1 /* 2 * Driver for the Freescale Semiconductor MC13783 adc. 3 * 4 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. 5 * Copyright (C) 2009 Sascha Hauer, Pengutronix 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for 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., 51 18 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #include <linux/mfd/mc13783-private.h> 22 #include <linux/platform_device.h> 23 #include <linux/hwmon-sysfs.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/hwmon.h> 27 #include <linux/init.h> 28 #include <linux/err.h> 29 30 #define MC13783_ADC_NAME "mc13783-adc" 31 32 struct mc13783_adc_priv { 33 struct mc13783 *mc13783; 34 struct device *hwmon_dev; 35 }; 36 37 static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute 38 *devattr, char *buf) 39 { 40 return sprintf(buf, "mc13783_adc\n"); 41 } 42 43 static int mc13783_adc_read(struct device *dev, 44 struct device_attribute *devattr, unsigned int *val) 45 { 46 struct platform_device *pdev = to_platform_device(dev); 47 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); 48 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 49 unsigned int channel = attr->index; 50 unsigned int sample[4]; 51 int ret; 52 53 ret = mc13783_adc_do_conversion(priv->mc13783, 54 MC13783_ADC_MODE_MULT_CHAN, 55 channel, sample); 56 if (ret) 57 return ret; 58 59 channel &= 0x7; 60 61 *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff; 62 63 return 0; 64 } 65 66 static ssize_t mc13783_adc_read_bp(struct device *dev, 67 struct device_attribute *devattr, char *buf) 68 { 69 unsigned val; 70 int ret = mc13783_adc_read(dev, devattr, &val); 71 72 if (ret) 73 return ret; 74 75 /* 76 * BP (channel 2) reports with offset 2.4V to the actual value to fit 77 * the input range of the ADC. unit = 2.25mV = 9/4 mV. 78 */ 79 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400; 80 81 return sprintf(buf, "%u\n", val); 82 } 83 84 static ssize_t mc13783_adc_read_gp(struct device *dev, 85 struct device_attribute *devattr, char *buf) 86 { 87 unsigned val; 88 int ret = mc13783_adc_read(dev, devattr, &val); 89 90 if (ret) 91 return ret; 92 93 /* 94 * input range is [0, 2.3V], val has 10 bits, so each bit 95 * is worth 9/4 mV. 96 */ 97 val = DIV_ROUND_CLOSEST(val * 9, 4); 98 99 return sprintf(buf, "%u\n", val); 100 } 101 102 static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL); 103 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2); 104 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5); 105 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6); 106 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7); 107 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8); 108 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9); 109 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10); 110 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11); 111 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12); 112 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13); 113 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14); 114 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15); 115 116 static struct attribute *mc13783_attr[] = { 117 &dev_attr_name.attr, 118 &sensor_dev_attr_in2_input.dev_attr.attr, 119 &sensor_dev_attr_in5_input.dev_attr.attr, 120 &sensor_dev_attr_in6_input.dev_attr.attr, 121 &sensor_dev_attr_in7_input.dev_attr.attr, 122 &sensor_dev_attr_in8_input.dev_attr.attr, 123 &sensor_dev_attr_in9_input.dev_attr.attr, 124 &sensor_dev_attr_in10_input.dev_attr.attr, 125 &sensor_dev_attr_in11_input.dev_attr.attr, 126 NULL 127 }; 128 129 static const struct attribute_group mc13783_group = { 130 .attrs = mc13783_attr, 131 }; 132 133 /* last four channels may be occupied by the touchscreen */ 134 static struct attribute *mc13783_attr_ts[] = { 135 &sensor_dev_attr_in12_input.dev_attr.attr, 136 &sensor_dev_attr_in13_input.dev_attr.attr, 137 &sensor_dev_attr_in14_input.dev_attr.attr, 138 &sensor_dev_attr_in15_input.dev_attr.attr, 139 NULL 140 }; 141 142 static const struct attribute_group mc13783_group_ts = { 143 .attrs = mc13783_attr_ts, 144 }; 145 146 static int __init mc13783_adc_probe(struct platform_device *pdev) 147 { 148 struct mc13783_adc_priv *priv; 149 int ret; 150 151 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 152 if (!priv) 153 return -ENOMEM; 154 155 priv->mc13783 = dev_get_drvdata(pdev->dev.parent); 156 157 platform_set_drvdata(pdev, priv); 158 159 /* Register sysfs hooks */ 160 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group); 161 if (ret) 162 goto out_err_create1; 163 164 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) 165 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts); 166 if (ret) 167 goto out_err_create2; 168 169 priv->hwmon_dev = hwmon_device_register(&pdev->dev); 170 if (IS_ERR(priv->hwmon_dev)) { 171 ret = PTR_ERR(priv->hwmon_dev); 172 dev_err(&pdev->dev, 173 "hwmon_device_register failed with %d.\n", ret); 174 goto out_err_register; 175 } 176 177 178 return 0; 179 180 out_err_register: 181 182 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) 183 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); 184 out_err_create2: 185 186 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); 187 out_err_create1: 188 189 platform_set_drvdata(pdev, NULL); 190 kfree(priv); 191 192 return ret; 193 } 194 195 static int __devexit mc13783_adc_remove(struct platform_device *pdev) 196 { 197 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); 198 199 hwmon_device_unregister(priv->hwmon_dev); 200 201 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) 202 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); 203 204 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); 205 206 platform_set_drvdata(pdev, NULL); 207 kfree(priv); 208 209 return 0; 210 } 211 212 static struct platform_driver mc13783_adc_driver = { 213 .remove = __devexit_p(mc13783_adc_remove), 214 .driver = { 215 .owner = THIS_MODULE, 216 .name = MC13783_ADC_NAME, 217 }, 218 }; 219 220 static int __init mc13783_adc_init(void) 221 { 222 return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe); 223 } 224 225 static void __exit mc13783_adc_exit(void) 226 { 227 platform_driver_unregister(&mc13783_adc_driver); 228 } 229 230 module_init(mc13783_adc_init); 231 module_exit(mc13783_adc_exit); 232 233 MODULE_DESCRIPTION("MC13783 ADC driver"); 234 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 235 MODULE_LICENSE("GPL"); 236 MODULE_ALIAS("platform:" MC13783_ADC_NAME); 237