drivers/platform/x86/intel/bytcrc_pwrsrc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Power-source driver for Bay Trail Crystal Cove PMIC
   4  *
   5  * Copyright (c) 2023 Hans de Goede <hdegoede@redhat.com>
   6  *
   7  * Based on intel_crystalcove_pwrsrc.c from Android kernel sources, which is:
   8  * Copyright (C) 2013 Intel Corporation
   9  */
  10
  11 #include <linux/debugfs.h>
  12 #include <linux/mfd/intel_soc_pmic.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 #define CRYSTALCOVE_SPWRSRC_REG         0x1E
  18 #define CRYSTALCOVE_RESETSRC0_REG       0x20
  19 #define CRYSTALCOVE_RESETSRC1_REG       0x21
  20 #define CRYSTALCOVE_WAKESRC_REG         0x22
  21
  22 struct crc_pwrsrc_data {
  23         struct regmap *regmap;
  24         struct dentry *debug_dentry;
  25         unsigned int resetsrc0;
  26         unsigned int resetsrc1;
  27         unsigned int wakesrc;
  28 };
  29
  30 static const char * const pwrsrc_pwrsrc_info[] = {
  31         /* bit 0 */ "USB",
  32         /* bit 1 */ "DC in",
  33         /* bit 2 */ "Battery",
  34         NULL,
  35 };
  36
  37 static const char * const pwrsrc_resetsrc0_info[] = {
  38         /* bit 0 */ "SOC reporting a thermal event",
  39         /* bit 1 */ "critical PMIC temperature",
  40         /* bit 2 */ "critical system temperature",
  41         /* bit 3 */ "critical battery temperature",
  42         /* bit 4 */ "VSYS under voltage",
  43         /* bit 5 */ "VSYS over voltage",
  44         /* bit 6 */ "battery removal",
  45         NULL,
  46 };
  47
  48 static const char * const pwrsrc_resetsrc1_info[] = {
  49         /* bit 0 */ "VCRIT threshold",
  50         /* bit 1 */ "BATID reporting battery removal",
  51         /* bit 2 */ "user pressing the power button",
  52         NULL,
  53 };
  54
  55 static const char * const pwrsrc_wakesrc_info[] = {
  56         /* bit 0 */ "user pressing the power button",
  57         /* bit 1 */ "a battery insertion",
  58         /* bit 2 */ "a USB charger insertion",
  59         /* bit 3 */ "an adapter insertion",
  60         NULL,
  61 };
  62
  63 static void crc_pwrsrc_log(struct seq_file *seq, const char *prefix,
  64                            const char * const *info, unsigned int reg_val)
  65 {
  66         int i;
  67
  68         for (i = 0; info[i]; i++) {
  69                 if (reg_val & BIT(i))
  70                         seq_printf(seq, "%s by %s\n", prefix, info[i]);
  71         }
  72 }
  73
  74 static int pwrsrc_show(struct seq_file *seq, void *unused)
  75 {
  76         struct crc_pwrsrc_data *data = seq->private;
  77         unsigned int reg_val;
  78         int ret;
  79
  80         ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, &reg_val);
  81         if (ret)
  82                 return ret;
  83
  84         crc_pwrsrc_log(seq, "System powered", pwrsrc_pwrsrc_info, reg_val);
  85         return 0;
  86 }
  87
  88 static int resetsrc_show(struct seq_file *seq, void *unused)
  89 {
  90         struct crc_pwrsrc_data *data = seq->private;
  91
  92         crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc0_info, data->resetsrc0);
  93         crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc1_info, data->resetsrc1);
  94         return 0;
  95 }
  96
  97 static int wakesrc_show(struct seq_file *seq, void *unused)
  98 {
  99         struct crc_pwrsrc_data *data = seq->private;
 100
 101         crc_pwrsrc_log(seq, "Last wake caused", pwrsrc_wakesrc_info, data->wakesrc);
 102         return 0;
 103 }
 104
 105 DEFINE_SHOW_ATTRIBUTE(pwrsrc);
 106 DEFINE_SHOW_ATTRIBUTE(resetsrc);
 107 DEFINE_SHOW_ATTRIBUTE(wakesrc);
 108
 109 static int crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data *data,
 110                                      unsigned int reg, unsigned int *val)
 111 {
 112         int ret;
 113
 114         ret = regmap_read(data->regmap, reg, val);
 115         if (ret)
 116                 return ret;
 117
 118         return regmap_write(data->regmap, reg, *val);
 119 }
 120
 121 static int crc_pwrsrc_probe(struct platform_device *pdev)
 122 {
 123         struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 124         struct crc_pwrsrc_data *data;
 125         int ret;
 126
 127         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 128         if (!data)
 129                 return -ENOMEM;
 130
 131         data->regmap = pmic->regmap;
 132
 133         /*
 134          * Read + clear resetsrc0/1 and wakesrc now, so that they get
 135          * cleared even if the debugfs interface is never used.
 136          *
 137          * Properly clearing the wakesrc is important, leaving bit 0 of it
 138          * set turns reboot into poweroff on some tablets.
 139          */
 140         ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC0_REG, &data->resetsrc0);
 141         if (ret)
 142                 return ret;
 143
 144         ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC1_REG, &data->resetsrc1);
 145         if (ret)
 146                 return ret;
 147
 148         ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_WAKESRC_REG, &data->wakesrc);
 149         if (ret)
 150                 return ret;
 151
 152         data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);
 153         debugfs_create_file("pwrsrc", 0444, data->debug_dentry, data, &pwrsrc_fops);
 154         debugfs_create_file("resetsrc", 0444, data->debug_dentry, data, &resetsrc_fops);
 155         debugfs_create_file("wakesrc", 0444, data->debug_dentry, data, &wakesrc_fops);
 156
 157         platform_set_drvdata(pdev, data);
 158         return 0;
 159 }
 160
 161 static void crc_pwrsrc_remove(struct platform_device *pdev)
 162 {
 163         struct crc_pwrsrc_data *data = platform_get_drvdata(pdev);
 164
 165         debugfs_remove_recursive(data->debug_dentry);
 166 }
 167
 168 static struct platform_driver crc_pwrsrc_driver = {
 169         .probe = crc_pwrsrc_probe,
 170         .remove = crc_pwrsrc_remove,
 171         .driver = {
 172                 .name = "crystal_cove_pwrsrc",
 173         },
 174 };
 175 module_platform_driver(crc_pwrsrc_driver);
 176
 177 MODULE_ALIAS("platform:crystal_cove_pwrsrc");
 178 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 179 MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC");
 180 MODULE_LICENSE("GPL");