1/*
  2 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
  3 * JZ4740 SoC HWMON driver
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under  the terms of the GNU General  Public License as published by the
  7 * Free Software Foundation;  either version 2 of the License, or (at your
  8 * option) any later version.
  9 *
 10 * You should have received a copy of the GNU General Public License along
 11 * with this program; if not, write to the Free Software Foundation, Inc.,
 12 * 675 Mass Ave, Cambridge, MA 02139, USA.
 13 *
 14 */
 15
 16#include <linux/err.h>
 17#include <linux/interrupt.h>
 18#include <linux/kernel.h>
 19#include <linux/module.h>
 20#include <linux/mutex.h>
 21#include <linux/platform_device.h>
 22#include <linux/slab.h>
 23
 24#include <linux/completion.h>
 25#include <linux/mfd/core.h>
 26
 27#include <linux/hwmon.h>
 28
 29struct jz4740_hwmon {
 30	struct resource *mem;
 31	void __iomem *base;
 32
 33	int irq;
 34
 35	const struct mfd_cell *cell;
 36	struct device *hwmon;
 37
 38	struct completion read_completion;
 39
 40	struct mutex lock;
 41};
 42
 43static ssize_t jz4740_hwmon_show_name(struct device *dev,
 44	struct device_attribute *dev_attr, char *buf)
 45{
 46	return sprintf(buf, "jz4740\n");
 47}
 48
 49static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
 50{
 51	struct jz4740_hwmon *hwmon = data;
 52
 53	complete(&hwmon->read_completion);
 54	return IRQ_HANDLED;
 55}
 56
 57static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
 58	struct device_attribute *dev_attr, char *buf)
 59{
 60	struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
 61	struct completion *completion = &hwmon->read_completion;
 62	unsigned long t;
 63	unsigned long val;
 64	int ret;
 65
 66	mutex_lock(&hwmon->lock);
 67
 68	INIT_COMPLETION(*completion);
 69
 70	enable_irq(hwmon->irq);
 71	hwmon->cell->enable(to_platform_device(dev));
 72
 73	t = wait_for_completion_interruptible_timeout(completion, HZ);
 74
 75	if (t > 0) {
 76		val = readw(hwmon->base) & 0xfff;
 77		val = (val * 3300) >> 12;
 78		ret = sprintf(buf, "%lu\n", val);
 79	} else {
 80		ret = t ? t : -ETIMEDOUT;
 81	}
 82
 83	hwmon->cell->disable(to_platform_device(dev));
 84	disable_irq(hwmon->irq);
 85
 86	mutex_unlock(&hwmon->lock);
 87
 88	return ret;
 89}
 90
 91static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
 92static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);
 93
 94static struct attribute *jz4740_hwmon_attributes[] = {
 95	&dev_attr_name.attr,
 96	&dev_attr_in0_input.attr,
 97	NULL
 98};
 99
100static const struct attribute_group jz4740_hwmon_attr_group = {
101	.attrs = jz4740_hwmon_attributes,
102};
103
104static int __devinit jz4740_hwmon_probe(struct platform_device *pdev)
105{
106	int ret;
107	struct jz4740_hwmon *hwmon;
108
109	hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL);
110	if (!hwmon) {
111		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
112		return -ENOMEM;
113	}
114
115	hwmon->cell = mfd_get_cell(pdev);
116
117	hwmon->irq = platform_get_irq(pdev, 0);
118	if (hwmon->irq < 0) {
119		ret = hwmon->irq;
120		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
121		goto err_free;
122	}
123
124	hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
125	if (!hwmon->mem) {
126		ret = -ENOENT;
127		dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
128		goto err_free;
129	}
130
131	hwmon->mem = request_mem_region(hwmon->mem->start,
132			resource_size(hwmon->mem), pdev->name);
133	if (!hwmon->mem) {
134		ret = -EBUSY;
135		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
136		goto err_free;
137	}
138
139	hwmon->base = ioremap_nocache(hwmon->mem->start,
140			resource_size(hwmon->mem));
141	if (!hwmon->base) {
142		ret = -EBUSY;
143		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
144		goto err_release_mem_region;
145	}
146
147	init_completion(&hwmon->read_completion);
148	mutex_init(&hwmon->lock);
149
150	platform_set_drvdata(pdev, hwmon);
151
152	ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon);
153	if (ret) {
154		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
155		goto err_iounmap;
156	}
157	disable_irq(hwmon->irq);
158
159	ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
160	if (ret) {
161		dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
162		goto err_free_irq;
163	}
164
165	hwmon->hwmon = hwmon_device_register(&pdev->dev);
166	if (IS_ERR(hwmon->hwmon)) {
167		ret = PTR_ERR(hwmon->hwmon);
168		goto err_remove_file;
169	}
170
171	return 0;
172
173err_remove_file:
174	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
175err_free_irq:
176	free_irq(hwmon->irq, hwmon);
177err_iounmap:
178	platform_set_drvdata(pdev, NULL);
179	iounmap(hwmon->base);
180err_release_mem_region:
181	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
182err_free:
183	kfree(hwmon);
184
185	return ret;
186}
187
188static int __devexit jz4740_hwmon_remove(struct platform_device *pdev)
189{
190	struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
191
192	hwmon_device_unregister(hwmon->hwmon);
193	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
194
195	free_irq(hwmon->irq, hwmon);
196
197	iounmap(hwmon->base);
198	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
199
200	platform_set_drvdata(pdev, NULL);
201	kfree(hwmon);
202
203	return 0;
204}
205
206struct platform_driver jz4740_hwmon_driver = {
207	.probe	= jz4740_hwmon_probe,
208	.remove = __devexit_p(jz4740_hwmon_remove),
209	.driver = {
210		.name = "jz4740-hwmon",
211		.owner = THIS_MODULE,
212	},
213};
214
215static int __init jz4740_hwmon_init(void)
216{
217	return platform_driver_register(&jz4740_hwmon_driver);
218}
219module_init(jz4740_hwmon_init);
220
221static void __exit jz4740_hwmon_exit(void)
222{
223	platform_driver_unregister(&jz4740_hwmon_driver);
224}
225module_exit(jz4740_hwmon_exit);
226
227MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
228MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
229MODULE_LICENSE("GPL");
230MODULE_ALIAS("platform:jz4740-hwmon");