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.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/slab.h> 28 #include <linux/init.h> 29 #include <linux/err.h> 30 31 #define MC13783_ADC_NAME "mc13783-adc" 32 33 struct mc13783_adc_priv { 34 struct mc13783 *mc13783; 35 struct device *hwmon_dev; 36 }; 37 38 static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute 39 *devattr, char *buf) 40 { 41 return sprintf(buf, "mc13783_adc\n"); 42 } 43 44 static int mc13783_adc_read(struct device *dev, 45 struct device_attribute *devattr, unsigned int *val) 46 { 47 struct platform_device *pdev = to_platform_device(dev); 48 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); 49 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 50 unsigned int channel = attr->index; 51 unsigned int sample[4]; 52 int ret; 53 54 ret = mc13783_adc_do_conversion(priv->mc13783, 55 MC13783_ADC_MODE_MULT_CHAN, 56 channel, sample); 57 if (ret) 58 return ret; 59 60 channel &= 0x7; 61 62 *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff; 63 64 return 0; 65 } 66 67 static ssize_t mc13783_adc_read_bp(struct device *dev, 68 struct device_attribute *devattr, char *buf) 69 { 70 unsigned val; 71 int ret = mc13783_adc_read(dev, devattr, &val); 72 73 if (ret) 74 return ret; 75 76 /* 77 * BP (channel 2) reports with offset 2.4V to the actual value to fit 78 * the input range of the ADC. unit = 2.25mV = 9/4 mV. 79 */ 80 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400; 81 82 return sprintf(buf, "%u\n", val); 83 } 84 85 static ssize_t mc13783_adc_read_gp(struct device *dev, 86 struct device_attribute *devattr, char *buf) 87 { 88 unsigned val; 89 int ret = mc13783_adc_read(dev, devattr, &val); 90 91 if (ret) 92 return ret; 93 94 /* 95 * input range is [0, 2.3V], val has 10 bits, so each bit 96 * is worth 9/4 mV. 97 */ 98 val = DIV_ROUND_CLOSEST(val * 9, 4); 99 100 return sprintf(buf, "%u\n", val); 101 } 102 103 static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL); 104 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2); 105 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5); 106 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6); 107 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7); 108 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8); 109 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9); 110 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10); 111 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11); 112 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12); 113 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13); 114 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14); 115 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15); 116 117 static struct attribute *mc13783_attr[] = { 118 &dev_attr_name.attr, 119 &sensor_dev_attr_in2_input.dev_attr.attr, 120 &sensor_dev_attr_in5_input.dev_attr.attr, 121 &sensor_dev_attr_in6_input.dev_attr.attr, 122 &sensor_dev_attr_in7_input.dev_attr.attr, 123 &sensor_dev_attr_in8_input.dev_attr.attr, 124 &sensor_dev_attr_in9_input.dev_attr.attr, 125 &sensor_dev_attr_in10_input.dev_attr.attr, 126 &sensor_dev_attr_in11_input.dev_attr.attr, 127 NULL 128 }; 129 130 static const struct attribute_group mc13783_group = { 131 .attrs = mc13783_attr, 132 }; 133 134 /* last four channels may be occupied by the touchscreen */ 135 static struct attribute *mc13783_attr_ts[] = { 136 &sensor_dev_attr_in12_input.dev_attr.attr, 137 &sensor_dev_attr_in13_input.dev_attr.attr, 138 &sensor_dev_attr_in14_input.dev_attr.attr, 139 &sensor_dev_attr_in15_input.dev_attr.attr, 140 NULL 141 }; 142 143 static const struct attribute_group mc13783_group_ts = { 144 .attrs = mc13783_attr_ts, 145 }; 146 147 static int mc13783_adc_use_touchscreen(struct platform_device *pdev) 148 { 149 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); 150 unsigned flags = mc13783_get_flags(priv->mc13783); 151 152 return flags & MC13783_USE_TOUCHSCREEN; 153 } 154 155 static int __init mc13783_adc_probe(struct platform_device *pdev) 156 { 157 struct mc13783_adc_priv *priv; 158 int ret; 159 160 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 161 if (!priv) 162 return -ENOMEM; 163 164 priv->mc13783 = dev_get_drvdata(pdev->dev.parent); 165 166 platform_set_drvdata(pdev, priv); 167 168 /* Register sysfs hooks */ 169 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group); 170 if (ret) 171 goto out_err_create1; 172 173 if (!mc13783_adc_use_touchscreen(pdev)) { 174 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts); 175 if (ret) 176 goto out_err_create2; 177 } 178 179 priv->hwmon_dev = hwmon_device_register(&pdev->dev); 180 if (IS_ERR(priv->hwmon_dev)) { 181 ret = PTR_ERR(priv->hwmon_dev); 182 dev_err(&pdev->dev, 183 "hwmon_device_register failed with %d.\n", ret); 184 goto out_err_register; 185 } 186 187 188 return 0; 189 190 out_err_register: 191 192 if (!mc13783_adc_use_touchscreen(pdev)) 193 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); 194 out_err_create2: 195 196 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); 197 out_err_create1: 198 199 platform_set_drvdata(pdev, NULL); 200 kfree(priv); 201 202 return ret; 203 } 204 205 static int __devexit mc13783_adc_remove(struct platform_device *pdev) 206 { 207 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); 208 209 hwmon_device_unregister(priv->hwmon_dev); 210 211 if (!mc13783_adc_use_touchscreen(pdev)) 212 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); 213 214 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); 215 216 platform_set_drvdata(pdev, NULL); 217 kfree(priv); 218 219 return 0; 220 } 221 222 static struct platform_driver mc13783_adc_driver = { 223 .remove = __devexit_p(mc13783_adc_remove), 224 .driver = { 225 .owner = THIS_MODULE, 226 .name = MC13783_ADC_NAME, 227 }, 228 }; 229 230 static int __init mc13783_adc_init(void) 231 { 232 return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe); 233 } 234 235 static void __exit mc13783_adc_exit(void) 236 { 237 platform_driver_unregister(&mc13783_adc_driver); 238 } 239 240 module_init(mc13783_adc_init); 241 module_exit(mc13783_adc_exit); 242 243 MODULE_DESCRIPTION("MC13783 ADC driver"); 244 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 245 MODULE_LICENSE("GPL"); 246 MODULE_ALIAS("platform:" MC13783_ADC_NAME); 247