| 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 | #include <linux/io.h> |
| 24 | |
| 25 | #include <linux/completion.h> |
| 26 | #include <linux/mfd/core.h> |
| 27 | |
| 28 | #include <linux/hwmon.h> |
| 29 | |
| 30 | struct jz4740_hwmon { |
| 31 | void __iomem *base; |
| 32 | int irq; |
| 33 | const struct mfd_cell *cell; |
| 34 | struct platform_device *pdev; |
| 35 | struct completion read_completion; |
| 36 | struct mutex lock; |
| 37 | }; |
| 38 | |
| 39 | static irqreturn_t jz4740_hwmon_irq(int irq, void *data) |
| 40 | { |
| 41 | struct jz4740_hwmon *hwmon = data; |
| 42 | |
| 43 | complete(&hwmon->read_completion); |
| 44 | return IRQ_HANDLED; |
| 45 | } |
| 46 | |
| 47 | static ssize_t jz4740_hwmon_read_adcin(struct device *dev, |
| 48 | struct device_attribute *dev_attr, char *buf) |
| 49 | { |
| 50 | struct jz4740_hwmon *hwmon = dev_get_drvdata(dev); |
| 51 | struct platform_device *pdev = hwmon->pdev; |
| 52 | struct completion *completion = &hwmon->read_completion; |
| 53 | long t; |
| 54 | unsigned long val; |
| 55 | int ret; |
| 56 | |
| 57 | mutex_lock(&hwmon->lock); |
| 58 | |
| 59 | reinit_completion(completion); |
| 60 | |
| 61 | enable_irq(hwmon->irq); |
| 62 | hwmon->cell->enable(pdev); |
| 63 | |
| 64 | t = wait_for_completion_interruptible_timeout(completion, HZ); |
| 65 | |
| 66 | if (t > 0) { |
| 67 | val = readw(hwmon->base) & 0xfff; |
| 68 | val = (val * 3300) >> 12; |
| 69 | ret = sprintf(buf, "%lu\n", val); |
| 70 | } else { |
| 71 | ret = t ? t : -ETIMEDOUT; |
| 72 | } |
| 73 | |
| 74 | hwmon->cell->disable(pdev); |
| 75 | disable_irq(hwmon->irq); |
| 76 | |
| 77 | mutex_unlock(&hwmon->lock); |
| 78 | |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL); |
| 83 | |
| 84 | static struct attribute *jz4740_attrs[] = { |
| 85 | &dev_attr_in0_input.attr, |
| 86 | NULL |
| 87 | }; |
| 88 | |
| 89 | ATTRIBUTE_GROUPS(jz4740); |
| 90 | |
| 91 | static int jz4740_hwmon_probe(struct platform_device *pdev) |
| 92 | { |
| 93 | int ret; |
| 94 | struct device *dev = &pdev->dev; |
| 95 | struct jz4740_hwmon *hwmon; |
| 96 | struct device *hwmon_dev; |
| 97 | struct resource *mem; |
| 98 | |
| 99 | hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL); |
| 100 | if (!hwmon) |
| 101 | return -ENOMEM; |
| 102 | |
| 103 | hwmon->cell = mfd_get_cell(pdev); |
| 104 | |
| 105 | hwmon->irq = platform_get_irq(pdev, 0); |
| 106 | if (hwmon->irq < 0) { |
| 107 | dev_err(&pdev->dev, "Failed to get platform irq: %d\n", |
| 108 | hwmon->irq); |
| 109 | return hwmon->irq; |
| 110 | } |
| 111 | |
| 112 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 113 | hwmon->base = devm_ioremap_resource(&pdev->dev, mem); |
| 114 | if (IS_ERR(hwmon->base)) |
| 115 | return PTR_ERR(hwmon->base); |
| 116 | |
| 117 | hwmon->pdev = pdev; |
| 118 | init_completion(&hwmon->read_completion); |
| 119 | mutex_init(&hwmon->lock); |
| 120 | |
| 121 | ret = devm_request_irq(dev, hwmon->irq, jz4740_hwmon_irq, 0, |
| 122 | pdev->name, hwmon); |
| 123 | if (ret) { |
| 124 | dev_err(&pdev->dev, "Failed to request irq: %d\n", ret); |
| 125 | return ret; |
| 126 | } |
| 127 | disable_irq(hwmon->irq); |
| 128 | |
| 129 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, "jz4740", hwmon, |
| 130 | jz4740_groups); |
| 131 | return PTR_ERR_OR_ZERO(hwmon_dev); |
| 132 | } |
| 133 | |
| 134 | static struct platform_driver jz4740_hwmon_driver = { |
| 135 | .probe = jz4740_hwmon_probe, |
| 136 | .driver = { |
| 137 | .name = "jz4740-hwmon", |
| 138 | }, |
| 139 | }; |
| 140 | |
| 141 | module_platform_driver(jz4740_hwmon_driver); |
| 142 | |
| 143 | MODULE_DESCRIPTION("JZ4740 SoC HWMON driver"); |
| 144 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| 145 | MODULE_LICENSE("GPL"); |
| 146 | MODULE_ALIAS("platform:jz4740-hwmon"); |