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Linux/drivers/hwmon/mc13783-adc.c

  1 /*
  2  * Driver for the ADC on Freescale Semiconductor MC13783 and MC13892 PMICs.
  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/mc13xxx.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 DRIVER_NAME     "mc13783-adc"
 32 
 33 /* platform device id driver data */
 34 #define MC13783_ADC_16CHANS     1
 35 #define MC13783_ADC_BPDIV2      2
 36 
 37 struct mc13783_adc_priv {
 38         struct mc13xxx *mc13xxx;
 39         struct device *hwmon_dev;
 40         char name[PLATFORM_NAME_SIZE];
 41 };
 42 
 43 static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
 44                               *devattr, char *buf)
 45 {
 46         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
 47 
 48         return sprintf(buf, "%s\n", priv->name);
 49 }
 50 
 51 static int mc13783_adc_read(struct device *dev,
 52                 struct device_attribute *devattr, unsigned int *val)
 53 {
 54         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
 55         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 56         unsigned int channel = attr->index;
 57         unsigned int sample[4];
 58         int ret;
 59 
 60         ret = mc13xxx_adc_do_conversion(priv->mc13xxx,
 61                         MC13XXX_ADC_MODE_MULT_CHAN,
 62                         channel, 0, 0, sample);
 63         if (ret)
 64                 return ret;
 65 
 66         channel &= 0x7;
 67 
 68         *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
 69 
 70         return 0;
 71 }
 72 
 73 static ssize_t mc13783_adc_read_bp(struct device *dev,
 74                 struct device_attribute *devattr, char *buf)
 75 {
 76         unsigned val;
 77         struct platform_device *pdev = to_platform_device(dev);
 78         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
 79         int ret = mc13783_adc_read(dev, devattr, &val);
 80 
 81         if (ret)
 82                 return ret;
 83 
 84         if (driver_data & MC13783_ADC_BPDIV2)
 85                 val = DIV_ROUND_CLOSEST(val * 9, 2);
 86         else
 87                 /*
 88                  * BP (channel 2) reports with offset 2.4V to the actual value
 89                  * to fit the input range of the ADC.  unit = 2.25mV = 9/4 mV.
 90                  */
 91                 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
 92 
 93         return sprintf(buf, "%u\n", val);
 94 }
 95 
 96 static ssize_t mc13783_adc_read_gp(struct device *dev,
 97                 struct device_attribute *devattr, char *buf)
 98 {
 99         unsigned val;
100         int ret = mc13783_adc_read(dev, devattr, &val);
101 
102         if (ret)
103                 return ret;
104 
105         /*
106          * input range is [0, 2.3V], val has 10 bits, so each bit
107          * is worth 9/4 mV.
108          */
109         val = DIV_ROUND_CLOSEST(val * 9, 4);
110 
111         return sprintf(buf, "%u\n", val);
112 }
113 
114 static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
115 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
116 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
117 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
118 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
119 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
120 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
121 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
122 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
123 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
124 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
125 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
126 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
127 
128 static struct attribute *mc13783_attr_base[] = {
129         &dev_attr_name.attr,
130         &sensor_dev_attr_in2_input.dev_attr.attr,
131         &sensor_dev_attr_in5_input.dev_attr.attr,
132         &sensor_dev_attr_in6_input.dev_attr.attr,
133         &sensor_dev_attr_in7_input.dev_attr.attr,
134         NULL
135 };
136 
137 static const struct attribute_group mc13783_group_base = {
138         .attrs = mc13783_attr_base,
139 };
140 
141 /* these are only used if MC13783_ADC_16CHANS is provided in driver data */
142 static struct attribute *mc13783_attr_16chans[] = {
143         &sensor_dev_attr_in8_input.dev_attr.attr,
144         &sensor_dev_attr_in9_input.dev_attr.attr,
145         &sensor_dev_attr_in10_input.dev_attr.attr,
146         &sensor_dev_attr_in11_input.dev_attr.attr,
147         NULL
148 };
149 
150 static const struct attribute_group mc13783_group_16chans = {
151         .attrs = mc13783_attr_16chans,
152 };
153 
154 /* last four channels may be occupied by the touchscreen */
155 static struct attribute *mc13783_attr_ts[] = {
156         &sensor_dev_attr_in12_input.dev_attr.attr,
157         &sensor_dev_attr_in13_input.dev_attr.attr,
158         &sensor_dev_attr_in14_input.dev_attr.attr,
159         &sensor_dev_attr_in15_input.dev_attr.attr,
160         NULL
161 };
162 
163 static const struct attribute_group mc13783_group_ts = {
164         .attrs = mc13783_attr_ts,
165 };
166 
167 static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
168 {
169         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
170         unsigned flags = mc13xxx_get_flags(priv->mc13xxx);
171 
172         return flags & MC13XXX_USE_TOUCHSCREEN;
173 }
174 
175 static int __init mc13783_adc_probe(struct platform_device *pdev)
176 {
177         struct mc13783_adc_priv *priv;
178         int ret;
179         const struct platform_device_id *id = platform_get_device_id(pdev);
180         char *dash;
181 
182         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
183         if (!priv)
184                 return -ENOMEM;
185 
186         priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
187         snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
188         dash = strchr(priv->name, '-');
189         if (dash)
190                 *dash = '\0';
191 
192         platform_set_drvdata(pdev, priv);
193 
194         /* Register sysfs hooks */
195         ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
196         if (ret)
197                 return ret;
198 
199         if (id->driver_data & MC13783_ADC_16CHANS) {
200                 ret = sysfs_create_group(&pdev->dev.kobj,
201                                 &mc13783_group_16chans);
202                 if (ret)
203                         goto out_err_create_16chans;
204         }
205 
206         if (!mc13783_adc_use_touchscreen(pdev)) {
207                 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
208                 if (ret)
209                         goto out_err_create_ts;
210         }
211 
212         priv->hwmon_dev = hwmon_device_register(&pdev->dev);
213         if (IS_ERR(priv->hwmon_dev)) {
214                 ret = PTR_ERR(priv->hwmon_dev);
215                 dev_err(&pdev->dev,
216                                 "hwmon_device_register failed with %d.\n", ret);
217                 goto out_err_register;
218         }
219 
220         return 0;
221 
222 out_err_register:
223 
224         if (!mc13783_adc_use_touchscreen(pdev))
225                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
226 out_err_create_ts:
227 
228         if (id->driver_data & MC13783_ADC_16CHANS)
229                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
230 out_err_create_16chans:
231 
232         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
233         return ret;
234 }
235 
236 static int mc13783_adc_remove(struct platform_device *pdev)
237 {
238         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
239         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
240 
241         hwmon_device_unregister(priv->hwmon_dev);
242 
243         if (!mc13783_adc_use_touchscreen(pdev))
244                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
245 
246         if (driver_data & MC13783_ADC_16CHANS)
247                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
248 
249         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
250 
251         return 0;
252 }
253 
254 static const struct platform_device_id mc13783_adc_idtable[] = {
255         {
256                 .name = "mc13783-adc",
257                 .driver_data = MC13783_ADC_16CHANS,
258         }, {
259                 .name = "mc13892-adc",
260                 .driver_data = MC13783_ADC_BPDIV2,
261         }, {
262                 /* sentinel */
263         }
264 };
265 MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
266 
267 static struct platform_driver mc13783_adc_driver = {
268         .remove         = mc13783_adc_remove,
269         .driver         = {
270                 .owner  = THIS_MODULE,
271                 .name   = DRIVER_NAME,
272         },
273         .id_table       = mc13783_adc_idtable,
274 };
275 
276 module_platform_driver_probe(mc13783_adc_driver, mc13783_adc_probe);
277 
278 MODULE_DESCRIPTION("MC13783 ADC driver");
279 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
280 MODULE_LICENSE("GPL");
281 

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