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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/acpi.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/spinlock.h>
16 #include <linux/io.h>
17 #include <linux/of.h>
18 #include <linux/of_gpio.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_platform.h>
22 #include <linux/property.h>
23 #include <linux/mod_devicetable.h>
24 #include <linux/slab.h>
25 #include <linux/irq.h>
26 #include <linux/gpio/driver.h>
27 #include <linux/bitops.h>
28 #include <linux/interrupt.h>
29 
30 #define MPC8XXX_GPIO_PINS	32
31 
32 #define GPIO_DIR		0x00
33 #define GPIO_ODR		0x04
34 #define GPIO_DAT		0x08
35 #define GPIO_IER		0x0c
36 #define GPIO_IMR		0x10
37 #define GPIO_ICR		0x14
38 #define GPIO_ICR2		0x18
39 #define GPIO_IBE		0x18
40 
41 struct mpc8xxx_gpio_chip {
42 	struct gpio_chip	gc;
43 	void __iomem *regs;
44 	raw_spinlock_t lock;
45 
46 	int (*direction_output)(struct gpio_chip *chip,
47 				unsigned offset, int value);
48 
49 	struct irq_domain *irq;
50 	int irqn;
51 };
52 
53 /*
54  * This hardware has a big endian bit assignment such that GPIO line 0 is
55  * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
56  * This inline helper give the right bitmask for a certain line.
57  */
mpc_pin2mask(unsigned int offset)58 static inline u32 mpc_pin2mask(unsigned int offset)
59 {
60 	return BIT(31 - offset);
61 }
62 
63 /* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
64  * defined as output cannot be determined by reading GPDAT register,
65  * so we use shadow data register instead. The status of input pins
66  * is determined by reading GPDAT register.
67  */
mpc8572_gpio_get(struct gpio_chip * gc,unsigned int gpio)68 static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
69 {
70 	u32 val;
71 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
72 	u32 out_mask, out_shadow;
73 
74 	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
75 	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
76 	out_shadow = gc->bgpio_data & out_mask;
77 
78 	return !!((val | out_shadow) & mpc_pin2mask(gpio));
79 }
80 
mpc5121_gpio_dir_out(struct gpio_chip * gc,unsigned int gpio,int val)81 static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
82 				unsigned int gpio, int val)
83 {
84 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
85 	/* GPIO 28..31 are input only on MPC5121 */
86 	if (gpio >= 28)
87 		return -EINVAL;
88 
89 	return mpc8xxx_gc->direction_output(gc, gpio, val);
90 }
91 
mpc5125_gpio_dir_out(struct gpio_chip * gc,unsigned int gpio,int val)92 static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
93 				unsigned int gpio, int val)
94 {
95 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
96 	/* GPIO 0..3 are input only on MPC5125 */
97 	if (gpio <= 3)
98 		return -EINVAL;
99 
100 	return mpc8xxx_gc->direction_output(gc, gpio, val);
101 }
102 
mpc8xxx_gpio_to_irq(struct gpio_chip * gc,unsigned offset)103 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
104 {
105 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
106 
107 	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
108 		return irq_create_mapping(mpc8xxx_gc->irq, offset);
109 	else
110 		return -ENXIO;
111 }
112 
mpc8xxx_gpio_irq_cascade(int irq,void * data)113 static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
114 {
115 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
116 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
117 	unsigned long mask;
118 	int i;
119 
120 	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
121 		& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
122 	for_each_set_bit(i, &mask, 32)
123 		generic_handle_domain_irq(mpc8xxx_gc->irq, 31 - i);
124 
125 	return IRQ_HANDLED;
126 }
127 
mpc8xxx_irq_unmask(struct irq_data * d)128 static void mpc8xxx_irq_unmask(struct irq_data *d)
129 {
130 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
131 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
132 	unsigned long flags;
133 
134 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
135 
136 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
137 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
138 		| mpc_pin2mask(irqd_to_hwirq(d)));
139 
140 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
141 }
142 
mpc8xxx_irq_mask(struct irq_data * d)143 static void mpc8xxx_irq_mask(struct irq_data *d)
144 {
145 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
146 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
147 	unsigned long flags;
148 
149 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
150 
151 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
152 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
153 		& ~mpc_pin2mask(irqd_to_hwirq(d)));
154 
155 	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
156 }
157 
mpc8xxx_irq_ack(struct irq_data * d)158 static void mpc8xxx_irq_ack(struct irq_data *d)
159 {
160 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
161 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
162 
163 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
164 		      mpc_pin2mask(irqd_to_hwirq(d)));
165 }
166 
mpc8xxx_irq_set_type(struct irq_data * d,unsigned int flow_type)167 static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
168 {
169 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
170 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
171 	unsigned long flags;
172 
173 	switch (flow_type) {
174 	case IRQ_TYPE_EDGE_FALLING:
175 	case IRQ_TYPE_LEVEL_LOW:
176 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
177 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
178 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
179 			| mpc_pin2mask(irqd_to_hwirq(d)));
180 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
181 		break;
182 
183 	case IRQ_TYPE_EDGE_BOTH:
184 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
185 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
186 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
187 			& ~mpc_pin2mask(irqd_to_hwirq(d)));
188 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
189 		break;
190 
191 	default:
192 		return -EINVAL;
193 	}
194 
195 	return 0;
196 }
197 
mpc512x_irq_set_type(struct irq_data * d,unsigned int flow_type)198 static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
199 {
200 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
201 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
202 	unsigned long gpio = irqd_to_hwirq(d);
203 	void __iomem *reg;
204 	unsigned int shift;
205 	unsigned long flags;
206 
207 	if (gpio < 16) {
208 		reg = mpc8xxx_gc->regs + GPIO_ICR;
209 		shift = (15 - gpio) * 2;
210 	} else {
211 		reg = mpc8xxx_gc->regs + GPIO_ICR2;
212 		shift = (15 - (gpio % 16)) * 2;
213 	}
214 
215 	switch (flow_type) {
216 	case IRQ_TYPE_EDGE_FALLING:
217 	case IRQ_TYPE_LEVEL_LOW:
218 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
219 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
220 			| (2 << shift));
221 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
222 		break;
223 
224 	case IRQ_TYPE_EDGE_RISING:
225 	case IRQ_TYPE_LEVEL_HIGH:
226 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
227 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
228 			| (1 << shift));
229 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
230 		break;
231 
232 	case IRQ_TYPE_EDGE_BOTH:
233 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
234 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
235 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
236 		break;
237 
238 	default:
239 		return -EINVAL;
240 	}
241 
242 	return 0;
243 }
244 
245 static struct irq_chip mpc8xxx_irq_chip = {
246 	.name		= "mpc8xxx-gpio",
247 	.irq_unmask	= mpc8xxx_irq_unmask,
248 	.irq_mask	= mpc8xxx_irq_mask,
249 	.irq_ack	= mpc8xxx_irq_ack,
250 	/* this might get overwritten in mpc8xxx_probe() */
251 	.irq_set_type	= mpc8xxx_irq_set_type,
252 };
253 
mpc8xxx_gpio_irq_map(struct irq_domain * h,unsigned int irq,irq_hw_number_t hwirq)254 static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
255 				irq_hw_number_t hwirq)
256 {
257 	irq_set_chip_data(irq, h->host_data);
258 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);
259 
260 	return 0;
261 }
262 
263 static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
264 	.map	= mpc8xxx_gpio_irq_map,
265 	.xlate	= irq_domain_xlate_twocell,
266 };
267 
268 struct mpc8xxx_gpio_devtype {
269 	int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
270 	int (*gpio_get)(struct gpio_chip *, unsigned int);
271 	int (*irq_set_type)(struct irq_data *, unsigned int);
272 };
273 
274 static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
275 	.gpio_dir_out = mpc5121_gpio_dir_out,
276 	.irq_set_type = mpc512x_irq_set_type,
277 };
278 
279 static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
280 	.gpio_dir_out = mpc5125_gpio_dir_out,
281 	.irq_set_type = mpc512x_irq_set_type,
282 };
283 
284 static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
285 	.gpio_get = mpc8572_gpio_get,
286 };
287 
288 static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
289 	.irq_set_type = mpc8xxx_irq_set_type,
290 };
291 
292 static const struct of_device_id mpc8xxx_gpio_ids[] = {
293 	{ .compatible = "fsl,mpc8349-gpio", },
294 	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
295 	{ .compatible = "fsl,mpc8610-gpio", },
296 	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
297 	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
298 	{ .compatible = "fsl,pq3-gpio",     },
299 	{ .compatible = "fsl,ls1028a-gpio", },
300 	{ .compatible = "fsl,ls1088a-gpio", },
301 	{ .compatible = "fsl,qoriq-gpio",   },
302 	{}
303 };
304 
mpc8xxx_probe(struct platform_device * pdev)305 static int mpc8xxx_probe(struct platform_device *pdev)
306 {
307 	struct device_node *np = pdev->dev.of_node;
308 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
309 	struct gpio_chip	*gc;
310 	const struct mpc8xxx_gpio_devtype *devtype = NULL;
311 	struct fwnode_handle *fwnode;
312 	int ret;
313 
314 	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
315 	if (!mpc8xxx_gc)
316 		return -ENOMEM;
317 
318 	platform_set_drvdata(pdev, mpc8xxx_gc);
319 
320 	raw_spin_lock_init(&mpc8xxx_gc->lock);
321 
322 	mpc8xxx_gc->regs = devm_platform_ioremap_resource(pdev, 0);
323 	if (IS_ERR(mpc8xxx_gc->regs))
324 		return PTR_ERR(mpc8xxx_gc->regs);
325 
326 	gc = &mpc8xxx_gc->gc;
327 	gc->parent = &pdev->dev;
328 
329 	if (device_property_read_bool(&pdev->dev, "little-endian")) {
330 		ret = bgpio_init(gc, &pdev->dev, 4,
331 				 mpc8xxx_gc->regs + GPIO_DAT,
332 				 NULL, NULL,
333 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
334 				 BGPIOF_BIG_ENDIAN);
335 		if (ret)
336 			return ret;
337 		dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
338 	} else {
339 		ret = bgpio_init(gc, &pdev->dev, 4,
340 				 mpc8xxx_gc->regs + GPIO_DAT,
341 				 NULL, NULL,
342 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
343 				 BGPIOF_BIG_ENDIAN
344 				 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
345 		if (ret)
346 			return ret;
347 		dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
348 	}
349 
350 	mpc8xxx_gc->direction_output = gc->direction_output;
351 
352 	devtype = device_get_match_data(&pdev->dev);
353 	if (!devtype)
354 		devtype = &mpc8xxx_gpio_devtype_default;
355 
356 	/*
357 	 * It's assumed that only a single type of gpio controller is available
358 	 * on the current machine, so overwriting global data is fine.
359 	 */
360 	if (devtype->irq_set_type)
361 		mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
362 
363 	if (devtype->gpio_dir_out)
364 		gc->direction_output = devtype->gpio_dir_out;
365 	if (devtype->gpio_get)
366 		gc->get = devtype->gpio_get;
367 
368 	gc->to_irq = mpc8xxx_gpio_to_irq;
369 
370 	/*
371 	 * The GPIO Input Buffer Enable register(GPIO_IBE) is used to control
372 	 * the input enable of each individual GPIO port.  When an individual
373 	 * GPIO port’s direction is set to input (GPIO_GPDIR[DRn=0]), the
374 	 * associated input enable must be set (GPIOxGPIE[IEn]=1) to propagate
375 	 * the port value to the GPIO Data Register.
376 	 */
377 	fwnode = dev_fwnode(&pdev->dev);
378 	if (of_device_is_compatible(np, "fsl,qoriq-gpio") ||
379 	    of_device_is_compatible(np, "fsl,ls1028a-gpio") ||
380 	    of_device_is_compatible(np, "fsl,ls1088a-gpio") ||
381 	    is_acpi_node(fwnode))
382 		gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);
383 
384 	ret = devm_gpiochip_add_data(&pdev->dev, gc, mpc8xxx_gc);
385 	if (ret) {
386 		dev_err(&pdev->dev,
387 			"GPIO chip registration failed with status %d\n", ret);
388 		return ret;
389 	}
390 
391 	mpc8xxx_gc->irqn = platform_get_irq(pdev, 0);
392 	if (mpc8xxx_gc->irqn < 0)
393 		return mpc8xxx_gc->irqn;
394 
395 	mpc8xxx_gc->irq = irq_domain_create_linear(fwnode,
396 						   MPC8XXX_GPIO_PINS,
397 						   &mpc8xxx_gpio_irq_ops,
398 						   mpc8xxx_gc);
399 
400 	if (!mpc8xxx_gc->irq)
401 		return 0;
402 
403 	/* ack and mask all irqs */
404 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
405 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
406 
407 	ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
408 			       mpc8xxx_gpio_irq_cascade,
409 			       IRQF_NO_THREAD | IRQF_SHARED, "gpio-cascade",
410 			       mpc8xxx_gc);
411 	if (ret) {
412 		dev_err(&pdev->dev,
413 			"failed to devm_request_irq(%d), ret = %d\n",
414 			mpc8xxx_gc->irqn, ret);
415 		goto err;
416 	}
417 
418 	return 0;
419 err:
420 	irq_domain_remove(mpc8xxx_gc->irq);
421 	return ret;
422 }
423 
mpc8xxx_remove(struct platform_device * pdev)424 static int mpc8xxx_remove(struct platform_device *pdev)
425 {
426 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);
427 
428 	if (mpc8xxx_gc->irq) {
429 		irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, NULL, NULL);
430 		irq_domain_remove(mpc8xxx_gc->irq);
431 	}
432 
433 	return 0;
434 }
435 
436 #ifdef CONFIG_ACPI
437 static const struct acpi_device_id gpio_acpi_ids[] = {
438 	{"NXP0031",},
439 	{ }
440 };
441 MODULE_DEVICE_TABLE(acpi, gpio_acpi_ids);
442 #endif
443 
444 static struct platform_driver mpc8xxx_plat_driver = {
445 	.probe		= mpc8xxx_probe,
446 	.remove		= mpc8xxx_remove,
447 	.driver		= {
448 		.name = "gpio-mpc8xxx",
449 		.of_match_table	= mpc8xxx_gpio_ids,
450 		.acpi_match_table = ACPI_PTR(gpio_acpi_ids),
451 	},
452 };
453 
mpc8xxx_init(void)454 static int __init mpc8xxx_init(void)
455 {
456 	return platform_driver_register(&mpc8xxx_plat_driver);
457 }
458 
459 arch_initcall(mpc8xxx_init);
460