cpuidle.c 5.5 KB

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  1. /* linux/arch/arm/mach-exynos4/cpuidle.c
  2. *
  3. * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  4. * http://www.samsung.com
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License version 2 as
  8. * published by the Free Software Foundation.
  9. */
  10. #include <linux/kernel.h>
  11. #include <linux/init.h>
  12. #include <linux/cpuidle.h>
  13. #include <linux/cpu_pm.h>
  14. #include <linux/io.h>
  15. #include <linux/export.h>
  16. #include <linux/time.h>
  17. #include <asm/proc-fns.h>
  18. #include <asm/smp_scu.h>
  19. #include <asm/suspend.h>
  20. #include <asm/unified.h>
  21. #include <asm/cpuidle.h>
  22. #include <mach/regs-clock.h>
  23. #include <mach/regs-pmu.h>
  24. #include <plat/cpu.h>
  25. #include "common.h"
  26. #define REG_DIRECTGO_ADDR (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  27. S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  28. (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0))
  29. #define REG_DIRECTGO_FLAG (samsung_rev() == EXYNOS4210_REV_1_1 ? \
  30. S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \
  31. (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1))
  32. #define S5P_CHECK_AFTR 0xFCBA0D10
  33. static int exynos4_enter_lowpower(struct cpuidle_device *dev,
  34. struct cpuidle_driver *drv,
  35. int index);
  36. static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
  37. static struct cpuidle_driver exynos4_idle_driver = {
  38. .name = "exynos4_idle",
  39. .owner = THIS_MODULE,
  40. .states = {
  41. [0] = ARM_CPUIDLE_WFI_STATE,
  42. [1] = {
  43. .enter = exynos4_enter_lowpower,
  44. .exit_latency = 300,
  45. .target_residency = 100000,
  46. .flags = CPUIDLE_FLAG_TIME_VALID,
  47. .name = "C1",
  48. .desc = "ARM power down",
  49. },
  50. },
  51. .state_count = 2,
  52. .safe_state_index = 0,
  53. };
  54. /* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
  55. static void exynos4_set_wakeupmask(void)
  56. {
  57. __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK);
  58. }
  59. static unsigned int g_pwr_ctrl, g_diag_reg;
  60. static void save_cpu_arch_register(void)
  61. {
  62. /*read power control register*/
  63. asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc");
  64. /*read diagnostic register*/
  65. asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
  66. return;
  67. }
  68. static void restore_cpu_arch_register(void)
  69. {
  70. /*write power control register*/
  71. asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc");
  72. /*write diagnostic register*/
  73. asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
  74. return;
  75. }
  76. static int idle_finisher(unsigned long flags)
  77. {
  78. cpu_do_idle();
  79. return 1;
  80. }
  81. static int exynos4_enter_core0_aftr(struct cpuidle_device *dev,
  82. struct cpuidle_driver *drv,
  83. int index)
  84. {
  85. unsigned long tmp;
  86. exynos4_set_wakeupmask();
  87. /* Set value of power down register for aftr mode */
  88. exynos_sys_powerdown_conf(SYS_AFTR);
  89. __raw_writel(virt_to_phys(s3c_cpu_resume), REG_DIRECTGO_ADDR);
  90. __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG);
  91. save_cpu_arch_register();
  92. /* Setting Central Sequence Register for power down mode */
  93. tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
  94. tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
  95. __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
  96. cpu_pm_enter();
  97. cpu_suspend(0, idle_finisher);
  98. #ifdef CONFIG_SMP
  99. if (!soc_is_exynos5250())
  100. scu_enable(S5P_VA_SCU);
  101. #endif
  102. cpu_pm_exit();
  103. restore_cpu_arch_register();
  104. /*
  105. * If PMU failed while entering sleep mode, WFI will be
  106. * ignored by PMU and then exiting cpu_do_idle().
  107. * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
  108. * in this situation.
  109. */
  110. tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
  111. if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
  112. tmp |= S5P_CENTRAL_LOWPWR_CFG;
  113. __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
  114. }
  115. /* Clear wakeup state register */
  116. __raw_writel(0x0, S5P_WAKEUP_STAT);
  117. return index;
  118. }
  119. static int exynos4_enter_lowpower(struct cpuidle_device *dev,
  120. struct cpuidle_driver *drv,
  121. int index)
  122. {
  123. int new_index = index;
  124. /* This mode only can be entered when other core's are offline */
  125. if (num_online_cpus() > 1)
  126. new_index = drv->safe_state_index;
  127. if (new_index == 0)
  128. return arm_cpuidle_simple_enter(dev, drv, new_index);
  129. else
  130. return exynos4_enter_core0_aftr(dev, drv, new_index);
  131. }
  132. static void __init exynos5_core_down_clk(void)
  133. {
  134. unsigned int tmp;
  135. /*
  136. * Enable arm clock down (in idle) and set arm divider
  137. * ratios in WFI/WFE state.
  138. */
  139. tmp = PWR_CTRL1_CORE2_DOWN_RATIO | \
  140. PWR_CTRL1_CORE1_DOWN_RATIO | \
  141. PWR_CTRL1_DIV2_DOWN_EN | \
  142. PWR_CTRL1_DIV1_DOWN_EN | \
  143. PWR_CTRL1_USE_CORE1_WFE | \
  144. PWR_CTRL1_USE_CORE0_WFE | \
  145. PWR_CTRL1_USE_CORE1_WFI | \
  146. PWR_CTRL1_USE_CORE0_WFI;
  147. __raw_writel(tmp, EXYNOS5_PWR_CTRL1);
  148. /*
  149. * Enable arm clock up (on exiting idle). Set arm divider
  150. * ratios when not in idle along with the standby duration
  151. * ratios.
  152. */
  153. tmp = PWR_CTRL2_DIV2_UP_EN | \
  154. PWR_CTRL2_DIV1_UP_EN | \
  155. PWR_CTRL2_DUR_STANDBY2_VAL | \
  156. PWR_CTRL2_DUR_STANDBY1_VAL | \
  157. PWR_CTRL2_CORE2_UP_RATIO | \
  158. PWR_CTRL2_CORE1_UP_RATIO;
  159. __raw_writel(tmp, EXYNOS5_PWR_CTRL2);
  160. }
  161. static int __init exynos4_init_cpuidle(void)
  162. {
  163. int cpu_id, ret;
  164. struct cpuidle_device *device;
  165. if (soc_is_exynos5250())
  166. exynos5_core_down_clk();
  167. ret = cpuidle_register_driver(&exynos4_idle_driver);
  168. if (ret) {
  169. printk(KERN_ERR "CPUidle failed to register driver\n");
  170. return ret;
  171. }
  172. for_each_online_cpu(cpu_id) {
  173. device = &per_cpu(exynos4_cpuidle_device, cpu_id);
  174. device->cpu = cpu_id;
  175. /* Support IDLE only */
  176. if (cpu_id != 0)
  177. device->state_count = 1;
  178. ret = cpuidle_register_device(device);
  179. if (ret) {
  180. printk(KERN_ERR "CPUidle register device failed\n");
  181. return ret;
  182. }
  183. }
  184. return 0;
  185. }
  186. device_initcall(exynos4_init_cpuidle);