pm.c 5.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) ST-Ericsson SA 2010-2013
  4. * Author: Rickard Andersson <rickard.andersson@stericsson.com> for
  5. * ST-Ericsson.
  6. * Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
  7. * Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
  8. */
  9. #include <linux/kernel.h>
  10. #include <linux/irqchip/arm-gic.h>
  11. #include <linux/delay.h>
  12. #include <linux/io.h>
  13. #include <linux/suspend.h>
  14. #include <linux/platform_data/arm-ux500-pm.h>
  15. #include <linux/of.h>
  16. #include <linux/of_address.h>
  17. #include "db8500-regs.h"
  18. /* ARM WFI Standby signal register */
  19. #define PRCM_ARM_WFI_STANDBY (prcmu_base + 0x130)
  20. #define PRCM_ARM_WFI_STANDBY_WFI0 0x08
  21. #define PRCM_ARM_WFI_STANDBY_WFI1 0x10
  22. #define PRCM_IOCR (prcmu_base + 0x310)
  23. #define PRCM_IOCR_IOFORCE 0x1
  24. /* Dual A9 core interrupt management unit registers */
  25. #define PRCM_A9_MASK_REQ (prcmu_base + 0x328)
  26. #define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ 0x1
  27. #define PRCM_A9_MASK_ACK (prcmu_base + 0x32c)
  28. #define PRCM_ARMITMSK31TO0 (prcmu_base + 0x11c)
  29. #define PRCM_ARMITMSK63TO32 (prcmu_base + 0x120)
  30. #define PRCM_ARMITMSK95TO64 (prcmu_base + 0x124)
  31. #define PRCM_ARMITMSK127TO96 (prcmu_base + 0x128)
  32. #define PRCM_POWER_STATE_VAL (prcmu_base + 0x25C)
  33. #define PRCM_ARMITVAL31TO0 (prcmu_base + 0x260)
  34. #define PRCM_ARMITVAL63TO32 (prcmu_base + 0x264)
  35. #define PRCM_ARMITVAL95TO64 (prcmu_base + 0x268)
  36. #define PRCM_ARMITVAL127TO96 (prcmu_base + 0x26C)
  37. static void __iomem *prcmu_base;
  38. static void __iomem *dist_base;
  39. /* This function decouple the gic from the prcmu */
  40. int prcmu_gic_decouple(void)
  41. {
  42. u32 val = readl(PRCM_A9_MASK_REQ);
  43. /* Set bit 0 register value to 1 */
  44. writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
  45. PRCM_A9_MASK_REQ);
  46. /* Make sure the register is updated */
  47. readl(PRCM_A9_MASK_REQ);
  48. /* Wait a few cycles for the gic mask completion */
  49. udelay(1);
  50. return 0;
  51. }
  52. /* This function recouple the gic with the prcmu */
  53. int prcmu_gic_recouple(void)
  54. {
  55. u32 val = readl(PRCM_A9_MASK_REQ);
  56. /* Set bit 0 register value to 0 */
  57. writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);
  58. return 0;
  59. }
  60. #define PRCMU_GIC_NUMBER_REGS 5
  61. /*
  62. * This function checks if there are pending irq on the gic. It only
  63. * makes sense if the gic has been decoupled before with the
  64. * db8500_prcmu_gic_decouple function. Disabling an interrupt only
  65. * disables the forwarding of the interrupt to any CPU interface. It
  66. * does not prevent the interrupt from changing state, for example
  67. * becoming pending, or active and pending if it is already
  68. * active. Hence, we have to check the interrupt is pending *and* is
  69. * active.
  70. */
  71. bool prcmu_gic_pending_irq(void)
  72. {
  73. u32 pr; /* Pending register */
  74. u32 er; /* Enable register */
  75. int i;
  76. /* 5 registers. STI & PPI not skipped */
  77. for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {
  78. pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
  79. er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
  80. if (pr & er)
  81. return true; /* There is a pending interrupt */
  82. }
  83. return false;
  84. }
  85. /*
  86. * This function checks if there are pending interrupt on the
  87. * prcmu which has been delegated to monitor the irqs with the
  88. * db8500_prcmu_copy_gic_settings function.
  89. */
  90. bool prcmu_pending_irq(void)
  91. {
  92. u32 it, im;
  93. int i;
  94. for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
  95. it = readl(PRCM_ARMITVAL31TO0 + i * 4);
  96. im = readl(PRCM_ARMITMSK31TO0 + i * 4);
  97. if (it & im)
  98. return true; /* There is a pending interrupt */
  99. }
  100. return false;
  101. }
  102. /*
  103. * This function checks if the specified cpu is in in WFI. It's usage
  104. * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
  105. * function. Of course passing smp_processor_id() to this function will
  106. * always return false...
  107. */
  108. bool prcmu_is_cpu_in_wfi(int cpu)
  109. {
  110. return readl(PRCM_ARM_WFI_STANDBY) &
  111. (cpu ? PRCM_ARM_WFI_STANDBY_WFI1 : PRCM_ARM_WFI_STANDBY_WFI0);
  112. }
  113. /*
  114. * This function copies the gic SPI settings to the prcmu in order to
  115. * monitor them and abort/finish the retention/off sequence or state.
  116. */
  117. int prcmu_copy_gic_settings(void)
  118. {
  119. u32 er; /* Enable register */
  120. int i;
  121. /* We skip the STI and PPI */
  122. for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
  123. er = readl_relaxed(dist_base +
  124. GIC_DIST_ENABLE_SET + (i + 1) * 4);
  125. writel(er, PRCM_ARMITMSK31TO0 + i * 4);
  126. }
  127. return 0;
  128. }
  129. #ifdef CONFIG_SUSPEND
  130. static int ux500_suspend_enter(suspend_state_t state)
  131. {
  132. cpu_do_idle();
  133. return 0;
  134. }
  135. static int ux500_suspend_valid(suspend_state_t state)
  136. {
  137. return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
  138. }
  139. static const struct platform_suspend_ops ux500_suspend_ops = {
  140. .enter = ux500_suspend_enter,
  141. .valid = ux500_suspend_valid,
  142. };
  143. #define UX500_SUSPEND_OPS (&ux500_suspend_ops)
  144. #else
  145. #define UX500_SUSPEND_OPS NULL
  146. #endif
  147. void __init ux500_pm_init(u32 phy_base, u32 size)
  148. {
  149. struct device_node *np;
  150. prcmu_base = ioremap(phy_base, size);
  151. if (!prcmu_base) {
  152. pr_err("could not remap PRCMU for PM functions\n");
  153. return;
  154. }
  155. np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
  156. dist_base = of_iomap(np, 0);
  157. of_node_put(np);
  158. if (!dist_base) {
  159. pr_err("could not remap GIC dist base for PM functions\n");
  160. return;
  161. }
  162. /*
  163. * On watchdog reboot the GIC is in some cases decoupled.
  164. * This will make sure that the GIC is correctly configured.
  165. */
  166. prcmu_gic_recouple();
  167. /* Set up ux500 suspend callbacks. */
  168. suspend_set_ops(UX500_SUSPEND_OPS);
  169. }