xref: /openbmc/linux/drivers/gpio/gpio-mpc8xxx.c (revision 715f23b6)
1 /*
2  * GPIOs on MPC512x/8349/8572/8610/QorIQ and compatible
3  *
4  * Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
5  * Copyright (C) 2016 Freescale Semiconductor Inc.
6  *
7  * This file is licensed under the terms of the GNU General Public License
8  * version 2.  This program is licensed "as is" without any warranty of any
9  * kind, whether express or implied.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/spinlock.h>
15 #include <linux/io.h>
16 #include <linux/of.h>
17 #include <linux/of_gpio.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/slab.h>
22 #include <linux/irq.h>
23 #include <linux/gpio/driver.h>
24 #include <linux/bitops.h>
25 #include <linux/interrupt.h>
26 
27 #define MPC8XXX_GPIO_PINS	32
28 
29 #define GPIO_DIR		0x00
30 #define GPIO_ODR		0x04
31 #define GPIO_DAT		0x08
32 #define GPIO_IER		0x0c
33 #define GPIO_IMR		0x10
34 #define GPIO_ICR		0x14
35 #define GPIO_ICR2		0x18
36 #define GPIO_IBE		0x18
37 
38 struct mpc8xxx_gpio_chip {
39 	struct gpio_chip	gc;
40 	void __iomem *regs;
41 	raw_spinlock_t lock;
42 
43 	int (*direction_output)(struct gpio_chip *chip,
44 				unsigned offset, int value);
45 
46 	struct irq_domain *irq;
47 	unsigned int irqn;
48 };
49 
50 /* The GPIO Input Buffer Enable register(GPIO_IBE) is used to
51  * control the input enable of each individual GPIO port.
52  * When an individual GPIO port’s direction is set to
53  * input (GPIO_GPDIR[DRn=0]), the associated input enable must be
54  * set (GPIOxGPIE[IEn]=1) to propagate the port value to the GPIO
55  * Data Register.
56  */
57 static int ls1028a_gpio_dir_in_init(struct gpio_chip *gc)
58 {
59 	unsigned long flags;
60 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
61 
62 	spin_lock_irqsave(&gc->bgpio_lock, flags);
63 
64 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);
65 
66 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
67 
68 	return 0;
69 }
70 
71 /*
72  * This hardware has a big endian bit assignment such that GPIO line 0 is
73  * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
74  * This inline helper give the right bitmask for a certain line.
75  */
76 static inline u32 mpc_pin2mask(unsigned int offset)
77 {
78 	return BIT(31 - offset);
79 }
80 
81 /* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
82  * defined as output cannot be determined by reading GPDAT register,
83  * so we use shadow data register instead. The status of input pins
84  * is determined by reading GPDAT register.
85  */
86 static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
87 {
88 	u32 val;
89 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
90 	u32 out_mask, out_shadow;
91 
92 	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
93 	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
94 	out_shadow = gc->bgpio_data & out_mask;
95 
96 	return !!((val | out_shadow) & mpc_pin2mask(gpio));
97 }
98 
99 static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
100 				unsigned int gpio, int val)
101 {
102 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
103 	/* GPIO 28..31 are input only on MPC5121 */
104 	if (gpio >= 28)
105 		return -EINVAL;
106 
107 	return mpc8xxx_gc->direction_output(gc, gpio, val);
108 }
109 
110 static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
111 				unsigned int gpio, int val)
112 {
113 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
114 	/* GPIO 0..3 are input only on MPC5125 */
115 	if (gpio <= 3)
116 		return -EINVAL;
117 
118 	return mpc8xxx_gc->direction_output(gc, gpio, val);
119 }
120 
121 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
122 {
123 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
124 
125 	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
126 		return irq_create_mapping(mpc8xxx_gc->irq, offset);
127 	else
128 		return -ENXIO;
129 }
130 
131 static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
132 {
133 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
134 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
135 	unsigned long mask;
136 	int i;
137 
138 	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
139 		& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
140 	for_each_set_bit(i, &mask, 32)
141 		generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq, 31 - i));
142 
143 	return IRQ_HANDLED;
144 }
145 
146 static void mpc8xxx_irq_unmask(struct irq_data *d)
147 {
148 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
149 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
150 	unsigned long flags;
151 
152 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
153 
154 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
155 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
156 		| mpc_pin2mask(irqd_to_hwirq(d)));
157 
158 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
159 }
160 
161 static void mpc8xxx_irq_mask(struct irq_data *d)
162 {
163 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
164 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
165 	unsigned long flags;
166 
167 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
168 
169 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
170 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
171 		& ~mpc_pin2mask(irqd_to_hwirq(d)));
172 
173 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
174 }
175 
176 static void mpc8xxx_irq_ack(struct irq_data *d)
177 {
178 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
179 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
180 
181 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
182 		      mpc_pin2mask(irqd_to_hwirq(d)));
183 }
184 
185 static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
186 {
187 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
188 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
189 	unsigned long flags;
190 
191 	switch (flow_type) {
192 	case IRQ_TYPE_EDGE_FALLING:
193 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
194 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
195 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
196 			| mpc_pin2mask(irqd_to_hwirq(d)));
197 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
198 		break;
199 
200 	case IRQ_TYPE_EDGE_BOTH:
201 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
202 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
203 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
204 			& ~mpc_pin2mask(irqd_to_hwirq(d)));
205 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
206 		break;
207 
208 	default:
209 		return -EINVAL;
210 	}
211 
212 	return 0;
213 }
214 
215 static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
216 {
217 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
218 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
219 	unsigned long gpio = irqd_to_hwirq(d);
220 	void __iomem *reg;
221 	unsigned int shift;
222 	unsigned long flags;
223 
224 	if (gpio < 16) {
225 		reg = mpc8xxx_gc->regs + GPIO_ICR;
226 		shift = (15 - gpio) * 2;
227 	} else {
228 		reg = mpc8xxx_gc->regs + GPIO_ICR2;
229 		shift = (15 - (gpio % 16)) * 2;
230 	}
231 
232 	switch (flow_type) {
233 	case IRQ_TYPE_EDGE_FALLING:
234 	case IRQ_TYPE_LEVEL_LOW:
235 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
236 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
237 			| (2 << shift));
238 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
239 		break;
240 
241 	case IRQ_TYPE_EDGE_RISING:
242 	case IRQ_TYPE_LEVEL_HIGH:
243 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
244 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
245 			| (1 << shift));
246 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
247 		break;
248 
249 	case IRQ_TYPE_EDGE_BOTH:
250 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
251 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
252 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
253 		break;
254 
255 	default:
256 		return -EINVAL;
257 	}
258 
259 	return 0;
260 }
261 
262 static struct irq_chip mpc8xxx_irq_chip = {
263 	.name		= "mpc8xxx-gpio",
264 	.irq_unmask	= mpc8xxx_irq_unmask,
265 	.irq_mask	= mpc8xxx_irq_mask,
266 	.irq_ack	= mpc8xxx_irq_ack,
267 	/* this might get overwritten in mpc8xxx_probe() */
268 	.irq_set_type	= mpc8xxx_irq_set_type,
269 };
270 
271 static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
272 				irq_hw_number_t hwirq)
273 {
274 	irq_set_chip_data(irq, h->host_data);
275 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);
276 
277 	return 0;
278 }
279 
280 static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
281 	.map	= mpc8xxx_gpio_irq_map,
282 	.xlate	= irq_domain_xlate_twocell,
283 };
284 
285 struct mpc8xxx_gpio_devtype {
286 	int (*gpio_dir_in_init)(struct gpio_chip *chip);
287 	int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
288 	int (*gpio_get)(struct gpio_chip *, unsigned int);
289 	int (*irq_set_type)(struct irq_data *, unsigned int);
290 };
291 
292 static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
293 	.gpio_dir_out = mpc5121_gpio_dir_out,
294 	.irq_set_type = mpc512x_irq_set_type,
295 };
296 
297 static const struct mpc8xxx_gpio_devtype ls1028a_gpio_devtype = {
298 	.gpio_dir_in_init = ls1028a_gpio_dir_in_init,
299 };
300 
301 static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
302 	.gpio_dir_out = mpc5125_gpio_dir_out,
303 	.irq_set_type = mpc512x_irq_set_type,
304 };
305 
306 static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
307 	.gpio_get = mpc8572_gpio_get,
308 };
309 
310 static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
311 	.irq_set_type = mpc8xxx_irq_set_type,
312 };
313 
314 static const struct of_device_id mpc8xxx_gpio_ids[] = {
315 	{ .compatible = "fsl,mpc8349-gpio", },
316 	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
317 	{ .compatible = "fsl,mpc8610-gpio", },
318 	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
319 	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
320 	{ .compatible = "fsl,pq3-gpio",     },
321 	{ .compatible = "fsl,ls1028a-gpio", .data = &ls1028a_gpio_devtype, },
322 	{ .compatible = "fsl,ls1088a-gpio", .data = &ls1028a_gpio_devtype, },
323 	{ .compatible = "fsl,qoriq-gpio",   },
324 	{}
325 };
326 
327 static int mpc8xxx_probe(struct platform_device *pdev)
328 {
329 	struct device_node *np = pdev->dev.of_node;
330 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
331 	struct gpio_chip	*gc;
332 	const struct mpc8xxx_gpio_devtype *devtype =
333 		of_device_get_match_data(&pdev->dev);
334 	int ret;
335 
336 	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
337 	if (!mpc8xxx_gc)
338 		return -ENOMEM;
339 
340 	platform_set_drvdata(pdev, mpc8xxx_gc);
341 
342 	raw_spin_lock_init(&mpc8xxx_gc->lock);
343 
344 	mpc8xxx_gc->regs = of_iomap(np, 0);
345 	if (!mpc8xxx_gc->regs)
346 		return -ENOMEM;
347 
348 	gc = &mpc8xxx_gc->gc;
349 	gc->parent = &pdev->dev;
350 
351 	if (of_property_read_bool(np, "little-endian")) {
352 		ret = bgpio_init(gc, &pdev->dev, 4,
353 				 mpc8xxx_gc->regs + GPIO_DAT,
354 				 NULL, NULL,
355 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
356 				 BGPIOF_BIG_ENDIAN);
357 		if (ret)
358 			goto err;
359 		dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
360 	} else {
361 		ret = bgpio_init(gc, &pdev->dev, 4,
362 				 mpc8xxx_gc->regs + GPIO_DAT,
363 				 NULL, NULL,
364 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
365 				 BGPIOF_BIG_ENDIAN
366 				 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
367 		if (ret)
368 			goto err;
369 		dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
370 	}
371 
372 	mpc8xxx_gc->direction_output = gc->direction_output;
373 
374 	if (!devtype)
375 		devtype = &mpc8xxx_gpio_devtype_default;
376 
377 	/*
378 	 * It's assumed that only a single type of gpio controller is available
379 	 * on the current machine, so overwriting global data is fine.
380 	 */
381 	if (devtype->irq_set_type)
382 		mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
383 
384 	if (devtype->gpio_dir_out)
385 		gc->direction_output = devtype->gpio_dir_out;
386 	if (devtype->gpio_get)
387 		gc->get = devtype->gpio_get;
388 
389 	gc->to_irq = mpc8xxx_gpio_to_irq;
390 
391 	if (of_device_is_compatible(np, "fsl,qoriq-gpio"))
392 		gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);
393 
394 	ret = gpiochip_add_data(gc, mpc8xxx_gc);
395 	if (ret) {
396 		pr_err("%pOF: GPIO chip registration failed with status %d\n",
397 		       np, ret);
398 		goto err;
399 	}
400 
401 	mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
402 	if (!mpc8xxx_gc->irqn)
403 		return 0;
404 
405 	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
406 					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
407 	if (!mpc8xxx_gc->irq)
408 		return 0;
409 
410 	/* ack and mask all irqs */
411 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
412 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
413 	/* enable input buffer  */
414 	if (devtype->gpio_dir_in_init)
415 		devtype->gpio_dir_in_init(gc);
416 
417 	ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
418 			       mpc8xxx_gpio_irq_cascade,
419 			       IRQF_NO_THREAD | IRQF_SHARED, "gpio-cascade",
420 			       mpc8xxx_gc);
421 	if (ret) {
422 		dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret = %d\n",
423 			np->full_name, mpc8xxx_gc->irqn, ret);
424 		goto err;
425 	}
426 
427 	return 0;
428 err:
429 	iounmap(mpc8xxx_gc->regs);
430 	return ret;
431 }
432 
433 static int mpc8xxx_remove(struct platform_device *pdev)
434 {
435 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);
436 
437 	if (mpc8xxx_gc->irq) {
438 		irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, NULL, NULL);
439 		irq_domain_remove(mpc8xxx_gc->irq);
440 	}
441 
442 	gpiochip_remove(&mpc8xxx_gc->gc);
443 	iounmap(mpc8xxx_gc->regs);
444 
445 	return 0;
446 }
447 
448 static struct platform_driver mpc8xxx_plat_driver = {
449 	.probe		= mpc8xxx_probe,
450 	.remove		= mpc8xxx_remove,
451 	.driver		= {
452 		.name = "gpio-mpc8xxx",
453 		.of_match_table	= mpc8xxx_gpio_ids,
454 	},
455 };
456 
457 static int __init mpc8xxx_init(void)
458 {
459 	return platform_driver_register(&mpc8xxx_plat_driver);
460 }
461 
462 arch_initcall(mpc8xxx_init);
463