drivers/sysreset/sysreset_sti.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   4  * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <regmap.h>
  10 #include <syscon.h>
  11 #include <sysreset.h>
  12 #include <asm/io.h>
  13 #include <linux/bitops.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 struct sti_sysreset_priv {
  18         phys_addr_t base;
  19 };
  20
  21 static int sti_sysreset_request(struct udevice *dev, enum sysreset_t type)
  22 {
  23         struct sti_sysreset_priv *priv = dev_get_priv(dev);
  24
  25         generic_clear_bit(0, (void __iomem *)priv->base);
  26
  27         return -EINPROGRESS;
  28 }
  29
  30 static int sti_sysreset_probe(struct udevice *dev)
  31 {
  32         struct sti_sysreset_priv *priv = dev_get_priv(dev);
  33         struct udevice *syscon;
  34         struct regmap *regmap;
  35         struct fdtdec_phandle_args syscfg_phandle;
  36         int ret;
  37
  38         /* get corresponding syscon phandle */
  39         ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
  40                                              "st,syscfg", NULL, 0, 0,
  41                                              &syscfg_phandle);
  42         if (ret < 0) {
  43                 pr_err("Can't get syscfg phandle: %d\n", ret);
  44                 return ret;
  45         }
  46
  47         ret = uclass_get_device_by_of_offset(UCLASS_SYSCON,
  48                                              syscfg_phandle.node,
  49                                              &syscon);
  50         if (ret) {
  51                 pr_err("%s: uclass_get_device_by_of_offset failed: %d\n",
  52                       __func__, ret);
  53                 return ret;
  54         }
  55
  56         regmap = syscon_get_regmap(syscon);
  57         if (!regmap) {
  58                 pr_err("unable to get regmap for %s\n", syscon->name);
  59                 return -ENODEV;
  60         }
  61
  62         priv->base = regmap->ranges[0].start;
  63
  64         return 0;
  65 }
  66
  67 static struct sysreset_ops sti_sysreset = {
  68         .request        = sti_sysreset_request,
  69 };
  70
  71 static const struct udevice_id sti_sysreset_ids[] = {
  72         { .compatible = "st,stih407-restart" },
  73         { }
  74 };
  75
  76 U_BOOT_DRIVER(sysreset_sti) = {
  77         .name = "sysreset_sti",
  78         .id = UCLASS_SYSRESET,
  79         .ops = &sti_sysreset,
  80         .probe = sti_sysreset_probe,
  81         .of_match = sti_sysreset_ids,
  82         .priv_auto_alloc_size = sizeof(struct sti_sysreset_priv),
  83 };