/* * 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/completion.h> #include <linux/mfd/core.h> #include <linux/hwmon.h> struct jz4740_hwmon { struct resource *mem; void __iomem *base; int irq; const struct mfd_cell *cell; struct device *hwmon; struct completion read_completion; struct mutex lock; }; static ssize_t jz4740_hwmon_show_name(struct device *dev, struct device_attribute *dev_attr, char *buf) { return sprintf(buf, "jz4740\n"); } 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 jz4740_hwmon_read_adcin(struct device *dev, struct device_attribute *dev_attr, char *buf) { struct jz4740_hwmon *hwmon = dev_get_drvdata(dev); struct completion *completion = &hwmon->read_completion; long t; unsigned long val; int ret; mutex_lock(&hwmon->lock); INIT_COMPLETION(*completion); enable_irq(hwmon->irq); hwmon->cell->enable(to_platform_device(dev)); 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(to_platform_device(dev)); disable_irq(hwmon->irq); mutex_unlock(&hwmon->lock); return ret; } static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL); static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL); static struct attribute *jz4740_hwmon_attributes[] = { &dev_attr_name.attr, &dev_attr_in0_input.attr, NULL }; static const struct attribute_group jz4740_hwmon_attr_group = { .attrs = jz4740_hwmon_attributes, }; static int __devinit jz4740_hwmon_probe(struct platform_device *pdev) { int ret; struct jz4740_hwmon *hwmon; hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL); if (!hwmon) { dev_err(&pdev->dev, "Failed to allocate driver structure\n"); return -ENOMEM; } hwmon->cell = mfd_get_cell(pdev); hwmon->irq = platform_get_irq(pdev, 0); if (hwmon->irq < 0) { ret = hwmon->irq; dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret); goto err_free; } hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!hwmon->mem) { ret = -ENOENT; dev_err(&pdev->dev, "Failed to get platform mmio resource\n"); goto err_free; } hwmon->mem = request_mem_region(hwmon->mem->start, resource_size(hwmon->mem), pdev->name); if (!hwmon->mem) { ret = -EBUSY; dev_err(&pdev->dev, "Failed to request mmio memory region\n"); goto err_free; } hwmon->base = ioremap_nocache(hwmon->mem->start, resource_size(hwmon->mem)); if (!hwmon->base) { ret = -EBUSY; dev_err(&pdev->dev, "Failed to ioremap mmio memory\n"); goto err_release_mem_region; } init_completion(&hwmon->read_completion); mutex_init(&hwmon->lock); platform_set_drvdata(pdev, hwmon); ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon); if (ret) { dev_err(&pdev->dev, "Failed to request irq: %d\n", ret); goto err_iounmap; } disable_irq(hwmon->irq); ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); if (ret) { dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret); goto err_free_irq; } hwmon->hwmon = hwmon_device_register(&pdev->dev); if (IS_ERR(hwmon->hwmon)) { ret = PTR_ERR(hwmon->hwmon); goto err_remove_file; } return 0; err_remove_file: sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); err_free_irq: free_irq(hwmon->irq, hwmon); err_iounmap: platform_set_drvdata(pdev, NULL); iounmap(hwmon->base); err_release_mem_region: release_mem_region(hwmon->mem->start, resource_size(hwmon->mem)); err_free: kfree(hwmon); return ret; } static int __devexit jz4740_hwmon_remove(struct platform_device *pdev) { struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev); hwmon_device_unregister(hwmon->hwmon); sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); free_irq(hwmon->irq, hwmon); iounmap(hwmon->base); release_mem_region(hwmon->mem->start, resource_size(hwmon->mem)); platform_set_drvdata(pdev, NULL); kfree(hwmon); return 0; } static struct platform_driver jz4740_hwmon_driver = { .probe = jz4740_hwmon_probe, .remove = __devexit_p(jz4740_hwmon_remove), .driver = { .name = "jz4740-hwmon", .owner = THIS_MODULE, }, }; 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");