blob: bae96d246760c2298f96be53e9449313c8747612 [file] [log] [blame]
Magnus Dammc767db02008-07-11 18:55:27 +09001/*
2 * drivers/uio/uio_pdrv_genirq.c
3 *
4 * Userspace I/O platform driver with generic IRQ handling code.
5 *
6 * Copyright (C) 2008 Magnus Damm
7 *
8 * Based on uio_pdrv.c by Uwe Kleine-Koenig,
9 * Copyright (C) 2008 by Digi International Inc.
10 * All rights reserved.
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License version 2 as published by
14 * the Free Software Foundation.
15 */
16
17#include <linux/platform_device.h>
18#include <linux/uio_driver.h>
19#include <linux/spinlock.h>
20#include <linux/bitops.h>
21#include <linux/interrupt.h>
22#include <linux/stringify.h>
Magnus Dammaf76756e2009-08-14 10:49:38 +000023#include <linux/pm_runtime.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
Magnus Dammc767db02008-07-11 18:55:27 +090025
Hans J. Koch27760f82011-07-07 23:11:38 +020026#include <linux/of.h>
27#include <linux/of_platform.h>
28#include <linux/of_address.h>
29
Magnus Dammc767db02008-07-11 18:55:27 +090030#define DRIVER_NAME "uio_pdrv_genirq"
31
32struct uio_pdrv_genirq_platdata {
33 struct uio_info *uioinfo;
34 spinlock_t lock;
35 unsigned long flags;
Magnus Dammaf76756e2009-08-14 10:49:38 +000036 struct platform_device *pdev;
Magnus Dammc767db02008-07-11 18:55:27 +090037};
38
Magnus Dammaf76756e2009-08-14 10:49:38 +000039static int uio_pdrv_genirq_open(struct uio_info *info, struct inode *inode)
40{
41 struct uio_pdrv_genirq_platdata *priv = info->priv;
42
43 /* Wait until the Runtime PM code has woken up the device */
44 pm_runtime_get_sync(&priv->pdev->dev);
45 return 0;
46}
47
48static int uio_pdrv_genirq_release(struct uio_info *info, struct inode *inode)
49{
50 struct uio_pdrv_genirq_platdata *priv = info->priv;
51
52 /* Tell the Runtime PM code that the device has become idle */
53 pm_runtime_put_sync(&priv->pdev->dev);
54 return 0;
55}
56
Magnus Dammc767db02008-07-11 18:55:27 +090057static irqreturn_t uio_pdrv_genirq_handler(int irq, struct uio_info *dev_info)
58{
59 struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
60
61 /* Just disable the interrupt in the interrupt controller, and
62 * remember the state so we can allow user space to enable it later.
63 */
64
65 if (!test_and_set_bit(0, &priv->flags))
66 disable_irq_nosync(irq);
67
68 return IRQ_HANDLED;
69}
70
71static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
72{
73 struct uio_pdrv_genirq_platdata *priv = dev_info->priv;
74 unsigned long flags;
75
76 /* Allow user space to enable and disable the interrupt
77 * in the interrupt controller, but keep track of the
78 * state to prevent per-irq depth damage.
79 *
80 * Serialize this operation to support multiple tasks.
81 */
82
83 spin_lock_irqsave(&priv->lock, flags);
84 if (irq_on) {
85 if (test_and_clear_bit(0, &priv->flags))
86 enable_irq(dev_info->irq);
87 } else {
88 if (!test_and_set_bit(0, &priv->flags))
89 disable_irq(dev_info->irq);
90 }
91 spin_unlock_irqrestore(&priv->lock, flags);
92
93 return 0;
94}
95
96static int uio_pdrv_genirq_probe(struct platform_device *pdev)
97{
98 struct uio_info *uioinfo = pdev->dev.platform_data;
99 struct uio_pdrv_genirq_platdata *priv;
100 struct uio_mem *uiomem;
101 int ret = -EINVAL;
102 int i;
103
Hans J. Koch27760f82011-07-07 23:11:38 +0200104 if (!uioinfo) {
105 int irq;
106
107 /* alloc uioinfo for one device */
108 uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL);
109 if (!uioinfo) {
110 ret = -ENOMEM;
111 dev_err(&pdev->dev, "unable to kmalloc\n");
112 goto bad2;
113 }
114 uioinfo->name = pdev->dev.of_node->name;
115 uioinfo->version = "devicetree";
116
117 /* Multiple IRQs are not supported */
118 irq = platform_get_irq(pdev, 0);
119 if (irq == -ENXIO)
120 uioinfo->irq = UIO_IRQ_NONE;
121 else
122 uioinfo->irq = irq;
123 }
124
Magnus Dammc767db02008-07-11 18:55:27 +0900125 if (!uioinfo || !uioinfo->name || !uioinfo->version) {
126 dev_err(&pdev->dev, "missing platform_data\n");
127 goto bad0;
128 }
129
Mike Frysingere543ae82008-10-29 18:35:52 -0400130 if (uioinfo->handler || uioinfo->irqcontrol ||
131 uioinfo->irq_flags & IRQF_SHARED) {
Magnus Dammc767db02008-07-11 18:55:27 +0900132 dev_err(&pdev->dev, "interrupt configuration error\n");
133 goto bad0;
134 }
135
136 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
137 if (!priv) {
138 ret = -ENOMEM;
139 dev_err(&pdev->dev, "unable to kmalloc\n");
140 goto bad0;
141 }
142
143 priv->uioinfo = uioinfo;
144 spin_lock_init(&priv->lock);
145 priv->flags = 0; /* interrupt is enabled to begin with */
Magnus Dammaf76756e2009-08-14 10:49:38 +0000146 priv->pdev = pdev;
Magnus Dammc767db02008-07-11 18:55:27 +0900147
148 uiomem = &uioinfo->mem[0];
149
150 for (i = 0; i < pdev->num_resources; ++i) {
151 struct resource *r = &pdev->resource[i];
152
153 if (r->flags != IORESOURCE_MEM)
154 continue;
155
156 if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
157 dev_warn(&pdev->dev, "device has more than "
158 __stringify(MAX_UIO_MAPS)
159 " I/O memory resources.\n");
160 break;
161 }
162
163 uiomem->memtype = UIO_MEM_PHYS;
164 uiomem->addr = r->start;
Joe Perches28f65c112011-06-09 09:13:32 -0700165 uiomem->size = resource_size(r);
Magnus Dammc767db02008-07-11 18:55:27 +0900166 ++uiomem;
167 }
168
169 while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
170 uiomem->size = 0;
171 ++uiomem;
172 }
173
174 /* This driver requires no hardware specific kernel code to handle
175 * interrupts. Instead, the interrupt handler simply disables the
176 * interrupt in the interrupt controller. User space is responsible
177 * for performing hardware specific acknowledge and re-enabling of
178 * the interrupt in the interrupt controller.
179 *
180 * Interrupt sharing is not supported.
181 */
182
Magnus Dammc767db02008-07-11 18:55:27 +0900183 uioinfo->handler = uio_pdrv_genirq_handler;
184 uioinfo->irqcontrol = uio_pdrv_genirq_irqcontrol;
Magnus Dammaf76756e2009-08-14 10:49:38 +0000185 uioinfo->open = uio_pdrv_genirq_open;
186 uioinfo->release = uio_pdrv_genirq_release;
Magnus Dammc767db02008-07-11 18:55:27 +0900187 uioinfo->priv = priv;
188
Magnus Dammaf76756e2009-08-14 10:49:38 +0000189 /* Enable Runtime PM for this device:
190 * The device starts in suspended state to allow the hardware to be
191 * turned off by default. The Runtime PM bus code should power on the
192 * hardware and enable clocks at open().
193 */
194 pm_runtime_enable(&pdev->dev);
195
Magnus Dammc767db02008-07-11 18:55:27 +0900196 ret = uio_register_device(&pdev->dev, priv->uioinfo);
197 if (ret) {
198 dev_err(&pdev->dev, "unable to register uio device\n");
199 goto bad1;
200 }
201
202 platform_set_drvdata(pdev, priv);
203 return 0;
204 bad1:
205 kfree(priv);
Kuninori Morimoto68fb2e42009-11-09 02:42:47 +0000206 pm_runtime_disable(&pdev->dev);
Magnus Dammc767db02008-07-11 18:55:27 +0900207 bad0:
Hans J. Koch27760f82011-07-07 23:11:38 +0200208 /* kfree uioinfo for OF */
209 if (pdev->dev.of_node)
210 kfree(uioinfo);
211 bad2:
Magnus Dammc767db02008-07-11 18:55:27 +0900212 return ret;
213}
214
215static int uio_pdrv_genirq_remove(struct platform_device *pdev)
216{
217 struct uio_pdrv_genirq_platdata *priv = platform_get_drvdata(pdev);
218
219 uio_unregister_device(priv->uioinfo);
Magnus Dammaf76756e2009-08-14 10:49:38 +0000220 pm_runtime_disable(&pdev->dev);
Jie Zhou47296b12011-04-06 14:42:40 +0800221
222 priv->uioinfo->handler = NULL;
223 priv->uioinfo->irqcontrol = NULL;
224
Hans J. Koch27760f82011-07-07 23:11:38 +0200225 /* kfree uioinfo for OF */
226 if (pdev->dev.of_node)
227 kfree(priv->uioinfo);
228
Magnus Dammc767db02008-07-11 18:55:27 +0900229 kfree(priv);
230 return 0;
231}
232
Magnus Dammaf76756e2009-08-14 10:49:38 +0000233static int uio_pdrv_genirq_runtime_nop(struct device *dev)
234{
235 /* Runtime PM callback shared between ->runtime_suspend()
236 * and ->runtime_resume(). Simply returns success.
237 *
238 * In this driver pm_runtime_get_sync() and pm_runtime_put_sync()
239 * are used at open() and release() time. This allows the
240 * Runtime PM code to turn off power to the device while the
241 * device is unused, ie before open() and after release().
242 *
243 * This Runtime PM callback does not need to save or restore
244 * any registers since user space is responsbile for hardware
245 * register reinitialization after open().
246 */
247 return 0;
248}
249
Alexey Dobriyan47145212009-12-14 18:00:08 -0800250static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {
Magnus Dammaf76756e2009-08-14 10:49:38 +0000251 .runtime_suspend = uio_pdrv_genirq_runtime_nop,
252 .runtime_resume = uio_pdrv_genirq_runtime_nop,
253};
254
Hans J. Koch27760f82011-07-07 23:11:38 +0200255#ifdef CONFIG_OF
256static const struct of_device_id __devinitconst uio_of_genirq_match[] = {
257 { /* empty for now */ },
258};
259MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
260#else
261# define uio_of_genirq_match NULL
262#endif
263
Magnus Dammc767db02008-07-11 18:55:27 +0900264static struct platform_driver uio_pdrv_genirq = {
265 .probe = uio_pdrv_genirq_probe,
266 .remove = uio_pdrv_genirq_remove,
267 .driver = {
268 .name = DRIVER_NAME,
269 .owner = THIS_MODULE,
Magnus Dammaf76756e2009-08-14 10:49:38 +0000270 .pm = &uio_pdrv_genirq_dev_pm_ops,
Hans J. Koch27760f82011-07-07 23:11:38 +0200271 .of_match_table = uio_of_genirq_match,
Magnus Dammc767db02008-07-11 18:55:27 +0900272 },
273};
274
275static int __init uio_pdrv_genirq_init(void)
276{
277 return platform_driver_register(&uio_pdrv_genirq);
278}
279
280static void __exit uio_pdrv_genirq_exit(void)
281{
282 platform_driver_unregister(&uio_pdrv_genirq);
283}
284
285module_init(uio_pdrv_genirq_init);
286module_exit(uio_pdrv_genirq_exit);
287
288MODULE_AUTHOR("Magnus Damm");
289MODULE_DESCRIPTION("Userspace I/O platform driver with generic IRQ handling");
290MODULE_LICENSE("GPL v2");
291MODULE_ALIAS("platform:" DRIVER_NAME);