xref: /openbmc/linux/drivers/gpio/gpio-mpc8xxx.c (revision e2c75e76)
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 
26 #define MPC8XXX_GPIO_PINS	32
27 
28 #define GPIO_DIR		0x00
29 #define GPIO_ODR		0x04
30 #define GPIO_DAT		0x08
31 #define GPIO_IER		0x0c
32 #define GPIO_IMR		0x10
33 #define GPIO_ICR		0x14
34 #define GPIO_ICR2		0x18
35 
36 struct mpc8xxx_gpio_chip {
37 	struct gpio_chip	gc;
38 	void __iomem *regs;
39 	raw_spinlock_t lock;
40 
41 	int (*direction_output)(struct gpio_chip *chip,
42 				unsigned offset, int value);
43 
44 	struct irq_domain *irq;
45 	unsigned int irqn;
46 };
47 
48 /*
49  * This hardware has a big endian bit assignment such that GPIO line 0 is
50  * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
51  * This inline helper give the right bitmask for a certain line.
52  */
53 static inline u32 mpc_pin2mask(unsigned int offset)
54 {
55 	return BIT(31 - offset);
56 }
57 
58 /* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
59  * defined as output cannot be determined by reading GPDAT register,
60  * so we use shadow data register instead. The status of input pins
61  * is determined by reading GPDAT register.
62  */
63 static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
64 {
65 	u32 val;
66 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
67 	u32 out_mask, out_shadow;
68 
69 	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
70 	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
71 	out_shadow = gc->bgpio_data & out_mask;
72 
73 	return !!((val | out_shadow) & mpc_pin2mask(gpio));
74 }
75 
76 static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
77 				unsigned int gpio, int val)
78 {
79 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
80 	/* GPIO 28..31 are input only on MPC5121 */
81 	if (gpio >= 28)
82 		return -EINVAL;
83 
84 	return mpc8xxx_gc->direction_output(gc, gpio, val);
85 }
86 
87 static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
88 				unsigned int gpio, int val)
89 {
90 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
91 	/* GPIO 0..3 are input only on MPC5125 */
92 	if (gpio <= 3)
93 		return -EINVAL;
94 
95 	return mpc8xxx_gc->direction_output(gc, gpio, val);
96 }
97 
98 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
99 {
100 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
101 
102 	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
103 		return irq_create_mapping(mpc8xxx_gc->irq, offset);
104 	else
105 		return -ENXIO;
106 }
107 
108 static void mpc8xxx_gpio_irq_cascade(struct irq_desc *desc)
109 {
110 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
111 	struct irq_chip *chip = irq_desc_get_chip(desc);
112 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
113 	unsigned int mask;
114 
115 	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
116 		& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
117 	if (mask)
118 		generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
119 						     32 - ffs(mask)));
120 	if (chip->irq_eoi)
121 		chip->irq_eoi(&desc->irq_data);
122 }
123 
124 static void mpc8xxx_irq_unmask(struct irq_data *d)
125 {
126 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
127 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
128 	unsigned long flags;
129 
130 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
131 
132 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
133 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
134 		| mpc_pin2mask(irqd_to_hwirq(d)));
135 
136 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
137 }
138 
139 static void mpc8xxx_irq_mask(struct irq_data *d)
140 {
141 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
142 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
143 	unsigned long flags;
144 
145 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
146 
147 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
148 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
149 		& ~mpc_pin2mask(irqd_to_hwirq(d)));
150 
151 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
152 }
153 
154 static void mpc8xxx_irq_ack(struct irq_data *d)
155 {
156 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
157 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
158 
159 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
160 		      mpc_pin2mask(irqd_to_hwirq(d)));
161 }
162 
163 static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
164 {
165 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
166 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
167 	unsigned long flags;
168 
169 	switch (flow_type) {
170 	case IRQ_TYPE_EDGE_FALLING:
171 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
172 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
173 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
174 			| mpc_pin2mask(irqd_to_hwirq(d)));
175 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
176 		break;
177 
178 	case IRQ_TYPE_EDGE_BOTH:
179 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
180 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
181 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
182 			& ~mpc_pin2mask(irqd_to_hwirq(d)));
183 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
184 		break;
185 
186 	default:
187 		return -EINVAL;
188 	}
189 
190 	return 0;
191 }
192 
193 static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
194 {
195 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
196 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
197 	unsigned long gpio = irqd_to_hwirq(d);
198 	void __iomem *reg;
199 	unsigned int shift;
200 	unsigned long flags;
201 
202 	if (gpio < 16) {
203 		reg = mpc8xxx_gc->regs + GPIO_ICR;
204 		shift = (15 - gpio) * 2;
205 	} else {
206 		reg = mpc8xxx_gc->regs + GPIO_ICR2;
207 		shift = (15 - (gpio % 16)) * 2;
208 	}
209 
210 	switch (flow_type) {
211 	case IRQ_TYPE_EDGE_FALLING:
212 	case IRQ_TYPE_LEVEL_LOW:
213 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
214 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
215 			| (2 << shift));
216 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
217 		break;
218 
219 	case IRQ_TYPE_EDGE_RISING:
220 	case IRQ_TYPE_LEVEL_HIGH:
221 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
222 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
223 			| (1 << shift));
224 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
225 		break;
226 
227 	case IRQ_TYPE_EDGE_BOTH:
228 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
229 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
230 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
231 		break;
232 
233 	default:
234 		return -EINVAL;
235 	}
236 
237 	return 0;
238 }
239 
240 static struct irq_chip mpc8xxx_irq_chip = {
241 	.name		= "mpc8xxx-gpio",
242 	.irq_unmask	= mpc8xxx_irq_unmask,
243 	.irq_mask	= mpc8xxx_irq_mask,
244 	.irq_ack	= mpc8xxx_irq_ack,
245 	/* this might get overwritten in mpc8xxx_probe() */
246 	.irq_set_type	= mpc8xxx_irq_set_type,
247 };
248 
249 static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
250 				irq_hw_number_t hwirq)
251 {
252 	irq_set_chip_data(irq, h->host_data);
253 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);
254 
255 	return 0;
256 }
257 
258 static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
259 	.map	= mpc8xxx_gpio_irq_map,
260 	.xlate	= irq_domain_xlate_twocell,
261 };
262 
263 struct mpc8xxx_gpio_devtype {
264 	int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
265 	int (*gpio_get)(struct gpio_chip *, unsigned int);
266 	int (*irq_set_type)(struct irq_data *, unsigned int);
267 };
268 
269 static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
270 	.gpio_dir_out = mpc5121_gpio_dir_out,
271 	.irq_set_type = mpc512x_irq_set_type,
272 };
273 
274 static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
275 	.gpio_dir_out = mpc5125_gpio_dir_out,
276 	.irq_set_type = mpc512x_irq_set_type,
277 };
278 
279 static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
280 	.gpio_get = mpc8572_gpio_get,
281 };
282 
283 static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
284 	.irq_set_type = mpc8xxx_irq_set_type,
285 };
286 
287 static const struct of_device_id mpc8xxx_gpio_ids[] = {
288 	{ .compatible = "fsl,mpc8349-gpio", },
289 	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
290 	{ .compatible = "fsl,mpc8610-gpio", },
291 	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
292 	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
293 	{ .compatible = "fsl,pq3-gpio",     },
294 	{ .compatible = "fsl,qoriq-gpio",   },
295 	{}
296 };
297 
298 static int mpc8xxx_probe(struct platform_device *pdev)
299 {
300 	struct device_node *np = pdev->dev.of_node;
301 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
302 	struct gpio_chip	*gc;
303 	const struct mpc8xxx_gpio_devtype *devtype =
304 		of_device_get_match_data(&pdev->dev);
305 	int ret;
306 
307 	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
308 	if (!mpc8xxx_gc)
309 		return -ENOMEM;
310 
311 	platform_set_drvdata(pdev, mpc8xxx_gc);
312 
313 	raw_spin_lock_init(&mpc8xxx_gc->lock);
314 
315 	mpc8xxx_gc->regs = of_iomap(np, 0);
316 	if (!mpc8xxx_gc->regs)
317 		return -ENOMEM;
318 
319 	gc = &mpc8xxx_gc->gc;
320 
321 	if (of_property_read_bool(np, "little-endian")) {
322 		ret = bgpio_init(gc, &pdev->dev, 4,
323 				 mpc8xxx_gc->regs + GPIO_DAT,
324 				 NULL, NULL,
325 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
326 				 BGPIOF_BIG_ENDIAN);
327 		if (ret)
328 			goto err;
329 		dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
330 	} else {
331 		ret = bgpio_init(gc, &pdev->dev, 4,
332 				 mpc8xxx_gc->regs + GPIO_DAT,
333 				 NULL, NULL,
334 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
335 				 BGPIOF_BIG_ENDIAN
336 				 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
337 		if (ret)
338 			goto err;
339 		dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
340 	}
341 
342 	mpc8xxx_gc->direction_output = gc->direction_output;
343 
344 	if (!devtype)
345 		devtype = &mpc8xxx_gpio_devtype_default;
346 
347 	/*
348 	 * It's assumed that only a single type of gpio controller is available
349 	 * on the current machine, so overwriting global data is fine.
350 	 */
351 	mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
352 
353 	if (devtype->gpio_dir_out)
354 		gc->direction_output = devtype->gpio_dir_out;
355 	if (devtype->gpio_get)
356 		gc->get = devtype->gpio_get;
357 
358 	gc->to_irq = mpc8xxx_gpio_to_irq;
359 
360 	ret = gpiochip_add_data(gc, mpc8xxx_gc);
361 	if (ret) {
362 		pr_err("%pOF: GPIO chip registration failed with status %d\n",
363 		       np, ret);
364 		goto err;
365 	}
366 
367 	mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
368 	if (!mpc8xxx_gc->irqn)
369 		return 0;
370 
371 	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
372 					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
373 	if (!mpc8xxx_gc->irq)
374 		return 0;
375 
376 	/* ack and mask all irqs */
377 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
378 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
379 
380 	irq_set_chained_handler_and_data(mpc8xxx_gc->irqn,
381 					 mpc8xxx_gpio_irq_cascade, mpc8xxx_gc);
382 	return 0;
383 err:
384 	iounmap(mpc8xxx_gc->regs);
385 	return ret;
386 }
387 
388 static int mpc8xxx_remove(struct platform_device *pdev)
389 {
390 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);
391 
392 	if (mpc8xxx_gc->irq) {
393 		irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, NULL, NULL);
394 		irq_domain_remove(mpc8xxx_gc->irq);
395 	}
396 
397 	gpiochip_remove(&mpc8xxx_gc->gc);
398 	iounmap(mpc8xxx_gc->regs);
399 
400 	return 0;
401 }
402 
403 static struct platform_driver mpc8xxx_plat_driver = {
404 	.probe		= mpc8xxx_probe,
405 	.remove		= mpc8xxx_remove,
406 	.driver		= {
407 		.name = "gpio-mpc8xxx",
408 		.of_match_table	= mpc8xxx_gpio_ids,
409 	},
410 };
411 
412 static int __init mpc8xxx_init(void)
413 {
414 	return platform_driver_register(&mpc8xxx_plat_driver);
415 }
416 
417 arch_initcall(mpc8xxx_init);
418