147 строки
3.4 KiB
C
147 строки
3.4 KiB
C
/*
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* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
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* JZ4740 SoC HWMON driver
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/completion.h>
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#include <linux/mfd/core.h>
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#include <linux/hwmon.h>
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struct jz4740_hwmon {
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void __iomem *base;
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int irq;
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const struct mfd_cell *cell;
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struct platform_device *pdev;
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struct completion read_completion;
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struct mutex lock;
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};
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static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
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{
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struct jz4740_hwmon *hwmon = data;
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complete(&hwmon->read_completion);
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return IRQ_HANDLED;
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}
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static ssize_t in0_input_show(struct device *dev,
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struct device_attribute *dev_attr, char *buf)
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{
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struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
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struct platform_device *pdev = hwmon->pdev;
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struct completion *completion = &hwmon->read_completion;
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long t;
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unsigned long val;
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int ret;
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mutex_lock(&hwmon->lock);
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reinit_completion(completion);
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enable_irq(hwmon->irq);
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hwmon->cell->enable(pdev);
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t = wait_for_completion_interruptible_timeout(completion, HZ);
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if (t > 0) {
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val = readw(hwmon->base) & 0xfff;
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val = (val * 3300) >> 12;
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ret = sprintf(buf, "%lu\n", val);
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} else {
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ret = t ? t : -ETIMEDOUT;
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}
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hwmon->cell->disable(pdev);
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disable_irq(hwmon->irq);
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mutex_unlock(&hwmon->lock);
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return ret;
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}
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static DEVICE_ATTR_RO(in0_input);
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static struct attribute *jz4740_attrs[] = {
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&dev_attr_in0_input.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(jz4740);
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static int jz4740_hwmon_probe(struct platform_device *pdev)
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{
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int ret;
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struct device *dev = &pdev->dev;
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struct jz4740_hwmon *hwmon;
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struct device *hwmon_dev;
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struct resource *mem;
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hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
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if (!hwmon)
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return -ENOMEM;
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hwmon->cell = mfd_get_cell(pdev);
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hwmon->irq = platform_get_irq(pdev, 0);
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if (hwmon->irq < 0) {
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dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
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hwmon->irq);
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return hwmon->irq;
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}
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(hwmon->base))
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return PTR_ERR(hwmon->base);
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hwmon->pdev = pdev;
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init_completion(&hwmon->read_completion);
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mutex_init(&hwmon->lock);
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ret = devm_request_irq(dev, hwmon->irq, jz4740_hwmon_irq, 0,
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pdev->name, hwmon);
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if (ret) {
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dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
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return ret;
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}
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disable_irq(hwmon->irq);
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hwmon_dev = devm_hwmon_device_register_with_groups(dev, "jz4740", hwmon,
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jz4740_groups);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static struct platform_driver jz4740_hwmon_driver = {
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.probe = jz4740_hwmon_probe,
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.driver = {
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.name = "jz4740-hwmon",
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},
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};
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module_platform_driver(jz4740_hwmon_driver);
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MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:jz4740-hwmon");
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