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[10];
41 };
42 
mc13783_adc_show_name(struct device * dev,struct device_attribute * devattr,char * buf)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 
mc13783_adc_read(struct device * dev,struct device_attribute * devattr,unsigned int * val)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 
mc13783_adc_read_bp(struct device * dev,struct device_attribute * devattr,char * buf)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 
mc13783_adc_read_gp(struct device * dev,struct device_attribute * devattr,char * buf)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 
mc13783_adc_use_touchscreen(struct platform_device * pdev)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 
mc13783_adc_probe(struct platform_device * pdev)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 = kzalloc(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 		goto out_err_create_base;
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 out_err_create_base:
234 
235 	platform_set_drvdata(pdev, NULL);
236 	kfree(priv);
237 
238 	return ret;
239 }
240 
mc13783_adc_remove(struct platform_device * pdev)241 static int __devexit mc13783_adc_remove(struct platform_device *pdev)
242 {
243 	struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
244 	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
245 
246 	hwmon_device_unregister(priv->hwmon_dev);
247 
248 	if (!mc13783_adc_use_touchscreen(pdev))
249 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
250 
251 	if (driver_data & MC13783_ADC_16CHANS)
252 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
253 
254 	sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
255 
256 	platform_set_drvdata(pdev, NULL);
257 	kfree(priv);
258 
259 	return 0;
260 }
261 
262 static const struct platform_device_id mc13783_adc_idtable[] = {
263 	{
264 		.name = "mc13783-adc",
265 		.driver_data = MC13783_ADC_16CHANS,
266 	}, {
267 		.name = "mc13892-adc",
268 		.driver_data = MC13783_ADC_BPDIV2,
269 	}, {
270 		/* sentinel */
271 	}
272 };
273 MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
274 
275 static struct platform_driver mc13783_adc_driver = {
276 	.remove		= __devexit_p(mc13783_adc_remove),
277 	.driver		= {
278 		.owner	= THIS_MODULE,
279 		.name	= DRIVER_NAME,
280 	},
281 	.id_table	= mc13783_adc_idtable,
282 };
283 
mc13783_adc_init(void)284 static int __init mc13783_adc_init(void)
285 {
286 	return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe);
287 }
288 
mc13783_adc_exit(void)289 static void __exit mc13783_adc_exit(void)
290 {
291 	platform_driver_unregister(&mc13783_adc_driver);
292 }
293 
294 module_init(mc13783_adc_init);
295 module_exit(mc13783_adc_exit);
296 
297 MODULE_DESCRIPTION("MC13783 ADC driver");
298 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
299 MODULE_LICENSE("GPL");
300