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 28 #include <linux/mfd/wm831x/core.h> 29 #include <linux/mfd/wm831x/auxadc.h> 30 31 struct wm831x_hwmon { 32 struct wm831x *wm831x; 33 struct device *classdev; 34 }; 35 36 static ssize_t show_name(struct device *dev, 37 struct device_attribute *attr, char *buf) 38 { 39 return sprintf(buf, "wm831x\n"); 40 } 41 42 static const char *input_names[] = { 43 [WM831X_AUX_SYSVDD] = "SYSVDD", 44 [WM831X_AUX_USB] = "USB", 45 [WM831X_AUX_BKUP_BATT] = "Backup battery", 46 [WM831X_AUX_BATT] = "Battery", 47 [WM831X_AUX_WALL] = "WALL", 48 [WM831X_AUX_CHIP_TEMP] = "PMIC", 49 [WM831X_AUX_BATT_TEMP] = "Battery", 50 }; 51 52 53 static ssize_t show_voltage(struct device *dev, 54 struct device_attribute *attr, char *buf) 55 { 56 struct wm831x_hwmon *hwmon = dev_get_drvdata(dev); 57 int channel = to_sensor_dev_attr(attr)->index; 58 int ret; 59 60 ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel); 61 if (ret < 0) 62 return ret; 63 64 return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000)); 65 } 66 67 static ssize_t show_chip_temp(struct device *dev, 68 struct device_attribute *attr, char *buf) 69 { 70 struct wm831x_hwmon *hwmon = dev_get_drvdata(dev); 71 int channel = to_sensor_dev_attr(attr)->index; 72 int ret; 73 74 ret = wm831x_auxadc_read(hwmon->wm831x, channel); 75 if (ret < 0) 76 return ret; 77 78 /* Degrees celsius = (512.18-ret) / 1.0983 */ 79 ret = 512180 - (ret * 1000); 80 ret = DIV_ROUND_CLOSEST(ret * 10000, 10983); 81 82 return sprintf(buf, "%d\n", ret); 83 } 84 85 static ssize_t show_label(struct device *dev, 86 struct device_attribute *attr, char *buf) 87 { 88 int channel = to_sensor_dev_attr(attr)->index; 89 90 return sprintf(buf, "%s\n", input_names[channel]); 91 } 92 93 #define WM831X_VOLTAGE(id, name) \ 94 static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \ 95 NULL, name) 96 97 #define WM831X_NAMED_VOLTAGE(id, name) \ 98 WM831X_VOLTAGE(id, name); \ 99 static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label, \ 100 NULL, name) 101 102 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); 103 104 WM831X_VOLTAGE(0, WM831X_AUX_AUX1); 105 WM831X_VOLTAGE(1, WM831X_AUX_AUX2); 106 WM831X_VOLTAGE(2, WM831X_AUX_AUX3); 107 WM831X_VOLTAGE(3, WM831X_AUX_AUX4); 108 109 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD); 110 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB); 111 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT); 112 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL); 113 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT); 114 115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL, 116 WM831X_AUX_CHIP_TEMP); 117 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 118 WM831X_AUX_CHIP_TEMP); 119 /* Report as a voltage since conversion depends on external components 120 * and that's what the ABI wants. */ 121 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL, 122 WM831X_AUX_BATT_TEMP); 123 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL, 124 WM831X_AUX_BATT_TEMP); 125 126 static struct attribute *wm831x_attributes[] = { 127 &dev_attr_name.attr, 128 129 &sensor_dev_attr_in0_input.dev_attr.attr, 130 &sensor_dev_attr_in1_input.dev_attr.attr, 131 &sensor_dev_attr_in2_input.dev_attr.attr, 132 &sensor_dev_attr_in3_input.dev_attr.attr, 133 134 &sensor_dev_attr_in4_input.dev_attr.attr, 135 &sensor_dev_attr_in4_label.dev_attr.attr, 136 &sensor_dev_attr_in5_input.dev_attr.attr, 137 &sensor_dev_attr_in5_label.dev_attr.attr, 138 &sensor_dev_attr_in6_input.dev_attr.attr, 139 &sensor_dev_attr_in6_label.dev_attr.attr, 140 &sensor_dev_attr_in7_input.dev_attr.attr, 141 &sensor_dev_attr_in7_label.dev_attr.attr, 142 &sensor_dev_attr_in8_input.dev_attr.attr, 143 &sensor_dev_attr_in8_label.dev_attr.attr, 144 145 &sensor_dev_attr_temp1_input.dev_attr.attr, 146 &sensor_dev_attr_temp1_label.dev_attr.attr, 147 &sensor_dev_attr_temp2_input.dev_attr.attr, 148 &sensor_dev_attr_temp2_label.dev_attr.attr, 149 150 NULL 151 }; 152 153 static const struct attribute_group wm831x_attr_group = { 154 .attrs = wm831x_attributes, 155 }; 156 157 static int __devinit wm831x_hwmon_probe(struct platform_device *pdev) 158 { 159 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 160 struct wm831x_hwmon *hwmon; 161 int ret; 162 163 hwmon = kzalloc(sizeof(struct wm831x_hwmon), GFP_KERNEL); 164 if (!hwmon) 165 return -ENOMEM; 166 167 hwmon->wm831x = wm831x; 168 169 ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group); 170 if (ret) 171 goto err; 172 173 hwmon->classdev = hwmon_device_register(&pdev->dev); 174 if (IS_ERR(hwmon->classdev)) { 175 ret = PTR_ERR(hwmon->classdev); 176 goto err_sysfs; 177 } 178 179 platform_set_drvdata(pdev, hwmon); 180 181 return 0; 182 183 err_sysfs: 184 sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group); 185 err: 186 kfree(hwmon); 187 return ret; 188 } 189 190 static int __devexit wm831x_hwmon_remove(struct platform_device *pdev) 191 { 192 struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev); 193 194 hwmon_device_unregister(hwmon->classdev); 195 sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group); 196 platform_set_drvdata(pdev, NULL); 197 kfree(hwmon); 198 199 return 0; 200 } 201 202 static struct platform_driver wm831x_hwmon_driver = { 203 .probe = wm831x_hwmon_probe, 204 .remove = __devexit_p(wm831x_hwmon_remove), 205 .driver = { 206 .name = "wm831x-hwmon", 207 .owner = THIS_MODULE, 208 }, 209 }; 210 211 static int __init wm831x_hwmon_init(void) 212 { 213 return platform_driver_register(&wm831x_hwmon_driver); 214 } 215 module_init(wm831x_hwmon_init); 216 217 static void __exit wm831x_hwmon_exit(void) 218 { 219 platform_driver_unregister(&wm831x_hwmon_driver); 220 } 221 module_exit(wm831x_hwmon_exit); 222 223 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 224 MODULE_DESCRIPTION("WM831x Hardware Monitoring"); 225 MODULE_LICENSE("GPL"); 226 MODULE_ALIAS("platform:wm831x-hwmon"); 227