2 * Timberdale FPGA GPIO driver
3 * Copyright (c) 2009 Intel Corporation
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 * Timberdale FPGA GPIO
23 #include <linux/module.h>
24 #include <linux/gpio.h>
25 #include <linux/platform_device.h>
26 #include <linux/irq.h>
28 #include <linux/timb_gpio.h>
29 #include <linux/interrupt.h>
30 #include <linux/slab.h>
32 #define DRIVER_NAME "timb-gpio"
36 #define TGPIO_IER 0x08
37 #define TGPIO_ISR 0x0c
38 #define TGPIO_IPR 0x10
39 #define TGPIO_ICR 0x14
40 #define TGPIO_FLR 0x18
41 #define TGPIO_LVR 0x1c
42 #define TGPIO_VER 0x20
43 #define TGPIO_BFLR 0x24
46 void __iomem *membase;
47 spinlock_t lock; /* mutual exclusion */
48 struct gpio_chip gpio;
50 unsigned long last_ier;
53 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
54 unsigned offset, bool enabled)
56 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
59 spin_lock(&tgpio->lock);
60 reg = ioread32(tgpio->membase + offset);
67 iowrite32(reg, tgpio->membase + offset);
68 spin_unlock(&tgpio->lock);
73 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
75 return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
78 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
80 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
83 value = ioread32(tgpio->membase + TGPIOVAL);
84 return (value & (1 << nr)) ? 1 : 0;
87 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
90 return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
93 static void timbgpio_gpio_set(struct gpio_chip *gpio,
96 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
99 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
101 struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
103 if (tgpio->irq_base <= 0)
106 return tgpio->irq_base + offset;
112 static void timbgpio_irq_disable(struct irq_data *d)
114 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
115 int offset = d->irq - tgpio->irq_base;
118 spin_lock_irqsave(&tgpio->lock, flags);
119 tgpio->last_ier &= ~(1UL << offset);
120 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
121 spin_unlock_irqrestore(&tgpio->lock, flags);
124 static void timbgpio_irq_enable(struct irq_data *d)
126 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
127 int offset = d->irq - tgpio->irq_base;
130 spin_lock_irqsave(&tgpio->lock, flags);
131 tgpio->last_ier |= 1UL << offset;
132 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
133 spin_unlock_irqrestore(&tgpio->lock, flags);
136 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
138 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
139 int offset = d->irq - tgpio->irq_base;
141 u32 lvr, flr, bflr = 0;
145 if (offset < 0 || offset > tgpio->gpio.ngpio)
148 ver = ioread32(tgpio->membase + TGPIO_VER);
150 spin_lock_irqsave(&tgpio->lock, flags);
152 lvr = ioread32(tgpio->membase + TGPIO_LVR);
153 flr = ioread32(tgpio->membase + TGPIO_FLR);
155 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
157 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
158 bflr &= ~(1 << offset);
159 flr &= ~(1 << offset);
160 if (trigger & IRQ_TYPE_LEVEL_HIGH)
163 lvr &= ~(1 << offset);
166 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
175 bflr &= ~(1 << offset);
177 if (trigger & IRQ_TYPE_EDGE_FALLING)
178 lvr &= ~(1 << offset);
183 iowrite32(lvr, tgpio->membase + TGPIO_LVR);
184 iowrite32(flr, tgpio->membase + TGPIO_FLR);
186 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
188 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
191 spin_unlock_irqrestore(&tgpio->lock, flags);
195 static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
197 struct timbgpio *tgpio = irq_get_handler_data(irq);
201 desc->irq_data.chip->irq_ack(irq_get_irq_data(irq));
202 ipr = ioread32(tgpio->membase + TGPIO_IPR);
203 iowrite32(ipr, tgpio->membase + TGPIO_ICR);
206 * Some versions of the hardware trash the IER register if more than
207 * one interrupt is received simultaneously.
209 iowrite32(0, tgpio->membase + TGPIO_IER);
211 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
212 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
214 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
217 static struct irq_chip timbgpio_irqchip = {
219 .irq_enable = timbgpio_irq_enable,
220 .irq_disable = timbgpio_irq_disable,
221 .irq_set_type = timbgpio_irq_type,
224 static int timbgpio_probe(struct platform_device *pdev)
227 struct device *dev = &pdev->dev;
228 struct gpio_chip *gc;
229 struct timbgpio *tgpio;
230 struct resource *iomem;
231 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
232 int irq = platform_get_irq(pdev, 0);
234 if (!pdata || pdata->nr_pins > 32) {
235 dev_err(dev, "Invalid platform data\n");
239 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
241 dev_err(dev, "Unable to get resource\n");
245 tgpio = devm_kzalloc(dev, sizeof(struct timbgpio), GFP_KERNEL);
247 dev_err(dev, "Memory alloc failed\n");
250 tgpio->irq_base = pdata->irq_base;
252 spin_lock_init(&tgpio->lock);
254 if (!devm_request_mem_region(dev, iomem->start, resource_size(iomem),
256 dev_err(dev, "Region already claimed\n");
260 tgpio->membase = devm_ioremap(dev, iomem->start, resource_size(iomem));
261 if (!tgpio->membase) {
262 dev_err(dev, "Cannot ioremap\n");
268 gc->label = dev_name(&pdev->dev);
269 gc->owner = THIS_MODULE;
270 gc->dev = &pdev->dev;
271 gc->direction_input = timbgpio_gpio_direction_input;
272 gc->get = timbgpio_gpio_get;
273 gc->direction_output = timbgpio_gpio_direction_output;
274 gc->set = timbgpio_gpio_set;
275 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
277 gc->base = pdata->gpio_base;
278 gc->ngpio = pdata->nr_pins;
279 gc->can_sleep = false;
281 err = gpiochip_add(gc);
285 platform_set_drvdata(pdev, tgpio);
287 /* make sure to disable interrupts */
288 iowrite32(0x0, tgpio->membase + TGPIO_IER);
290 if (irq < 0 || tgpio->irq_base <= 0)
293 for (i = 0; i < pdata->nr_pins; i++) {
294 irq_set_chip_and_handler(tgpio->irq_base + i,
295 &timbgpio_irqchip, handle_simple_irq);
296 irq_set_chip_data(tgpio->irq_base + i, tgpio);
298 set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
302 irq_set_handler_data(irq, tgpio);
303 irq_set_chained_handler(irq, timbgpio_irq);
308 static int timbgpio_remove(struct platform_device *pdev)
310 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
311 struct timbgpio *tgpio = platform_get_drvdata(pdev);
312 int irq = platform_get_irq(pdev, 0);
314 if (irq >= 0 && tgpio->irq_base > 0) {
316 for (i = 0; i < pdata->nr_pins; i++) {
317 irq_set_chip(tgpio->irq_base + i, NULL);
318 irq_set_chip_data(tgpio->irq_base + i, NULL);
321 irq_set_handler(irq, NULL);
322 irq_set_handler_data(irq, NULL);
325 gpiochip_remove(&tgpio->gpio);
330 static struct platform_driver timbgpio_platform_driver = {
334 .probe = timbgpio_probe,
335 .remove = timbgpio_remove,
338 /*--------------------------------------------------------------------------*/
340 module_platform_driver(timbgpio_platform_driver);
342 MODULE_DESCRIPTION("Timberdale GPIO driver");
343 MODULE_LICENSE("GPL v2");
344 MODULE_AUTHOR("Mocean Laboratories");
345 MODULE_ALIAS("platform:"DRIVER_NAME);