1// SPDX-License-Identifier: GPL-2.0
2/*
3 * GPIO driver for NXP LPC18xx/43xx.
4 *
5 * Copyright (C) 2018 Vladimir Zapolskiy <vz@mleia.com>
6 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
7 *
8 */
9
10#include <linux/clk.h>
11#include <linux/gpio/driver.h>
12#include <linux/io.h>
13#include <linux/irqdomain.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/of_gpio.h>
18#include <linux/of_irq.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/platform_device.h>
21
22/* LPC18xx GPIO register offsets */
23#define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32))
24
25#define LPC18XX_MAX_PORTS 8
26#define LPC18XX_PINS_PER_PORT 32
27
28/* LPC18xx GPIO pin interrupt controller register offsets */
29#define LPC18XX_GPIO_PIN_IC_ISEL 0x00
30#define LPC18XX_GPIO_PIN_IC_IENR 0x04
31#define LPC18XX_GPIO_PIN_IC_SIENR 0x08
32#define LPC18XX_GPIO_PIN_IC_CIENR 0x0c
33#define LPC18XX_GPIO_PIN_IC_IENF 0x10
34#define LPC18XX_GPIO_PIN_IC_SIENF 0x14
35#define LPC18XX_GPIO_PIN_IC_CIENF 0x18
36#define LPC18XX_GPIO_PIN_IC_RISE 0x1c
37#define LPC18XX_GPIO_PIN_IC_FALL 0x20
38#define LPC18XX_GPIO_PIN_IC_IST 0x24
39
40#define NR_LPC18XX_GPIO_PIN_IC_IRQS 8
41
42struct lpc18xx_gpio_pin_ic {
43 void __iomem *base;
44 struct irq_domain *domain;
45 struct raw_spinlock lock;
46};
47
48struct lpc18xx_gpio_chip {
49 struct gpio_chip gpio;
50 void __iomem *base;
51 struct clk *clk;
52 struct lpc18xx_gpio_pin_ic *pin_ic;
53 spinlock_t lock;
54};
55
56static inline void lpc18xx_gpio_pin_ic_isel(struct lpc18xx_gpio_pin_ic *ic,
57 u32 pin, bool set)
58{
59 u32 val = readl_relaxed(ic->base + LPC18XX_GPIO_PIN_IC_ISEL);
60
61 if (set)
62 val &= ~BIT(pin);
63 else
64 val |= BIT(pin);
65
66 writel_relaxed(val, ic->base + LPC18XX_GPIO_PIN_IC_ISEL);
67}
68
69static inline void lpc18xx_gpio_pin_ic_set(struct lpc18xx_gpio_pin_ic *ic,
70 u32 pin, u32 reg)
71{
72 writel_relaxed(BIT(pin), ic->base + reg);
73}
74
75static void lpc18xx_gpio_pin_ic_mask(struct irq_data *d)
76{
77 struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
78 u32 type = irqd_get_trigger_type(d);
79
80 raw_spin_lock(&ic->lock);
81
82 if (type & IRQ_TYPE_LEVEL_MASK || type & IRQ_TYPE_EDGE_RISING)
83 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
84 LPC18XX_GPIO_PIN_IC_CIENR);
85
86 if (type & IRQ_TYPE_EDGE_FALLING)
87 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
88 LPC18XX_GPIO_PIN_IC_CIENF);
89
90 raw_spin_unlock(&ic->lock);
91
92 irq_chip_mask_parent(d);
93}
94
95static void lpc18xx_gpio_pin_ic_unmask(struct irq_data *d)
96{
97 struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
98 u32 type = irqd_get_trigger_type(d);
99
100 raw_spin_lock(&ic->lock);
101
102 if (type & IRQ_TYPE_LEVEL_MASK || type & IRQ_TYPE_EDGE_RISING)
103 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
104 LPC18XX_GPIO_PIN_IC_SIENR);
105
106 if (type & IRQ_TYPE_EDGE_FALLING)
107 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
108 LPC18XX_GPIO_PIN_IC_SIENF);
109
110 raw_spin_unlock(&ic->lock);
111
112 irq_chip_unmask_parent(d);
113}
114
115static void lpc18xx_gpio_pin_ic_eoi(struct irq_data *d)
116{
117 struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
118 u32 type = irqd_get_trigger_type(d);
119
120 raw_spin_lock(&ic->lock);
121
122 if (type & IRQ_TYPE_EDGE_BOTH)
123 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
124 LPC18XX_GPIO_PIN_IC_IST);
125
126 raw_spin_unlock(&ic->lock);
127
128 irq_chip_eoi_parent(d);
129}
130
131static int lpc18xx_gpio_pin_ic_set_type(struct irq_data *d, unsigned int type)
132{
133 struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
134
135 raw_spin_lock(&ic->lock);
136
137 if (type & IRQ_TYPE_LEVEL_HIGH) {
138 lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, true);
139 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
140 LPC18XX_GPIO_PIN_IC_SIENF);
141 } else if (type & IRQ_TYPE_LEVEL_LOW) {
142 lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, true);
143 lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
144 LPC18XX_GPIO_PIN_IC_CIENF);
145 } else {
146 lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, false);
147 }
148
149 raw_spin_unlock(&ic->lock);
150
151 return 0;
152}
153
154static struct irq_chip lpc18xx_gpio_pin_ic = {
155 .name = "LPC18xx GPIO pin",
156 .irq_mask = lpc18xx_gpio_pin_ic_mask,
157 .irq_unmask = lpc18xx_gpio_pin_ic_unmask,
158 .irq_eoi = lpc18xx_gpio_pin_ic_eoi,
159 .irq_set_type = lpc18xx_gpio_pin_ic_set_type,
160 .flags = IRQCHIP_SET_TYPE_MASKED,
161};
162
163static int lpc18xx_gpio_pin_ic_domain_alloc(struct irq_domain *domain,
164 unsigned int virq,
165 unsigned int nr_irqs, void *data)
166{
167 struct irq_fwspec parent_fwspec, *fwspec = data;
168 struct lpc18xx_gpio_pin_ic *ic = domain->host_data;
169 irq_hw_number_t hwirq;
170 int ret;
171
172 if (nr_irqs != 1)
173 return -EINVAL;
174
175 hwirq = fwspec->param[0];
176 if (hwirq >= NR_LPC18XX_GPIO_PIN_IC_IRQS)
177 return -EINVAL;
178
179 /*
180 * All LPC18xx/LPC43xx GPIO pin hardware interrupts are translated
181 * into edge interrupts 32...39 on parent Cortex-M3/M4 NVIC
182 */
183 parent_fwspec.fwnode = domain->parent->fwnode;
184 parent_fwspec.param_count = 1;
185 parent_fwspec.param[0] = hwirq + 32;
186
187 ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
188 if (ret < 0) {
189 pr_err("failed to allocate parent irq %u: %d\n",
190 parent_fwspec.param[0], ret);
191 return ret;
192 }
193
194 return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
195 &lpc18xx_gpio_pin_ic, ic);
196}
197
198static const struct irq_domain_ops lpc18xx_gpio_pin_ic_domain_ops = {
199 .alloc = lpc18xx_gpio_pin_ic_domain_alloc,
200 .xlate = irq_domain_xlate_twocell,
201 .free = irq_domain_free_irqs_common,
202};
203
204static int lpc18xx_gpio_pin_ic_probe(struct lpc18xx_gpio_chip *gc)
205{
206 struct device *dev = gc->gpio.parent;
207 struct irq_domain *parent_domain;
208 struct device_node *parent_node;
209 struct lpc18xx_gpio_pin_ic *ic;
210 struct resource res;
211 int ret, index;
212
213 parent_node = of_irq_find_parent(dev->of_node);
214 if (!parent_node)
215 return -ENXIO;
216
217 parent_domain = irq_find_host(parent_node);
218 of_node_put(parent_node);
219 if (!parent_domain)
220 return -ENXIO;
221
222 ic = devm_kzalloc(dev, sizeof(*ic), GFP_KERNEL);
223 if (!ic)
224 return -ENOMEM;
225
226 index = of_property_match_string(dev->of_node, "reg-names",
227 "gpio-pin-ic");
228 if (index < 0) {
229 ret = -ENODEV;
230 goto free_ic;
231 }
232
233 ret = of_address_to_resource(dev->of_node, index, &res);
234 if (ret < 0)
235 goto free_ic;
236
237 ic->base = devm_ioremap_resource(dev, &res);
238 if (IS_ERR(ic->base)) {
239 ret = PTR_ERR(ic->base);
240 goto free_ic;
241 }
242
243 raw_spin_lock_init(&ic->lock);
244
245 ic->domain = irq_domain_add_hierarchy(parent_domain, 0,
246 NR_LPC18XX_GPIO_PIN_IC_IRQS,
247 dev->of_node,
248 &lpc18xx_gpio_pin_ic_domain_ops,
249 ic);
250 if (!ic->domain) {
251 pr_err("unable to add irq domain\n");
252 ret = -ENODEV;
253 goto free_iomap;
254 }
255
256 gc->pin_ic = ic;
257
258 return 0;
259
260free_iomap:
261 devm_iounmap(dev, ic->base);
262free_ic:
263 devm_kfree(dev, ic);
264
265 return ret;
266}
267
268static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
269{
270 struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
271 writeb(value ? 1 : 0, gc->base + offset);
272}
273
274static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset)
275{
276 struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
277 return !!readb(gc->base + offset);
278}
279
280static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset,
281 bool out)
282{
283 struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
284 unsigned long flags;
285 u32 port, pin, dir;
286
287 port = offset / LPC18XX_PINS_PER_PORT;
288 pin = offset % LPC18XX_PINS_PER_PORT;
289
290 spin_lock_irqsave(&gc->lock, flags);
291 dir = readl(gc->base + LPC18XX_REG_DIR(port));
292 if (out)
293 dir |= BIT(pin);
294 else
295 dir &= ~BIT(pin);
296 writel(dir, gc->base + LPC18XX_REG_DIR(port));
297 spin_unlock_irqrestore(&gc->lock, flags);
298
299 return 0;
300}
301
302static int lpc18xx_gpio_direction_input(struct gpio_chip *chip,
303 unsigned offset)
304{
305 return lpc18xx_gpio_direction(chip, offset, false);
306}
307
308static int lpc18xx_gpio_direction_output(struct gpio_chip *chip,
309 unsigned offset, int value)
310{
311 lpc18xx_gpio_set(chip, offset, value);
312 return lpc18xx_gpio_direction(chip, offset, true);
313}
314
315static const struct gpio_chip lpc18xx_chip = {
316 .label = "lpc18xx/43xx-gpio",
317 .request = gpiochip_generic_request,
318 .free = gpiochip_generic_free,
319 .direction_input = lpc18xx_gpio_direction_input,
320 .direction_output = lpc18xx_gpio_direction_output,
321 .set = lpc18xx_gpio_set,
322 .get = lpc18xx_gpio_get,
323 .ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT,
324 .owner = THIS_MODULE,
325};
326
327static int lpc18xx_gpio_probe(struct platform_device *pdev)
328{
329 struct device *dev = &pdev->dev;
330 struct lpc18xx_gpio_chip *gc;
331 int index, ret;
332
333 gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
334 if (!gc)
335 return -ENOMEM;
336
337 gc->gpio = lpc18xx_chip;
338 platform_set_drvdata(pdev, gc);
339
340 index = of_property_match_string(dev->of_node, "reg-names", "gpio");
341 if (index < 0) {
342 /* To support backward compatibility take the first resource */
343 struct resource *res;
344
345 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
346 gc->base = devm_ioremap_resource(dev, res);
347 } else {
348 struct resource res;
349
350 ret = of_address_to_resource(dev->of_node, index, &res);
351 if (ret < 0)
352 return ret;
353
354 gc->base = devm_ioremap_resource(dev, &res);
355 }
356 if (IS_ERR(gc->base))
357 return PTR_ERR(gc->base);
358
359 gc->clk = devm_clk_get(dev, NULL);
360 if (IS_ERR(gc->clk)) {
361 dev_err(dev, "input clock not found\n");
362 return PTR_ERR(gc->clk);
363 }
364
365 ret = clk_prepare_enable(gc->clk);
366 if (ret) {
367 dev_err(dev, "unable to enable clock\n");
368 return ret;
369 }
370
371 spin_lock_init(&gc->lock);
372
373 gc->gpio.parent = dev;
374
375 ret = devm_gpiochip_add_data(dev, &gc->gpio, gc);
376 if (ret) {
377 dev_err(dev, "failed to add gpio chip\n");
378 clk_disable_unprepare(gc->clk);
379 return ret;
380 }
381
382 /* On error GPIO pin interrupt controller just won't be registered */
383 lpc18xx_gpio_pin_ic_probe(gc);
384
385 return 0;
386}
387
388static int lpc18xx_gpio_remove(struct platform_device *pdev)
389{
390 struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev);
391
392 if (gc->pin_ic)
393 irq_domain_remove(gc->pin_ic->domain);
394
395 clk_disable_unprepare(gc->clk);
396
397 return 0;
398}
399
400static const struct of_device_id lpc18xx_gpio_match[] = {
401 { .compatible = "nxp,lpc1850-gpio" },
402 { }
403};
404MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match);
405
406static struct platform_driver lpc18xx_gpio_driver = {
407 .probe = lpc18xx_gpio_probe,
408 .remove = lpc18xx_gpio_remove,
409 .driver = {
410 .name = "lpc18xx-gpio",
411 .of_match_table = lpc18xx_gpio_match,
412 },
413};
414module_platform_driver(lpc18xx_gpio_driver);
415
416MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
417MODULE_AUTHOR("Vladimir Zapolskiy <vz@mleia.com>");
418MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx");
419MODULE_LICENSE("GPL v2");
420