xref: /openbmc/linux/arch/arm/mach-ep93xx/core.c (revision a1e58bbd)
1 /*
2  * arch/arm/mach-ep93xx/core.c
3  * Core routines for Cirrus EP93xx chips.
4  *
5  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
6  * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>
7  *
8  * Thanks go to Michael Burian and Ray Lehtiniemi for their key
9  * role in the ep93xx linux community.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/sched.h>
21 #include <linux/interrupt.h>
22 #include <linux/serial.h>
23 #include <linux/tty.h>
24 #include <linux/bitops.h>
25 #include <linux/serial_8250.h>
26 #include <linux/serial_core.h>
27 #include <linux/device.h>
28 #include <linux/mm.h>
29 #include <linux/time.h>
30 #include <linux/timex.h>
31 #include <linux/delay.h>
32 #include <linux/termios.h>
33 #include <linux/amba/bus.h>
34 #include <linux/amba/serial.h>
35 
36 #include <asm/types.h>
37 #include <asm/setup.h>
38 #include <asm/memory.h>
39 #include <asm/hardware.h>
40 #include <asm/irq.h>
41 #include <asm/system.h>
42 #include <asm/tlbflush.h>
43 #include <asm/pgtable.h>
44 #include <asm/io.h>
45 
46 #include <asm/mach/map.h>
47 #include <asm/mach/time.h>
48 #include <asm/mach/irq.h>
49 #include <asm/arch/gpio.h>
50 
51 #include <asm/hardware/vic.h>
52 
53 
54 /*************************************************************************
55  * Static I/O mappings that are needed for all EP93xx platforms
56  *************************************************************************/
57 static struct map_desc ep93xx_io_desc[] __initdata = {
58 	{
59 		.virtual	= EP93XX_AHB_VIRT_BASE,
60 		.pfn		= __phys_to_pfn(EP93XX_AHB_PHYS_BASE),
61 		.length		= EP93XX_AHB_SIZE,
62 		.type		= MT_DEVICE,
63 	}, {
64 		.virtual	= EP93XX_APB_VIRT_BASE,
65 		.pfn		= __phys_to_pfn(EP93XX_APB_PHYS_BASE),
66 		.length		= EP93XX_APB_SIZE,
67 		.type		= MT_DEVICE,
68 	},
69 };
70 
71 void __init ep93xx_map_io(void)
72 {
73 	iotable_init(ep93xx_io_desc, ARRAY_SIZE(ep93xx_io_desc));
74 }
75 
76 
77 /*************************************************************************
78  * Timer handling for EP93xx
79  *************************************************************************
80  * The ep93xx has four internal timers.  Timers 1, 2 (both 16 bit) and
81  * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate
82  * an interrupt on underflow.  Timer 4 (40 bit) counts down at 983.04 kHz,
83  * is free-running, and can't generate interrupts.
84  *
85  * The 508 kHz timers are ideal for use for the timer interrupt, as the
86  * most common values of HZ divide 508 kHz nicely.  We pick one of the 16
87  * bit timers (timer 1) since we don't need more than 16 bits of reload
88  * value as long as HZ >= 8.
89  *
90  * The higher clock rate of timer 4 makes it a better choice than the
91  * other timers for use in gettimeoffset(), while the fact that it can't
92  * generate interrupts means we don't have to worry about not being able
93  * to use this timer for something else.  We also use timer 4 for keeping
94  * track of lost jiffies.
95  */
96 static unsigned int last_jiffy_time;
97 
98 #define TIMER4_TICKS_PER_JIFFY		((CLOCK_TICK_RATE + (HZ/2)) / HZ)
99 
100 static int ep93xx_timer_interrupt(int irq, void *dev_id)
101 {
102 	__raw_writel(1, EP93XX_TIMER1_CLEAR);
103 	while ((signed long)
104 		(__raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time)
105 						>= TIMER4_TICKS_PER_JIFFY) {
106 		last_jiffy_time += TIMER4_TICKS_PER_JIFFY;
107 		timer_tick();
108 	}
109 
110 	return IRQ_HANDLED;
111 }
112 
113 static struct irqaction ep93xx_timer_irq = {
114 	.name		= "ep93xx timer",
115 	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
116 	.handler	= ep93xx_timer_interrupt,
117 };
118 
119 static void __init ep93xx_timer_init(void)
120 {
121 	/* Enable periodic HZ timer.  */
122 	__raw_writel(0x48, EP93XX_TIMER1_CONTROL);
123 	__raw_writel((508469 / HZ) - 1, EP93XX_TIMER1_LOAD);
124 	__raw_writel(0xc8, EP93XX_TIMER1_CONTROL);
125 
126 	/* Enable lost jiffy timer.  */
127 	__raw_writel(0x100, EP93XX_TIMER4_VALUE_HIGH);
128 
129 	setup_irq(IRQ_EP93XX_TIMER1, &ep93xx_timer_irq);
130 }
131 
132 static unsigned long ep93xx_gettimeoffset(void)
133 {
134 	int offset;
135 
136 	offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
137 
138 	/* Calculate (1000000 / 983040) * offset.  */
139 	return offset + (53 * offset / 3072);
140 }
141 
142 struct sys_timer ep93xx_timer = {
143 	.init		= ep93xx_timer_init,
144 	.offset		= ep93xx_gettimeoffset,
145 };
146 
147 
148 /*************************************************************************
149  * GPIO handling for EP93xx
150  *************************************************************************/
151 static unsigned char gpio_int_unmasked[3];
152 static unsigned char gpio_int_enabled[3];
153 static unsigned char gpio_int_type1[3];
154 static unsigned char gpio_int_type2[3];
155 
156 /* Port ordering is: A B F */
157 static const u8 int_type1_register_offset[3]	= { 0x90, 0xac, 0x4c };
158 static const u8 int_type2_register_offset[3]	= { 0x94, 0xb0, 0x50 };
159 static const u8 eoi_register_offset[3]		= { 0x98, 0xb4, 0x54 };
160 static const u8 int_en_register_offset[3]	= { 0x9c, 0xb8, 0x5c };
161 
162 static void update_gpio_int_params(unsigned port)
163 {
164 	BUG_ON(port > 2);
165 
166 	__raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
167 
168 	__raw_writeb(gpio_int_type2[port],
169 		EP93XX_GPIO_REG(int_type2_register_offset[port]));
170 
171 	__raw_writeb(gpio_int_type1[port],
172 		EP93XX_GPIO_REG(int_type1_register_offset[port]));
173 
174 	__raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
175 		EP93XX_GPIO_REG(int_en_register_offset[port]));
176 }
177 
178 /* Port ordering is: A B F D E C G H */
179 static const u8 data_register_offset[8] = {
180 	0x00, 0x04, 0x30, 0x0c, 0x20, 0x08, 0x38, 0x40,
181 };
182 
183 static const u8 data_direction_register_offset[8] = {
184 	0x10, 0x14, 0x34, 0x1c, 0x24, 0x18, 0x3c, 0x44,
185 };
186 
187 #define GPIO_IN		0
188 #define GPIO_OUT	1
189 
190 static void ep93xx_gpio_set_direction(unsigned line, int direction)
191 {
192 	unsigned int data_direction_register;
193 	unsigned long flags;
194 	unsigned char v;
195 
196 	data_direction_register =
197 		EP93XX_GPIO_REG(data_direction_register_offset[line >> 3]);
198 
199 	local_irq_save(flags);
200 	if (direction == GPIO_OUT) {
201 		if (line >= 0 && line <= EP93XX_GPIO_LINE_MAX_IRQ) {
202 			/* Port A/B/F */
203 			gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
204 			update_gpio_int_params(line >> 3);
205 		}
206 
207 		v = __raw_readb(data_direction_register);
208 		v |= 1 << (line & 7);
209 		__raw_writeb(v, data_direction_register);
210 	} else if (direction == GPIO_IN) {
211 		v = __raw_readb(data_direction_register);
212 		v &= ~(1 << (line & 7));
213 		__raw_writeb(v, data_direction_register);
214 	}
215 	local_irq_restore(flags);
216 }
217 
218 int gpio_direction_input(unsigned gpio)
219 {
220 	if (gpio > EP93XX_GPIO_LINE_MAX)
221 		return -EINVAL;
222 
223 	ep93xx_gpio_set_direction(gpio, GPIO_IN);
224 
225 	return 0;
226 }
227 EXPORT_SYMBOL(gpio_direction_input);
228 
229 int gpio_direction_output(unsigned gpio, int value)
230 {
231 	if (gpio > EP93XX_GPIO_LINE_MAX)
232 		return -EINVAL;
233 
234 	gpio_set_value(gpio, value);
235 	ep93xx_gpio_set_direction(gpio, GPIO_OUT);
236 
237 	return 0;
238 }
239 EXPORT_SYMBOL(gpio_direction_output);
240 
241 int gpio_get_value(unsigned gpio)
242 {
243 	unsigned int data_register;
244 
245 	data_register = EP93XX_GPIO_REG(data_register_offset[gpio >> 3]);
246 
247 	return !!(__raw_readb(data_register) & (1 << (gpio & 7)));
248 }
249 EXPORT_SYMBOL(gpio_get_value);
250 
251 void gpio_set_value(unsigned gpio, int value)
252 {
253 	unsigned int data_register;
254 	unsigned long flags;
255 	unsigned char v;
256 
257 	data_register = EP93XX_GPIO_REG(data_register_offset[gpio >> 3]);
258 
259 	local_irq_save(flags);
260 	v = __raw_readb(data_register);
261 	if (value)
262 		v |= 1 << (gpio & 7);
263 	else
264 		v &= ~(1 << (gpio & 7));
265 	__raw_writeb(v, data_register);
266 	local_irq_restore(flags);
267 }
268 EXPORT_SYMBOL(gpio_set_value);
269 
270 
271 /*************************************************************************
272  * EP93xx IRQ handling
273  *************************************************************************/
274 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
275 {
276 	unsigned char status;
277 	int i;
278 
279 	status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
280 	for (i = 0; i < 8; i++) {
281 		if (status & (1 << i)) {
282 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
283 			desc = irq_desc + gpio_irq;
284 			desc_handle_irq(gpio_irq, desc);
285 		}
286 	}
287 
288 	status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
289 	for (i = 0; i < 8; i++) {
290 		if (status & (1 << i)) {
291 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
292 			desc = irq_desc + gpio_irq;
293 			desc_handle_irq(gpio_irq, desc);
294 		}
295 	}
296 }
297 
298 static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
299 {
300 	/*
301 	 * map discontiguous hw irq range to continous sw irq range:
302 	 *
303 	 *  IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
304 	 */
305 	int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
306 	int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
307 
308 	desc_handle_irq(gpio_irq, irq_desc + gpio_irq);
309 }
310 
311 static void ep93xx_gpio_irq_ack(unsigned int irq)
312 {
313 	int line = irq_to_gpio(irq);
314 	int port = line >> 3;
315 	int port_mask = 1 << (line & 7);
316 
317 	if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {
318 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */
319 		update_gpio_int_params(port);
320 	}
321 
322 	__raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
323 }
324 
325 static void ep93xx_gpio_irq_mask_ack(unsigned int irq)
326 {
327 	int line = irq_to_gpio(irq);
328 	int port = line >> 3;
329 	int port_mask = 1 << (line & 7);
330 
331 	if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE)
332 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */
333 
334 	gpio_int_unmasked[port] &= ~port_mask;
335 	update_gpio_int_params(port);
336 
337 	__raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
338 }
339 
340 static void ep93xx_gpio_irq_mask(unsigned int irq)
341 {
342 	int line = irq_to_gpio(irq);
343 	int port = line >> 3;
344 
345 	gpio_int_unmasked[port] &= ~(1 << (line & 7));
346 	update_gpio_int_params(port);
347 }
348 
349 static void ep93xx_gpio_irq_unmask(unsigned int irq)
350 {
351 	int line = irq_to_gpio(irq);
352 	int port = line >> 3;
353 
354 	gpio_int_unmasked[port] |= 1 << (line & 7);
355 	update_gpio_int_params(port);
356 }
357 
358 
359 /*
360  * gpio_int_type1 controls whether the interrupt is level (0) or
361  * edge (1) triggered, while gpio_int_type2 controls whether it
362  * triggers on low/falling (0) or high/rising (1).
363  */
364 static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type)
365 {
366 	struct irq_desc *desc = irq_desc + irq;
367 	const int gpio = irq_to_gpio(irq);
368 	const int port = gpio >> 3;
369 	const int port_mask = 1 << (gpio & 7);
370 
371 	ep93xx_gpio_set_direction(gpio, GPIO_IN);
372 
373 	switch (type) {
374 	case IRQT_RISING:
375 		gpio_int_type1[port] |= port_mask;
376 		gpio_int_type2[port] |= port_mask;
377 		desc->handle_irq = handle_edge_irq;
378 		break;
379 	case IRQT_FALLING:
380 		gpio_int_type1[port] |= port_mask;
381 		gpio_int_type2[port] &= ~port_mask;
382 		desc->handle_irq = handle_edge_irq;
383 		break;
384 	case IRQT_HIGH:
385 		gpio_int_type1[port] &= ~port_mask;
386 		gpio_int_type2[port] |= port_mask;
387 		desc->handle_irq = handle_level_irq;
388 		break;
389 	case IRQT_LOW:
390 		gpio_int_type1[port] &= ~port_mask;
391 		gpio_int_type2[port] &= ~port_mask;
392 		desc->handle_irq = handle_level_irq;
393 		break;
394 	case IRQT_BOTHEDGE:
395 		gpio_int_type1[port] |= port_mask;
396 		/* set initial polarity based on current input level */
397 		if (gpio_get_value(gpio))
398 			gpio_int_type2[port] &= ~port_mask; /* falling */
399 		else
400 			gpio_int_type2[port] |= port_mask; /* rising */
401 		desc->handle_irq = handle_edge_irq;
402 		break;
403 	default:
404 		pr_err("ep93xx: failed to set irq type %d for gpio %d\n",
405 		       type, gpio);
406 		return -EINVAL;
407 	}
408 
409 	gpio_int_enabled[port] |= port_mask;
410 
411 	desc->status &= ~IRQ_TYPE_SENSE_MASK;
412 	desc->status |= type & IRQ_TYPE_SENSE_MASK;
413 
414 	update_gpio_int_params(port);
415 
416 	return 0;
417 }
418 
419 static struct irq_chip ep93xx_gpio_irq_chip = {
420 	.name		= "GPIO",
421 	.ack		= ep93xx_gpio_irq_ack,
422 	.mask_ack	= ep93xx_gpio_irq_mask_ack,
423 	.mask		= ep93xx_gpio_irq_mask,
424 	.unmask		= ep93xx_gpio_irq_unmask,
425 	.set_type	= ep93xx_gpio_irq_type,
426 };
427 
428 
429 void __init ep93xx_init_irq(void)
430 {
431 	int gpio_irq;
432 
433 	vic_init((void *)EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK);
434 	vic_init((void *)EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK);
435 
436 	for (gpio_irq = gpio_to_irq(0);
437 	     gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
438 		set_irq_chip(gpio_irq, &ep93xx_gpio_irq_chip);
439 		set_irq_handler(gpio_irq, handle_level_irq);
440 		set_irq_flags(gpio_irq, IRQF_VALID);
441 	}
442 
443 	set_irq_chained_handler(IRQ_EP93XX_GPIO_AB, ep93xx_gpio_ab_irq_handler);
444 	set_irq_chained_handler(IRQ_EP93XX_GPIO0MUX, ep93xx_gpio_f_irq_handler);
445 	set_irq_chained_handler(IRQ_EP93XX_GPIO1MUX, ep93xx_gpio_f_irq_handler);
446 	set_irq_chained_handler(IRQ_EP93XX_GPIO2MUX, ep93xx_gpio_f_irq_handler);
447 	set_irq_chained_handler(IRQ_EP93XX_GPIO3MUX, ep93xx_gpio_f_irq_handler);
448 	set_irq_chained_handler(IRQ_EP93XX_GPIO4MUX, ep93xx_gpio_f_irq_handler);
449 	set_irq_chained_handler(IRQ_EP93XX_GPIO5MUX, ep93xx_gpio_f_irq_handler);
450 	set_irq_chained_handler(IRQ_EP93XX_GPIO6MUX, ep93xx_gpio_f_irq_handler);
451 	set_irq_chained_handler(IRQ_EP93XX_GPIO7MUX, ep93xx_gpio_f_irq_handler);
452 }
453 
454 
455 /*************************************************************************
456  * EP93xx peripheral handling
457  *************************************************************************/
458 #define EP93XX_UART_MCR_OFFSET		(0x0100)
459 
460 static void ep93xx_uart_set_mctrl(struct amba_device *dev,
461 				  void __iomem *base, unsigned int mctrl)
462 {
463 	unsigned int mcr;
464 
465 	mcr = 0;
466 	if (!(mctrl & TIOCM_RTS))
467 		mcr |= 2;
468 	if (!(mctrl & TIOCM_DTR))
469 		mcr |= 1;
470 
471 	__raw_writel(mcr, base + EP93XX_UART_MCR_OFFSET);
472 }
473 
474 static struct amba_pl010_data ep93xx_uart_data = {
475 	.set_mctrl	= ep93xx_uart_set_mctrl,
476 };
477 
478 static struct amba_device uart1_device = {
479 	.dev		= {
480 		.bus_id		= "apb:uart1",
481 		.platform_data	= &ep93xx_uart_data,
482 	},
483 	.res		= {
484 		.start	= EP93XX_UART1_PHYS_BASE,
485 		.end	= EP93XX_UART1_PHYS_BASE + 0x0fff,
486 		.flags	= IORESOURCE_MEM,
487 	},
488 	.irq		= { IRQ_EP93XX_UART1, NO_IRQ },
489 	.periphid	= 0x00041010,
490 };
491 
492 static struct amba_device uart2_device = {
493 	.dev		= {
494 		.bus_id		= "apb:uart2",
495 		.platform_data	= &ep93xx_uart_data,
496 	},
497 	.res		= {
498 		.start	= EP93XX_UART2_PHYS_BASE,
499 		.end	= EP93XX_UART2_PHYS_BASE + 0x0fff,
500 		.flags	= IORESOURCE_MEM,
501 	},
502 	.irq		= { IRQ_EP93XX_UART2, NO_IRQ },
503 	.periphid	= 0x00041010,
504 };
505 
506 static struct amba_device uart3_device = {
507 	.dev		= {
508 		.bus_id		= "apb:uart3",
509 		.platform_data	= &ep93xx_uart_data,
510 	},
511 	.res		= {
512 		.start	= EP93XX_UART3_PHYS_BASE,
513 		.end	= EP93XX_UART3_PHYS_BASE + 0x0fff,
514 		.flags	= IORESOURCE_MEM,
515 	},
516 	.irq		= { IRQ_EP93XX_UART3, NO_IRQ },
517 	.periphid	= 0x00041010,
518 };
519 
520 
521 static struct platform_device ep93xx_rtc_device = {
522        .name           = "ep93xx-rtc",
523        .id             = -1,
524        .num_resources  = 0,
525 };
526 
527 
528 static struct resource ep93xx_ohci_resources[] = {
529 	[0] = {
530 		.start	= EP93XX_USB_PHYS_BASE,
531 		.end	= EP93XX_USB_PHYS_BASE + 0x0fff,
532 		.flags	= IORESOURCE_MEM,
533 	},
534 	[1] = {
535 		.start	= IRQ_EP93XX_USB,
536 		.end	= IRQ_EP93XX_USB,
537 		.flags	= IORESOURCE_IRQ,
538 	},
539 };
540 
541 static struct platform_device ep93xx_ohci_device = {
542 	.name		= "ep93xx-ohci",
543 	.id		= -1,
544 	.dev		= {
545 		.dma_mask		= (void *)0xffffffff,
546 		.coherent_dma_mask	= 0xffffffff,
547 	},
548 	.num_resources	= ARRAY_SIZE(ep93xx_ohci_resources),
549 	.resource	= ep93xx_ohci_resources,
550 };
551 
552 
553 void __init ep93xx_init_devices(void)
554 {
555 	unsigned int v;
556 
557 	/*
558 	 * Disallow access to MaverickCrunch initially.
559 	 */
560 	v = __raw_readl(EP93XX_SYSCON_DEVICE_CONFIG);
561 	v &= ~EP93XX_SYSCON_DEVICE_CONFIG_CRUNCH_ENABLE;
562 	__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
563 	__raw_writel(v, EP93XX_SYSCON_DEVICE_CONFIG);
564 
565 	amba_device_register(&uart1_device, &iomem_resource);
566 	amba_device_register(&uart2_device, &iomem_resource);
567 	amba_device_register(&uart3_device, &iomem_resource);
568 
569 	platform_device_register(&ep93xx_rtc_device);
570 	platform_device_register(&ep93xx_ohci_device);
571 }
572