xref: /openbmc/linux/drivers/gpio/gpio-xgene-sb.c (revision be709d48)
1 /*
2  * AppliedMicro X-Gene SoC GPIO-Standby Driver
3  *
4  * Copyright (c) 2014, Applied Micro Circuits Corporation
5  * Author:	Tin Huynh <tnhuynh@apm.com>.
6  *		Y Vo <yvo@apm.com>.
7  *		Quan Nguyen <qnguyen@apm.com>.
8  *
9  * This program is free software; you can redistribute  it and/or modify it
10  * under  the terms of  the GNU General  Public License as published by the
11  * Free Software Foundation;  either version 2 of the  License, or (at your
12  * option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include <linux/module.h>
24 #include <linux/io.h>
25 #include <linux/platform_device.h>
26 #include <linux/of_gpio.h>
27 #include <linux/gpio/driver.h>
28 #include <linux/acpi.h>
29 
30 #include "gpiolib.h"
31 
32 /* Common property names */
33 #define XGENE_NIRQ_PROPERTY		"apm,nr-irqs"
34 #define XGENE_NGPIO_PROPERTY		"apm,nr-gpios"
35 #define XGENE_IRQ_START_PROPERTY	"apm,irq-start"
36 
37 #define XGENE_DFLT_MAX_NGPIO		22
38 #define XGENE_DFLT_MAX_NIRQ		6
39 #define XGENE_DFLT_IRQ_START_PIN	8
40 #define GPIO_MASK(x)			(1U << ((x) % 32))
41 
42 #define MPA_GPIO_INT_LVL		0x0290
43 #define MPA_GPIO_OE_ADDR		0x029c
44 #define MPA_GPIO_OUT_ADDR		0x02a0
45 #define MPA_GPIO_IN_ADDR 		0x02a4
46 #define MPA_GPIO_SEL_LO 		0x0294
47 
48 #define GPIO_INT_LEVEL_H	0x000001
49 #define GPIO_INT_LEVEL_L	0x000000
50 
51 /**
52  * struct xgene_gpio_sb - GPIO-Standby private data structure.
53  * @gc:				memory-mapped GPIO controllers.
54  * @regs:			GPIO register base offset
55  * @irq_domain:			GPIO interrupt domain
56  * @irq_start:			GPIO pin that start support interrupt
57  * @nirq:			Number of GPIO pins that supports interrupt
58  * @parent_irq_base:		Start parent HWIRQ
59  */
60 struct xgene_gpio_sb {
61 	struct gpio_chip	gc;
62 	void __iomem		*regs;
63 	struct irq_domain	*irq_domain;
64 	u16			irq_start;
65 	u16			nirq;
66 	u16			parent_irq_base;
67 };
68 
69 #define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
70 #define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)
71 
72 static void xgene_gpio_set_bit(struct gpio_chip *gc,
73 				void __iomem *reg, u32 gpio, int val)
74 {
75 	u32 data;
76 
77 	data = gc->read_reg(reg);
78 	if (val)
79 		data |= GPIO_MASK(gpio);
80 	else
81 		data &= ~GPIO_MASK(gpio);
82 	gc->write_reg(reg, data);
83 }
84 
85 static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
86 {
87 	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
88 	int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
89 	int lvl_type = GPIO_INT_LEVEL_H;
90 
91 	switch (type & IRQ_TYPE_SENSE_MASK) {
92 	case IRQ_TYPE_EDGE_RISING:
93 	case IRQ_TYPE_LEVEL_HIGH:
94 		lvl_type = GPIO_INT_LEVEL_H;
95 		break;
96 	case IRQ_TYPE_EDGE_FALLING:
97 	case IRQ_TYPE_LEVEL_LOW:
98 		lvl_type = GPIO_INT_LEVEL_L;
99 		break;
100 	default:
101 		break;
102 	}
103 
104 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
105 			gpio * 2, 1);
106 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
107 			d->hwirq, lvl_type);
108 
109 	/* Propagate IRQ type setting to parent */
110 	if (type & IRQ_TYPE_EDGE_BOTH)
111 		return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
112 	else
113 		return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
114 }
115 
116 static struct irq_chip xgene_gpio_sb_irq_chip = {
117 	.name           = "sbgpio",
118 	.irq_eoi	= irq_chip_eoi_parent,
119 	.irq_mask       = irq_chip_mask_parent,
120 	.irq_unmask     = irq_chip_unmask_parent,
121 	.irq_set_type   = xgene_gpio_sb_irq_set_type,
122 };
123 
124 static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
125 {
126 	struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
127 	struct irq_fwspec fwspec;
128 
129 	if ((gpio < priv->irq_start) ||
130 			(gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
131 		return -ENXIO;
132 
133 	fwspec.fwnode = gc->parent->fwnode;
134 	fwspec.param_count = 2;
135 	fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
136 	fwspec.param[1] = IRQ_TYPE_NONE;
137 	return irq_create_fwspec_mapping(&fwspec);
138 }
139 
140 static int xgene_gpio_sb_domain_activate(struct irq_domain *d,
141 					 struct irq_data *irq_data,
142 					 bool reserve)
143 {
144 	struct xgene_gpio_sb *priv = d->host_data;
145 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
146 	int ret;
147 
148 	ret = gpiochip_lock_as_irq(&priv->gc, gpio);
149 	if (ret) {
150 		dev_err(priv->gc.parent,
151 		"Unable to configure XGene GPIO standby pin %d as IRQ\n",
152 				gpio);
153 		return ret;
154 	}
155 
156 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
157 			gpio * 2, 1);
158 	return 0;
159 }
160 
161 static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
162 		struct irq_data *irq_data)
163 {
164 	struct xgene_gpio_sb *priv = d->host_data;
165 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
166 
167 	gpiochip_unlock_as_irq(&priv->gc, gpio);
168 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
169 			gpio * 2, 0);
170 }
171 
172 static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
173 		struct irq_fwspec *fwspec,
174 		unsigned long *hwirq,
175 		unsigned int *type)
176 {
177 	struct xgene_gpio_sb *priv = d->host_data;
178 
179 	if ((fwspec->param_count != 2) ||
180 		(fwspec->param[0] >= priv->nirq))
181 		return -EINVAL;
182 	*hwirq = fwspec->param[0];
183 	*type = fwspec->param[1];
184 	return 0;
185 }
186 
187 static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
188 					unsigned int virq,
189 					unsigned int nr_irqs, void *data)
190 {
191 	struct irq_fwspec *fwspec = data;
192 	struct irq_fwspec parent_fwspec;
193 	struct xgene_gpio_sb *priv = domain->host_data;
194 	irq_hw_number_t hwirq;
195 	unsigned int i;
196 
197 	hwirq = fwspec->param[0];
198 	for (i = 0; i < nr_irqs; i++)
199 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
200 				&xgene_gpio_sb_irq_chip, priv);
201 
202 	parent_fwspec.fwnode = domain->parent->fwnode;
203 	if (is_of_node(parent_fwspec.fwnode)) {
204 		parent_fwspec.param_count = 3;
205 		parent_fwspec.param[0] = 0;/* SPI */
206 		/* Skip SGIs and PPIs*/
207 		parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
208 		parent_fwspec.param[2] = fwspec->param[1];
209 	} else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
210 		parent_fwspec.param_count = 2;
211 		parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
212 		parent_fwspec.param[1] = fwspec->param[1];
213 	} else
214 		return -EINVAL;
215 
216 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
217 			&parent_fwspec);
218 }
219 
220 static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
221 	.translate      = xgene_gpio_sb_domain_translate,
222 	.alloc          = xgene_gpio_sb_domain_alloc,
223 	.free           = irq_domain_free_irqs_common,
224 	.activate	= xgene_gpio_sb_domain_activate,
225 	.deactivate	= xgene_gpio_sb_domain_deactivate,
226 };
227 
228 static int xgene_gpio_sb_probe(struct platform_device *pdev)
229 {
230 	struct xgene_gpio_sb *priv;
231 	int ret;
232 	struct resource *res;
233 	void __iomem *regs;
234 	struct irq_domain *parent_domain = NULL;
235 	u32 val32;
236 
237 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
238 	if (!priv)
239 		return -ENOMEM;
240 
241 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
242 	regs = devm_ioremap_resource(&pdev->dev, res);
243 	if (IS_ERR(regs))
244 		return PTR_ERR(regs);
245 
246 	priv->regs = regs;
247 
248 	ret = platform_get_irq(pdev, 0);
249 	if (ret > 0) {
250 		priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
251 		parent_domain = irq_get_irq_data(ret)->domain;
252 	}
253 	if (!parent_domain) {
254 		dev_err(&pdev->dev, "unable to obtain parent domain\n");
255 		return -ENODEV;
256 	}
257 
258 	ret = bgpio_init(&priv->gc, &pdev->dev, 4,
259 			regs + MPA_GPIO_IN_ADDR,
260 			regs + MPA_GPIO_OUT_ADDR, NULL,
261 			regs + MPA_GPIO_OE_ADDR, NULL, 0);
262         if (ret)
263                 return ret;
264 
265 	priv->gc.to_irq = xgene_gpio_sb_to_irq;
266 
267 	/* Retrieve start irq pin, use default if property not found */
268 	priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
269 	if (!device_property_read_u32(&pdev->dev,
270 					XGENE_IRQ_START_PROPERTY, &val32))
271 		priv->irq_start = val32;
272 
273 	/* Retrieve number irqs, use default if property not found */
274 	priv->nirq = XGENE_DFLT_MAX_NIRQ;
275 	if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
276 		priv->nirq = val32;
277 
278 	/* Retrieve number gpio, use default if property not found */
279 	priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
280 	if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
281 		priv->gc.ngpio = val32;
282 
283 	dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
284 			priv->gc.ngpio, priv->nirq, priv->irq_start);
285 
286 	platform_set_drvdata(pdev, priv);
287 
288 	priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
289 					0, priv->nirq, pdev->dev.fwnode,
290 					&xgene_gpio_sb_domain_ops, priv);
291 	if (!priv->irq_domain)
292 		return -ENODEV;
293 
294 	priv->gc.irq.domain = priv->irq_domain;
295 
296 	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
297 	if (ret) {
298 		dev_err(&pdev->dev,
299 			"failed to register X-Gene GPIO Standby driver\n");
300 		irq_domain_remove(priv->irq_domain);
301 		return ret;
302 	}
303 
304 	dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
305 
306 	if (priv->nirq > 0) {
307 		/* Register interrupt handlers for gpio signaled acpi events */
308 		acpi_gpiochip_request_interrupts(&priv->gc);
309 	}
310 
311 	return ret;
312 }
313 
314 static int xgene_gpio_sb_remove(struct platform_device *pdev)
315 {
316 	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
317 
318 	if (priv->nirq > 0) {
319 		acpi_gpiochip_free_interrupts(&priv->gc);
320 	}
321 
322 	irq_domain_remove(priv->irq_domain);
323 
324 	return 0;
325 }
326 
327 static const struct of_device_id xgene_gpio_sb_of_match[] = {
328 	{.compatible = "apm,xgene-gpio-sb", },
329 	{},
330 };
331 MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
332 
333 #ifdef CONFIG_ACPI
334 static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
335 	{"APMC0D15", 0},
336 	{},
337 };
338 MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
339 #endif
340 
341 static struct platform_driver xgene_gpio_sb_driver = {
342 	.driver = {
343 		   .name = "xgene-gpio-sb",
344 		   .of_match_table = xgene_gpio_sb_of_match,
345 		   .acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
346 		   },
347 	.probe = xgene_gpio_sb_probe,
348 	.remove = xgene_gpio_sb_remove,
349 };
350 module_platform_driver(xgene_gpio_sb_driver);
351 
352 MODULE_AUTHOR("AppliedMicro");
353 MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
354 MODULE_LICENSE("GPL");
355