1 /*
2  * Copyright (c) 2019 Derek Hageman <hageman@inthat.cloud>
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #define DT_DRV_COMPAT atmel_sam0_eic
8 
9 #include <zephyr/device.h>
10 #include <zephyr/irq.h>
11 #include <soc.h>
12 #include <zephyr/drivers/interrupt_controller/sam0_eic.h>
13 #include "intc_sam0_eic_priv.h"
14 
15 struct sam0_eic_line_assignment {
16 	uint8_t pin : 5;
17 	uint8_t port : 2;
18 	uint8_t enabled : 1;
19 };
20 
21 struct sam0_eic_port_data {
22 	sam0_eic_callback_t cb;
23 	void *data;
24 };
25 
26 struct sam0_eic_data {
27 	struct sam0_eic_port_data ports[PORT_GROUPS];
28 	struct sam0_eic_line_assignment lines[EIC_EXTINT_NUM];
29 };
30 
wait_synchronization(void)31 static void wait_synchronization(void)
32 {
33 #ifdef REG_EIC_SYNCBUSY
34 	while (EIC->SYNCBUSY.reg) {
35 	}
36 #else
37 	while (EIC->STATUS.bit.SYNCBUSY) {
38 	}
39 #endif
40 }
41 
set_eic_enable(bool on)42 static inline void set_eic_enable(bool on)
43 {
44 #ifdef REG_EIC_CTRLA
45 	EIC->CTRLA.bit.ENABLE = on;
46 #else
47 	EIC->CTRL.bit.ENABLE = on;
48 #endif
49 }
50 
sam0_eic_isr(const struct device * dev)51 static void sam0_eic_isr(const struct device *dev)
52 {
53 	struct sam0_eic_data *const dev_data = dev->data;
54 	uint16_t bits = EIC->INTFLAG.reg;
55 	uint32_t line_index;
56 
57 	/* Acknowledge all interrupts */
58 	EIC->INTFLAG.reg = bits;
59 
60 	/* No clz on M0, so just do a quick test */
61 #if __CORTEX_M >= 3
62 	line_index = __CLZ(__RBIT(bits));
63 	bits >>= line_index;
64 #else
65 	if (bits & 0xFF) {
66 		line_index = 0;
67 	} else {
68 		line_index = 8;
69 		bits >>= 8;
70 	}
71 #endif
72 
73 	/*
74 	 * Map the EIC lines to the port pin masks based on which port is
75 	 * selected in the line data.
76 	 */
77 	for (; bits; bits >>= 1, line_index++) {
78 		if (!(bits & 1)) {
79 			continue;
80 		}
81 
82 		/*
83 		 * These could be aggregated together into one call, but
84 		 * usually on a single one will be set, so just call them
85 		 * one by one.
86 		 */
87 		struct sam0_eic_line_assignment *line_assignment =
88 			&dev_data->lines[line_index];
89 		struct sam0_eic_port_data *port_data =
90 			&dev_data->ports[line_assignment->port];
91 
92 		port_data->cb(BIT(line_assignment->pin), port_data->data);
93 	}
94 }
95 
sam0_eic_acquire(int port,int pin,enum sam0_eic_trigger trigger,bool filter,sam0_eic_callback_t cb,void * data)96 int sam0_eic_acquire(int port, int pin, enum sam0_eic_trigger trigger,
97 		     bool filter, sam0_eic_callback_t cb, void *data)
98 {
99 	const struct device *const dev = DEVICE_DT_INST_GET(0);
100 	struct sam0_eic_data *dev_data = dev->data;
101 	struct sam0_eic_port_data *port_data;
102 	struct sam0_eic_line_assignment *line_assignment;
103 	uint32_t mask;
104 	int line_index;
105 	int config_index;
106 	int config_shift;
107 	unsigned int key;
108 	uint32_t config;
109 
110 	line_index = sam0_eic_map_to_line(port, pin);
111 	if (line_index < 0) {
112 		return line_index;
113 	}
114 
115 	mask = BIT(line_index);
116 	config_index = line_index / 8;
117 	config_shift = (line_index % 8) * 4;
118 
119 	/* Lock everything so it's safe to reconfigure */
120 	key = irq_lock();
121 	/* Disable the EIC for reconfiguration */
122 	set_eic_enable(0);
123 
124 	line_assignment = &dev_data->lines[line_index];
125 
126 	/* Check that the required line is available */
127 	if (line_assignment->enabled) {
128 		if (line_assignment->port != port ||
129 		    line_assignment->pin != pin) {
130 			goto err_in_use;
131 		}
132 	}
133 
134 	/* Set the EIC configuration data */
135 	port_data = &dev_data->ports[port];
136 	port_data->cb = cb;
137 	port_data->data = data;
138 	line_assignment->pin = pin;
139 	line_assignment->port = port;
140 	line_assignment->enabled = 1;
141 
142 	config = EIC->CONFIG[config_index].reg;
143 	config &= ~(0xF << config_shift);
144 	switch (trigger) {
145 	case SAM0_EIC_RISING:
146 		config |= EIC_CONFIG_SENSE0_RISE << config_shift;
147 		break;
148 	case SAM0_EIC_FALLING:
149 		config |= EIC_CONFIG_SENSE0_FALL << config_shift;
150 		break;
151 	case SAM0_EIC_BOTH:
152 		config |= EIC_CONFIG_SENSE0_BOTH << config_shift;
153 		break;
154 	case SAM0_EIC_HIGH:
155 		config |= EIC_CONFIG_SENSE0_HIGH << config_shift;
156 		break;
157 	case SAM0_EIC_LOW:
158 		config |= EIC_CONFIG_SENSE0_LOW << config_shift;
159 		break;
160 	}
161 
162 	if (filter) {
163 		config |= EIC_CONFIG_FILTEN0 << config_shift;
164 	}
165 
166 	/* Apply the config to the EIC itself */
167 	EIC->CONFIG[config_index].reg = config;
168 
169 	set_eic_enable(1);
170 	wait_synchronization();
171 	/*
172 	 * Errata: The EIC generates a spurious interrupt for the newly
173 	 * enabled pin after being enabled, so clear it before re-enabling
174 	 * the IRQ.
175 	 */
176 	EIC->INTFLAG.reg = mask;
177 	irq_unlock(key);
178 	return 0;
179 
180 err_in_use:
181 	set_eic_enable(1);
182 	wait_synchronization();
183 	irq_unlock(key);
184 	return -EBUSY;
185 }
186 
sam0_eic_check_ownership(int port,int pin,int line_index)187 static bool sam0_eic_check_ownership(int port, int pin, int line_index)
188 {
189 	const struct device *const dev = DEVICE_DT_INST_GET(0);
190 	struct sam0_eic_data *dev_data = dev->data;
191 	struct sam0_eic_line_assignment *line_assignment =
192 		&dev_data->lines[line_index];
193 
194 	if (!line_assignment->enabled) {
195 		return false;
196 	}
197 
198 	if (line_assignment->port != port ||
199 	    line_assignment->pin != pin) {
200 		return false;
201 	}
202 
203 	return true;
204 }
205 
sam0_eic_release(int port,int pin)206 int sam0_eic_release(int port, int pin)
207 {
208 	const struct device *const dev = DEVICE_DT_INST_GET(0);
209 	struct sam0_eic_data *dev_data = dev->data;
210 	uint32_t mask;
211 	int line_index;
212 	int config_index;
213 	int config_shift;
214 	unsigned int key;
215 
216 	line_index = sam0_eic_map_to_line(port, pin);
217 	if (line_index < 0) {
218 		return line_index;
219 	}
220 
221 	mask = BIT(line_index);
222 	config_index = line_index / 8;
223 	config_shift = (line_index % 8) * 4;
224 
225 	/* Lock everything so it's safe to reconfigure */
226 	key = irq_lock();
227 	/* Disable the EIC */
228 	set_eic_enable(0);
229 	wait_synchronization();
230 
231 	/*
232 	 * Check to make sure the requesting actually owns the line and do
233 	 * nothing if it does not.
234 	 */
235 	if (!sam0_eic_check_ownership(port, pin, line_index)) {
236 		goto done;
237 	}
238 
239 	dev_data->lines[line_index].enabled = 0;
240 
241 	/* Clear the EIC config, including the trigger condition */
242 	EIC->CONFIG[config_index].reg &= ~(0xF << config_shift);
243 
244 	/* Clear any pending interrupt for it */
245 	EIC->INTENCLR.reg = mask;
246 	EIC->INTFLAG.reg = mask;
247 
248 done:
249 	set_eic_enable(1);
250 	wait_synchronization();
251 	irq_unlock(key);
252 	return 0;
253 }
254 
sam0_eic_enable_interrupt(int port,int pin)255 int sam0_eic_enable_interrupt(int port, int pin)
256 {
257 	uint32_t mask;
258 	int line_index;
259 
260 	line_index = sam0_eic_map_to_line(port, pin);
261 	if (line_index < 0) {
262 		return line_index;
263 	}
264 
265 	if (!sam0_eic_check_ownership(port, pin, line_index)) {
266 		return -EBUSY;
267 	}
268 
269 	mask = BIT(line_index);
270 	EIC->INTFLAG.reg = mask;
271 	EIC->INTENSET.reg = mask;
272 
273 	return 0;
274 }
275 
sam0_eic_disable_interrupt(int port,int pin)276 int sam0_eic_disable_interrupt(int port, int pin)
277 {
278 	uint32_t mask;
279 	int line_index;
280 
281 	line_index = sam0_eic_map_to_line(port, pin);
282 	if (line_index < 0) {
283 		return line_index;
284 	}
285 
286 	if (!sam0_eic_check_ownership(port, pin, line_index)) {
287 		return -EBUSY;
288 	}
289 
290 	mask = BIT(line_index);
291 	EIC->INTENCLR.reg = mask;
292 	EIC->INTFLAG.reg = mask;
293 
294 	return 0;
295 }
296 
sam0_eic_interrupt_pending(int port)297 uint32_t sam0_eic_interrupt_pending(int port)
298 {
299 	const struct device *const dev = DEVICE_DT_INST_GET(0);
300 	struct sam0_eic_data *dev_data = dev->data;
301 	struct sam0_eic_line_assignment *line_assignment;
302 	uint32_t set = EIC->INTFLAG.reg;
303 	uint32_t mask = 0;
304 
305 	for (int line_index = 0; line_index < EIC_EXTINT_NUM; line_index++) {
306 		line_assignment = &dev_data->lines[line_index];
307 
308 		if (!line_assignment->enabled) {
309 			continue;
310 		}
311 
312 		if (line_assignment->port != port) {
313 			continue;
314 		}
315 
316 		if (!(set & BIT(line_index))) {
317 			continue;
318 		}
319 
320 		mask |= BIT(line_assignment->pin);
321 	}
322 
323 	return mask;
324 }
325 
326 
327 #define SAM0_EIC_IRQ_CONNECT(n)						\
328 	do {								\
329 		IRQ_CONNECT(DT_INST_IRQ_BY_IDX(0, n, irq),		\
330 			    DT_INST_IRQ_BY_IDX(0, n, priority),		\
331 			    sam0_eic_isr, DEVICE_DT_INST_GET(0), 0);	\
332 		irq_enable(DT_INST_IRQ_BY_IDX(0, n, irq));		\
333 	} while (false)
334 
sam0_eic_init(const struct device * dev)335 static int sam0_eic_init(const struct device *dev)
336 {
337 	ARG_UNUSED(dev);
338 
339 #ifdef MCLK
340 	/* Enable the EIC clock in APBAMASK */
341 	MCLK->APBAMASK.reg |= MCLK_APBAMASK_EIC;
342 
343 	/* Enable the GCLK */
344 	GCLK->PCHCTRL[EIC_GCLK_ID].reg = GCLK_PCHCTRL_GEN_GCLK0 |
345 					 GCLK_PCHCTRL_CHEN;
346 #else
347 	/* Enable the EIC clock in PM */
348 	PM->APBAMASK.bit.EIC_ = 1;
349 
350 	/* Enable the GCLK */
351 	GCLK->CLKCTRL.reg = GCLK_CLKCTRL_ID_EIC | GCLK_CLKCTRL_GEN_GCLK0 |
352 			    GCLK_CLKCTRL_CLKEN;
353 #endif
354 
355 #if DT_INST_IRQ_HAS_CELL(0, irq)
356 	SAM0_EIC_IRQ_CONNECT(0);
357 #endif
358 #if DT_INST_IRQ_HAS_IDX(0, 1)
359 	SAM0_EIC_IRQ_CONNECT(1);
360 #endif
361 #if DT_INST_IRQ_HAS_IDX(0, 2)
362 	SAM0_EIC_IRQ_CONNECT(2);
363 #endif
364 #if DT_INST_IRQ_HAS_IDX(0, 3)
365 	SAM0_EIC_IRQ_CONNECT(3);
366 #endif
367 #if DT_INST_IRQ_HAS_IDX(0, 4)
368 	SAM0_EIC_IRQ_CONNECT(4);
369 #endif
370 #if DT_INST_IRQ_HAS_IDX(0, 5)
371 	SAM0_EIC_IRQ_CONNECT(5);
372 #endif
373 #if DT_INST_IRQ_HAS_IDX(0, 6)
374 	SAM0_EIC_IRQ_CONNECT(6);
375 #endif
376 #if DT_INST_IRQ_HAS_IDX(0, 7)
377 	SAM0_EIC_IRQ_CONNECT(7);
378 #endif
379 #if DT_INST_IRQ_HAS_IDX(0, 8)
380 	SAM0_EIC_IRQ_CONNECT(8);
381 #endif
382 #if DT_INST_IRQ_HAS_IDX(0, 9)
383 	SAM0_EIC_IRQ_CONNECT(9);
384 #endif
385 #if DT_INST_IRQ_HAS_IDX(0, 10)
386 	SAM0_EIC_IRQ_CONNECT(10);
387 #endif
388 #if DT_INST_IRQ_HAS_IDX(0, 11)
389 	SAM0_EIC_IRQ_CONNECT(11);
390 #endif
391 #if DT_INST_IRQ_HAS_IDX(0, 12)
392 	SAM0_EIC_IRQ_CONNECT(12);
393 #endif
394 #if DT_INST_IRQ_HAS_IDX(0, 13)
395 	SAM0_EIC_IRQ_CONNECT(13);
396 #endif
397 #if DT_INST_IRQ_HAS_IDX(0, 14)
398 	SAM0_EIC_IRQ_CONNECT(14);
399 #endif
400 #if DT_INST_IRQ_HAS_IDX(0, 15)
401 	SAM0_EIC_IRQ_CONNECT(15);
402 #endif
403 
404 	set_eic_enable(1);
405 	wait_synchronization();
406 
407 	return 0;
408 }
409 
410 static struct sam0_eic_data eic_data;
411 DEVICE_DT_INST_DEFINE(0, sam0_eic_init,
412 	      NULL, &eic_data, NULL,
413 	      PRE_KERNEL_1, CONFIG_INTC_INIT_PRIORITY,
414 	      NULL);
415