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
34 struct 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
timbgpio_update_bit(struct gpio_chip * gpio,unsigned index,unsigned offset,bool enabled)42 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
43 unsigned offset, bool enabled)
44 {
45 struct timbgpio *tgpio = gpiochip_get_data(gpio);
46 u32 reg;
47
48 spin_lock(&tgpio->lock);
49 reg = ioread32(tgpio->membase + offset);
50
51 if (enabled)
52 reg |= (1 << index);
53 else
54 reg &= ~(1 << index);
55
56 iowrite32(reg, tgpio->membase + offset);
57 spin_unlock(&tgpio->lock);
58
59 return 0;
60 }
61
timbgpio_gpio_direction_input(struct gpio_chip * gpio,unsigned nr)62 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
63 {
64 return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
65 }
66
timbgpio_gpio_get(struct gpio_chip * gpio,unsigned nr)67 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
68 {
69 struct timbgpio *tgpio = gpiochip_get_data(gpio);
70 u32 value;
71
72 value = ioread32(tgpio->membase + TGPIOVAL);
73 return (value & (1 << nr)) ? 1 : 0;
74 }
75
timbgpio_gpio_direction_output(struct gpio_chip * gpio,unsigned nr,int val)76 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
77 unsigned nr, int val)
78 {
79 return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
80 }
81
timbgpio_gpio_set(struct gpio_chip * gpio,unsigned nr,int val)82 static void timbgpio_gpio_set(struct gpio_chip *gpio,
83 unsigned nr, int val)
84 {
85 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
86 }
87
timbgpio_to_irq(struct gpio_chip * gpio,unsigned offset)88 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
89 {
90 struct timbgpio *tgpio = gpiochip_get_data(gpio);
91
92 if (tgpio->irq_base <= 0)
93 return -EINVAL;
94
95 return tgpio->irq_base + offset;
96 }
97
98 /*
99 * GPIO IRQ
100 */
timbgpio_irq_disable(struct irq_data * d)101 static void timbgpio_irq_disable(struct irq_data *d)
102 {
103 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
104 int offset = d->irq - tgpio->irq_base;
105 unsigned long flags;
106
107 spin_lock_irqsave(&tgpio->lock, flags);
108 tgpio->last_ier &= ~(1UL << offset);
109 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
110 spin_unlock_irqrestore(&tgpio->lock, flags);
111 }
112
timbgpio_irq_enable(struct irq_data * d)113 static void timbgpio_irq_enable(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
timbgpio_irq_type(struct irq_data * d,unsigned trigger)125 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
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 u32 lvr, flr, bflr = 0;
131 u32 ver;
132 int ret = 0;
133
134 if (offset < 0 || offset > tgpio->gpio.ngpio)
135 return -EINVAL;
136
137 ver = ioread32(tgpio->membase + TGPIO_VER);
138
139 spin_lock_irqsave(&tgpio->lock, flags);
140
141 lvr = ioread32(tgpio->membase + TGPIO_LVR);
142 flr = ioread32(tgpio->membase + TGPIO_FLR);
143 if (ver > 2)
144 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
145
146 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
147 bflr &= ~(1 << offset);
148 flr &= ~(1 << offset);
149 if (trigger & IRQ_TYPE_LEVEL_HIGH)
150 lvr |= 1 << offset;
151 else
152 lvr &= ~(1 << offset);
153 }
154
155 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
156 if (ver < 3) {
157 ret = -EINVAL;
158 goto out;
159 } else {
160 flr |= 1 << offset;
161 bflr |= 1 << offset;
162 }
163 } else {
164 bflr &= ~(1 << offset);
165 flr |= 1 << offset;
166 if (trigger & IRQ_TYPE_EDGE_FALLING)
167 lvr &= ~(1 << offset);
168 else
169 lvr |= 1 << offset;
170 }
171
172 iowrite32(lvr, tgpio->membase + TGPIO_LVR);
173 iowrite32(flr, tgpio->membase + TGPIO_FLR);
174 if (ver > 2)
175 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
176
177 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
178
179 out:
180 spin_unlock_irqrestore(&tgpio->lock, flags);
181 return ret;
182 }
183
timbgpio_irq(struct irq_desc * desc)184 static void timbgpio_irq(struct irq_desc *desc)
185 {
186 struct timbgpio *tgpio = irq_desc_get_handler_data(desc);
187 struct irq_data *data = irq_desc_get_irq_data(desc);
188 unsigned long ipr;
189 int offset;
190
191 data->chip->irq_ack(data);
192 ipr = ioread32(tgpio->membase + TGPIO_IPR);
193 iowrite32(ipr, tgpio->membase + TGPIO_ICR);
194
195 /*
196 * Some versions of the hardware trash the IER register if more than
197 * one interrupt is received simultaneously.
198 */
199 iowrite32(0, tgpio->membase + TGPIO_IER);
200
201 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
202 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
203
204 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
205 }
206
207 static struct irq_chip timbgpio_irqchip = {
208 .name = "GPIO",
209 .irq_enable = timbgpio_irq_enable,
210 .irq_disable = timbgpio_irq_disable,
211 .irq_set_type = timbgpio_irq_type,
212 };
213
timbgpio_probe(struct platform_device * pdev)214 static int timbgpio_probe(struct platform_device *pdev)
215 {
216 int err, i;
217 struct device *dev = &pdev->dev;
218 struct gpio_chip *gc;
219 struct timbgpio *tgpio;
220 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
221 int irq = platform_get_irq(pdev, 0);
222
223 if (!pdata || pdata->nr_pins > 32) {
224 dev_err(dev, "Invalid platform data\n");
225 return -EINVAL;
226 }
227
228 tgpio = devm_kzalloc(dev, sizeof(*tgpio), GFP_KERNEL);
229 if (!tgpio)
230 return -EINVAL;
231
232 tgpio->irq_base = pdata->irq_base;
233
234 spin_lock_init(&tgpio->lock);
235
236 tgpio->membase = devm_platform_ioremap_resource(pdev, 0);
237 if (IS_ERR(tgpio->membase))
238 return PTR_ERR(tgpio->membase);
239
240 gc = &tgpio->gpio;
241
242 gc->label = dev_name(&pdev->dev);
243 gc->owner = THIS_MODULE;
244 gc->parent = &pdev->dev;
245 gc->direction_input = timbgpio_gpio_direction_input;
246 gc->get = timbgpio_gpio_get;
247 gc->direction_output = timbgpio_gpio_direction_output;
248 gc->set = timbgpio_gpio_set;
249 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
250 gc->dbg_show = NULL;
251 gc->base = pdata->gpio_base;
252 gc->ngpio = pdata->nr_pins;
253 gc->can_sleep = false;
254
255 err = devm_gpiochip_add_data(&pdev->dev, gc, tgpio);
256 if (err)
257 return err;
258
259 platform_set_drvdata(pdev, tgpio);
260
261 /* make sure to disable interrupts */
262 iowrite32(0x0, tgpio->membase + TGPIO_IER);
263
264 if (irq < 0 || tgpio->irq_base <= 0)
265 return 0;
266
267 for (i = 0; i < pdata->nr_pins; i++) {
268 irq_set_chip_and_handler(tgpio->irq_base + i,
269 &timbgpio_irqchip, handle_simple_irq);
270 irq_set_chip_data(tgpio->irq_base + i, tgpio);
271 irq_clear_status_flags(tgpio->irq_base + i, IRQ_NOREQUEST | IRQ_NOPROBE);
272 }
273
274 irq_set_chained_handler_and_data(irq, timbgpio_irq, tgpio);
275
276 return 0;
277 }
278
279 static struct platform_driver timbgpio_platform_driver = {
280 .driver = {
281 .name = DRIVER_NAME,
282 .suppress_bind_attrs = true,
283 },
284 .probe = timbgpio_probe,
285 };
286
287 /*--------------------------------------------------------------------------*/
288
289 builtin_platform_driver(timbgpio_platform_driver);
290