xref: /openbmc/linux/drivers/mfd/vexpress-sysreg.c (revision f35e839a)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License version 2 as
4  * published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  * GNU General Public License for more details.
10  *
11  * Copyright (C) 2012 ARM Limited
12  */
13 
14 #include <linux/err.h>
15 #include <linux/gpio.h>
16 #include <linux/io.h>
17 #include <linux/leds.h>
18 #include <linux/of_address.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/driver.h>
21 #include <linux/slab.h>
22 #include <linux/stat.h>
23 #include <linux/timer.h>
24 #include <linux/vexpress.h>
25 
26 #define SYS_ID			0x000
27 #define SYS_SW			0x004
28 #define SYS_LED			0x008
29 #define SYS_100HZ		0x024
30 #define SYS_FLAGS		0x030
31 #define SYS_FLAGSSET		0x030
32 #define SYS_FLAGSCLR		0x034
33 #define SYS_NVFLAGS		0x038
34 #define SYS_NVFLAGSSET		0x038
35 #define SYS_NVFLAGSCLR		0x03c
36 #define SYS_MCI			0x048
37 #define SYS_FLASH		0x04c
38 #define SYS_CFGSW		0x058
39 #define SYS_24MHZ		0x05c
40 #define SYS_MISC		0x060
41 #define SYS_DMA			0x064
42 #define SYS_PROCID0		0x084
43 #define SYS_PROCID1		0x088
44 #define SYS_CFGDATA		0x0a0
45 #define SYS_CFGCTRL		0x0a4
46 #define SYS_CFGSTAT		0x0a8
47 
48 #define SYS_HBI_MASK		0xfff
49 #define SYS_ID_HBI_SHIFT	16
50 #define SYS_PROCIDx_HBI_SHIFT	0
51 
52 #define SYS_LED_LED(n)		(1 << (n))
53 
54 #define SYS_MCI_CARDIN		(1 << 0)
55 #define SYS_MCI_WPROT		(1 << 1)
56 
57 #define SYS_FLASH_WPn		(1 << 0)
58 
59 #define SYS_MISC_MASTERSITE	(1 << 14)
60 
61 #define SYS_CFGCTRL_START	(1 << 31)
62 #define SYS_CFGCTRL_WRITE	(1 << 30)
63 #define SYS_CFGCTRL_DCC(n)	(((n) & 0xf) << 26)
64 #define SYS_CFGCTRL_FUNC(n)	(((n) & 0x3f) << 20)
65 #define SYS_CFGCTRL_SITE(n)	(((n) & 0x3) << 16)
66 #define SYS_CFGCTRL_POSITION(n)	(((n) & 0xf) << 12)
67 #define SYS_CFGCTRL_DEVICE(n)	(((n) & 0xfff) << 0)
68 
69 #define SYS_CFGSTAT_ERR		(1 << 1)
70 #define SYS_CFGSTAT_COMPLETE	(1 << 0)
71 
72 
73 static void __iomem *vexpress_sysreg_base;
74 static struct device *vexpress_sysreg_dev;
75 static int vexpress_master_site;
76 
77 
78 void vexpress_flags_set(u32 data)
79 {
80 	writel(~0, vexpress_sysreg_base + SYS_FLAGSCLR);
81 	writel(data, vexpress_sysreg_base + SYS_FLAGSSET);
82 }
83 
84 u32 vexpress_get_procid(int site)
85 {
86 	if (site == VEXPRESS_SITE_MASTER)
87 		site = vexpress_master_site;
88 
89 	return readl(vexpress_sysreg_base + (site == VEXPRESS_SITE_DB1 ?
90 			SYS_PROCID0 : SYS_PROCID1));
91 }
92 
93 u32 vexpress_get_hbi(int site)
94 {
95 	u32 id;
96 
97 	switch (site) {
98 	case VEXPRESS_SITE_MB:
99 		id = readl(vexpress_sysreg_base + SYS_ID);
100 		return (id >> SYS_ID_HBI_SHIFT) & SYS_HBI_MASK;
101 	case VEXPRESS_SITE_MASTER:
102 	case VEXPRESS_SITE_DB1:
103 	case VEXPRESS_SITE_DB2:
104 		id = vexpress_get_procid(site);
105 		return (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
106 	}
107 
108 	return ~0;
109 }
110 
111 void __iomem *vexpress_get_24mhz_clock_base(void)
112 {
113 	return vexpress_sysreg_base + SYS_24MHZ;
114 }
115 
116 
117 static void vexpress_sysreg_find_prop(struct device_node *node,
118 		const char *name, u32 *val)
119 {
120 	of_node_get(node);
121 	while (node) {
122 		if (of_property_read_u32(node, name, val) == 0) {
123 			of_node_put(node);
124 			return;
125 		}
126 		node = of_get_next_parent(node);
127 	}
128 }
129 
130 unsigned __vexpress_get_site(struct device *dev, struct device_node *node)
131 {
132 	u32 site = 0;
133 
134 	WARN_ON(dev && node && dev->of_node != node);
135 	if (dev && !node)
136 		node = dev->of_node;
137 
138 	if (node) {
139 		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
140 	} else if (dev && dev->bus == &platform_bus_type) {
141 		struct platform_device *pdev = to_platform_device(dev);
142 
143 		if (pdev->num_resources == 1 &&
144 				pdev->resource[0].flags == IORESOURCE_BUS)
145 			site = pdev->resource[0].start;
146 	} else if (dev && strncmp(dev_name(dev), "ct:", 3) == 0) {
147 		site = VEXPRESS_SITE_MASTER;
148 	}
149 
150 	if (site == VEXPRESS_SITE_MASTER)
151 		site = vexpress_master_site;
152 
153 	return site;
154 }
155 
156 
157 struct vexpress_sysreg_config_func {
158 	u32 template;
159 	u32 device;
160 };
161 
162 static struct vexpress_config_bridge *vexpress_sysreg_config_bridge;
163 static struct timer_list vexpress_sysreg_config_timer;
164 static u32 *vexpress_sysreg_config_data;
165 static int vexpress_sysreg_config_tries;
166 
167 static void *vexpress_sysreg_config_func_get(struct device *dev,
168 		struct device_node *node)
169 {
170 	struct vexpress_sysreg_config_func *config_func;
171 	u32 site;
172 	u32 position = 0;
173 	u32 dcc = 0;
174 	u32 func_device[2];
175 	int err = -EFAULT;
176 
177 	if (node) {
178 		of_node_get(node);
179 		vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
180 		vexpress_sysreg_find_prop(node, "arm,vexpress,position",
181 				&position);
182 		vexpress_sysreg_find_prop(node, "arm,vexpress,dcc", &dcc);
183 		err = of_property_read_u32_array(node,
184 				"arm,vexpress-sysreg,func", func_device,
185 				ARRAY_SIZE(func_device));
186 		of_node_put(node);
187 	} else if (dev && dev->bus == &platform_bus_type) {
188 		struct platform_device *pdev = to_platform_device(dev);
189 
190 		if (pdev->num_resources == 1 &&
191 				pdev->resource[0].flags == IORESOURCE_BUS) {
192 			site = pdev->resource[0].start;
193 			func_device[0] = pdev->resource[0].end;
194 			func_device[1] = pdev->id;
195 			err = 0;
196 		}
197 	}
198 	if (err)
199 		return NULL;
200 
201 	config_func = kzalloc(sizeof(*config_func), GFP_KERNEL);
202 	if (!config_func)
203 		return NULL;
204 
205 	config_func->template = SYS_CFGCTRL_DCC(dcc);
206 	config_func->template |= SYS_CFGCTRL_FUNC(func_device[0]);
207 	config_func->template |= SYS_CFGCTRL_SITE(site == VEXPRESS_SITE_MASTER ?
208 			vexpress_master_site : site);
209 	config_func->template |= SYS_CFGCTRL_POSITION(position);
210 	config_func->device |= func_device[1];
211 
212 	dev_dbg(vexpress_sysreg_dev, "func 0x%p = 0x%x, %d\n", config_func,
213 			config_func->template, config_func->device);
214 
215 	return config_func;
216 }
217 
218 static void vexpress_sysreg_config_func_put(void *func)
219 {
220 	kfree(func);
221 }
222 
223 static int vexpress_sysreg_config_func_exec(void *func, int offset,
224 		bool write, u32 *data)
225 {
226 	int status;
227 	struct vexpress_sysreg_config_func *config_func = func;
228 	u32 command;
229 
230 	if (WARN_ON(!vexpress_sysreg_base))
231 		return -ENOENT;
232 
233 	command = readl(vexpress_sysreg_base + SYS_CFGCTRL);
234 	if (WARN_ON(command & SYS_CFGCTRL_START))
235 		return -EBUSY;
236 
237 	command = SYS_CFGCTRL_START;
238 	command |= write ? SYS_CFGCTRL_WRITE : 0;
239 	command |= config_func->template;
240 	command |= SYS_CFGCTRL_DEVICE(config_func->device + offset);
241 
242 	/* Use a canary for reads */
243 	if (!write)
244 		*data = 0xdeadbeef;
245 
246 	dev_dbg(vexpress_sysreg_dev, "command %x, data %x\n",
247 			command, *data);
248 	writel(*data, vexpress_sysreg_base + SYS_CFGDATA);
249 	writel(0, vexpress_sysreg_base + SYS_CFGSTAT);
250 	writel(command, vexpress_sysreg_base + SYS_CFGCTRL);
251 	mb();
252 
253 	if (vexpress_sysreg_dev) {
254 		/* Schedule completion check */
255 		if (!write)
256 			vexpress_sysreg_config_data = data;
257 		vexpress_sysreg_config_tries = 100;
258 		mod_timer(&vexpress_sysreg_config_timer,
259 				jiffies + usecs_to_jiffies(100));
260 		status = VEXPRESS_CONFIG_STATUS_WAIT;
261 	} else {
262 		/* Early execution, no timer available, have to spin */
263 		u32 cfgstat;
264 
265 		do {
266 			cpu_relax();
267 			cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
268 		} while (!cfgstat);
269 
270 		if (!write && (cfgstat & SYS_CFGSTAT_COMPLETE))
271 			*data = readl(vexpress_sysreg_base + SYS_CFGDATA);
272 		status = VEXPRESS_CONFIG_STATUS_DONE;
273 
274 		if (cfgstat & SYS_CFGSTAT_ERR)
275 			status = -EINVAL;
276 	}
277 
278 	return status;
279 }
280 
281 struct vexpress_config_bridge_info vexpress_sysreg_config_bridge_info = {
282 	.name = "vexpress-sysreg",
283 	.func_get = vexpress_sysreg_config_func_get,
284 	.func_put = vexpress_sysreg_config_func_put,
285 	.func_exec = vexpress_sysreg_config_func_exec,
286 };
287 
288 static void vexpress_sysreg_config_complete(unsigned long data)
289 {
290 	int status = VEXPRESS_CONFIG_STATUS_DONE;
291 	u32 cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
292 
293 	if (cfgstat & SYS_CFGSTAT_ERR)
294 		status = -EINVAL;
295 	if (!vexpress_sysreg_config_tries--)
296 		status = -ETIMEDOUT;
297 
298 	if (status < 0) {
299 		dev_err(vexpress_sysreg_dev, "error %d\n", status);
300 	} else if (!(cfgstat & SYS_CFGSTAT_COMPLETE)) {
301 		mod_timer(&vexpress_sysreg_config_timer,
302 				jiffies + usecs_to_jiffies(50));
303 		return;
304 	}
305 
306 	if (vexpress_sysreg_config_data) {
307 		*vexpress_sysreg_config_data = readl(vexpress_sysreg_base +
308 				SYS_CFGDATA);
309 		dev_dbg(vexpress_sysreg_dev, "read data %x\n",
310 				*vexpress_sysreg_config_data);
311 		vexpress_sysreg_config_data = NULL;
312 	}
313 
314 	vexpress_config_complete(vexpress_sysreg_config_bridge, status);
315 }
316 
317 
318 void vexpress_sysreg_setup(struct device_node *node)
319 {
320 	if (WARN_ON(!vexpress_sysreg_base))
321 		return;
322 
323 	if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
324 		vexpress_master_site = VEXPRESS_SITE_DB2;
325 	else
326 		vexpress_master_site = VEXPRESS_SITE_DB1;
327 
328 	vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
329 			node, &vexpress_sysreg_config_bridge_info);
330 	WARN_ON(!vexpress_sysreg_config_bridge);
331 }
332 
333 void __init vexpress_sysreg_early_init(void __iomem *base)
334 {
335 	vexpress_sysreg_base = base;
336 	vexpress_sysreg_setup(NULL);
337 }
338 
339 void __init vexpress_sysreg_of_early_init(void)
340 {
341 	struct device_node *node;
342 
343 	if (vexpress_sysreg_base)
344 		return;
345 
346 	node = of_find_compatible_node(NULL, NULL, "arm,vexpress-sysreg");
347 	if (node) {
348 		vexpress_sysreg_base = of_iomap(node, 0);
349 		vexpress_sysreg_setup(node);
350 	}
351 }
352 
353 
354 #define VEXPRESS_SYSREG_GPIO(_name, _reg, _value) \
355 	[VEXPRESS_GPIO_##_name] = { \
356 		.reg = _reg, \
357 		.value = _reg##_##_value, \
358 	}
359 
360 static struct vexpress_sysreg_gpio {
361 	unsigned long reg;
362 	u32 value;
363 } vexpress_sysreg_gpios[] = {
364 	VEXPRESS_SYSREG_GPIO(MMC_CARDIN,	SYS_MCI,	CARDIN),
365 	VEXPRESS_SYSREG_GPIO(MMC_WPROT,		SYS_MCI,	WPROT),
366 	VEXPRESS_SYSREG_GPIO(FLASH_WPn,		SYS_FLASH,	WPn),
367 	VEXPRESS_SYSREG_GPIO(LED0,		SYS_LED,	LED(0)),
368 	VEXPRESS_SYSREG_GPIO(LED1,		SYS_LED,	LED(1)),
369 	VEXPRESS_SYSREG_GPIO(LED2,		SYS_LED,	LED(2)),
370 	VEXPRESS_SYSREG_GPIO(LED3,		SYS_LED,	LED(3)),
371 	VEXPRESS_SYSREG_GPIO(LED4,		SYS_LED,	LED(4)),
372 	VEXPRESS_SYSREG_GPIO(LED5,		SYS_LED,	LED(5)),
373 	VEXPRESS_SYSREG_GPIO(LED6,		SYS_LED,	LED(6)),
374 	VEXPRESS_SYSREG_GPIO(LED7,		SYS_LED,	LED(7)),
375 };
376 
377 static int vexpress_sysreg_gpio_direction_input(struct gpio_chip *chip,
378 				       unsigned offset)
379 {
380 	return 0;
381 }
382 
383 static int vexpress_sysreg_gpio_get(struct gpio_chip *chip,
384 				       unsigned offset)
385 {
386 	struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
387 	u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);
388 
389 	return !!(reg_value & gpio->value);
390 }
391 
392 static void vexpress_sysreg_gpio_set(struct gpio_chip *chip,
393 				       unsigned offset, int value)
394 {
395 	struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
396 	u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);
397 
398 	if (value)
399 		reg_value |= gpio->value;
400 	else
401 		reg_value &= ~gpio->value;
402 
403 	writel(reg_value, vexpress_sysreg_base + gpio->reg);
404 }
405 
406 static int vexpress_sysreg_gpio_direction_output(struct gpio_chip *chip,
407 						unsigned offset, int value)
408 {
409 	vexpress_sysreg_gpio_set(chip, offset, value);
410 
411 	return 0;
412 }
413 
414 static struct gpio_chip vexpress_sysreg_gpio_chip = {
415 	.label = "vexpress-sysreg",
416 	.direction_input = vexpress_sysreg_gpio_direction_input,
417 	.direction_output = vexpress_sysreg_gpio_direction_output,
418 	.get = vexpress_sysreg_gpio_get,
419 	.set = vexpress_sysreg_gpio_set,
420 	.ngpio = ARRAY_SIZE(vexpress_sysreg_gpios),
421 	.base = 0,
422 };
423 
424 
425 #define VEXPRESS_SYSREG_GREEN_LED(_name, _default_trigger, _gpio) \
426 	{ \
427 		.name = "v2m:green:"_name, \
428 		.default_trigger = _default_trigger, \
429 		.gpio = VEXPRESS_GPIO_##_gpio, \
430 	}
431 
432 struct gpio_led vexpress_sysreg_leds[] = {
433 	VEXPRESS_SYSREG_GREEN_LED("user1",	"heartbeat",	LED0),
434 	VEXPRESS_SYSREG_GREEN_LED("user2",	"mmc0",		LED1),
435 	VEXPRESS_SYSREG_GREEN_LED("user3",	"cpu0",		LED2),
436 	VEXPRESS_SYSREG_GREEN_LED("user4",	"cpu1",		LED3),
437 	VEXPRESS_SYSREG_GREEN_LED("user5",	"cpu2",		LED4),
438 	VEXPRESS_SYSREG_GREEN_LED("user6",	"cpu3",		LED5),
439 	VEXPRESS_SYSREG_GREEN_LED("user7",	"cpu4",		LED6),
440 	VEXPRESS_SYSREG_GREEN_LED("user8",	"cpu5",		LED7),
441 };
442 
443 struct gpio_led_platform_data vexpress_sysreg_leds_pdata = {
444 	.num_leds = ARRAY_SIZE(vexpress_sysreg_leds),
445 	.leds = vexpress_sysreg_leds,
446 };
447 
448 
449 static ssize_t vexpress_sysreg_sys_id_show(struct device *dev,
450 		struct device_attribute *attr, char *buf)
451 {
452 	return sprintf(buf, "0x%08x\n", readl(vexpress_sysreg_base + SYS_ID));
453 }
454 
455 DEVICE_ATTR(sys_id, S_IRUGO, vexpress_sysreg_sys_id_show, NULL);
456 
457 static int vexpress_sysreg_probe(struct platform_device *pdev)
458 {
459 	int err;
460 	struct resource *res = platform_get_resource(pdev,
461 			IORESOURCE_MEM, 0);
462 
463 	if (!devm_request_mem_region(&pdev->dev, res->start,
464 			resource_size(res), pdev->name)) {
465 		dev_err(&pdev->dev, "Failed to request memory region!\n");
466 		return -EBUSY;
467 	}
468 
469 	if (!vexpress_sysreg_base) {
470 		vexpress_sysreg_base = devm_ioremap(&pdev->dev, res->start,
471 				resource_size(res));
472 		vexpress_sysreg_setup(pdev->dev.of_node);
473 	}
474 
475 	if (!vexpress_sysreg_base) {
476 		dev_err(&pdev->dev, "Failed to obtain base address!\n");
477 		return -EFAULT;
478 	}
479 
480 	setup_timer(&vexpress_sysreg_config_timer,
481 			vexpress_sysreg_config_complete, 0);
482 
483 	vexpress_sysreg_gpio_chip.dev = &pdev->dev;
484 	err = gpiochip_add(&vexpress_sysreg_gpio_chip);
485 	if (err) {
486 		vexpress_config_bridge_unregister(
487 				vexpress_sysreg_config_bridge);
488 		dev_err(&pdev->dev, "Failed to register GPIO chip! (%d)\n",
489 				err);
490 		return err;
491 	}
492 
493 	vexpress_sysreg_dev = &pdev->dev;
494 
495 	platform_device_register_data(vexpress_sysreg_dev, "leds-gpio",
496 			PLATFORM_DEVID_AUTO, &vexpress_sysreg_leds_pdata,
497 			sizeof(vexpress_sysreg_leds_pdata));
498 
499 	device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);
500 
501 	return 0;
502 }
503 
504 static const struct of_device_id vexpress_sysreg_match[] = {
505 	{ .compatible = "arm,vexpress-sysreg", },
506 	{},
507 };
508 
509 static struct platform_driver vexpress_sysreg_driver = {
510 	.driver = {
511 		.name = "vexpress-sysreg",
512 		.of_match_table = vexpress_sysreg_match,
513 	},
514 	.probe = vexpress_sysreg_probe,
515 };
516 
517 static int __init vexpress_sysreg_init(void)
518 {
519 	vexpress_sysreg_of_early_init();
520 	return platform_driver_register(&vexpress_sysreg_driver);
521 }
522 core_initcall(vexpress_sysreg_init);
523