diff options
Diffstat (limited to 'drivers/hwmon/jz4740-hwmon.c')
| -rw-r--r-- | drivers/hwmon/jz4740-hwmon.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/hwmon/jz4740-hwmon.c b/drivers/hwmon/jz4740-hwmon.c new file mode 100644 index 000000000000..1c8b3d9e2051 --- /dev/null +++ b/drivers/hwmon/jz4740-hwmon.c @@ -0,0 +1,230 @@ +/* + * 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; + + 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; + unsigned 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 = pdev->dev.platform_data; + + 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; +} + +struct platform_driver jz4740_hwmon_driver = { + .probe = jz4740_hwmon_probe, + .remove = __devexit_p(jz4740_hwmon_remove), + .driver = { + .name = "jz4740-hwmon", + .owner = THIS_MODULE, + }, +}; + +static int __init jz4740_hwmon_init(void) +{ + return platform_driver_register(&jz4740_hwmon_driver); +} +module_init(jz4740_hwmon_init); + +static void __exit jz4740_hwmon_exit(void) +{ + platform_driver_unregister(&jz4740_hwmon_driver); +} +module_exit(jz4740_hwmon_exit); + +MODULE_DESCRIPTION("JZ4740 SoC HWMON driver"); +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:jz4740-hwmon"); |