1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Timberdale FPGA GPIO driver
4 * Author: Mocean Laboratories
5 * Copyright (c) 2009 Intel Corporation
6 */
7
8/* Supports:
9 * Timberdale FPGA GPIO
10 */
11
12#include <linux/init.h>
13#include <linux/gpio/driver.h>
14#include <linux/platform_device.h>
15#include <linux/irq.h>
16#include <linux/io.h>
17#include <linux/timb_gpio.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20
21#define DRIVER_NAME "timb-gpio"
22
23#define TGPIOVAL 0x00
24#define TGPIODIR 0x04
25#define TGPIO_IER 0x08
26#define TGPIO_ISR 0x0c
27#define TGPIO_IPR 0x10
28#define TGPIO_ICR 0x14
29#define TGPIO_FLR 0x18
30#define TGPIO_LVR 0x1c
31#define TGPIO_VER 0x20
32#define TGPIO_BFLR 0x24
33
34struct timbgpio {
35 void __iomem *membase;
36 spinlock_t lock; /* mutual exclusion */
37 struct gpio_chip gpio;
38 int irq_base;
39 unsigned long last_ier;
40};
41
42static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
43 unsigned offset, bool enabled)
44{
45 struct timbgpio *tgpio = gpiochip_get_data(gc: gpio);
46 unsigned long flags;
47 u32 reg;
48
49 spin_lock_irqsave(&tgpio->lock, flags);
50 reg = ioread32(tgpio->membase + offset);
51
52 if (enabled)
53 reg |= (1 << index);
54 else
55 reg &= ~(1 << index);
56
57 iowrite32(reg, tgpio->membase + offset);
58 spin_unlock_irqrestore(lock: &tgpio->lock, flags);
59
60 return 0;
61}
62
63static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
64{
65 return timbgpio_update_bit(gpio, index: nr, TGPIODIR, enabled: true);
66}
67
68static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
69{
70 struct timbgpio *tgpio = gpiochip_get_data(gc: gpio);
71 u32 value;
72
73 value = ioread32(tgpio->membase + TGPIOVAL);
74 return (value & (1 << nr)) ? 1 : 0;
75}
76
77static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
78 unsigned nr, int val)
79{
80 return timbgpio_update_bit(gpio, index: nr, TGPIODIR, enabled: false);
81}
82
83static void timbgpio_gpio_set(struct gpio_chip *gpio,
84 unsigned nr, int val)
85{
86 timbgpio_update_bit(gpio, index: nr, TGPIOVAL, enabled: val != 0);
87}
88
89static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
90{
91 struct timbgpio *tgpio = gpiochip_get_data(gc: gpio);
92
93 if (tgpio->irq_base <= 0)
94 return -EINVAL;
95
96 return tgpio->irq_base + offset;
97}
98
99/*
100 * GPIO IRQ
101 */
102static void timbgpio_irq_disable(struct irq_data *d)
103{
104 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
105 int offset = d->irq - tgpio->irq_base;
106 unsigned long flags;
107
108 spin_lock_irqsave(&tgpio->lock, flags);
109 tgpio->last_ier &= ~(1UL << offset);
110 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
111 spin_unlock_irqrestore(lock: &tgpio->lock, flags);
112}
113
114static void timbgpio_irq_enable(struct irq_data *d)
115{
116 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
117 int offset = d->irq - tgpio->irq_base;
118 unsigned long flags;
119
120 spin_lock_irqsave(&tgpio->lock, flags);
121 tgpio->last_ier |= 1UL << offset;
122 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
123 spin_unlock_irqrestore(lock: &tgpio->lock, flags);
124}
125
126static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
127{
128 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
129 int offset = d->irq - tgpio->irq_base;
130 unsigned long flags;
131 u32 lvr, flr, bflr = 0;
132 u32 ver;
133 int ret = 0;
134
135 if (offset < 0 || offset > tgpio->gpio.ngpio)
136 return -EINVAL;
137
138 ver = ioread32(tgpio->membase + TGPIO_VER);
139
140 spin_lock_irqsave(&tgpio->lock, flags);
141
142 lvr = ioread32(tgpio->membase + TGPIO_LVR);
143 flr = ioread32(tgpio->membase + TGPIO_FLR);
144 if (ver > 2)
145 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
146
147 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
148 bflr &= ~(1 << offset);
149 flr &= ~(1 << offset);
150 if (trigger & IRQ_TYPE_LEVEL_HIGH)
151 lvr |= 1 << offset;
152 else
153 lvr &= ~(1 << offset);
154 }
155
156 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
157 if (ver < 3) {
158 ret = -EINVAL;
159 goto out;
160 } else {
161 flr |= 1 << offset;
162 bflr |= 1 << offset;
163 }
164 } else {
165 bflr &= ~(1 << offset);
166 flr |= 1 << offset;
167 if (trigger & IRQ_TYPE_EDGE_FALLING)
168 lvr &= ~(1 << offset);
169 else
170 lvr |= 1 << offset;
171 }
172
173 iowrite32(lvr, tgpio->membase + TGPIO_LVR);
174 iowrite32(flr, tgpio->membase + TGPIO_FLR);
175 if (ver > 2)
176 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
177
178 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
179
180out:
181 spin_unlock_irqrestore(lock: &tgpio->lock, flags);
182 return ret;
183}
184
185static void timbgpio_irq(struct irq_desc *desc)
186{
187 struct timbgpio *tgpio = irq_desc_get_handler_data(desc);
188 struct irq_data *data = irq_desc_get_irq_data(desc);
189 unsigned long ipr;
190 int offset;
191
192 data->chip->irq_ack(data);
193 ipr = ioread32(tgpio->membase + TGPIO_IPR);
194 iowrite32(ipr, tgpio->membase + TGPIO_ICR);
195
196 /*
197 * Some versions of the hardware trash the IER register if more than
198 * one interrupt is received simultaneously.
199 */
200 iowrite32(0, tgpio->membase + TGPIO_IER);
201
202 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
203 generic_handle_irq(irq: timbgpio_to_irq(gpio: &tgpio->gpio, offset));
204
205 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
206}
207
208static struct irq_chip timbgpio_irqchip = {
209 .name = "GPIO",
210 .irq_enable = timbgpio_irq_enable,
211 .irq_disable = timbgpio_irq_disable,
212 .irq_set_type = timbgpio_irq_type,
213};
214
215static int timbgpio_probe(struct platform_device *pdev)
216{
217 int err, i;
218 struct device *dev = &pdev->dev;
219 struct gpio_chip *gc;
220 struct timbgpio *tgpio;
221 struct timbgpio_platform_data *pdata = dev_get_platdata(dev: &pdev->dev);
222 int irq = platform_get_irq(pdev, 0);
223
224 if (!pdata || pdata->nr_pins > 32) {
225 dev_err(dev, "Invalid platform data\n");
226 return -EINVAL;
227 }
228
229 tgpio = devm_kzalloc(dev, size: sizeof(*tgpio), GFP_KERNEL);
230 if (!tgpio)
231 return -EINVAL;
232
233 tgpio->irq_base = pdata->irq_base;
234
235 spin_lock_init(&tgpio->lock);
236
237 tgpio->membase = devm_platform_ioremap_resource(pdev, index: 0);
238 if (IS_ERR(ptr: tgpio->membase))
239 return PTR_ERR(ptr: tgpio->membase);
240
241 gc = &tgpio->gpio;
242
243 gc->label = dev_name(dev: &pdev->dev);
244 gc->owner = THIS_MODULE;
245 gc->parent = &pdev->dev;
246 gc->direction_input = timbgpio_gpio_direction_input;
247 gc->get = timbgpio_gpio_get;
248 gc->direction_output = timbgpio_gpio_direction_output;
249 gc->set = timbgpio_gpio_set;
250 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
251 gc->dbg_show = NULL;
252 gc->base = pdata->gpio_base;
253 gc->ngpio = pdata->nr_pins;
254 gc->can_sleep = false;
255
256 err = devm_gpiochip_add_data(&pdev->dev, gc, tgpio);
257 if (err)
258 return err;
259
260 /* make sure to disable interrupts */
261 iowrite32(0x0, tgpio->membase + TGPIO_IER);
262
263 if (irq < 0 || tgpio->irq_base <= 0)
264 return 0;
265
266 for (i = 0; i < pdata->nr_pins; i++) {
267 irq_set_chip_and_handler(irq: tgpio->irq_base + i,
268 chip: &timbgpio_irqchip, handle: handle_simple_irq);
269 irq_set_chip_data(irq: tgpio->irq_base + i, data: tgpio);
270 irq_clear_status_flags(irq: tgpio->irq_base + i, clr: IRQ_NOREQUEST | IRQ_NOPROBE);
271 }
272
273 irq_set_chained_handler_and_data(irq, handle: timbgpio_irq, data: tgpio);
274
275 return 0;
276}
277
278static struct platform_driver timbgpio_platform_driver = {
279 .driver = {
280 .name = DRIVER_NAME,
281 .suppress_bind_attrs = true,
282 },
283 .probe = timbgpio_probe,
284};
285
286/*--------------------------------------------------------------------------*/
287
288builtin_platform_driver(timbgpio_platform_driver);
289

source code of linux/drivers/gpio/gpio-timberdale.c