xref: /linux/drivers/gpio/gpio-aspeed-sgpio.c (revision 64b14a184e83eb62ea0615e31a409956049d40e7) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2019 American Megatrends International LLC.
4  *
5  * Author: Karthikeyan Mani <karthikeyanm@amiindia.co.in>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/clk.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/hashtable.h>
12 #include <linux/init.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <linux/string.h>
19 
20 #define ASPEED_SGPIO_CTRL		0x54
21 
22 #define ASPEED_SGPIO_CLK_DIV_MASK	GENMASK(31, 16)
23 #define ASPEED_SGPIO_ENABLE		BIT(0)
24 #define ASPEED_SGPIO_PINS_SHIFT		6
25 
26 struct aspeed_sgpio_pdata {
27 	const u32 pin_mask;
28 };
29 
30 struct aspeed_sgpio {
31 	struct gpio_chip chip;
32 	struct irq_chip intc;
33 	struct clk *pclk;
34 	raw_spinlock_t lock;
35 	void __iomem *base;
36 	int irq;
37 };
38 
39 struct aspeed_sgpio_bank {
40 	u16    val_regs;
41 	u16    rdata_reg;
42 	u16    irq_regs;
43 	u16    tolerance_regs;
44 	const char  names[4][3];
45 };
46 
47 /*
48  * Note: The "value" register returns the input value when the GPIO is
49  *	 configured as an input.
50  *
51  *	 The "rdata" register returns the output value when the GPIO is
52  *	 configured as an output.
53  */
54 static const struct aspeed_sgpio_bank aspeed_sgpio_banks[] = {
55 	{
56 		.val_regs = 0x0000,
57 		.rdata_reg = 0x0070,
58 		.irq_regs = 0x0004,
59 		.tolerance_regs = 0x0018,
60 		.names = { "A", "B", "C", "D" },
61 	},
62 	{
63 		.val_regs = 0x001C,
64 		.rdata_reg = 0x0074,
65 		.irq_regs = 0x0020,
66 		.tolerance_regs = 0x0034,
67 		.names = { "E", "F", "G", "H" },
68 	},
69 	{
70 		.val_regs = 0x0038,
71 		.rdata_reg = 0x0078,
72 		.irq_regs = 0x003C,
73 		.tolerance_regs = 0x0050,
74 		.names = { "I", "J", "K", "L" },
75 	},
76 	{
77 		.val_regs = 0x0090,
78 		.rdata_reg = 0x007C,
79 		.irq_regs = 0x0094,
80 		.tolerance_regs = 0x00A8,
81 		.names = { "M", "N", "O", "P" },
82 	},
83 };
84 
85 enum aspeed_sgpio_reg {
86 	reg_val,
87 	reg_rdata,
88 	reg_irq_enable,
89 	reg_irq_type0,
90 	reg_irq_type1,
91 	reg_irq_type2,
92 	reg_irq_status,
93 	reg_tolerance,
94 };
95 
96 #define GPIO_VAL_VALUE      0x00
97 #define GPIO_IRQ_ENABLE     0x00
98 #define GPIO_IRQ_TYPE0      0x04
99 #define GPIO_IRQ_TYPE1      0x08
100 #define GPIO_IRQ_TYPE2      0x0C
101 #define GPIO_IRQ_STATUS     0x10
102 
103 static void __iomem *bank_reg(struct aspeed_sgpio *gpio,
104 				     const struct aspeed_sgpio_bank *bank,
105 				     const enum aspeed_sgpio_reg reg)
106 {
107 	switch (reg) {
108 	case reg_val:
109 		return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
110 	case reg_rdata:
111 		return gpio->base + bank->rdata_reg;
112 	case reg_irq_enable:
113 		return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
114 	case reg_irq_type0:
115 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
116 	case reg_irq_type1:
117 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
118 	case reg_irq_type2:
119 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
120 	case reg_irq_status:
121 		return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
122 	case reg_tolerance:
123 		return gpio->base + bank->tolerance_regs;
124 	default:
125 		/* acturally if code runs to here, it's an error case */
126 		BUG();
127 	}
128 }
129 
130 #define GPIO_BANK(x)    ((x) >> 6)
131 #define GPIO_OFFSET(x)  ((x) & GENMASK(5, 0))
132 #define GPIO_BIT(x)     BIT(GPIO_OFFSET(x) >> 1)
133 
134 static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
135 {
136 	unsigned int bank;
137 
138 	bank = GPIO_BANK(offset);
139 
140 	WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
141 	return &aspeed_sgpio_banks[bank];
142 }
143 
144 static int aspeed_sgpio_init_valid_mask(struct gpio_chip *gc,
145 		unsigned long *valid_mask, unsigned int ngpios)
146 {
147 	bitmap_set(valid_mask, 0, ngpios);
148 	return 0;
149 }
150 
151 static void aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
152 		unsigned long *valid_mask, unsigned int ngpios)
153 {
154 	unsigned int i;
155 
156 	/* input GPIOs are even bits */
157 	for (i = 0; i < ngpios; i++) {
158 		if (i % 2)
159 			clear_bit(i, valid_mask);
160 	}
161 }
162 
163 static bool aspeed_sgpio_is_input(unsigned int offset)
164 {
165 	return !(offset % 2);
166 }
167 
168 static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
169 {
170 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
171 	const struct aspeed_sgpio_bank *bank = to_bank(offset);
172 	unsigned long flags;
173 	enum aspeed_sgpio_reg reg;
174 	int rc = 0;
175 
176 	raw_spin_lock_irqsave(&gpio->lock, flags);
177 
178 	reg = aspeed_sgpio_is_input(offset) ? reg_val : reg_rdata;
179 	rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
180 
181 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
182 
183 	return rc;
184 }
185 
186 static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset, int val)
187 {
188 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
189 	const struct aspeed_sgpio_bank *bank = to_bank(offset);
190 	void __iomem *addr_r, *addr_w;
191 	u32 reg = 0;
192 
193 	if (aspeed_sgpio_is_input(offset))
194 		return -EINVAL;
195 
196 	/* Since this is an output, read the cached value from rdata, then
197 	 * update val. */
198 	addr_r = bank_reg(gpio, bank, reg_rdata);
199 	addr_w = bank_reg(gpio, bank, reg_val);
200 
201 	reg = ioread32(addr_r);
202 
203 	if (val)
204 		reg |= GPIO_BIT(offset);
205 	else
206 		reg &= ~GPIO_BIT(offset);
207 
208 	iowrite32(reg, addr_w);
209 
210 	return 0;
211 }
212 
213 static void aspeed_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val)
214 {
215 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
216 	unsigned long flags;
217 
218 	raw_spin_lock_irqsave(&gpio->lock, flags);
219 
220 	sgpio_set_value(gc, offset, val);
221 
222 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
223 }
224 
225 static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
226 {
227 	return aspeed_sgpio_is_input(offset) ? 0 : -EINVAL;
228 }
229 
230 static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
231 {
232 	struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
233 	unsigned long flags;
234 	int rc;
235 
236 	/* No special action is required for setting the direction; we'll
237 	 * error-out in sgpio_set_value if this isn't an output GPIO */
238 
239 	raw_spin_lock_irqsave(&gpio->lock, flags);
240 	rc = sgpio_set_value(gc, offset, val);
241 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
242 
243 	return rc;
244 }
245 
246 static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset)
247 {
248 	return !!aspeed_sgpio_is_input(offset);
249 }
250 
251 static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
252 					struct aspeed_sgpio **gpio,
253 					const struct aspeed_sgpio_bank **bank,
254 					u32 *bit, int *offset)
255 {
256 	struct aspeed_sgpio *internal;
257 
258 	*offset = irqd_to_hwirq(d);
259 	internal = irq_data_get_irq_chip_data(d);
260 	WARN_ON(!internal);
261 
262 	*gpio = internal;
263 	*bank = to_bank(*offset);
264 	*bit = GPIO_BIT(*offset);
265 }
266 
267 static void aspeed_sgpio_irq_ack(struct irq_data *d)
268 {
269 	const struct aspeed_sgpio_bank *bank;
270 	struct aspeed_sgpio *gpio;
271 	unsigned long flags;
272 	void __iomem *status_addr;
273 	int offset;
274 	u32 bit;
275 
276 	irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
277 
278 	status_addr = bank_reg(gpio, bank, reg_irq_status);
279 
280 	raw_spin_lock_irqsave(&gpio->lock, flags);
281 
282 	iowrite32(bit, status_addr);
283 
284 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
285 }
286 
287 static void aspeed_sgpio_irq_set_mask(struct irq_data *d, bool set)
288 {
289 	const struct aspeed_sgpio_bank *bank;
290 	struct aspeed_sgpio *gpio;
291 	unsigned long flags;
292 	u32 reg, bit;
293 	void __iomem *addr;
294 	int offset;
295 
296 	irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
297 	addr = bank_reg(gpio, bank, reg_irq_enable);
298 
299 	raw_spin_lock_irqsave(&gpio->lock, flags);
300 
301 	reg = ioread32(addr);
302 	if (set)
303 		reg |= bit;
304 	else
305 		reg &= ~bit;
306 
307 	iowrite32(reg, addr);
308 
309 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
310 }
311 
312 static void aspeed_sgpio_irq_mask(struct irq_data *d)
313 {
314 	aspeed_sgpio_irq_set_mask(d, false);
315 }
316 
317 static void aspeed_sgpio_irq_unmask(struct irq_data *d)
318 {
319 	aspeed_sgpio_irq_set_mask(d, true);
320 }
321 
322 static int aspeed_sgpio_set_type(struct irq_data *d, unsigned int type)
323 {
324 	u32 type0 = 0;
325 	u32 type1 = 0;
326 	u32 type2 = 0;
327 	u32 bit, reg;
328 	const struct aspeed_sgpio_bank *bank;
329 	irq_flow_handler_t handler;
330 	struct aspeed_sgpio *gpio;
331 	unsigned long flags;
332 	void __iomem *addr;
333 	int offset;
334 
335 	irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
336 
337 	switch (type & IRQ_TYPE_SENSE_MASK) {
338 	case IRQ_TYPE_EDGE_BOTH:
339 		type2 |= bit;
340 		fallthrough;
341 	case IRQ_TYPE_EDGE_RISING:
342 		type0 |= bit;
343 		fallthrough;
344 	case IRQ_TYPE_EDGE_FALLING:
345 		handler = handle_edge_irq;
346 		break;
347 	case IRQ_TYPE_LEVEL_HIGH:
348 		type0 |= bit;
349 		fallthrough;
350 	case IRQ_TYPE_LEVEL_LOW:
351 		type1 |= bit;
352 		handler = handle_level_irq;
353 		break;
354 	default:
355 		return -EINVAL;
356 	}
357 
358 	raw_spin_lock_irqsave(&gpio->lock, flags);
359 
360 	addr = bank_reg(gpio, bank, reg_irq_type0);
361 	reg = ioread32(addr);
362 	reg = (reg & ~bit) | type0;
363 	iowrite32(reg, addr);
364 
365 	addr = bank_reg(gpio, bank, reg_irq_type1);
366 	reg = ioread32(addr);
367 	reg = (reg & ~bit) | type1;
368 	iowrite32(reg, addr);
369 
370 	addr = bank_reg(gpio, bank, reg_irq_type2);
371 	reg = ioread32(addr);
372 	reg = (reg & ~bit) | type2;
373 	iowrite32(reg, addr);
374 
375 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
376 
377 	irq_set_handler_locked(d, handler);
378 
379 	return 0;
380 }
381 
382 static void aspeed_sgpio_irq_handler(struct irq_desc *desc)
383 {
384 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
385 	struct irq_chip *ic = irq_desc_get_chip(desc);
386 	struct aspeed_sgpio *data = gpiochip_get_data(gc);
387 	unsigned int i, p;
388 	unsigned long reg;
389 
390 	chained_irq_enter(ic, desc);
391 
392 	for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
393 		const struct aspeed_sgpio_bank *bank = &aspeed_sgpio_banks[i];
394 
395 		reg = ioread32(bank_reg(data, bank, reg_irq_status));
396 
397 		for_each_set_bit(p, &reg, 32)
398 			generic_handle_domain_irq(gc->irq.domain, (i * 32 + p) * 2);
399 	}
400 
401 	chained_irq_exit(ic, desc);
402 }
403 
404 static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio,
405 				   struct platform_device *pdev)
406 {
407 	int rc, i;
408 	const struct aspeed_sgpio_bank *bank;
409 	struct gpio_irq_chip *irq;
410 
411 	rc = platform_get_irq(pdev, 0);
412 	if (rc < 0)
413 		return rc;
414 
415 	gpio->irq = rc;
416 
417 	/* Disable IRQ and clear Interrupt status registers for all SGPIO Pins. */
418 	for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
419 		bank =  &aspeed_sgpio_banks[i];
420 		/* disable irq enable bits */
421 		iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_enable));
422 		/* clear status bits */
423 		iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_status));
424 	}
425 
426 	gpio->intc.name = dev_name(&pdev->dev);
427 	gpio->intc.irq_ack = aspeed_sgpio_irq_ack;
428 	gpio->intc.irq_mask = aspeed_sgpio_irq_mask;
429 	gpio->intc.irq_unmask = aspeed_sgpio_irq_unmask;
430 	gpio->intc.irq_set_type = aspeed_sgpio_set_type;
431 
432 	irq = &gpio->chip.irq;
433 	irq->chip = &gpio->intc;
434 	irq->init_valid_mask = aspeed_sgpio_irq_init_valid_mask;
435 	irq->handler = handle_bad_irq;
436 	irq->default_type = IRQ_TYPE_NONE;
437 	irq->parent_handler = aspeed_sgpio_irq_handler;
438 	irq->parent_handler_data = gpio;
439 	irq->parents = &gpio->irq;
440 	irq->num_parents = 1;
441 
442 	/* Apply default IRQ settings */
443 	for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
444 		bank = &aspeed_sgpio_banks[i];
445 		/* set falling or level-low irq */
446 		iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type0));
447 		/* trigger type is edge */
448 		iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type1));
449 		/* single edge trigger */
450 		iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type2));
451 	}
452 
453 	return 0;
454 }
455 
456 static const struct aspeed_sgpio_pdata ast2400_sgpio_pdata = {
457 	.pin_mask = GENMASK(9, 6),
458 };
459 
460 static int aspeed_sgpio_reset_tolerance(struct gpio_chip *chip,
461 					unsigned int offset, bool enable)
462 {
463 	struct aspeed_sgpio *gpio = gpiochip_get_data(chip);
464 	unsigned long flags;
465 	void __iomem *reg;
466 	u32 val;
467 
468 	reg = bank_reg(gpio, to_bank(offset), reg_tolerance);
469 
470 	raw_spin_lock_irqsave(&gpio->lock, flags);
471 
472 	val = readl(reg);
473 
474 	if (enable)
475 		val |= GPIO_BIT(offset);
476 	else
477 		val &= ~GPIO_BIT(offset);
478 
479 	writel(val, reg);
480 
481 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
482 
483 	return 0;
484 }
485 
486 static int aspeed_sgpio_set_config(struct gpio_chip *chip, unsigned int offset,
487 				   unsigned long config)
488 {
489 	unsigned long param = pinconf_to_config_param(config);
490 	u32 arg = pinconf_to_config_argument(config);
491 
492 	if (param == PIN_CONFIG_PERSIST_STATE)
493 		return aspeed_sgpio_reset_tolerance(chip, offset, arg);
494 
495 	return -ENOTSUPP;
496 }
497 
498 static const struct aspeed_sgpio_pdata ast2600_sgpiom_pdata = {
499 	.pin_mask = GENMASK(10, 6),
500 };
501 
502 static const struct of_device_id aspeed_sgpio_of_table[] = {
503 	{ .compatible = "aspeed,ast2400-sgpio", .data = &ast2400_sgpio_pdata, },
504 	{ .compatible = "aspeed,ast2500-sgpio", .data = &ast2400_sgpio_pdata, },
505 	{ .compatible = "aspeed,ast2600-sgpiom", .data = &ast2600_sgpiom_pdata, },
506 	{}
507 };
508 
509 MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table);
510 
511 static int __init aspeed_sgpio_probe(struct platform_device *pdev)
512 {
513 	u32 nr_gpios, sgpio_freq, sgpio_clk_div, gpio_cnt_regval, pin_mask;
514 	const struct aspeed_sgpio_pdata *pdata;
515 	struct aspeed_sgpio *gpio;
516 	unsigned long apb_freq;
517 	int rc;
518 
519 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
520 	if (!gpio)
521 		return -ENOMEM;
522 
523 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
524 	if (IS_ERR(gpio->base))
525 		return PTR_ERR(gpio->base);
526 
527 	pdata = device_get_match_data(&pdev->dev);
528 	if (!pdata)
529 		return -EINVAL;
530 
531 	pin_mask = pdata->pin_mask;
532 
533 	rc = device_property_read_u32(&pdev->dev, "ngpios", &nr_gpios);
534 	if (rc < 0) {
535 		dev_err(&pdev->dev, "Could not read ngpios property\n");
536 		return -EINVAL;
537 	} else if (nr_gpios % 8) {
538 		dev_err(&pdev->dev, "Number of GPIOs not multiple of 8: %d\n",
539 			nr_gpios);
540 		return -EINVAL;
541 	}
542 
543 	rc = device_property_read_u32(&pdev->dev, "bus-frequency", &sgpio_freq);
544 	if (rc < 0) {
545 		dev_err(&pdev->dev, "Could not read bus-frequency property\n");
546 		return -EINVAL;
547 	}
548 
549 	gpio->pclk = devm_clk_get(&pdev->dev, NULL);
550 	if (IS_ERR(gpio->pclk)) {
551 		dev_err(&pdev->dev, "devm_clk_get failed\n");
552 		return PTR_ERR(gpio->pclk);
553 	}
554 
555 	apb_freq = clk_get_rate(gpio->pclk);
556 
557 	/*
558 	 * From the datasheet,
559 	 *	SGPIO period = 1/PCLK * 2 * (GPIO254[31:16] + 1)
560 	 *	period = 2 * (GPIO254[31:16] + 1) / PCLK
561 	 *	frequency = 1 / (2 * (GPIO254[31:16] + 1) / PCLK)
562 	 *	frequency = PCLK / (2 * (GPIO254[31:16] + 1))
563 	 *	frequency * 2 * (GPIO254[31:16] + 1) = PCLK
564 	 *	GPIO254[31:16] = PCLK / (frequency * 2) - 1
565 	 */
566 	if (sgpio_freq == 0)
567 		return -EINVAL;
568 
569 	sgpio_clk_div = (apb_freq / (sgpio_freq * 2)) - 1;
570 
571 	if (sgpio_clk_div > (1 << 16) - 1)
572 		return -EINVAL;
573 
574 	gpio_cnt_regval = ((nr_gpios / 8) << ASPEED_SGPIO_PINS_SHIFT) & pin_mask;
575 	iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) | gpio_cnt_regval |
576 		  ASPEED_SGPIO_ENABLE, gpio->base + ASPEED_SGPIO_CTRL);
577 
578 	raw_spin_lock_init(&gpio->lock);
579 
580 	gpio->chip.parent = &pdev->dev;
581 	gpio->chip.ngpio = nr_gpios * 2;
582 	gpio->chip.init_valid_mask = aspeed_sgpio_init_valid_mask;
583 	gpio->chip.direction_input = aspeed_sgpio_dir_in;
584 	gpio->chip.direction_output = aspeed_sgpio_dir_out;
585 	gpio->chip.get_direction = aspeed_sgpio_get_direction;
586 	gpio->chip.request = NULL;
587 	gpio->chip.free = NULL;
588 	gpio->chip.get = aspeed_sgpio_get;
589 	gpio->chip.set = aspeed_sgpio_set;
590 	gpio->chip.set_config = aspeed_sgpio_set_config;
591 	gpio->chip.label = dev_name(&pdev->dev);
592 	gpio->chip.base = -1;
593 
594 	aspeed_sgpio_setup_irqs(gpio, pdev);
595 
596 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
597 	if (rc < 0)
598 		return rc;
599 
600 	return 0;
601 }
602 
603 static struct platform_driver aspeed_sgpio_driver = {
604 	.driver = {
605 		.name = KBUILD_MODNAME,
606 		.of_match_table = aspeed_sgpio_of_table,
607 	},
608 };
609 
610 module_platform_driver_probe(aspeed_sgpio_driver, aspeed_sgpio_probe);
611 MODULE_DESCRIPTION("Aspeed Serial GPIO Driver");
612 MODULE_LICENSE("GPL");
613