xref: /linux/drivers/hwmon/mc13783-adc.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
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 name_show(struct device *dev, struct device_attribute *devattr,
44 			 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 	/* ADIN7 subchannels */
67 	if (channel >= 16)
68 		channel = 7;
69 
70 	channel &= 0x7;
71 
72 	*val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
73 
74 	return 0;
75 }
76 
77 static ssize_t mc13783_adc_read_bp(struct device *dev,
78 		struct device_attribute *devattr, char *buf)
79 {
80 	unsigned val;
81 	struct platform_device *pdev = to_platform_device(dev);
82 	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
83 	int ret = mc13783_adc_read(dev, devattr, &val);
84 
85 	if (ret)
86 		return ret;
87 
88 	if (driver_data & MC13783_ADC_BPDIV2)
89 		val = DIV_ROUND_CLOSEST(val * 9, 2);
90 	else
91 		/*
92 		 * BP (channel 2) reports with offset 2.4V to the actual value
93 		 * to fit the input range of the ADC.  unit = 2.25mV = 9/4 mV.
94 		 */
95 		val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
96 
97 	return sprintf(buf, "%u\n", val);
98 }
99 
100 static ssize_t mc13783_adc_read_gp(struct device *dev,
101 		struct device_attribute *devattr, char *buf)
102 {
103 	unsigned val;
104 	int ret = mc13783_adc_read(dev, devattr, &val);
105 
106 	if (ret)
107 		return ret;
108 
109 	/*
110 	 * input range is [0, 2.3V], val has 10 bits, so each bit
111 	 * is worth 9/4 mV.
112 	 */
113 	val = DIV_ROUND_CLOSEST(val * 9, 4);
114 
115 	return sprintf(buf, "%u\n", val);
116 }
117 
118 static ssize_t mc13783_adc_read_uid(struct device *dev,
119 		struct device_attribute *devattr, char *buf)
120 {
121 	unsigned int val;
122 	struct platform_device *pdev = to_platform_device(dev);
123 	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
124 	int ret = mc13783_adc_read(dev, devattr, &val);
125 
126 	if (ret)
127 		return ret;
128 
129 	if (driver_data & MC13783_ADC_BPDIV2)
130 		/* MC13892 have 1/2 divider, input range is [0, 4.800V] */
131 		val = DIV_ROUND_CLOSEST(val * 4800, 1024);
132 	else
133 		/* MC13783 have 0.9 divider, input range is [0, 2.555V] */
134 		val = DIV_ROUND_CLOSEST(val * 2555, 1024);
135 
136 	return sprintf(buf, "%u\n", val);
137 }
138 
139 static ssize_t mc13783_adc_read_temp(struct device *dev,
140 		struct device_attribute *devattr, char *buf)
141 {
142 	unsigned int val;
143 	struct platform_device *pdev = to_platform_device(dev);
144 	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
145 	int ret = mc13783_adc_read(dev, devattr, &val);
146 
147 	if (ret)
148 		return ret;
149 
150 	if (driver_data & MC13783_ADC_BPDIV2) {
151 		/*
152 		 * MC13892:
153 		 * Die Temperature Read Out Code at 25C 680
154 		 * Temperature change per LSB +0.4244C
155 		 */
156 		ret = DIV_ROUND_CLOSEST(-2635920 + val * 4244, 10);
157 	} else {
158 		/*
159 		 * MC13783:
160 		 * Die Temperature Read Out Code at 25C 282
161 		 * Temperature change per LSB -1.14C
162 		 */
163 		ret = 346480 - 1140 * val;
164 	}
165 
166 	return sprintf(buf, "%d\n", ret);
167 }
168 
169 static DEVICE_ATTR_RO(name);
170 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
171 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
172 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
173 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
174 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
175 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
176 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
177 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
178 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
179 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
180 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
181 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
182 static SENSOR_DEVICE_ATTR(in16_input, S_IRUGO, mc13783_adc_read_uid, NULL, 16);
183 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
184 			  mc13783_adc_read_temp, NULL, 17);
185 
186 static struct attribute *mc13783_attr_base[] = {
187 	&dev_attr_name.attr,
188 	&sensor_dev_attr_in2_input.dev_attr.attr,
189 	&sensor_dev_attr_in5_input.dev_attr.attr,
190 	&sensor_dev_attr_in6_input.dev_attr.attr,
191 	&sensor_dev_attr_in7_input.dev_attr.attr,
192 	&sensor_dev_attr_in16_input.dev_attr.attr,
193 	&sensor_dev_attr_temp1_input.dev_attr.attr,
194 	NULL
195 };
196 
197 static const struct attribute_group mc13783_group_base = {
198 	.attrs = mc13783_attr_base,
199 };
200 
201 /* these are only used if MC13783_ADC_16CHANS is provided in driver data */
202 static struct attribute *mc13783_attr_16chans[] = {
203 	&sensor_dev_attr_in8_input.dev_attr.attr,
204 	&sensor_dev_attr_in9_input.dev_attr.attr,
205 	&sensor_dev_attr_in10_input.dev_attr.attr,
206 	&sensor_dev_attr_in11_input.dev_attr.attr,
207 	NULL
208 };
209 
210 static const struct attribute_group mc13783_group_16chans = {
211 	.attrs = mc13783_attr_16chans,
212 };
213 
214 /* last four channels may be occupied by the touchscreen */
215 static struct attribute *mc13783_attr_ts[] = {
216 	&sensor_dev_attr_in12_input.dev_attr.attr,
217 	&sensor_dev_attr_in13_input.dev_attr.attr,
218 	&sensor_dev_attr_in14_input.dev_attr.attr,
219 	&sensor_dev_attr_in15_input.dev_attr.attr,
220 	NULL
221 };
222 
223 static const struct attribute_group mc13783_group_ts = {
224 	.attrs = mc13783_attr_ts,
225 };
226 
227 static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
228 {
229 	struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
230 	unsigned flags = mc13xxx_get_flags(priv->mc13xxx);
231 
232 	return flags & MC13XXX_USE_TOUCHSCREEN;
233 }
234 
235 static int __init mc13783_adc_probe(struct platform_device *pdev)
236 {
237 	struct mc13783_adc_priv *priv;
238 	int ret;
239 	const struct platform_device_id *id = platform_get_device_id(pdev);
240 	char *dash;
241 
242 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
243 	if (!priv)
244 		return -ENOMEM;
245 
246 	priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
247 	snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
248 	dash = strchr(priv->name, '-');
249 	if (dash)
250 		*dash = '\0';
251 
252 	platform_set_drvdata(pdev, priv);
253 
254 	/* Register sysfs hooks */
255 	ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
256 	if (ret)
257 		return ret;
258 
259 	if (id->driver_data & MC13783_ADC_16CHANS) {
260 		ret = sysfs_create_group(&pdev->dev.kobj,
261 				&mc13783_group_16chans);
262 		if (ret)
263 			goto out_err_create_16chans;
264 	}
265 
266 	if (!mc13783_adc_use_touchscreen(pdev)) {
267 		ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
268 		if (ret)
269 			goto out_err_create_ts;
270 	}
271 
272 	priv->hwmon_dev = hwmon_device_register(&pdev->dev);
273 	if (IS_ERR(priv->hwmon_dev)) {
274 		ret = PTR_ERR(priv->hwmon_dev);
275 		dev_err(&pdev->dev,
276 				"hwmon_device_register failed with %d.\n", ret);
277 		goto out_err_register;
278 	}
279 
280 	return 0;
281 
282 out_err_register:
283 
284 	if (!mc13783_adc_use_touchscreen(pdev))
285 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
286 out_err_create_ts:
287 
288 	if (id->driver_data & MC13783_ADC_16CHANS)
289 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
290 out_err_create_16chans:
291 
292 	sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
293 	return ret;
294 }
295 
296 static int mc13783_adc_remove(struct platform_device *pdev)
297 {
298 	struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
299 	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
300 
301 	hwmon_device_unregister(priv->hwmon_dev);
302 
303 	if (!mc13783_adc_use_touchscreen(pdev))
304 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
305 
306 	if (driver_data & MC13783_ADC_16CHANS)
307 		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
308 
309 	sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
310 
311 	return 0;
312 }
313 
314 static const struct platform_device_id mc13783_adc_idtable[] = {
315 	{
316 		.name = "mc13783-adc",
317 		.driver_data = MC13783_ADC_16CHANS,
318 	}, {
319 		.name = "mc13892-adc",
320 		.driver_data = MC13783_ADC_BPDIV2,
321 	}, {
322 		/* sentinel */
323 	}
324 };
325 MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
326 
327 static struct platform_driver mc13783_adc_driver = {
328 	.remove		= mc13783_adc_remove,
329 	.driver		= {
330 		.name	= DRIVER_NAME,
331 	},
332 	.id_table	= mc13783_adc_idtable,
333 };
334 
335 module_platform_driver_probe(mc13783_adc_driver, mc13783_adc_probe);
336 
337 MODULE_DESCRIPTION("MC13783 ADC driver");
338 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
339 MODULE_LICENSE("GPL");
340