1 /* 2 * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC 3 * hardware monitoring features. 4 * 5 * Copyright (C) 2009 Wolfson Microelectronics plc 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License v2 as published by the 9 * Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/platform_device.h> 24 #include <linux/err.h> 25 #include <linux/hwmon.h> 26 #include <linux/hwmon-sysfs.h> 27 #include <linux/slab.h> 28 29 #include <linux/mfd/wm831x/core.h> 30 #include <linux/mfd/wm831x/auxadc.h> 31 32 struct wm831x_hwmon { 33 struct wm831x *wm831x; 34 struct device *classdev; 35 }; 36 37 static ssize_t show_name(struct device *dev, 38 struct device_attribute *attr, char *buf) 39 { 40 return sprintf(buf, "wm831x\n"); 41 } 42 43 static const char * const input_names[] = { 44 [WM831X_AUX_SYSVDD] = "SYSVDD", 45 [WM831X_AUX_USB] = "USB", 46 [WM831X_AUX_BKUP_BATT] = "Backup battery", 47 [WM831X_AUX_BATT] = "Battery", 48 [WM831X_AUX_WALL] = "WALL", 49 [WM831X_AUX_CHIP_TEMP] = "PMIC", 50 [WM831X_AUX_BATT_TEMP] = "Battery", 51 }; 52 53 54 static ssize_t show_voltage(struct device *dev, 55 struct device_attribute *attr, char *buf) 56 { 57 struct wm831x_hwmon *hwmon = dev_get_drvdata(dev); 58 int channel = to_sensor_dev_attr(attr)->index; 59 int ret; 60 61 ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel); 62 if (ret < 0) 63 return ret; 64 65 return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000)); 66 } 67 68 static ssize_t show_chip_temp(struct device *dev, 69 struct device_attribute *attr, char *buf) 70 { 71 struct wm831x_hwmon *hwmon = dev_get_drvdata(dev); 72 int channel = to_sensor_dev_attr(attr)->index; 73 int ret; 74 75 ret = wm831x_auxadc_read(hwmon->wm831x, channel); 76 if (ret < 0) 77 return ret; 78 79 /* Degrees celsius = (512.18-ret) / 1.0983 */ 80 ret = 512180 - (ret * 1000); 81 ret = DIV_ROUND_CLOSEST(ret * 10000, 10983); 82 83 return sprintf(buf, "%d\n", ret); 84 } 85 86 static ssize_t show_label(struct device *dev, 87 struct device_attribute *attr, char *buf) 88 { 89 int channel = to_sensor_dev_attr(attr)->index; 90 91 return sprintf(buf, "%s\n", input_names[channel]); 92 } 93 94 #define WM831X_VOLTAGE(id, name) \ 95 static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \ 96 NULL, name) 97 98 #define WM831X_NAMED_VOLTAGE(id, name) \ 99 WM831X_VOLTAGE(id, name); \ 100 static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label, \ 101 NULL, name) 102 103 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); 104 105 WM831X_VOLTAGE(0, WM831X_AUX_AUX1); 106 WM831X_VOLTAGE(1, WM831X_AUX_AUX2); 107 WM831X_VOLTAGE(2, WM831X_AUX_AUX3); 108 WM831X_VOLTAGE(3, WM831X_AUX_AUX4); 109 110 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD); 111 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB); 112 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT); 113 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL); 114 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT); 115 116 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL, 117 WM831X_AUX_CHIP_TEMP); 118 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 119 WM831X_AUX_CHIP_TEMP); 120 /* 121 * Report as a voltage since conversion depends on external components 122 * and that's what the ABI wants. 123 */ 124 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL, 125 WM831X_AUX_BATT_TEMP); 126 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL, 127 WM831X_AUX_BATT_TEMP); 128 129 static struct attribute *wm831x_attributes[] = { 130 &dev_attr_name.attr, 131 132 &sensor_dev_attr_in0_input.dev_attr.attr, 133 &sensor_dev_attr_in1_input.dev_attr.attr, 134 &sensor_dev_attr_in2_input.dev_attr.attr, 135 &sensor_dev_attr_in3_input.dev_attr.attr, 136 137 &sensor_dev_attr_in4_input.dev_attr.attr, 138 &sensor_dev_attr_in4_label.dev_attr.attr, 139 &sensor_dev_attr_in5_input.dev_attr.attr, 140 &sensor_dev_attr_in5_label.dev_attr.attr, 141 &sensor_dev_attr_in6_input.dev_attr.attr, 142 &sensor_dev_attr_in6_label.dev_attr.attr, 143 &sensor_dev_attr_in7_input.dev_attr.attr, 144 &sensor_dev_attr_in7_label.dev_attr.attr, 145 &sensor_dev_attr_in8_input.dev_attr.attr, 146 &sensor_dev_attr_in8_label.dev_attr.attr, 147 148 &sensor_dev_attr_temp1_input.dev_attr.attr, 149 &sensor_dev_attr_temp1_label.dev_attr.attr, 150 &sensor_dev_attr_temp2_input.dev_attr.attr, 151 &sensor_dev_attr_temp2_label.dev_attr.attr, 152 153 NULL 154 }; 155 156 static const struct attribute_group wm831x_attr_group = { 157 .attrs = wm831x_attributes, 158 }; 159 160 static int wm831x_hwmon_probe(struct platform_device *pdev) 161 { 162 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 163 struct wm831x_hwmon *hwmon; 164 int ret; 165 166 hwmon = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_hwmon), 167 GFP_KERNEL); 168 if (!hwmon) 169 return -ENOMEM; 170 171 hwmon->wm831x = wm831x; 172 173 ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group); 174 if (ret) 175 return ret; 176 177 hwmon->classdev = hwmon_device_register(&pdev->dev); 178 if (IS_ERR(hwmon->classdev)) { 179 ret = PTR_ERR(hwmon->classdev); 180 goto err_sysfs; 181 } 182 183 platform_set_drvdata(pdev, hwmon); 184 185 return 0; 186 187 err_sysfs: 188 sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group); 189 return ret; 190 } 191 192 static int wm831x_hwmon_remove(struct platform_device *pdev) 193 { 194 struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev); 195 196 hwmon_device_unregister(hwmon->classdev); 197 sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group); 198 199 return 0; 200 } 201 202 static struct platform_driver wm831x_hwmon_driver = { 203 .probe = wm831x_hwmon_probe, 204 .remove = wm831x_hwmon_remove, 205 .driver = { 206 .name = "wm831x-hwmon", 207 .owner = THIS_MODULE, 208 }, 209 }; 210 211 module_platform_driver(wm831x_hwmon_driver); 212 213 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 214 MODULE_DESCRIPTION("WM831x Hardware Monitoring"); 215 MODULE_LICENSE("GPL"); 216 MODULE_ALIAS("platform:wm831x-hwmon"); 217