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