pxa3xx_smemc_resume(void)
36{
37 __raw_writel(val: msc[0], MSC0);
38 __raw_writel(val: msc[1], MSC1);
39 __raw_writel(val: sxcnfg, SXCNFG);
40 __raw_writel(val: memclkcfg, MEMCLKCFG);
41 __raw_writel(val: csadrcfg[0], CSADRCFG0);
42 __raw_writel(val: csadrcfg[1], CSADRCFG1);
43 __raw_writel(val: csadrcfg[2], CSADRCFG2);
44 __raw_writel(val: csadrcfg[3], CSADRCFG3);
45 /* CSMSADRCFG wakes up in its default state (0), so we need to set it */
46 __raw_writel(val: 0x2, CSMSADRCFG);
47}
48
49static struct syscore_ops smemc_syscore_ops = {
50 .suspend = pxa3xx_smemc_suspend,
51 .resume = pxa3xx_smemc_resume,
52};
53
54static int __init smemc_init(void)
55{
56 if (cpu_is_pxa3xx()) {
57 /*
58 * The only documentation we have on the
59 * Chip Select Configuration Register (CSMSADRCFG) is that
60 * it must be programmed to 0x2.
61 * Moreover, in the bit definitions, the second bit
62 * (CSMSADRCFG[1]) is called "SETALWAYS".
63 * Other bits are reserved in this register.
64 */
65 __raw_writel(val: 0x2, CSMSADRCFG);
66
67 register_syscore_ops(ops: &smemc_syscore_ops);
68 }
69
70 return 0;
71}
72subsys_initcall(smemc_init);
73#endif
74
75static const unsigned int df_clkdiv[4] = { 1, 2, 4, 1 };
76unsigned int pxa3xx_smemc_get_memclkdiv(void)
77{
78 unsigned long memclkcfg = __raw_readl(MEMCLKCFG);
79
80 return df_clkdiv[(memclkcfg >> 16) & 0x3];
81}
82

source code of linux/arch/arm/mach-pxa/smemc.c