linuxdebug/arch/arm/mach-pxa/smemc.c

82 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Static Memory Controller
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>
#include <linux/soc/pxa/cpu.h>
#include "smemc.h"
#include <linux/soc/pxa/smemc.h>
#ifdef CONFIG_PM
static unsigned long msc[2];
static unsigned long sxcnfg, memclkcfg;
static unsigned long csadrcfg[4];
static int pxa3xx_smemc_suspend(void)
{
msc[0] = __raw_readl(MSC0);
msc[1] = __raw_readl(MSC1);
sxcnfg = __raw_readl(SXCNFG);
memclkcfg = __raw_readl(MEMCLKCFG);
csadrcfg[0] = __raw_readl(CSADRCFG0);
csadrcfg[1] = __raw_readl(CSADRCFG1);
csadrcfg[2] = __raw_readl(CSADRCFG2);
csadrcfg[3] = __raw_readl(CSADRCFG3);
return 0;
}
static void pxa3xx_smemc_resume(void)
{
__raw_writel(msc[0], MSC0);
__raw_writel(msc[1], MSC1);
__raw_writel(sxcnfg, SXCNFG);
__raw_writel(memclkcfg, MEMCLKCFG);
__raw_writel(csadrcfg[0], CSADRCFG0);
__raw_writel(csadrcfg[1], CSADRCFG1);
__raw_writel(csadrcfg[2], CSADRCFG2);
__raw_writel(csadrcfg[3], CSADRCFG3);
/* CSMSADRCFG wakes up in its default state (0), so we need to set it */
__raw_writel(0x2, CSMSADRCFG);
}
static struct syscore_ops smemc_syscore_ops = {
.suspend = pxa3xx_smemc_suspend,
.resume = pxa3xx_smemc_resume,
};
static int __init smemc_init(void)
{
if (cpu_is_pxa3xx()) {
/*
* The only documentation we have on the
* Chip Select Configuration Register (CSMSADRCFG) is that
* it must be programmed to 0x2.
* Moreover, in the bit definitions, the second bit
* (CSMSADRCFG[1]) is called "SETALWAYS".
* Other bits are reserved in this register.
*/
__raw_writel(0x2, CSMSADRCFG);
register_syscore_ops(&smemc_syscore_ops);
}
return 0;
}
subsys_initcall(smemc_init);
#endif
static const unsigned int df_clkdiv[4] = { 1, 2, 4, 1 };
unsigned int pxa3xx_smemc_get_memclkdiv(void)
{
unsigned long memclkcfg = __raw_readl(MEMCLKCFG);
return df_clkdiv[(memclkcfg >> 16) & 0x3];
}