1/*
2 * Timberdale FPGA GPIO driver
3 * Author: Mocean Laboratories
4 * Copyright (c) 2009 Intel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20/* Supports:
21 * Timberdale FPGA GPIO
22 */
23
24#include <linux/init.h>
25#include <linux/gpio/driver.h>
26#include <linux/platform_device.h>
27#include <linux/irq.h>
28#include <linux/io.h>
29#include <linux/timb_gpio.h>
30#include <linux/interrupt.h>
31#include <linux/slab.h>
32
33#define DRIVER_NAME "timb-gpio"
34
35#define TGPIOVAL 0x00
36#define TGPIODIR 0x04
37#define TGPIO_IER 0x08
38#define TGPIO_ISR 0x0c
39#define TGPIO_IPR 0x10
40#define TGPIO_ICR 0x14
41#define TGPIO_FLR 0x18
42#define TGPIO_LVR 0x1c
43#define TGPIO_VER 0x20
44#define TGPIO_BFLR 0x24
45
46struct timbgpio {
47 void __iomem *membase;
48 spinlock_t lock; /* mutual exclusion */
49 struct gpio_chip gpio;
50 int irq_base;
51 unsigned long last_ier;
52};
53
54static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
55 unsigned offset, bool enabled)
56{
57 struct timbgpio *tgpio = gpiochip_get_data(gpio);
58 u32 reg;
59
60 spin_lock(&tgpio->lock);
61 reg = ioread32(tgpio->membase + offset);
62
63 if (enabled)
64 reg |= (1 << index);
65 else
66 reg &= ~(1 << index);
67
68 iowrite32(reg, tgpio->membase + offset);
69 spin_unlock(&tgpio->lock);
70
71 return 0;
72}
73
74static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
75{
76 return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
77}
78
79static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
80{
81 struct timbgpio *tgpio = gpiochip_get_data(gpio);
82 u32 value;
83
84 value = ioread32(tgpio->membase + TGPIOVAL);
85 return (value & (1 << nr)) ? 1 : 0;
86}
87
88static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
89 unsigned nr, int val)
90{
91 return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
92}
93
94static void timbgpio_gpio_set(struct gpio_chip *gpio,
95 unsigned nr, int val)
96{
97 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
98}
99
100static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
101{
102 struct timbgpio *tgpio = gpiochip_get_data(gpio);
103
104 if (tgpio->irq_base <= 0)
105 return -EINVAL;
106
107 return tgpio->irq_base + offset;
108}
109
110/*
111 * GPIO IRQ
112 */
113static void timbgpio_irq_disable(struct irq_data *d)
114{
115 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
116 int offset = d->irq - tgpio->irq_base;
117 unsigned long flags;
118
119 spin_lock_irqsave(&tgpio->lock, flags);
120 tgpio->last_ier &= ~(1UL << offset);
121 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
122 spin_unlock_irqrestore(&tgpio->lock, flags);
123}
124
125static void timbgpio_irq_enable(struct irq_data *d)
126{
127 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
128 int offset = d->irq - tgpio->irq_base;
129 unsigned long flags;
130
131 spin_lock_irqsave(&tgpio->lock, flags);
132 tgpio->last_ier |= 1UL << offset;
133 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
134 spin_unlock_irqrestore(&tgpio->lock, flags);
135}
136
137static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
138{
139 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
140 int offset = d->irq - tgpio->irq_base;
141 unsigned long flags;
142 u32 lvr, flr, bflr = 0;
143 u32 ver;
144 int ret = 0;
145
146 if (offset < 0 || offset > tgpio->gpio.ngpio)
147 return -EINVAL;
148
149 ver = ioread32(tgpio->membase + TGPIO_VER);
150
151 spin_lock_irqsave(&tgpio->lock, flags);
152
153 lvr = ioread32(tgpio->membase + TGPIO_LVR);
154 flr = ioread32(tgpio->membase + TGPIO_FLR);
155 if (ver > 2)
156 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
157
158 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
159 bflr &= ~(1 << offset);
160 flr &= ~(1 << offset);
161 if (trigger & IRQ_TYPE_LEVEL_HIGH)
162 lvr |= 1 << offset;
163 else
164 lvr &= ~(1 << offset);
165 }
166
167 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
168 if (ver < 3) {
169 ret = -EINVAL;
170 goto out;
171 } else {
172 flr |= 1 << offset;
173 bflr |= 1 << offset;
174 }
175 } else {
176 bflr &= ~(1 << offset);
177 flr |= 1 << offset;
178 if (trigger & IRQ_TYPE_EDGE_FALLING)
179 lvr &= ~(1 << offset);
180 else
181 lvr |= 1 << offset;
182 }
183
184 iowrite32(lvr, tgpio->membase + TGPIO_LVR);
185 iowrite32(flr, tgpio->membase + TGPIO_FLR);
186 if (ver > 2)
187 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
188
189 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
190
191out:
192 spin_unlock_irqrestore(&tgpio->lock, flags);
193 return ret;
194}
195
196static void timbgpio_irq(struct irq_desc *desc)
197{
198 struct timbgpio *tgpio = irq_desc_get_handler_data(desc);
199 struct irq_data *data = irq_desc_get_irq_data(desc);
200 unsigned long ipr;
201 int offset;
202
203 data->chip->irq_ack(data);
204 ipr = ioread32(tgpio->membase + TGPIO_IPR);
205 iowrite32(ipr, tgpio->membase + TGPIO_ICR);
206
207 /*
208 * Some versions of the hardware trash the IER register if more than
209 * one interrupt is received simultaneously.
210 */
211 iowrite32(0, tgpio->membase + TGPIO_IER);
212
213 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
214 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
215
216 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
217}
218
219static struct irq_chip timbgpio_irqchip = {
220 .name = "GPIO",
221 .irq_enable = timbgpio_irq_enable,
222 .irq_disable = timbgpio_irq_disable,
223 .irq_set_type = timbgpio_irq_type,
224};
225
226static int timbgpio_probe(struct platform_device *pdev)
227{
228 int err, i;
229 struct device *dev = &pdev->dev;
230 struct gpio_chip *gc;
231 struct timbgpio *tgpio;
232 struct resource *iomem;
233 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
234 int irq = platform_get_irq(pdev, 0);
235
236 if (!pdata || pdata->nr_pins > 32) {
237 dev_err(dev, "Invalid platform data\n");
238 return -EINVAL;
239 }
240
241 tgpio = devm_kzalloc(dev, sizeof(*tgpio), GFP_KERNEL);
242 if (!tgpio)
243 return -EINVAL;
244
245 tgpio->irq_base = pdata->irq_base;
246
247 spin_lock_init(&tgpio->lock);
248
249 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
250 tgpio->membase = devm_ioremap_resource(dev, iomem);
251 if (IS_ERR(tgpio->membase))
252 return PTR_ERR(tgpio->membase);
253
254 gc = &tgpio->gpio;
255
256 gc->label = dev_name(&pdev->dev);
257 gc->owner = THIS_MODULE;
258 gc->parent = &pdev->dev;
259 gc->direction_input = timbgpio_gpio_direction_input;
260 gc->get = timbgpio_gpio_get;
261 gc->direction_output = timbgpio_gpio_direction_output;
262 gc->set = timbgpio_gpio_set;
263 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
264 gc->dbg_show = NULL;
265 gc->base = pdata->gpio_base;
266 gc->ngpio = pdata->nr_pins;
267 gc->can_sleep = false;
268
269 err = devm_gpiochip_add_data(&pdev->dev, gc, tgpio);
270 if (err)
271 return err;
272
273 platform_set_drvdata(pdev, tgpio);
274
275 /* make sure to disable interrupts */
276 iowrite32(0x0, tgpio->membase + TGPIO_IER);
277
278 if (irq < 0 || tgpio->irq_base <= 0)
279 return 0;
280
281 for (i = 0; i < pdata->nr_pins; i++) {
282 irq_set_chip_and_handler(tgpio->irq_base + i,
283 &timbgpio_irqchip, handle_simple_irq);
284 irq_set_chip_data(tgpio->irq_base + i, tgpio);
285 irq_clear_status_flags(tgpio->irq_base + i, IRQ_NOREQUEST | IRQ_NOPROBE);
286 }
287
288 irq_set_chained_handler_and_data(irq, timbgpio_irq, tgpio);
289
290 return 0;
291}
292
293static struct platform_driver timbgpio_platform_driver = {
294 .driver = {
295 .name = DRIVER_NAME,
296 .suppress_bind_attrs = true,
297 },
298 .probe = timbgpio_probe,
299};
300
301/*--------------------------------------------------------------------------*/
302
303builtin_platform_driver(timbgpio_platform_driver);
304