xref: /openbmc/linux/drivers/gpio/gpio-xgene-sb.c (revision 4419617e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AppliedMicro X-Gene SoC GPIO-Standby Driver
4  *
5  * Copyright (c) 2014, Applied Micro Circuits Corporation
6  * Author:	Tin Huynh <tnhuynh@apm.com>.
7  *		Y Vo <yvo@apm.com>.
8  *		Quan Nguyen <qnguyen@apm.com>.
9  */
10 
11 #include <linux/module.h>
12 #include <linux/io.h>
13 #include <linux/platform_device.h>
14 #include <linux/of_gpio.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/acpi.h>
17 
18 #include "gpiolib.h"
19 
20 /* Common property names */
21 #define XGENE_NIRQ_PROPERTY		"apm,nr-irqs"
22 #define XGENE_NGPIO_PROPERTY		"apm,nr-gpios"
23 #define XGENE_IRQ_START_PROPERTY	"apm,irq-start"
24 
25 #define XGENE_DFLT_MAX_NGPIO		22
26 #define XGENE_DFLT_MAX_NIRQ		6
27 #define XGENE_DFLT_IRQ_START_PIN	8
28 #define GPIO_MASK(x)			(1U << ((x) % 32))
29 
30 #define MPA_GPIO_INT_LVL		0x0290
31 #define MPA_GPIO_OE_ADDR		0x029c
32 #define MPA_GPIO_OUT_ADDR		0x02a0
33 #define MPA_GPIO_IN_ADDR 		0x02a4
34 #define MPA_GPIO_SEL_LO 		0x0294
35 
36 #define GPIO_INT_LEVEL_H	0x000001
37 #define GPIO_INT_LEVEL_L	0x000000
38 
39 /**
40  * struct xgene_gpio_sb - GPIO-Standby private data structure.
41  * @gc:				memory-mapped GPIO controllers.
42  * @regs:			GPIO register base offset
43  * @irq_domain:			GPIO interrupt domain
44  * @irq_start:			GPIO pin that start support interrupt
45  * @nirq:			Number of GPIO pins that supports interrupt
46  * @parent_irq_base:		Start parent HWIRQ
47  */
48 struct xgene_gpio_sb {
49 	struct gpio_chip	gc;
50 	void __iomem		*regs;
51 	struct irq_domain	*irq_domain;
52 	u16			irq_start;
53 	u16			nirq;
54 	u16			parent_irq_base;
55 };
56 
57 #define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
58 #define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)
59 
60 static void xgene_gpio_set_bit(struct gpio_chip *gc,
61 				void __iomem *reg, u32 gpio, int val)
62 {
63 	u32 data;
64 
65 	data = gc->read_reg(reg);
66 	if (val)
67 		data |= GPIO_MASK(gpio);
68 	else
69 		data &= ~GPIO_MASK(gpio);
70 	gc->write_reg(reg, data);
71 }
72 
73 static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
74 {
75 	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
76 	int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
77 	int lvl_type = GPIO_INT_LEVEL_H;
78 
79 	switch (type & IRQ_TYPE_SENSE_MASK) {
80 	case IRQ_TYPE_EDGE_RISING:
81 	case IRQ_TYPE_LEVEL_HIGH:
82 		lvl_type = GPIO_INT_LEVEL_H;
83 		break;
84 	case IRQ_TYPE_EDGE_FALLING:
85 	case IRQ_TYPE_LEVEL_LOW:
86 		lvl_type = GPIO_INT_LEVEL_L;
87 		break;
88 	default:
89 		break;
90 	}
91 
92 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
93 			gpio * 2, 1);
94 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
95 			d->hwirq, lvl_type);
96 
97 	/* Propagate IRQ type setting to parent */
98 	if (type & IRQ_TYPE_EDGE_BOTH)
99 		return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
100 	else
101 		return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
102 }
103 
104 static struct irq_chip xgene_gpio_sb_irq_chip = {
105 	.name           = "sbgpio",
106 	.irq_eoi	= irq_chip_eoi_parent,
107 	.irq_mask       = irq_chip_mask_parent,
108 	.irq_unmask     = irq_chip_unmask_parent,
109 	.irq_set_type   = xgene_gpio_sb_irq_set_type,
110 };
111 
112 static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
113 {
114 	struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
115 	struct irq_fwspec fwspec;
116 
117 	if ((gpio < priv->irq_start) ||
118 			(gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
119 		return -ENXIO;
120 
121 	fwspec.fwnode = gc->parent->fwnode;
122 	fwspec.param_count = 2;
123 	fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
124 	fwspec.param[1] = IRQ_TYPE_NONE;
125 	return irq_create_fwspec_mapping(&fwspec);
126 }
127 
128 static int xgene_gpio_sb_domain_activate(struct irq_domain *d,
129 					 struct irq_data *irq_data,
130 					 bool reserve)
131 {
132 	struct xgene_gpio_sb *priv = d->host_data;
133 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
134 	int ret;
135 
136 	ret = gpiochip_lock_as_irq(&priv->gc, gpio);
137 	if (ret) {
138 		dev_err(priv->gc.parent,
139 		"Unable to configure XGene GPIO standby pin %d as IRQ\n",
140 				gpio);
141 		return ret;
142 	}
143 
144 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
145 			gpio * 2, 1);
146 	return 0;
147 }
148 
149 static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
150 		struct irq_data *irq_data)
151 {
152 	struct xgene_gpio_sb *priv = d->host_data;
153 	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
154 
155 	gpiochip_unlock_as_irq(&priv->gc, gpio);
156 	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
157 			gpio * 2, 0);
158 }
159 
160 static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
161 		struct irq_fwspec *fwspec,
162 		unsigned long *hwirq,
163 		unsigned int *type)
164 {
165 	struct xgene_gpio_sb *priv = d->host_data;
166 
167 	if ((fwspec->param_count != 2) ||
168 		(fwspec->param[0] >= priv->nirq))
169 		return -EINVAL;
170 	*hwirq = fwspec->param[0];
171 	*type = fwspec->param[1];
172 	return 0;
173 }
174 
175 static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
176 					unsigned int virq,
177 					unsigned int nr_irqs, void *data)
178 {
179 	struct irq_fwspec *fwspec = data;
180 	struct irq_fwspec parent_fwspec;
181 	struct xgene_gpio_sb *priv = domain->host_data;
182 	irq_hw_number_t hwirq;
183 	unsigned int i;
184 
185 	hwirq = fwspec->param[0];
186 	for (i = 0; i < nr_irqs; i++)
187 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
188 				&xgene_gpio_sb_irq_chip, priv);
189 
190 	parent_fwspec.fwnode = domain->parent->fwnode;
191 	if (is_of_node(parent_fwspec.fwnode)) {
192 		parent_fwspec.param_count = 3;
193 		parent_fwspec.param[0] = 0;/* SPI */
194 		/* Skip SGIs and PPIs*/
195 		parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
196 		parent_fwspec.param[2] = fwspec->param[1];
197 	} else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
198 		parent_fwspec.param_count = 2;
199 		parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
200 		parent_fwspec.param[1] = fwspec->param[1];
201 	} else
202 		return -EINVAL;
203 
204 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
205 			&parent_fwspec);
206 }
207 
208 static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
209 	.translate      = xgene_gpio_sb_domain_translate,
210 	.alloc          = xgene_gpio_sb_domain_alloc,
211 	.free           = irq_domain_free_irqs_common,
212 	.activate	= xgene_gpio_sb_domain_activate,
213 	.deactivate	= xgene_gpio_sb_domain_deactivate,
214 };
215 
216 static int xgene_gpio_sb_probe(struct platform_device *pdev)
217 {
218 	struct xgene_gpio_sb *priv;
219 	int ret;
220 	void __iomem *regs;
221 	struct irq_domain *parent_domain = NULL;
222 	u32 val32;
223 
224 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
225 	if (!priv)
226 		return -ENOMEM;
227 
228 	regs = devm_platform_ioremap_resource(pdev, 0);
229 	if (IS_ERR(regs))
230 		return PTR_ERR(regs);
231 
232 	priv->regs = regs;
233 
234 	ret = platform_get_irq(pdev, 0);
235 	if (ret > 0) {
236 		priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
237 		parent_domain = irq_get_irq_data(ret)->domain;
238 	}
239 	if (!parent_domain) {
240 		dev_err(&pdev->dev, "unable to obtain parent domain\n");
241 		return -ENODEV;
242 	}
243 
244 	ret = bgpio_init(&priv->gc, &pdev->dev, 4,
245 			regs + MPA_GPIO_IN_ADDR,
246 			regs + MPA_GPIO_OUT_ADDR, NULL,
247 			regs + MPA_GPIO_OE_ADDR, NULL, 0);
248         if (ret)
249                 return ret;
250 
251 	priv->gc.to_irq = xgene_gpio_sb_to_irq;
252 
253 	/* Retrieve start irq pin, use default if property not found */
254 	priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
255 	if (!device_property_read_u32(&pdev->dev,
256 					XGENE_IRQ_START_PROPERTY, &val32))
257 		priv->irq_start = val32;
258 
259 	/* Retrieve number irqs, use default if property not found */
260 	priv->nirq = XGENE_DFLT_MAX_NIRQ;
261 	if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
262 		priv->nirq = val32;
263 
264 	/* Retrieve number gpio, use default if property not found */
265 	priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
266 	if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
267 		priv->gc.ngpio = val32;
268 
269 	dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
270 			priv->gc.ngpio, priv->nirq, priv->irq_start);
271 
272 	platform_set_drvdata(pdev, priv);
273 
274 	priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
275 					0, priv->nirq, pdev->dev.fwnode,
276 					&xgene_gpio_sb_domain_ops, priv);
277 	if (!priv->irq_domain)
278 		return -ENODEV;
279 
280 	priv->gc.irq.domain = priv->irq_domain;
281 
282 	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
283 	if (ret) {
284 		dev_err(&pdev->dev,
285 			"failed to register X-Gene GPIO Standby driver\n");
286 		irq_domain_remove(priv->irq_domain);
287 		return ret;
288 	}
289 
290 	dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
291 
292 	if (priv->nirq > 0) {
293 		/* Register interrupt handlers for gpio signaled acpi events */
294 		acpi_gpiochip_request_interrupts(&priv->gc);
295 	}
296 
297 	return ret;
298 }
299 
300 static int xgene_gpio_sb_remove(struct platform_device *pdev)
301 {
302 	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
303 
304 	if (priv->nirq > 0) {
305 		acpi_gpiochip_free_interrupts(&priv->gc);
306 	}
307 
308 	irq_domain_remove(priv->irq_domain);
309 
310 	return 0;
311 }
312 
313 static const struct of_device_id xgene_gpio_sb_of_match[] = {
314 	{.compatible = "apm,xgene-gpio-sb", },
315 	{},
316 };
317 MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
318 
319 #ifdef CONFIG_ACPI
320 static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
321 	{"APMC0D15", 0},
322 	{},
323 };
324 MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
325 #endif
326 
327 static struct platform_driver xgene_gpio_sb_driver = {
328 	.driver = {
329 		   .name = "xgene-gpio-sb",
330 		   .of_match_table = xgene_gpio_sb_of_match,
331 		   .acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
332 		   },
333 	.probe = xgene_gpio_sb_probe,
334 	.remove = xgene_gpio_sb_remove,
335 };
336 module_platform_driver(xgene_gpio_sb_driver);
337 
338 MODULE_AUTHOR("AppliedMicro");
339 MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
340 MODULE_LICENSE("GPL");
341