drivers/power/reset/qcom-pon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2017-18 Linaro Limited
   3
   4 #include <linux/delay.h>
   5 #include <linux/errno.h>
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/of.h>
   9 #include <linux/of_platform.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/reboot.h>
  12 #include <linux/reboot-mode.h>
  13 #include <linux/regmap.h>
  14
  15 #define PON_SOFT_RB_SPARE               0x8f
  16
  17 #define GEN1_REASON_SHIFT               2
  18 #define GEN2_REASON_SHIFT               1
  19
  20 struct pm8916_pon {
  21         struct device *dev;
  22         struct regmap *regmap;
  23         u32 baseaddr;
  24         struct reboot_mode_driver reboot_mode;
  25         long reason_shift;
  26 };
  27
  28 static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
  29                                     unsigned int magic)
  30 {
  31         struct pm8916_pon *pon = container_of
  32                         (reboot, struct pm8916_pon, reboot_mode);
  33         int ret;
  34
  35         ret = regmap_update_bits(pon->regmap,
  36                                  pon->baseaddr + PON_SOFT_RB_SPARE,
  37                                  GENMASK(7, pon->reason_shift),
  38                                  magic << pon->reason_shift);
  39         if (ret < 0)
  40                 dev_err(pon->dev, "update reboot mode bits failed\n");
  41
  42         return ret;
  43 }
  44
  45 static int pm8916_pon_probe(struct platform_device *pdev)
  46 {
  47         struct pm8916_pon *pon;
  48         int error;
  49
  50         pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
  51         if (!pon)
  52                 return -ENOMEM;
  53
  54         pon->dev = &pdev->dev;
  55
  56         pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  57         if (!pon->regmap) {
  58                 dev_err(&pdev->dev, "failed to locate regmap\n");
  59                 return -ENODEV;
  60         }
  61
  62         error = of_property_read_u32(pdev->dev.of_node, "reg",
  63                                      &pon->baseaddr);
  64         if (error)
  65                 return error;
  66
  67         pon->reboot_mode.dev = &pdev->dev;
  68         pon->reason_shift = (long)of_device_get_match_data(&pdev->dev);
  69         pon->reboot_mode.write = pm8916_reboot_mode_write;
  70         error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
  71         if (error) {
  72                 dev_err(&pdev->dev, "can't register reboot mode\n");
  73                 return error;
  74         }
  75
  76         platform_set_drvdata(pdev, pon);
  77
  78         return devm_of_platform_populate(&pdev->dev);
  79 }
  80
  81 static const struct of_device_id pm8916_pon_id_table[] = {
  82         { .compatible = "qcom,pm8916-pon", .data = (void *)GEN1_REASON_SHIFT },
  83         { .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
  84         { .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
  85         { }
  86 };
  87 MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
  88
  89 static struct platform_driver pm8916_pon_driver = {
  90         .probe = pm8916_pon_probe,
  91         .driver = {
  92                 .name = "pm8916-pon",
  93                 .of_match_table = of_match_ptr(pm8916_pon_id_table),
  94         },
  95 };
  96 module_platform_driver(pm8916_pon_driver);
  97
  98 MODULE_DESCRIPTION("pm8916 Power On driver");
  99 MODULE_LICENSE("GPL v2");