1 /*
2  * Copyright (C) 2015 Hisilicon Limited, All Rights Reserved.
3  * Author: Jun Ma <majun258@huawei.com>
4  * Author: Yun Wu <wuyun.wu@huawei.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/acpi.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqchip.h>
22 #include <linux/module.h>
23 #include <linux/msi.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_platform.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 
30 /* Interrupt numbers per mbigen node supported */
31 #define IRQS_PER_MBIGEN_NODE		128
32 
33 /* 64 irqs (Pin0-pin63) are reserved for each mbigen chip */
34 #define RESERVED_IRQ_PER_MBIGEN_CHIP	64
35 
36 /* The maximum IRQ pin number of mbigen chip(start from 0) */
37 #define MAXIMUM_IRQ_PIN_NUM		1407
38 
39 /**
40  * In mbigen vector register
41  * bit[21:12]:	event id value
42  * bit[11:0]:	device id
43  */
44 #define IRQ_EVENT_ID_SHIFT		12
45 #define IRQ_EVENT_ID_MASK		0x3ff
46 
47 /* register range of each mbigen node */
48 #define MBIGEN_NODE_OFFSET		0x1000
49 
50 /* offset of vector register in mbigen node */
51 #define REG_MBIGEN_VEC_OFFSET		0x200
52 
53 /**
54  * offset of clear register in mbigen node
55  * This register is used to clear the status
56  * of interrupt
57  */
58 #define REG_MBIGEN_CLEAR_OFFSET		0xa000
59 
60 /**
61  * offset of interrupt type register
62  * This register is used to configure interrupt
63  * trigger type
64  */
65 #define REG_MBIGEN_TYPE_OFFSET		0x0
66 
67 /**
68  * struct mbigen_device - holds the information of mbigen device.
69  *
70  * @pdev:		pointer to the platform device structure of mbigen chip.
71  * @base:		mapped address of this mbigen chip.
72  */
73 struct mbigen_device {
74 	struct platform_device	*pdev;
75 	void __iomem		*base;
76 };
77 
get_mbigen_vec_reg(irq_hw_number_t hwirq)78 static inline unsigned int get_mbigen_vec_reg(irq_hw_number_t hwirq)
79 {
80 	unsigned int nid, pin;
81 
82 	hwirq -= RESERVED_IRQ_PER_MBIGEN_CHIP;
83 	nid = hwirq / IRQS_PER_MBIGEN_NODE + 1;
84 	pin = hwirq % IRQS_PER_MBIGEN_NODE;
85 
86 	return pin * 4 + nid * MBIGEN_NODE_OFFSET
87 			+ REG_MBIGEN_VEC_OFFSET;
88 }
89 
get_mbigen_type_reg(irq_hw_number_t hwirq,u32 * mask,u32 * addr)90 static inline void get_mbigen_type_reg(irq_hw_number_t hwirq,
91 					u32 *mask, u32 *addr)
92 {
93 	unsigned int nid, irq_ofst, ofst;
94 
95 	hwirq -= RESERVED_IRQ_PER_MBIGEN_CHIP;
96 	nid = hwirq / IRQS_PER_MBIGEN_NODE + 1;
97 	irq_ofst = hwirq % IRQS_PER_MBIGEN_NODE;
98 
99 	*mask = 1 << (irq_ofst % 32);
100 	ofst = irq_ofst / 32 * 4;
101 
102 	*addr = ofst + nid * MBIGEN_NODE_OFFSET
103 		+ REG_MBIGEN_TYPE_OFFSET;
104 }
105 
get_mbigen_clear_reg(irq_hw_number_t hwirq,u32 * mask,u32 * addr)106 static inline void get_mbigen_clear_reg(irq_hw_number_t hwirq,
107 					u32 *mask, u32 *addr)
108 {
109 	unsigned int ofst = (hwirq / 32) * 4;
110 
111 	*mask = 1 << (hwirq % 32);
112 	*addr = ofst + REG_MBIGEN_CLEAR_OFFSET;
113 }
114 
mbigen_eoi_irq(struct irq_data * data)115 static void mbigen_eoi_irq(struct irq_data *data)
116 {
117 	void __iomem *base = data->chip_data;
118 	u32 mask, addr;
119 
120 	get_mbigen_clear_reg(data->hwirq, &mask, &addr);
121 
122 	writel_relaxed(mask, base + addr);
123 
124 	irq_chip_eoi_parent(data);
125 }
126 
mbigen_set_type(struct irq_data * data,unsigned int type)127 static int mbigen_set_type(struct irq_data *data, unsigned int type)
128 {
129 	void __iomem *base = data->chip_data;
130 	u32 mask, addr, val;
131 
132 	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
133 		return -EINVAL;
134 
135 	get_mbigen_type_reg(data->hwirq, &mask, &addr);
136 
137 	val = readl_relaxed(base + addr);
138 
139 	if (type == IRQ_TYPE_LEVEL_HIGH)
140 		val |= mask;
141 	else
142 		val &= ~mask;
143 
144 	writel_relaxed(val, base + addr);
145 
146 	return 0;
147 }
148 
149 static struct irq_chip mbigen_irq_chip = {
150 	.name =			"mbigen-v2",
151 	.irq_mask =		irq_chip_mask_parent,
152 	.irq_unmask =		irq_chip_unmask_parent,
153 	.irq_eoi =		mbigen_eoi_irq,
154 	.irq_set_type =		mbigen_set_type,
155 	.irq_set_affinity =	irq_chip_set_affinity_parent,
156 };
157 
mbigen_write_msg(struct msi_desc * desc,struct msi_msg * msg)158 static void mbigen_write_msg(struct msi_desc *desc, struct msi_msg *msg)
159 {
160 	struct irq_data *d = irq_get_irq_data(desc->irq);
161 	void __iomem *base = d->chip_data;
162 	u32 val;
163 
164 	if (!msg->address_lo && !msg->address_hi)
165 		return;
166 
167 	base += get_mbigen_vec_reg(d->hwirq);
168 	val = readl_relaxed(base);
169 
170 	val &= ~(IRQ_EVENT_ID_MASK << IRQ_EVENT_ID_SHIFT);
171 	val |= (msg->data << IRQ_EVENT_ID_SHIFT);
172 
173 	/* The address of doorbell is encoded in mbigen register by default
174 	 * So,we don't need to program the doorbell address at here
175 	 */
176 	writel_relaxed(val, base);
177 }
178 
mbigen_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)179 static int mbigen_domain_translate(struct irq_domain *d,
180 				    struct irq_fwspec *fwspec,
181 				    unsigned long *hwirq,
182 				    unsigned int *type)
183 {
184 	if (is_of_node(fwspec->fwnode) || is_acpi_device_node(fwspec->fwnode)) {
185 		if (fwspec->param_count != 2)
186 			return -EINVAL;
187 
188 		if ((fwspec->param[0] > MAXIMUM_IRQ_PIN_NUM) ||
189 			(fwspec->param[0] < RESERVED_IRQ_PER_MBIGEN_CHIP))
190 			return -EINVAL;
191 		else
192 			*hwirq = fwspec->param[0];
193 
194 		/* If there is no valid irq type, just use the default type */
195 		if ((fwspec->param[1] == IRQ_TYPE_EDGE_RISING) ||
196 			(fwspec->param[1] == IRQ_TYPE_LEVEL_HIGH))
197 			*type = fwspec->param[1];
198 		else
199 			return -EINVAL;
200 
201 		return 0;
202 	}
203 	return -EINVAL;
204 }
205 
mbigen_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)206 static int mbigen_irq_domain_alloc(struct irq_domain *domain,
207 					unsigned int virq,
208 					unsigned int nr_irqs,
209 					void *args)
210 {
211 	struct irq_fwspec *fwspec = args;
212 	irq_hw_number_t hwirq;
213 	unsigned int type;
214 	struct mbigen_device *mgn_chip;
215 	int i, err;
216 
217 	err = mbigen_domain_translate(domain, fwspec, &hwirq, &type);
218 	if (err)
219 		return err;
220 
221 	err = platform_msi_domain_alloc(domain, virq, nr_irqs);
222 	if (err)
223 		return err;
224 
225 	mgn_chip = platform_msi_get_host_data(domain);
226 
227 	for (i = 0; i < nr_irqs; i++)
228 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
229 				      &mbigen_irq_chip, mgn_chip->base);
230 
231 	return 0;
232 }
233 
mbigen_irq_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)234 static void mbigen_irq_domain_free(struct irq_domain *domain, unsigned int virq,
235 				   unsigned int nr_irqs)
236 {
237 	platform_msi_domain_free(domain, virq, nr_irqs);
238 }
239 
240 static const struct irq_domain_ops mbigen_domain_ops = {
241 	.translate	= mbigen_domain_translate,
242 	.alloc		= mbigen_irq_domain_alloc,
243 	.free		= mbigen_irq_domain_free,
244 };
245 
mbigen_of_create_domain(struct platform_device * pdev,struct mbigen_device * mgn_chip)246 static int mbigen_of_create_domain(struct platform_device *pdev,
247 				   struct mbigen_device *mgn_chip)
248 {
249 	struct device *parent;
250 	struct platform_device *child;
251 	struct irq_domain *domain;
252 	struct device_node *np;
253 	u32 num_pins;
254 
255 	for_each_child_of_node(pdev->dev.of_node, np) {
256 		if (!of_property_read_bool(np, "interrupt-controller"))
257 			continue;
258 
259 		parent = platform_bus_type.dev_root;
260 		child = of_platform_device_create(np, NULL, parent);
261 		if (!child)
262 			return -ENOMEM;
263 
264 		if (of_property_read_u32(child->dev.of_node, "num-pins",
265 					 &num_pins) < 0) {
266 			dev_err(&pdev->dev, "No num-pins property\n");
267 			return -EINVAL;
268 		}
269 
270 		domain = platform_msi_create_device_domain(&child->dev, num_pins,
271 							   mbigen_write_msg,
272 							   &mbigen_domain_ops,
273 							   mgn_chip);
274 		if (!domain)
275 			return -ENOMEM;
276 	}
277 
278 	return 0;
279 }
280 
281 #ifdef CONFIG_ACPI
mbigen_acpi_create_domain(struct platform_device * pdev,struct mbigen_device * mgn_chip)282 static int mbigen_acpi_create_domain(struct platform_device *pdev,
283 				     struct mbigen_device *mgn_chip)
284 {
285 	struct irq_domain *domain;
286 	u32 num_pins = 0;
287 	int ret;
288 
289 	/*
290 	 * "num-pins" is the total number of interrupt pins implemented in
291 	 * this mbigen instance, and mbigen is an interrupt controller
292 	 * connected to ITS  converting wired interrupts into MSI, so we
293 	 * use "num-pins" to alloc MSI vectors which are needed by client
294 	 * devices connected to it.
295 	 *
296 	 * Here is the DSDT device node used for mbigen in firmware:
297 	 *	Device(MBI0) {
298 	 *		Name(_HID, "HISI0152")
299 	 *		Name(_UID, Zero)
300 	 *		Name(_CRS, ResourceTemplate() {
301 	 *			Memory32Fixed(ReadWrite, 0xa0080000, 0x10000)
302 	 *		})
303 	 *
304 	 *		Name(_DSD, Package () {
305 	 *			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
306 	 *			Package () {
307 	 *				Package () {"num-pins", 378}
308 	 *			}
309 	 *		})
310 	 *	}
311 	 */
312 	ret = device_property_read_u32(&pdev->dev, "num-pins", &num_pins);
313 	if (ret || num_pins == 0)
314 		return -EINVAL;
315 
316 	domain = platform_msi_create_device_domain(&pdev->dev, num_pins,
317 						   mbigen_write_msg,
318 						   &mbigen_domain_ops,
319 						   mgn_chip);
320 	if (!domain)
321 		return -ENOMEM;
322 
323 	return 0;
324 }
325 #else
mbigen_acpi_create_domain(struct platform_device * pdev,struct mbigen_device * mgn_chip)326 static inline int mbigen_acpi_create_domain(struct platform_device *pdev,
327 					    struct mbigen_device *mgn_chip)
328 {
329 	return -ENODEV;
330 }
331 #endif
332 
mbigen_device_probe(struct platform_device * pdev)333 static int mbigen_device_probe(struct platform_device *pdev)
334 {
335 	struct mbigen_device *mgn_chip;
336 	struct resource *res;
337 	int err;
338 
339 	mgn_chip = devm_kzalloc(&pdev->dev, sizeof(*mgn_chip), GFP_KERNEL);
340 	if (!mgn_chip)
341 		return -ENOMEM;
342 
343 	mgn_chip->pdev = pdev;
344 
345 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
346 	if (!res)
347 		return -EINVAL;
348 
349 	mgn_chip->base = devm_ioremap(&pdev->dev, res->start,
350 				      resource_size(res));
351 	if (!mgn_chip->base) {
352 		dev_err(&pdev->dev, "failed to ioremap %pR\n", res);
353 		return -ENOMEM;
354 	}
355 
356 	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)
357 		err = mbigen_of_create_domain(pdev, mgn_chip);
358 	else if (ACPI_COMPANION(&pdev->dev))
359 		err = mbigen_acpi_create_domain(pdev, mgn_chip);
360 	else
361 		err = -EINVAL;
362 
363 	if (err) {
364 		dev_err(&pdev->dev, "Failed to create mbi-gen@%p irqdomain",
365 			mgn_chip->base);
366 		return err;
367 	}
368 
369 	platform_set_drvdata(pdev, mgn_chip);
370 	return 0;
371 }
372 
373 static const struct of_device_id mbigen_of_match[] = {
374 	{ .compatible = "hisilicon,mbigen-v2" },
375 	{ /* END */ }
376 };
377 MODULE_DEVICE_TABLE(of, mbigen_of_match);
378 
379 static const struct acpi_device_id mbigen_acpi_match[] = {
380 	{ "HISI0152", 0 },
381 	{}
382 };
383 MODULE_DEVICE_TABLE(acpi, mbigen_acpi_match);
384 
385 static struct platform_driver mbigen_platform_driver = {
386 	.driver = {
387 		.name		= "Hisilicon MBIGEN-V2",
388 		.of_match_table	= mbigen_of_match,
389 		.acpi_match_table = ACPI_PTR(mbigen_acpi_match),
390 		.suppress_bind_attrs = true,
391 	},
392 	.probe			= mbigen_device_probe,
393 };
394 
395 module_platform_driver(mbigen_platform_driver);
396 
397 MODULE_AUTHOR("Jun Ma <majun258@huawei.com>");
398 MODULE_AUTHOR("Yun Wu <wuyun.wu@huawei.com>");
399 MODULE_LICENSE("GPL");
400 MODULE_DESCRIPTION("Hisilicon MBI Generator driver");
401