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