smemc.c

 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 *data)
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 *data)
36{
37	__raw_writel(msc[0], MSC0);
38	__raw_writel(msc[1], MSC1);
39	__raw_writel(sxcnfg, SXCNFG);
40	__raw_writel(memclkcfg, MEMCLKCFG);
41	__raw_writel(csadrcfg[0], CSADRCFG0);
42	__raw_writel(csadrcfg[1], CSADRCFG1);
43	__raw_writel(csadrcfg[2], CSADRCFG2);
44	__raw_writel(csadrcfg[3], CSADRCFG3);
45	/* CSMSADRCFG wakes up in its default state (0), so we need to set it */
46	__raw_writel(0x2, CSMSADRCFG);
47}
48
49static const struct syscore_ops smemc_syscore_ops = {
50	.suspend	= pxa3xx_smemc_suspend,
51	.resume		= pxa3xx_smemc_resume,
52};
53
54static struct syscore smemc_syscore = {
55	.ops = &smemc_syscore_ops,
56};
57
58static int __init smemc_init(void)
59{
60	if (cpu_is_pxa3xx()) {
61		/*
62		 * The only documentation we have on the
63		 * Chip Select Configuration Register (CSMSADRCFG) is that
64		 * it must be programmed to 0x2.
65		 * Moreover, in the bit definitions, the second bit
66		 * (CSMSADRCFG[1]) is called "SETALWAYS".
67		 * Other bits are reserved in this register.
68		 */
69		__raw_writel(0x2, CSMSADRCFG);
70
71		register_syscore(&smemc_syscore);
72	}
73
74	return 0;
75}
76subsys_initcall(smemc_init);
77#endif
78
79static const unsigned int df_clkdiv[4] = { 1, 2, 4, 1 };
80unsigned int pxa3xx_smemc_get_memclkdiv(void)
81{
82	unsigned long memclkcfg = __raw_readl(MEMCLKCFG);
83
84	return	df_clkdiv[(memclkcfg >> 16) & 0x3];
85}