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 #define NO_REASON_SHIFT                 0
  21
  22 struct pm8916_pon {
  23         struct device *dev;
  24         struct regmap *regmap;
  25         u32 baseaddr;
  26         struct reboot_mode_driver reboot_mode;
  27         long reason_shift;
  28 };
  29
  30 static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
  31                                     unsigned int magic)
  32 {
  33         struct pm8916_pon *pon = container_of
  34                         (reboot, struct pm8916_pon, reboot_mode);
  35         int ret;
  36
  37         ret = regmap_update_bits(pon->regmap,
  38                                  pon->baseaddr + PON_SOFT_RB_SPARE,
  39                                  GENMASK(7, pon->reason_shift),
  40                                  magic << pon->reason_shift);
  41         if (ret < 0)
  42                 dev_err(pon->dev, "update reboot mode bits failed\n");
  43
  44         return ret;
  45 }
  46
  47 static int pm8916_pon_probe(struct platform_device *pdev)
  48 {
  49         struct pm8916_pon *pon;
  50         long reason_shift;
  51         int error;
  52
  53         pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
  54         if (!pon)
  55                 return -ENOMEM;
  56
  57         pon->dev = &pdev->dev;
  58
  59         pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  60         if (!pon->regmap) {
  61                 dev_err(&pdev->dev, "failed to locate regmap\n");
  62                 return -ENODEV;
  63         }
  64
  65         error = of_property_read_u32(pdev->dev.of_node, "reg",
  66                                      &pon->baseaddr);
  67         if (error)
  68                 return error;
  69
  70         reason_shift = (long)of_device_get_match_data(&pdev->dev);
  71
  72         if (reason_shift != NO_REASON_SHIFT) {
  73                 pon->reboot_mode.dev = &pdev->dev;
  74                 pon->reason_shift = reason_shift;
  75                 pon->reboot_mode.write = pm8916_reboot_mode_write;
  76                 error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
  77                 if (error) {
  78                         dev_err(&pdev->dev, "can't register reboot mode\n");
  79                         return error;
  80                 }
  81         }
  82
  83         platform_set_drvdata(pdev, pon);
  84
  85         return devm_of_platform_populate(&pdev->dev);
  86 }
  87
  88 static const struct of_device_id pm8916_pon_id_table[] = {
  89         { .compatible = "qcom,pm8916-pon", .data = (void *)GEN1_REASON_SHIFT },
  90         { .compatible = "qcom,pm8941-pon", .data = (void *)NO_REASON_SHIFT },
  91         { .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
  92         { .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
  93         { .compatible = "qcom,pmk8350-pon", .data = (void *)GEN2_REASON_SHIFT },
  94         { }
  95 };
  96 MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
  97
  98 static struct platform_driver pm8916_pon_driver = {
  99         .probe = pm8916_pon_probe,
 100         .driver = {
 101                 .name = "pm8916-pon",
 102                 .of_match_table = pm8916_pon_id_table,
 103         },
 104 };
 105 module_platform_driver(pm8916_pon_driver);
 106
 107 MODULE_DESCRIPTION("pm8916 Power On driver");
 108 MODULE_LICENSE("GPL v2");