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