smemc.c 1.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Static Memory Controller
  4. */
  5. #include <linux/module.h>
  6. #include <linux/kernel.h>
  7. #include <linux/init.h>
  8. #include <linux/io.h>
  9. #include <linux/syscore_ops.h>
  10. #include <linux/soc/pxa/cpu.h>
  11. #include "smemc.h"
  12. #include <linux/soc/pxa/smemc.h>
  13. #ifdef CONFIG_PM
  14. static unsigned long msc[2];
  15. static unsigned long sxcnfg, memclkcfg;
  16. static unsigned long csadrcfg[4];
  17. static int pxa3xx_smemc_suspend(void)
  18. {
  19. msc[0] = __raw_readl(MSC0);
  20. msc[1] = __raw_readl(MSC1);
  21. sxcnfg = __raw_readl(SXCNFG);
  22. memclkcfg = __raw_readl(MEMCLKCFG);
  23. csadrcfg[0] = __raw_readl(CSADRCFG0);
  24. csadrcfg[1] = __raw_readl(CSADRCFG1);
  25. csadrcfg[2] = __raw_readl(CSADRCFG2);
  26. csadrcfg[3] = __raw_readl(CSADRCFG3);
  27. return 0;
  28. }
  29. static void pxa3xx_smemc_resume(void)
  30. {
  31. __raw_writel(msc[0], MSC0);
  32. __raw_writel(msc[1], MSC1);
  33. __raw_writel(sxcnfg, SXCNFG);
  34. __raw_writel(memclkcfg, MEMCLKCFG);
  35. __raw_writel(csadrcfg[0], CSADRCFG0);
  36. __raw_writel(csadrcfg[1], CSADRCFG1);
  37. __raw_writel(csadrcfg[2], CSADRCFG2);
  38. __raw_writel(csadrcfg[3], CSADRCFG3);
  39. /* CSMSADRCFG wakes up in its default state (0), so we need to set it */
  40. __raw_writel(0x2, CSMSADRCFG);
  41. }
  42. static struct syscore_ops smemc_syscore_ops = {
  43. .suspend = pxa3xx_smemc_suspend,
  44. .resume = pxa3xx_smemc_resume,
  45. };
  46. static int __init smemc_init(void)
  47. {
  48. if (cpu_is_pxa3xx()) {
  49. /*
  50. * The only documentation we have on the
  51. * Chip Select Configuration Register (CSMSADRCFG) is that
  52. * it must be programmed to 0x2.
  53. * Moreover, in the bit definitions, the second bit
  54. * (CSMSADRCFG[1]) is called "SETALWAYS".
  55. * Other bits are reserved in this register.
  56. */
  57. __raw_writel(0x2, CSMSADRCFG);
  58. register_syscore_ops(&smemc_syscore_ops);
  59. }
  60. return 0;
  61. }
  62. subsys_initcall(smemc_init);
  63. #endif
  64. static const unsigned int df_clkdiv[4] = { 1, 2, 4, 1 };
  65. unsigned int pxa3xx_smemc_get_memclkdiv(void)
  66. {
  67. unsigned long memclkcfg = __raw_readl(MEMCLKCFG);
  68. return df_clkdiv[(memclkcfg >> 16) & 0x3];
  69. }