linux/arch/arm/mach-pxa/smemc.c
Igor Grinberg d107a20415 ARM: PXA3xx: program the CSMSADRCFG register
The Chip Select Configuration Register must be programmed to 0x2 in
order to achieve the correct behavior of the Static Memory Controller.

Without this patch devices wired to DFI and accessed through SMC cannot
be accessed after resume from S2.

Do not rely on the boot loader to program the CSMSADRCFG register by
programming it in the kernel smemc module.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Cc: stable@vger.kernel.org
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
2013-01-23 16:56:32 +08:00

72 lines
1.7 KiB
C

/*
* 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 <mach/hardware.h>
#include <mach/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