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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atheros AR71XX/AR724X/AR913X GPIO API support
4 *
5 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
6 * Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
7 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
8 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
9 */
10
11#include <linux/gpio/driver.h>
12#include <linux/platform_data/gpio-ath79.h>
13#include <linux/of_device.h>
14#include <linux/interrupt.h>
15#include <linux/module.h>
16#include <linux/irq.h>
17
18#define AR71XX_GPIO_REG_OE 0x00
19#define AR71XX_GPIO_REG_IN 0x04
20#define AR71XX_GPIO_REG_SET 0x0c
21#define AR71XX_GPIO_REG_CLEAR 0x10
22
23#define AR71XX_GPIO_REG_INT_ENABLE 0x14
24#define AR71XX_GPIO_REG_INT_TYPE 0x18
25#define AR71XX_GPIO_REG_INT_POLARITY 0x1c
26#define AR71XX_GPIO_REG_INT_PENDING 0x20
27#define AR71XX_GPIO_REG_INT_MASK 0x24
28
29struct ath79_gpio_ctrl {
30 struct gpio_chip gc;
31 void __iomem *base;
32 raw_spinlock_t lock;
33 unsigned long both_edges;
34};
35
36static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data)
37{
38 struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
39
40 return container_of(gc, struct ath79_gpio_ctrl, gc);
41}
42
43static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
44{
45 return readl(ctrl->base + reg);
46}
47
48static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
49 unsigned reg, u32 val)
50{
51 writel(val, ctrl->base + reg);
52}
53
54static bool ath79_gpio_update_bits(
55 struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
56{
57 u32 old_val, new_val;
58
59 old_val = ath79_gpio_read(ctrl, reg);
60 new_val = (old_val & ~mask) | (bits & mask);
61
62 if (new_val != old_val)
63 ath79_gpio_write(ctrl, reg, new_val);
64
65 return new_val != old_val;
66}
67
68static void ath79_gpio_irq_unmask(struct irq_data *data)
69{
70 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
71 u32 mask = BIT(irqd_to_hwirq(data));
72 unsigned long flags;
73
74 raw_spin_lock_irqsave(&ctrl->lock, flags);
75 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
76 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
77}
78
79static void ath79_gpio_irq_mask(struct irq_data *data)
80{
81 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
82 u32 mask = BIT(irqd_to_hwirq(data));
83 unsigned long flags;
84
85 raw_spin_lock_irqsave(&ctrl->lock, flags);
86 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
87 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
88}
89
90static void ath79_gpio_irq_enable(struct irq_data *data)
91{
92 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
93 u32 mask = BIT(irqd_to_hwirq(data));
94 unsigned long flags;
95
96 raw_spin_lock_irqsave(&ctrl->lock, flags);
97 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
98 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
99 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
100}
101
102static void ath79_gpio_irq_disable(struct irq_data *data)
103{
104 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
105 u32 mask = BIT(irqd_to_hwirq(data));
106 unsigned long flags;
107
108 raw_spin_lock_irqsave(&ctrl->lock, flags);
109 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
110 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
111 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
112}
113
114static int ath79_gpio_irq_set_type(struct irq_data *data,
115 unsigned int flow_type)
116{
117 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
118 u32 mask = BIT(irqd_to_hwirq(data));
119 u32 type = 0, polarity = 0;
120 unsigned long flags;
121 bool disabled;
122
123 switch (flow_type) {
124 case IRQ_TYPE_EDGE_RISING:
125 polarity |= mask;
126 case IRQ_TYPE_EDGE_FALLING:
127 case IRQ_TYPE_EDGE_BOTH:
128 break;
129
130 case IRQ_TYPE_LEVEL_HIGH:
131 polarity |= mask;
132 fallthrough;
133 case IRQ_TYPE_LEVEL_LOW:
134 type |= mask;
135 break;
136
137 default:
138 return -EINVAL;
139 }
140
141 raw_spin_lock_irqsave(&ctrl->lock, flags);
142
143 if (flow_type == IRQ_TYPE_EDGE_BOTH) {
144 ctrl->both_edges |= mask;
145 polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
146 } else {
147 ctrl->both_edges &= ~mask;
148 }
149
150 /* As the IRQ configuration can't be loaded atomically we
151 * have to disable the interrupt while the configuration state
152 * is invalid.
153 */
154 disabled = ath79_gpio_update_bits(
155 ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
156
157 ath79_gpio_update_bits(
158 ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
159 ath79_gpio_update_bits(
160 ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);
161
162 if (disabled)
163 ath79_gpio_update_bits(
164 ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
165
166 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
167
168 return 0;
169}
170
171static struct irq_chip ath79_gpio_irqchip = {
172 .name = "gpio-ath79",
173 .irq_enable = ath79_gpio_irq_enable,
174 .irq_disable = ath79_gpio_irq_disable,
175 .irq_mask = ath79_gpio_irq_mask,
176 .irq_unmask = ath79_gpio_irq_unmask,
177 .irq_set_type = ath79_gpio_irq_set_type,
178};
179
180static void ath79_gpio_irq_handler(struct irq_desc *desc)
181{
182 struct gpio_chip *gc = irq_desc_get_handler_data(desc);
183 struct irq_chip *irqchip = irq_desc_get_chip(desc);
184 struct ath79_gpio_ctrl *ctrl =
185 container_of(gc, struct ath79_gpio_ctrl, gc);
186 unsigned long flags, pending;
187 u32 both_edges, state;
188 int irq;
189
190 chained_irq_enter(irqchip, desc);
191
192 raw_spin_lock_irqsave(&ctrl->lock, flags);
193
194 pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);
195
196 /* Update the polarity of the both edges irqs */
197 both_edges = ctrl->both_edges & pending;
198 if (both_edges) {
199 state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
200 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
201 both_edges, ~state);
202 }
203
204 raw_spin_unlock_irqrestore(&ctrl->lock, flags);
205
206 if (pending) {
207 for_each_set_bit(irq, &pending, gc->ngpio)
208 generic_handle_irq(
209 irq_linear_revmap(gc->irq.domain, irq));
210 }
211
212 chained_irq_exit(irqchip, desc);
213}
214
215static const struct of_device_id ath79_gpio_of_match[] = {
216 { .compatible = "qca,ar7100-gpio" },
217 { .compatible = "qca,ar9340-gpio" },
218 {},
219};
220MODULE_DEVICE_TABLE(of, ath79_gpio_of_match);
221
222static int ath79_gpio_probe(struct platform_device *pdev)
223{
224 struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
225 struct device *dev = &pdev->dev;
226 struct device_node *np = dev->of_node;
227 struct ath79_gpio_ctrl *ctrl;
228 struct gpio_irq_chip *girq;
229 u32 ath79_gpio_count;
230 bool oe_inverted;
231 int err;
232
233 ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
234 if (!ctrl)
235 return -ENOMEM;
236 platform_set_drvdata(pdev, ctrl);
237
238 if (np) {
239 err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
240 if (err) {
241 dev_err(dev, "ngpios property is not valid\n");
242 return err;
243 }
244 oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
245 } else if (pdata) {
246 ath79_gpio_count = pdata->ngpios;
247 oe_inverted = pdata->oe_inverted;
248 } else {
249 dev_err(dev, "No DT node or platform data found\n");
250 return -EINVAL;
251 }
252
253 if (ath79_gpio_count >= 32) {
254 dev_err(dev, "ngpios must be less than 32\n");
255 return -EINVAL;
256 }
257
258 ctrl->base = devm_platform_ioremap_resource(pdev, 0);
259 if (IS_ERR(ctrl->base))
260 return PTR_ERR(ctrl->base);
261
262 raw_spin_lock_init(&ctrl->lock);
263 err = bgpio_init(&ctrl->gc, dev, 4,
264 ctrl->base + AR71XX_GPIO_REG_IN,
265 ctrl->base + AR71XX_GPIO_REG_SET,
266 ctrl->base + AR71XX_GPIO_REG_CLEAR,
267 oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
268 oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
269 0);
270 if (err) {
271 dev_err(dev, "bgpio_init failed\n");
272 return err;
273 }
274 /* Use base 0 to stay compatible with legacy platforms */
275 ctrl->gc.base = 0;
276
277 /* Optional interrupt setup */
278 if (!np || of_property_read_bool(np, "interrupt-controller")) {
279 girq = &ctrl->gc.irq;
280 girq->chip = &ath79_gpio_irqchip;
281 girq->parent_handler = ath79_gpio_irq_handler;
282 girq->num_parents = 1;
283 girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
284 GFP_KERNEL);
285 if (!girq->parents)
286 return -ENOMEM;
287 girq->parents[0] = platform_get_irq(pdev, 0);
288 girq->default_type = IRQ_TYPE_NONE;
289 girq->handler = handle_simple_irq;
290 }
291
292 err = devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
293 if (err) {
294 dev_err(dev,
295 "cannot add AR71xx GPIO chip, error=%d", err);
296 return err;
297 }
298 return 0;
299}
300
301static struct platform_driver ath79_gpio_driver = {
302 .driver = {
303 .name = "ath79-gpio",
304 .of_match_table = ath79_gpio_of_match,
305 },
306 .probe = ath79_gpio_probe,
307};
308
309module_platform_driver(ath79_gpio_driver);
310
311MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X GPIO API support");
312MODULE_LICENSE("GPL v2");