arch/arm/mach-socfpga/pm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  arch/arm/mach-socfpga/pm.c
   4  *
   5  * Copyright (C) 2014-2015 Altera Corporation. All rights reserved.
   6  *
   7  * with code from pm-imx6.c
   8  * Copyright 2011-2014 Freescale Semiconductor, Inc.
   9  * Copyright 2011 Linaro Ltd.
  10  */
  11
  12 #include <linux/bitops.h>
  13 #include <linux/genalloc.h>
  14 #include <linux/init.h>
  15 #include <linux/io.h>
  16 #include <linux/of.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/suspend.h>
  20 #include <asm/suspend.h>
  21 #include <asm/fncpy.h>
  22 #include "core.h"
  23
  24 /* Pointer to function copied to ocram */
  25 static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base);
  26
  27 static int socfpga_setup_ocram_self_refresh(void)
  28 {
  29         struct platform_device *pdev;
  30         phys_addr_t ocram_pbase;
  31         struct device_node *np;
  32         struct gen_pool *ocram_pool;
  33         unsigned long ocram_base;
  34         void __iomem *suspend_ocram_base;
  35         int ret = 0;
  36
  37         np = of_find_compatible_node(NULL, NULL, "mmio-sram");
  38         if (!np) {
  39                 pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
  40                 return -ENODEV;
  41         }
  42
  43         pdev = of_find_device_by_node(np);
  44         if (!pdev) {
  45                 pr_warn("%s: failed to find ocram device!\n", __func__);
  46                 ret = -ENODEV;
  47                 goto put_node;
  48         }
  49
  50         ocram_pool = gen_pool_get(&pdev->dev, NULL);
  51         if (!ocram_pool) {
  52                 pr_warn("%s: ocram pool unavailable!\n", __func__);
  53                 ret = -ENODEV;
  54                 goto put_device;
  55         }
  56
  57         ocram_base = gen_pool_alloc(ocram_pool, socfpga_sdram_self_refresh_sz);
  58         if (!ocram_base) {
  59                 pr_warn("%s: unable to alloc ocram!\n", __func__);
  60                 ret = -ENOMEM;
  61                 goto put_device;
  62         }
  63
  64         ocram_pbase = gen_pool_virt_to_phys(ocram_pool, ocram_base);
  65
  66         suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
  67                                                 socfpga_sdram_self_refresh_sz,
  68                                                 false);
  69         if (!suspend_ocram_base) {
  70                 pr_warn("%s: __arm_ioremap_exec failed!\n", __func__);
  71                 ret = -ENOMEM;
  72                 goto put_device;
  73         }
  74
  75         /* Copy the code that puts DDR in self refresh to ocram */
  76         socfpga_sdram_self_refresh_in_ocram =
  77                 (void *)fncpy(suspend_ocram_base,
  78                               &socfpga_sdram_self_refresh,
  79                               socfpga_sdram_self_refresh_sz);
  80
  81         WARN(!socfpga_sdram_self_refresh_in_ocram,
  82              "could not copy function to ocram");
  83         if (!socfpga_sdram_self_refresh_in_ocram)
  84                 ret = -EFAULT;
  85
  86 put_device:
  87         put_device(&pdev->dev);
  88 put_node:
  89         of_node_put(np);
  90
  91         return ret;
  92 }
  93
  94 static int socfpga_pm_suspend(unsigned long arg)
  95 {
  96         u32 ret;
  97
  98         if (!sdr_ctl_base_addr)
  99                 return -EFAULT;
 100
 101         ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr);
 102
 103         pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__,
 104                  ret & 0xffff, (ret >> 16) & 0xffff);
 105
 106         return 0;
 107 }
 108
 109 static int socfpga_pm_enter(suspend_state_t state)
 110 {
 111         switch (state) {
 112         case PM_SUSPEND_MEM:
 113                 outer_disable();
 114                 cpu_suspend(0, socfpga_pm_suspend);
 115                 outer_resume();
 116                 break;
 117         default:
 118                 return -EINVAL;
 119         }
 120         return 0;
 121 }
 122
 123 static const struct platform_suspend_ops socfpga_pm_ops = {
 124         .valid  = suspend_valid_only_mem,
 125         .enter  = socfpga_pm_enter,
 126 };
 127
 128 static int __init socfpga_pm_init(void)
 129 {
 130         int ret;
 131
 132         ret = socfpga_setup_ocram_self_refresh();
 133         if (ret)
 134                 return ret;
 135
 136         suspend_set_ops(&socfpga_pm_ops);
 137         pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n");
 138
 139         return 0;
 140 }
 141 arch_initcall(socfpga_pm_init);