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, ®_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 int 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 return 0; 167 } 168 169 static struct platform_driver crc_pwrsrc_driver = { 170 .probe = crc_pwrsrc_probe, 171 .remove = crc_pwrsrc_remove, 172 .driver = { 173 .name = "crystal_cove_pwrsrc", 174 }, 175 }; 176 module_platform_driver(crc_pwrsrc_driver); 177 178 MODULE_ALIAS("platform:crystal_cove_pwrsrc"); 179 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 180 MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC"); 181 MODULE_LICENSE("GPL"); 182