xref: /linux/drivers/gpio/gpio-npcm-sgpio.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Nuvoton NPCM Serial GPIO Driver
4  *
5  * Copyright (C) 2021 Nuvoton Technologies
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/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/spinlock.h>
17 #include <linux/string.h>
18 #include <linux/units.h>
19 
20 #define MAX_NR_HW_SGPIO		64
21 
22 #define  NPCM_IOXCFG1		0x2A
23 #define  NPCM_IOXCFG1_SFT_CLK	GENMASK(3, 0)
24 #define  NPCM_IOXCFG1_SCLK_POL	BIT(4)
25 #define  NPCM_IOXCFG1_LDSH_POL	BIT(5)
26 
27 #define  NPCM_IOXCTS			0x28
28 #define  NPCM_IOXCTS_IOXIF_EN		BIT(7)
29 #define  NPCM_IOXCTS_RD_MODE		GENMASK(2, 1)
30 #define  NPCM_IOXCTS_RD_MODE_PERIODIC	BIT(2)
31 
32 #define  NPCM_IOXCFG2		0x2B
33 #define  NPCM_IOXCFG2_PORT	GENMASK(3, 0)
34 
35 #define  NPCM_IXOEVCFG_MASK	GENMASK(1, 0)
36 #define  NPCM_IXOEVCFG_FALLING	BIT(1)
37 #define  NPCM_IXOEVCFG_RISING	BIT(0)
38 #define  NPCM_IXOEVCFG_BOTH	(NPCM_IXOEVCFG_FALLING | NPCM_IXOEVCFG_RISING)
39 
40 #define NPCM_CLK_MHZ	(8 * HZ_PER_MHZ)
41 #define NPCM_750_OPT	6
42 #define NPCM_845_OPT	5
43 
44 #define GPIO_BANK(x)    ((x) / 8)
45 #define GPIO_BIT(x)     ((x) % 8)
46 
47 /*
48  * Select the frequency of shift clock.
49  * The shift clock is a division of the APB clock.
50  */
51 struct npcm_clk_cfg {
52 	unsigned int	*sft_clk;
53 	unsigned int	*clk_sel;
54 	unsigned int	cfg_opt;
55 };
56 
57 struct npcm_sgpio {
58 	struct gpio_chip chip;
59 	struct clk *pclk;
60 	struct irq_chip intc;
61 	raw_spinlock_t lock;
62 
63 	void __iomem *base;
64 	int irq;
65 	u8 nin_sgpio;
66 	u8 nout_sgpio;
67 	u8 in_port;
68 	u8 out_port;
69 	u8 int_type[MAX_NR_HW_SGPIO];
70 };
71 
72 struct npcm_sgpio_bank {
73 	u8 rdata_reg;
74 	u8 wdata_reg;
75 	u8 event_config;
76 	u8 event_status;
77 };
78 
79 enum npcm_sgpio_reg {
80 	READ_DATA,
81 	WRITE_DATA,
82 	EVENT_CFG,
83 	EVENT_STS,
84 };
85 
86 static const struct npcm_sgpio_bank npcm_sgpio_banks[] = {
87 	{
88 		.wdata_reg = 0x00,
89 		.rdata_reg = 0x08,
90 		.event_config = 0x10,
91 		.event_status = 0x20,
92 	},
93 	{
94 		.wdata_reg = 0x01,
95 		.rdata_reg = 0x09,
96 		.event_config = 0x12,
97 		.event_status = 0x21,
98 	},
99 	{
100 		.wdata_reg = 0x02,
101 		.rdata_reg = 0x0a,
102 		.event_config = 0x14,
103 		.event_status = 0x22,
104 	},
105 	{
106 		.wdata_reg = 0x03,
107 		.rdata_reg = 0x0b,
108 		.event_config = 0x16,
109 		.event_status = 0x23,
110 	},
111 	{
112 		.wdata_reg = 0x04,
113 		.rdata_reg = 0x0c,
114 		.event_config = 0x18,
115 		.event_status = 0x24,
116 	},
117 	{
118 		.wdata_reg = 0x05,
119 		.rdata_reg = 0x0d,
120 		.event_config = 0x1a,
121 		.event_status = 0x25,
122 	},
123 	{
124 		.wdata_reg = 0x06,
125 		.rdata_reg = 0x0e,
126 		.event_config = 0x1c,
127 		.event_status = 0x26,
128 	},
129 	{
130 		.wdata_reg = 0x07,
131 		.rdata_reg = 0x0f,
132 		.event_config = 0x1e,
133 		.event_status = 0x27,
134 	},
135 };
136 
137 static void __iomem *bank_reg(struct npcm_sgpio *gpio,
138 			      const struct npcm_sgpio_bank *bank,
139 			      const enum npcm_sgpio_reg reg)
140 {
141 	switch (reg) {
142 	case READ_DATA:
143 		return gpio->base + bank->rdata_reg;
144 	case WRITE_DATA:
145 		return gpio->base + bank->wdata_reg;
146 	case EVENT_CFG:
147 		return gpio->base + bank->event_config;
148 	case EVENT_STS:
149 		return gpio->base + bank->event_status;
150 	default:
151 		/* actually if code runs to here, it's an error case */
152 		dev_WARN(gpio->chip.parent, "Getting here is an error condition");
153 		return NULL;
154 	}
155 }
156 
157 static const struct npcm_sgpio_bank *offset_to_bank(unsigned int offset)
158 {
159 	unsigned int bank = GPIO_BANK(offset);
160 
161 	return &npcm_sgpio_banks[bank];
162 }
163 
164 static void npcm_sgpio_irqd_to_data(struct irq_data *d,
165 				    struct npcm_sgpio **gpio,
166 				    const struct npcm_sgpio_bank **bank,
167 				    u8 *bit, unsigned int *offset)
168 {
169 	struct npcm_sgpio *internal;
170 
171 	*offset = irqd_to_hwirq(d);
172 	internal = irq_data_get_irq_chip_data(d);
173 
174 	*gpio = internal;
175 	*offset -= internal->nout_sgpio;
176 	*bank = offset_to_bank(*offset);
177 	*bit = GPIO_BIT(*offset);
178 }
179 
180 static int npcm_sgpio_init_port(struct npcm_sgpio *gpio)
181 {
182 	u8 in_port, out_port, set_port, reg;
183 
184 	in_port = GPIO_BANK(gpio->nin_sgpio);
185 	if (GPIO_BIT(gpio->nin_sgpio) > 0)
186 		in_port += 1;
187 
188 	out_port = GPIO_BANK(gpio->nout_sgpio);
189 	if (GPIO_BIT(gpio->nout_sgpio) > 0)
190 		out_port += 1;
191 
192 	gpio->in_port = in_port;
193 	gpio->out_port = out_port;
194 	set_port = (out_port & NPCM_IOXCFG2_PORT) << 4 |
195 		   (in_port & NPCM_IOXCFG2_PORT);
196 	iowrite8(set_port, gpio->base + NPCM_IOXCFG2);
197 
198 	reg = ioread8(gpio->base + NPCM_IOXCFG2);
199 
200 	return reg == set_port ? 0 : -EINVAL;
201 
202 }
203 
204 static int npcm_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
205 {
206 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
207 
208 	return offset <	gpio->nout_sgpio ? -EINVAL : 0;
209 
210 }
211 
212 static int npcm_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
213 {
214 	gc->set(gc, offset, val);
215 
216 	return 0;
217 }
218 
219 static int npcm_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset)
220 {
221 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
222 
223 	if (offset < gpio->nout_sgpio)
224 		return GPIO_LINE_DIRECTION_OUT;
225 
226 	return GPIO_LINE_DIRECTION_IN;
227 }
228 
229 static void npcm_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val)
230 {
231 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
232 	const struct  npcm_sgpio_bank *bank = offset_to_bank(offset);
233 	void __iomem *addr;
234 	u8 reg = 0;
235 
236 	addr = bank_reg(gpio, bank, WRITE_DATA);
237 	reg = ioread8(addr);
238 
239 	if (val)
240 		reg |= BIT(GPIO_BIT(offset));
241 	else
242 		reg &= ~BIT(GPIO_BIT(offset));
243 
244 	iowrite8(reg, addr);
245 }
246 
247 static int npcm_sgpio_get(struct gpio_chip *gc, unsigned int offset)
248 {
249 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
250 	const struct  npcm_sgpio_bank *bank;
251 	void __iomem *addr;
252 	u8 reg;
253 
254 	if (offset < gpio->nout_sgpio) {
255 		bank = offset_to_bank(offset);
256 		addr = bank_reg(gpio, bank, WRITE_DATA);
257 	} else {
258 		offset -= gpio->nout_sgpio;
259 		bank = offset_to_bank(offset);
260 		addr = bank_reg(gpio, bank, READ_DATA);
261 	}
262 
263 	reg = ioread8(addr);
264 
265 	return !!(reg & BIT(GPIO_BIT(offset)));
266 }
267 
268 static void npcm_sgpio_setup_enable(struct npcm_sgpio *gpio, bool enable)
269 {
270 	u8 reg;
271 
272 	reg = ioread8(gpio->base + NPCM_IOXCTS);
273 	reg = (reg & ~NPCM_IOXCTS_RD_MODE) | NPCM_IOXCTS_RD_MODE_PERIODIC;
274 
275 	if (enable)
276 		reg |= NPCM_IOXCTS_IOXIF_EN;
277 	else
278 		reg &= ~NPCM_IOXCTS_IOXIF_EN;
279 
280 	iowrite8(reg, gpio->base + NPCM_IOXCTS);
281 }
282 
283 static int npcm_sgpio_setup_clk(struct npcm_sgpio *gpio,
284 				const struct npcm_clk_cfg *clk_cfg)
285 {
286 	unsigned long apb_freq;
287 	u32 val;
288 	u8 tmp;
289 	int i;
290 
291 	apb_freq = clk_get_rate(gpio->pclk);
292 	tmp = ioread8(gpio->base + NPCM_IOXCFG1) & ~NPCM_IOXCFG1_SFT_CLK;
293 
294 	for (i = clk_cfg->cfg_opt-1; i > 0; i--) {
295 		val = apb_freq / clk_cfg->sft_clk[i];
296 		if (NPCM_CLK_MHZ > val) {
297 			iowrite8(clk_cfg->clk_sel[i] | tmp,
298 				 gpio->base + NPCM_IOXCFG1);
299 			return 0;
300 		}
301 	}
302 
303 	return -EINVAL;
304 }
305 
306 static void npcm_sgpio_irq_init_valid_mask(struct gpio_chip *gc,
307 					   unsigned long *valid_mask,
308 					   unsigned int ngpios)
309 {
310 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
311 
312 	/* input GPIOs in the high range */
313 	bitmap_set(valid_mask, gpio->nout_sgpio, gpio->nin_sgpio);
314 	bitmap_clear(valid_mask, 0, gpio->nout_sgpio);
315 }
316 
317 static void npcm_sgpio_irq_set_mask(struct irq_data *d, bool set)
318 {
319 	const struct npcm_sgpio_bank *bank;
320 	struct npcm_sgpio *gpio;
321 	unsigned long flags;
322 	void __iomem *addr;
323 	unsigned int offset;
324 	u16 reg, type;
325 	u8 bit;
326 
327 	npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset);
328 	addr = bank_reg(gpio, bank, EVENT_CFG);
329 
330 	reg = ioread16(addr);
331 	if (set) {
332 		reg &= ~(NPCM_IXOEVCFG_MASK << (bit * 2));
333 	} else {
334 		type = gpio->int_type[offset];
335 		reg |= (type << (bit * 2));
336 	}
337 
338 	raw_spin_lock_irqsave(&gpio->lock, flags);
339 
340 	npcm_sgpio_setup_enable(gpio, false);
341 
342 	iowrite16(reg, addr);
343 
344 	npcm_sgpio_setup_enable(gpio, true);
345 
346 	addr = bank_reg(gpio, bank, EVENT_STS);
347 	reg = ioread8(addr);
348 	reg |= BIT(bit);
349 	iowrite8(reg, addr);
350 
351 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
352 }
353 
354 static void npcm_sgpio_irq_ack(struct irq_data *d)
355 {
356 	const struct npcm_sgpio_bank *bank;
357 	struct npcm_sgpio *gpio;
358 	unsigned long flags;
359 	void __iomem *status_addr;
360 	unsigned int offset;
361 	u8 bit;
362 
363 	npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset);
364 	status_addr = bank_reg(gpio, bank, EVENT_STS);
365 	raw_spin_lock_irqsave(&gpio->lock, flags);
366 	iowrite8(BIT(bit), status_addr);
367 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
368 }
369 
370 static void npcm_sgpio_irq_mask(struct irq_data *d)
371 {
372 	npcm_sgpio_irq_set_mask(d, true);
373 }
374 
375 static void npcm_sgpio_irq_unmask(struct irq_data *d)
376 {
377 	npcm_sgpio_irq_set_mask(d, false);
378 }
379 
380 static int npcm_sgpio_set_type(struct irq_data *d, unsigned int type)
381 {
382 	const struct npcm_sgpio_bank *bank;
383 	irq_flow_handler_t handler;
384 	struct npcm_sgpio *gpio;
385 	unsigned long flags;
386 	void __iomem *addr;
387 	unsigned int offset;
388 	u16 reg, val;
389 	u8 bit;
390 
391 	npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset);
392 
393 	switch (type & IRQ_TYPE_SENSE_MASK) {
394 	case IRQ_TYPE_EDGE_BOTH:
395 		val = NPCM_IXOEVCFG_BOTH;
396 		break;
397 	case IRQ_TYPE_EDGE_RISING:
398 	case IRQ_TYPE_LEVEL_HIGH:
399 		val = NPCM_IXOEVCFG_RISING;
400 		break;
401 	case IRQ_TYPE_EDGE_FALLING:
402 	case IRQ_TYPE_LEVEL_LOW:
403 		val = NPCM_IXOEVCFG_FALLING;
404 		break;
405 	default:
406 		return -EINVAL;
407 	}
408 
409 	if (type & IRQ_TYPE_LEVEL_MASK)
410 		handler = handle_level_irq;
411 	else
412 		handler = handle_edge_irq;
413 
414 	gpio->int_type[offset] = val;
415 
416 	raw_spin_lock_irqsave(&gpio->lock, flags);
417 	npcm_sgpio_setup_enable(gpio, false);
418 	addr = bank_reg(gpio, bank, EVENT_CFG);
419 	reg = ioread16(addr);
420 
421 	reg |= (val << (bit * 2));
422 
423 	iowrite16(reg, addr);
424 	npcm_sgpio_setup_enable(gpio, true);
425 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
426 
427 	irq_set_handler_locked(d, handler);
428 
429 	return 0;
430 }
431 
432 static void npcm_sgpio_irq_handler(struct irq_desc *desc)
433 {
434 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
435 	struct irq_chip *ic = irq_desc_get_chip(desc);
436 	struct npcm_sgpio *gpio = gpiochip_get_data(gc);
437 	unsigned int i, j;
438 	unsigned long reg;
439 
440 	chained_irq_enter(ic, desc);
441 
442 	for (i = 0; i < ARRAY_SIZE(npcm_sgpio_banks); i++) {
443 		const struct npcm_sgpio_bank *bank = &npcm_sgpio_banks[i];
444 
445 		reg = ioread8(bank_reg(gpio, bank, EVENT_STS));
446 		for_each_set_bit(j, &reg, 8)
447 			generic_handle_domain_irq(gc->irq.domain,
448 						  i * 8 + gpio->nout_sgpio + j);
449 	}
450 
451 	chained_irq_exit(ic, desc);
452 }
453 
454 static const struct irq_chip sgpio_irq_chip = {
455 	.name = "sgpio-irq",
456 	.irq_ack = npcm_sgpio_irq_ack,
457 	.irq_mask = npcm_sgpio_irq_mask,
458 	.irq_unmask = npcm_sgpio_irq_unmask,
459 	.irq_set_type = npcm_sgpio_set_type,
460 	.flags	= IRQCHIP_IMMUTABLE | IRQCHIP_MASK_ON_SUSPEND,
461 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
462 };
463 
464 static int npcm_sgpio_setup_irqs(struct npcm_sgpio *gpio,
465 				 struct platform_device *pdev)
466 {
467 	int rc, i;
468 	struct gpio_irq_chip *irq;
469 
470 	rc = platform_get_irq(pdev, 0);
471 	if (rc < 0)
472 		return rc;
473 
474 	gpio->irq = rc;
475 
476 	npcm_sgpio_setup_enable(gpio, false);
477 
478 	/* Disable IRQ and clear Interrupt status registers for all SGPIO Pins. */
479 	for (i = 0; i < ARRAY_SIZE(npcm_sgpio_banks); i++) {
480 		const struct npcm_sgpio_bank *bank = &npcm_sgpio_banks[i];
481 
482 		iowrite16(0, bank_reg(gpio, bank, EVENT_CFG));
483 		iowrite8(0xff, bank_reg(gpio, bank, EVENT_STS));
484 	}
485 
486 	irq = &gpio->chip.irq;
487 	gpio_irq_chip_set_chip(irq, &sgpio_irq_chip);
488 	irq->init_valid_mask = npcm_sgpio_irq_init_valid_mask;
489 	irq->handler = handle_bad_irq;
490 	irq->default_type = IRQ_TYPE_NONE;
491 	irq->parent_handler = npcm_sgpio_irq_handler;
492 	irq->parent_handler_data = gpio;
493 	irq->parents = &gpio->irq;
494 	irq->num_parents = 1;
495 
496 	return 0;
497 }
498 
499 static int npcm_sgpio_probe(struct platform_device *pdev)
500 {
501 	struct npcm_sgpio *gpio;
502 	const struct npcm_clk_cfg *clk_cfg;
503 	int rc;
504 	u32 nin_gpios, nout_gpios;
505 
506 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
507 	if (!gpio)
508 		return -ENOMEM;
509 
510 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
511 	if (IS_ERR(gpio->base))
512 		return PTR_ERR(gpio->base);
513 
514 	clk_cfg = device_get_match_data(&pdev->dev);
515 	if (!clk_cfg)
516 		return -EINVAL;
517 
518 	rc = device_property_read_u32(&pdev->dev, "nuvoton,input-ngpios",
519 				      &nin_gpios);
520 	if (rc < 0)
521 		return dev_err_probe(&pdev->dev, rc, "Could not read ngpios property\n");
522 
523 	rc = device_property_read_u32(&pdev->dev, "nuvoton,output-ngpios",
524 				      &nout_gpios);
525 	if (rc < 0)
526 		return dev_err_probe(&pdev->dev, rc, "Could not read ngpios property\n");
527 
528 	gpio->nin_sgpio = nin_gpios;
529 	gpio->nout_sgpio = nout_gpios;
530 	if (gpio->nin_sgpio > MAX_NR_HW_SGPIO ||
531 	    gpio->nout_sgpio > MAX_NR_HW_SGPIO)
532 		return dev_err_probe(&pdev->dev, -EINVAL, "Number of GPIOs exceeds the maximum of %d: input: %d output: %d\n", MAX_NR_HW_SGPIO, nin_gpios, nout_gpios);
533 
534 	gpio->pclk = devm_clk_get(&pdev->dev, NULL);
535 	if (IS_ERR(gpio->pclk))
536 		return dev_err_probe(&pdev->dev, PTR_ERR(gpio->pclk), "Could not get pclk\n");
537 
538 	rc = npcm_sgpio_setup_clk(gpio, clk_cfg);
539 	if (rc < 0)
540 		return dev_err_probe(&pdev->dev, rc, "Failed to setup clock\n");
541 
542 	raw_spin_lock_init(&gpio->lock);
543 	gpio->chip.parent = &pdev->dev;
544 	gpio->chip.ngpio = gpio->nin_sgpio + gpio->nout_sgpio;
545 	gpio->chip.direction_input = npcm_sgpio_dir_in;
546 	gpio->chip.direction_output = npcm_sgpio_dir_out;
547 	gpio->chip.get_direction = npcm_sgpio_get_direction;
548 	gpio->chip.get = npcm_sgpio_get;
549 	gpio->chip.set = npcm_sgpio_set;
550 	gpio->chip.label = dev_name(&pdev->dev);
551 	gpio->chip.base = -1;
552 
553 	rc = npcm_sgpio_init_port(gpio);
554 	if (rc < 0)
555 		return rc;
556 
557 	rc = npcm_sgpio_setup_irqs(gpio, pdev);
558 	if (rc < 0)
559 		return rc;
560 
561 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
562 	if (rc)
563 		return dev_err_probe(&pdev->dev, rc, "GPIO registering failed\n");
564 
565 	npcm_sgpio_setup_enable(gpio, true);
566 
567 	return 0;
568 }
569 
570 static unsigned int npcm750_SFT_CLK[NPCM_750_OPT] = {
571 	1024, 32, 8, 4, 3, 2,
572 };
573 
574 static unsigned int npcm750_CLK_SEL[NPCM_750_OPT] = {
575 	0x00, 0x05, 0x07, 0x0C, 0x0D, 0x0E,
576 };
577 
578 static unsigned int npcm845_SFT_CLK[NPCM_845_OPT] = {
579 	1024, 32, 16, 8, 4,
580 };
581 
582 static unsigned int npcm845_CLK_SEL[NPCM_845_OPT] = {
583 	0x00, 0x05, 0x06, 0x07, 0x0C,
584 };
585 
586 static struct npcm_clk_cfg npcm750_sgpio_pdata = {
587 	.sft_clk = npcm750_SFT_CLK,
588 	.clk_sel = npcm750_CLK_SEL,
589 	.cfg_opt = NPCM_750_OPT,
590 };
591 
592 static const struct npcm_clk_cfg npcm845_sgpio_pdata = {
593 	.sft_clk = npcm845_SFT_CLK,
594 	.clk_sel = npcm845_CLK_SEL,
595 	.cfg_opt = NPCM_845_OPT,
596 };
597 
598 static const struct of_device_id npcm_sgpio_of_table[] = {
599 	{ .compatible = "nuvoton,npcm750-sgpio", .data = &npcm750_sgpio_pdata, },
600 	{ .compatible = "nuvoton,npcm845-sgpio", .data = &npcm845_sgpio_pdata, },
601 	{}
602 };
603 MODULE_DEVICE_TABLE(of, npcm_sgpio_of_table);
604 
605 static struct platform_driver npcm_sgpio_driver = {
606 	.driver = {
607 		.name = KBUILD_MODNAME,
608 		.of_match_table = npcm_sgpio_of_table,
609 	},
610 	.probe	= npcm_sgpio_probe,
611 };
612 module_platform_driver(npcm_sgpio_driver);
613 
614 MODULE_AUTHOR("Jim Liu <jjliu0@nuvoton.com>");
615 MODULE_AUTHOR("Joseph Liu <kwliu@nuvoton.com>");
616 MODULE_DESCRIPTION("Nuvoton NPCM Serial GPIO Driver");
617 MODULE_LICENSE("GPL v2");
618