diff options
Diffstat (limited to 'arch/arm/mach-pxa/smemc.c')
-rw-r--r-- | arch/arm/mach-pxa/smemc.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/smemc.c b/arch/arm/mach-pxa/smemc.c new file mode 100644 index 000000000..2d2a321d8 --- /dev/null +++ b/arch/arm/mach-pxa/smemc.c @@ -0,0 +1,81 @@ +// 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]; +} |