xref: /openbmc/linux/drivers/gpio/gpio-mpc8xxx.c (revision b4e18b29)
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 /*
51  * This hardware has a big endian bit assignment such that GPIO line 0 is
52  * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
53  * This inline helper give the right bitmask for a certain line.
54  */
55 static inline u32 mpc_pin2mask(unsigned int offset)
56 {
57 	return BIT(31 - offset);
58 }
59 
60 /* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
61  * defined as output cannot be determined by reading GPDAT register,
62  * so we use shadow data register instead. The status of input pins
63  * is determined by reading GPDAT register.
64  */
65 static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
66 {
67 	u32 val;
68 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
69 	u32 out_mask, out_shadow;
70 
71 	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
72 	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
73 	out_shadow = gc->bgpio_data & out_mask;
74 
75 	return !!((val | out_shadow) & mpc_pin2mask(gpio));
76 }
77 
78 static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
79 				unsigned int gpio, int val)
80 {
81 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
82 	/* GPIO 28..31 are input only on MPC5121 */
83 	if (gpio >= 28)
84 		return -EINVAL;
85 
86 	return mpc8xxx_gc->direction_output(gc, gpio, val);
87 }
88 
89 static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
90 				unsigned int gpio, int val)
91 {
92 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
93 	/* GPIO 0..3 are input only on MPC5125 */
94 	if (gpio <= 3)
95 		return -EINVAL;
96 
97 	return mpc8xxx_gc->direction_output(gc, gpio, val);
98 }
99 
100 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
101 {
102 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
103 
104 	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
105 		return irq_create_mapping(mpc8xxx_gc->irq, offset);
106 	else
107 		return -ENXIO;
108 }
109 
110 static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
111 {
112 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
113 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
114 	unsigned long mask;
115 	int i;
116 
117 	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
118 		& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
119 	for_each_set_bit(i, &mask, 32)
120 		generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq, 31 - i));
121 
122 	return IRQ_HANDLED;
123 }
124 
125 static void mpc8xxx_irq_unmask(struct irq_data *d)
126 {
127 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
128 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
129 	unsigned long flags;
130 
131 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
132 
133 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
134 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
135 		| mpc_pin2mask(irqd_to_hwirq(d)));
136 
137 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
138 }
139 
140 static void mpc8xxx_irq_mask(struct irq_data *d)
141 {
142 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
143 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
144 	unsigned long flags;
145 
146 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
147 
148 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
149 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
150 		& ~mpc_pin2mask(irqd_to_hwirq(d)));
151 
152 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
153 }
154 
155 static void mpc8xxx_irq_ack(struct irq_data *d)
156 {
157 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
158 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
159 
160 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
161 		      mpc_pin2mask(irqd_to_hwirq(d)));
162 }
163 
164 static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
165 {
166 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
167 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
168 	unsigned long flags;
169 
170 	switch (flow_type) {
171 	case IRQ_TYPE_EDGE_FALLING:
172 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
173 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
174 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
175 			| mpc_pin2mask(irqd_to_hwirq(d)));
176 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
177 		break;
178 
179 	case IRQ_TYPE_EDGE_BOTH:
180 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
181 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
182 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
183 			& ~mpc_pin2mask(irqd_to_hwirq(d)));
184 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
185 		break;
186 
187 	default:
188 		return -EINVAL;
189 	}
190 
191 	return 0;
192 }
193 
194 static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
195 {
196 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
197 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
198 	unsigned long gpio = irqd_to_hwirq(d);
199 	void __iomem *reg;
200 	unsigned int shift;
201 	unsigned long flags;
202 
203 	if (gpio < 16) {
204 		reg = mpc8xxx_gc->regs + GPIO_ICR;
205 		shift = (15 - gpio) * 2;
206 	} else {
207 		reg = mpc8xxx_gc->regs + GPIO_ICR2;
208 		shift = (15 - (gpio % 16)) * 2;
209 	}
210 
211 	switch (flow_type) {
212 	case IRQ_TYPE_EDGE_FALLING:
213 	case IRQ_TYPE_LEVEL_LOW:
214 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
215 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
216 			| (2 << shift));
217 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
218 		break;
219 
220 	case IRQ_TYPE_EDGE_RISING:
221 	case IRQ_TYPE_LEVEL_HIGH:
222 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
223 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
224 			| (1 << shift));
225 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
226 		break;
227 
228 	case IRQ_TYPE_EDGE_BOTH:
229 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
230 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
231 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
232 		break;
233 
234 	default:
235 		return -EINVAL;
236 	}
237 
238 	return 0;
239 }
240 
241 static struct irq_chip mpc8xxx_irq_chip = {
242 	.name		= "mpc8xxx-gpio",
243 	.irq_unmask	= mpc8xxx_irq_unmask,
244 	.irq_mask	= mpc8xxx_irq_mask,
245 	.irq_ack	= mpc8xxx_irq_ack,
246 	/* this might get overwritten in mpc8xxx_probe() */
247 	.irq_set_type	= mpc8xxx_irq_set_type,
248 };
249 
250 static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
251 				irq_hw_number_t hwirq)
252 {
253 	irq_set_chip_data(irq, h->host_data);
254 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);
255 
256 	return 0;
257 }
258 
259 static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
260 	.map	= mpc8xxx_gpio_irq_map,
261 	.xlate	= irq_domain_xlate_twocell,
262 };
263 
264 struct mpc8xxx_gpio_devtype {
265 	int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
266 	int (*gpio_get)(struct gpio_chip *, unsigned int);
267 	int (*irq_set_type)(struct irq_data *, unsigned int);
268 };
269 
270 static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
271 	.gpio_dir_out = mpc5121_gpio_dir_out,
272 	.irq_set_type = mpc512x_irq_set_type,
273 };
274 
275 static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
276 	.gpio_dir_out = mpc5125_gpio_dir_out,
277 	.irq_set_type = mpc512x_irq_set_type,
278 };
279 
280 static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
281 	.gpio_get = mpc8572_gpio_get,
282 };
283 
284 static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
285 	.irq_set_type = mpc8xxx_irq_set_type,
286 };
287 
288 static const struct of_device_id mpc8xxx_gpio_ids[] = {
289 	{ .compatible = "fsl,mpc8349-gpio", },
290 	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
291 	{ .compatible = "fsl,mpc8610-gpio", },
292 	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
293 	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
294 	{ .compatible = "fsl,pq3-gpio",     },
295 	{ .compatible = "fsl,ls1028a-gpio", },
296 	{ .compatible = "fsl,ls1088a-gpio", },
297 	{ .compatible = "fsl,qoriq-gpio",   },
298 	{}
299 };
300 
301 static int mpc8xxx_probe(struct platform_device *pdev)
302 {
303 	struct device_node *np = pdev->dev.of_node;
304 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
305 	struct gpio_chip	*gc;
306 	const struct mpc8xxx_gpio_devtype *devtype =
307 		of_device_get_match_data(&pdev->dev);
308 	int ret;
309 
310 	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
311 	if (!mpc8xxx_gc)
312 		return -ENOMEM;
313 
314 	platform_set_drvdata(pdev, mpc8xxx_gc);
315 
316 	raw_spin_lock_init(&mpc8xxx_gc->lock);
317 
318 	mpc8xxx_gc->regs = of_iomap(np, 0);
319 	if (!mpc8xxx_gc->regs)
320 		return -ENOMEM;
321 
322 	gc = &mpc8xxx_gc->gc;
323 	gc->parent = &pdev->dev;
324 
325 	if (of_property_read_bool(np, "little-endian")) {
326 		ret = bgpio_init(gc, &pdev->dev, 4,
327 				 mpc8xxx_gc->regs + GPIO_DAT,
328 				 NULL, NULL,
329 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
330 				 BGPIOF_BIG_ENDIAN);
331 		if (ret)
332 			goto err;
333 		dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
334 	} else {
335 		ret = bgpio_init(gc, &pdev->dev, 4,
336 				 mpc8xxx_gc->regs + GPIO_DAT,
337 				 NULL, NULL,
338 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
339 				 BGPIOF_BIG_ENDIAN
340 				 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
341 		if (ret)
342 			goto err;
343 		dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
344 	}
345 
346 	mpc8xxx_gc->direction_output = gc->direction_output;
347 
348 	if (!devtype)
349 		devtype = &mpc8xxx_gpio_devtype_default;
350 
351 	/*
352 	 * It's assumed that only a single type of gpio controller is available
353 	 * on the current machine, so overwriting global data is fine.
354 	 */
355 	if (devtype->irq_set_type)
356 		mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
357 
358 	if (devtype->gpio_dir_out)
359 		gc->direction_output = devtype->gpio_dir_out;
360 	if (devtype->gpio_get)
361 		gc->get = devtype->gpio_get;
362 
363 	gc->to_irq = mpc8xxx_gpio_to_irq;
364 
365 	/*
366 	 * The GPIO Input Buffer Enable register(GPIO_IBE) is used to control
367 	 * the input enable of each individual GPIO port.  When an individual
368 	 * GPIO port’s direction is set to input (GPIO_GPDIR[DRn=0]), the
369 	 * associated input enable must be set (GPIOxGPIE[IEn]=1) to propagate
370 	 * the port value to the GPIO Data Register.
371 	 */
372 	if (of_device_is_compatible(np, "fsl,qoriq-gpio") ||
373 	    of_device_is_compatible(np, "fsl,ls1028a-gpio") ||
374 	    of_device_is_compatible(np, "fsl,ls1088a-gpio"))
375 		gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);
376 
377 	ret = gpiochip_add_data(gc, mpc8xxx_gc);
378 	if (ret) {
379 		pr_err("%pOF: GPIO chip registration failed with status %d\n",
380 		       np, ret);
381 		goto err;
382 	}
383 
384 	mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
385 	if (!mpc8xxx_gc->irqn)
386 		return 0;
387 
388 	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
389 					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
390 	if (!mpc8xxx_gc->irq)
391 		return 0;
392 
393 	/* ack and mask all irqs */
394 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
395 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
396 
397 	ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
398 			       mpc8xxx_gpio_irq_cascade,
399 			       IRQF_SHARED, "gpio-cascade",
400 			       mpc8xxx_gc);
401 	if (ret) {
402 		dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret = %d\n",
403 			np->full_name, mpc8xxx_gc->irqn, ret);
404 		goto err;
405 	}
406 
407 	return 0;
408 err:
409 	iounmap(mpc8xxx_gc->regs);
410 	return ret;
411 }
412 
413 static int mpc8xxx_remove(struct platform_device *pdev)
414 {
415 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);
416 
417 	if (mpc8xxx_gc->irq) {
418 		irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, NULL, NULL);
419 		irq_domain_remove(mpc8xxx_gc->irq);
420 	}
421 
422 	gpiochip_remove(&mpc8xxx_gc->gc);
423 	iounmap(mpc8xxx_gc->regs);
424 
425 	return 0;
426 }
427 
428 static struct platform_driver mpc8xxx_plat_driver = {
429 	.probe		= mpc8xxx_probe,
430 	.remove		= mpc8xxx_remove,
431 	.driver		= {
432 		.name = "gpio-mpc8xxx",
433 		.of_match_table	= mpc8xxx_gpio_ids,
434 	},
435 };
436 
437 static int __init mpc8xxx_init(void)
438 {
439 	return platform_driver_register(&mpc8xxx_plat_driver);
440 }
441 
442 arch_initcall(mpc8xxx_init);
443