1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Generic EP93xx GPIO handling
4 *
5 * Copyright (c) 2008 Ryan Mallon
6 * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
7 *
8 * Based on code originally from:
9 * linux/arch/arm/mach-ep93xx/core.c
10 */
11
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/io.h>
16 #include <linux/irq.h>
17 #include <linux/slab.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/bitops.h>
20
21 #define EP93XX_GPIO_F_INT_STATUS 0x5c
22 #define EP93XX_GPIO_A_INT_STATUS 0xa0
23 #define EP93XX_GPIO_B_INT_STATUS 0xbc
24
25 /* Maximum value for gpio line identifiers */
26 #define EP93XX_GPIO_LINE_MAX 63
27
28 /* Maximum value for irq capable line identifiers */
29 #define EP93XX_GPIO_LINE_MAX_IRQ 23
30
31 /*
32 * Static mapping of GPIO bank F IRQS:
33 * F0..F7 (16..24) to irq 80..87.
34 */
35 #define EP93XX_GPIO_F_IRQ_BASE 80
36
37 struct ep93xx_gpio {
38 void __iomem *base;
39 struct gpio_chip gc[8];
40 };
41
42 /*************************************************************************
43 * Interrupt handling for EP93xx on-chip GPIOs
44 *************************************************************************/
45 static unsigned char gpio_int_unmasked[3];
46 static unsigned char gpio_int_enabled[3];
47 static unsigned char gpio_int_type1[3];
48 static unsigned char gpio_int_type2[3];
49 static unsigned char gpio_int_debounce[3];
50
51 /* Port ordering is: A B F */
52 static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
53 static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
54 static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
55 static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
56 static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
57
ep93xx_gpio_update_int_params(struct ep93xx_gpio * epg,unsigned port)58 static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg, unsigned port)
59 {
60 BUG_ON(port > 2);
61
62 writeb_relaxed(0, epg->base + int_en_register_offset[port]);
63
64 writeb_relaxed(gpio_int_type2[port],
65 epg->base + int_type2_register_offset[port]);
66
67 writeb_relaxed(gpio_int_type1[port],
68 epg->base + int_type1_register_offset[port]);
69
70 writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
71 epg->base + int_en_register_offset[port]);
72 }
73
ep93xx_gpio_port(struct gpio_chip * gc)74 static int ep93xx_gpio_port(struct gpio_chip *gc)
75 {
76 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
77 int port = 0;
78
79 while (port < ARRAY_SIZE(epg->gc) && gc != &epg->gc[port])
80 port++;
81
82 /* This should not happen but is there as a last safeguard */
83 if (port == ARRAY_SIZE(epg->gc)) {
84 pr_crit("can't find the GPIO port\n");
85 return 0;
86 }
87
88 return port;
89 }
90
ep93xx_gpio_int_debounce(struct gpio_chip * gc,unsigned int offset,bool enable)91 static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
92 unsigned int offset, bool enable)
93 {
94 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
95 int port = ep93xx_gpio_port(gc);
96 int port_mask = BIT(offset);
97
98 if (enable)
99 gpio_int_debounce[port] |= port_mask;
100 else
101 gpio_int_debounce[port] &= ~port_mask;
102
103 writeb(gpio_int_debounce[port],
104 epg->base + int_debounce_register_offset[port]);
105 }
106
ep93xx_gpio_ab_irq_handler(struct irq_desc * desc)107 static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
108 {
109 struct gpio_chip *gc = irq_desc_get_handler_data(desc);
110 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
111 struct irq_chip *irqchip = irq_desc_get_chip(desc);
112 unsigned long stat;
113 int offset;
114
115 chained_irq_enter(irqchip, desc);
116
117 /*
118 * Dispatch the IRQs to the irqdomain of each A and B
119 * gpiochip irqdomains depending on what has fired.
120 * The tricky part is that the IRQ line is shared
121 * between bank A and B and each has their own gpiochip.
122 */
123 stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
124 for_each_set_bit(offset, &stat, 8)
125 generic_handle_irq(irq_find_mapping(epg->gc[0].irq.domain,
126 offset));
127
128 stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
129 for_each_set_bit(offset, &stat, 8)
130 generic_handle_irq(irq_find_mapping(epg->gc[1].irq.domain,
131 offset));
132
133 chained_irq_exit(irqchip, desc);
134 }
135
ep93xx_gpio_f_irq_handler(struct irq_desc * desc)136 static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
137 {
138 /*
139 * map discontiguous hw irq range to continuous sw irq range:
140 *
141 * IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
142 */
143 struct irq_chip *irqchip = irq_desc_get_chip(desc);
144 unsigned int irq = irq_desc_get_irq(desc);
145 int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
146 int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;
147
148 chained_irq_enter(irqchip, desc);
149 generic_handle_irq(gpio_irq);
150 chained_irq_exit(irqchip, desc);
151 }
152
ep93xx_gpio_irq_ack(struct irq_data * d)153 static void ep93xx_gpio_irq_ack(struct irq_data *d)
154 {
155 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
156 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
157 int port = ep93xx_gpio_port(gc);
158 int port_mask = BIT(d->irq & 7);
159
160 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
161 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
162 ep93xx_gpio_update_int_params(epg, port);
163 }
164
165 writeb(port_mask, epg->base + eoi_register_offset[port]);
166 }
167
ep93xx_gpio_irq_mask_ack(struct irq_data * d)168 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
169 {
170 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
171 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
172 int port = ep93xx_gpio_port(gc);
173 int port_mask = BIT(d->irq & 7);
174
175 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
176 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
177
178 gpio_int_unmasked[port] &= ~port_mask;
179 ep93xx_gpio_update_int_params(epg, port);
180
181 writeb(port_mask, epg->base + eoi_register_offset[port]);
182 }
183
ep93xx_gpio_irq_mask(struct irq_data * d)184 static void ep93xx_gpio_irq_mask(struct irq_data *d)
185 {
186 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
187 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
188 int port = ep93xx_gpio_port(gc);
189
190 gpio_int_unmasked[port] &= ~BIT(d->irq & 7);
191 ep93xx_gpio_update_int_params(epg, port);
192 }
193
ep93xx_gpio_irq_unmask(struct irq_data * d)194 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
195 {
196 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
197 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
198 int port = ep93xx_gpio_port(gc);
199
200 gpio_int_unmasked[port] |= BIT(d->irq & 7);
201 ep93xx_gpio_update_int_params(epg, port);
202 }
203
204 /*
205 * gpio_int_type1 controls whether the interrupt is level (0) or
206 * edge (1) triggered, while gpio_int_type2 controls whether it
207 * triggers on low/falling (0) or high/rising (1).
208 */
ep93xx_gpio_irq_type(struct irq_data * d,unsigned int type)209 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
210 {
211 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
212 struct ep93xx_gpio *epg = gpiochip_get_data(gc);
213 int port = ep93xx_gpio_port(gc);
214 int offset = d->irq & 7;
215 int port_mask = BIT(offset);
216 irq_flow_handler_t handler;
217
218 gc->direction_input(gc, offset);
219
220 switch (type) {
221 case IRQ_TYPE_EDGE_RISING:
222 gpio_int_type1[port] |= port_mask;
223 gpio_int_type2[port] |= port_mask;
224 handler = handle_edge_irq;
225 break;
226 case IRQ_TYPE_EDGE_FALLING:
227 gpio_int_type1[port] |= port_mask;
228 gpio_int_type2[port] &= ~port_mask;
229 handler = handle_edge_irq;
230 break;
231 case IRQ_TYPE_LEVEL_HIGH:
232 gpio_int_type1[port] &= ~port_mask;
233 gpio_int_type2[port] |= port_mask;
234 handler = handle_level_irq;
235 break;
236 case IRQ_TYPE_LEVEL_LOW:
237 gpio_int_type1[port] &= ~port_mask;
238 gpio_int_type2[port] &= ~port_mask;
239 handler = handle_level_irq;
240 break;
241 case IRQ_TYPE_EDGE_BOTH:
242 gpio_int_type1[port] |= port_mask;
243 /* set initial polarity based on current input level */
244 if (gc->get(gc, offset))
245 gpio_int_type2[port] &= ~port_mask; /* falling */
246 else
247 gpio_int_type2[port] |= port_mask; /* rising */
248 handler = handle_edge_irq;
249 break;
250 default:
251 return -EINVAL;
252 }
253
254 irq_set_handler_locked(d, handler);
255
256 gpio_int_enabled[port] |= port_mask;
257
258 ep93xx_gpio_update_int_params(epg, port);
259
260 return 0;
261 }
262
263 static struct irq_chip ep93xx_gpio_irq_chip = {
264 .name = "GPIO",
265 .irq_ack = ep93xx_gpio_irq_ack,
266 .irq_mask_ack = ep93xx_gpio_irq_mask_ack,
267 .irq_mask = ep93xx_gpio_irq_mask,
268 .irq_unmask = ep93xx_gpio_irq_unmask,
269 .irq_set_type = ep93xx_gpio_irq_type,
270 };
271
272 /*************************************************************************
273 * gpiolib interface for EP93xx on-chip GPIOs
274 *************************************************************************/
275 struct ep93xx_gpio_bank {
276 const char *label;
277 int data;
278 int dir;
279 int base;
280 bool has_irq;
281 bool has_hierarchical_irq;
282 unsigned int irq_base;
283 };
284
285 #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _has_irq, _has_hier, _irq_base) \
286 { \
287 .label = _label, \
288 .data = _data, \
289 .dir = _dir, \
290 .base = _base, \
291 .has_irq = _has_irq, \
292 .has_hierarchical_irq = _has_hier, \
293 .irq_base = _irq_base, \
294 }
295
296 static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
297 /* Bank A has 8 IRQs */
298 EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true, false, 64),
299 /* Bank B has 8 IRQs */
300 EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true, false, 72),
301 EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false, false, 0),
302 EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false, false, 0),
303 EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false, false, 0),
304 /* Bank F has 8 IRQs */
305 EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, false, true, 0),
306 EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false, false, 0),
307 EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false, false, 0),
308 };
309
ep93xx_gpio_set_config(struct gpio_chip * gc,unsigned offset,unsigned long config)310 static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
311 unsigned long config)
312 {
313 u32 debounce;
314
315 if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
316 return -ENOTSUPP;
317
318 debounce = pinconf_to_config_argument(config);
319 ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);
320
321 return 0;
322 }
323
ep93xx_gpio_f_to_irq(struct gpio_chip * gc,unsigned offset)324 static int ep93xx_gpio_f_to_irq(struct gpio_chip *gc, unsigned offset)
325 {
326 return EP93XX_GPIO_F_IRQ_BASE + offset;
327 }
328
ep93xx_gpio_add_bank(struct gpio_chip * gc,struct platform_device * pdev,struct ep93xx_gpio * epg,struct ep93xx_gpio_bank * bank)329 static int ep93xx_gpio_add_bank(struct gpio_chip *gc,
330 struct platform_device *pdev,
331 struct ep93xx_gpio *epg,
332 struct ep93xx_gpio_bank *bank)
333 {
334 void __iomem *data = epg->base + bank->data;
335 void __iomem *dir = epg->base + bank->dir;
336 struct device *dev = &pdev->dev;
337 struct gpio_irq_chip *girq;
338 int err;
339
340 err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
341 if (err)
342 return err;
343
344 gc->label = bank->label;
345 gc->base = bank->base;
346
347 girq = &gc->irq;
348 if (bank->has_irq || bank->has_hierarchical_irq) {
349 gc->set_config = ep93xx_gpio_set_config;
350 girq->chip = &ep93xx_gpio_irq_chip;
351 }
352
353 if (bank->has_irq) {
354 int ab_parent_irq = platform_get_irq(pdev, 0);
355
356 girq->parent_handler = ep93xx_gpio_ab_irq_handler;
357 girq->num_parents = 1;
358 girq->parents = devm_kcalloc(dev, 1,
359 sizeof(*girq->parents),
360 GFP_KERNEL);
361 if (!girq->parents)
362 return -ENOMEM;
363 girq->default_type = IRQ_TYPE_NONE;
364 girq->handler = handle_level_irq;
365 girq->parents[0] = ab_parent_irq;
366 girq->first = bank->irq_base;
367 }
368
369 /* Only bank F has especially funky IRQ handling */
370 if (bank->has_hierarchical_irq) {
371 int gpio_irq;
372 int i;
373
374 /*
375 * FIXME: convert this to use hierarchical IRQ support!
376 * this requires fixing the root irqchip to be hierarchial.
377 */
378 girq->parent_handler = ep93xx_gpio_f_irq_handler;
379 girq->num_parents = 8;
380 girq->parents = devm_kcalloc(dev, 8,
381 sizeof(*girq->parents),
382 GFP_KERNEL);
383 if (!girq->parents)
384 return -ENOMEM;
385 /* Pick resources 1..8 for these IRQs */
386 for (i = 1; i <= 8; i++)
387 girq->parents[i - 1] = platform_get_irq(pdev, i);
388 for (i = 0; i < 8; i++) {
389 gpio_irq = EP93XX_GPIO_F_IRQ_BASE + i;
390 irq_set_chip_data(gpio_irq, &epg->gc[5]);
391 irq_set_chip_and_handler(gpio_irq,
392 &ep93xx_gpio_irq_chip,
393 handle_level_irq);
394 irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
395 }
396 girq->default_type = IRQ_TYPE_NONE;
397 girq->handler = handle_level_irq;
398 gc->to_irq = ep93xx_gpio_f_to_irq;
399 }
400
401 return devm_gpiochip_add_data(dev, gc, epg);
402 }
403
ep93xx_gpio_probe(struct platform_device * pdev)404 static int ep93xx_gpio_probe(struct platform_device *pdev)
405 {
406 struct ep93xx_gpio *epg;
407 int i;
408
409 epg = devm_kzalloc(&pdev->dev, sizeof(*epg), GFP_KERNEL);
410 if (!epg)
411 return -ENOMEM;
412
413 epg->base = devm_platform_ioremap_resource(pdev, 0);
414 if (IS_ERR(epg->base))
415 return PTR_ERR(epg->base);
416
417 for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
418 struct gpio_chip *gc = &epg->gc[i];
419 struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
420
421 if (ep93xx_gpio_add_bank(gc, pdev, epg, bank))
422 dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
423 bank->label);
424 }
425
426 return 0;
427 }
428
429 static struct platform_driver ep93xx_gpio_driver = {
430 .driver = {
431 .name = "gpio-ep93xx",
432 },
433 .probe = ep93xx_gpio_probe,
434 };
435
ep93xx_gpio_init(void)436 static int __init ep93xx_gpio_init(void)
437 {
438 return platform_driver_register(&ep93xx_gpio_driver);
439 }
440 postcore_initcall(ep93xx_gpio_init);
441
442 MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
443 "H Hartley Sweeten <hsweeten@visionengravers.com>");
444 MODULE_DESCRIPTION("EP93XX GPIO driver");
445 MODULE_LICENSE("GPL");
446