xref: /openbmc/u-boot/arch/arm/mach-mvebu/mbus.c (revision 274bced8)
1 /*
2  * Address map functions for Marvell EBU SoCs (Kirkwood, Armada
3  * 370/XP, Dove, Orion5x and MV78xx0)
4  *
5  * Ported from the Barebox version to U-Boot by:
6  * Stefan Roese <sr@denx.de>
7  *
8  * The Barebox version is:
9  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
10  *
11  * based on mbus driver from Linux
12  *   (C) Copyright 2008 Marvell Semiconductor
13  *
14  * SPDX-License-Identifier:	GPL-2.0
15  *
16  * The Marvell EBU SoCs have a configurable physical address space:
17  * the physical address at which certain devices (PCIe, NOR, NAND,
18  * etc.) sit can be configured. The configuration takes place through
19  * two sets of registers:
20  *
21  * - One to configure the access of the CPU to the devices. Depending
22  *   on the families, there are between 8 and 20 configurable windows,
23  *   each can be use to create a physical memory window that maps to a
24  *   specific device. Devices are identified by a tuple (target,
25  *   attribute).
26  *
27  * - One to configure the access to the CPU to the SDRAM. There are
28  *   either 2 (for Dove) or 4 (for other families) windows to map the
29  *   SDRAM into the physical address space.
30  *
31  * This driver:
32  *
33  * - Reads out the SDRAM address decoding windows at initialization
34  *   time, and fills the mbus_dram_info structure with these
35  *   informations. The exported function mv_mbus_dram_info() allow
36  *   device drivers to get those informations related to the SDRAM
37  *   address decoding windows. This is because devices also have their
38  *   own windows (configured through registers that are part of each
39  *   device register space), and therefore the drivers for Marvell
40  *   devices have to configure those device -> SDRAM windows to ensure
41  *   that DMA works properly.
42  *
43  * - Provides an API for platform code or device drivers to
44  *   dynamically add or remove address decoding windows for the CPU ->
45  *   device accesses. This API is mvebu_mbus_add_window_by_id(),
46  *   mvebu_mbus_add_window_remap_by_id() and
47  *   mvebu_mbus_del_window().
48  */
49 
50 #include <common.h>
51 #include <linux/errno.h>
52 #include <asm/io.h>
53 #include <asm/arch/cpu.h>
54 #include <asm/arch/soc.h>
55 #include <linux/log2.h>
56 #include <linux/mbus.h>
57 
58 /* DDR target is the same on all platforms */
59 #define TARGET_DDR		0
60 
61 /* CPU Address Decode Windows registers */
62 #define WIN_CTRL_OFF		0x0000
63 #define   WIN_CTRL_ENABLE       BIT(0)
64 #define   WIN_CTRL_TGT_MASK     0xf0
65 #define   WIN_CTRL_TGT_SHIFT    4
66 #define   WIN_CTRL_ATTR_MASK    0xff00
67 #define   WIN_CTRL_ATTR_SHIFT   8
68 #define   WIN_CTRL_SIZE_MASK    0xffff0000
69 #define   WIN_CTRL_SIZE_SHIFT   16
70 #define WIN_BASE_OFF		0x0004
71 #define   WIN_BASE_LOW          0xffff0000
72 #define   WIN_BASE_HIGH         0xf
73 #define WIN_REMAP_LO_OFF	0x0008
74 #define   WIN_REMAP_LOW         0xffff0000
75 #define WIN_REMAP_HI_OFF	0x000c
76 
77 #define ATTR_HW_COHERENCY	(0x1 << 4)
78 
79 #define DDR_BASE_CS_OFF(n)	(0x0000 + ((n) << 3))
80 #define  DDR_BASE_CS_HIGH_MASK  0xf
81 #define  DDR_BASE_CS_LOW_MASK   0xff000000
82 #define DDR_SIZE_CS_OFF(n)	(0x0004 + ((n) << 3))
83 #define  DDR_SIZE_ENABLED       BIT(0)
84 #define  DDR_SIZE_CS_MASK       0x1c
85 #define  DDR_SIZE_CS_SHIFT      2
86 #define  DDR_SIZE_MASK          0xff000000
87 
88 #define DOVE_DDR_BASE_CS_OFF(n) ((n) << 4)
89 
90 struct mvebu_mbus_state;
91 
92 struct mvebu_mbus_soc_data {
93 	unsigned int num_wins;
94 	unsigned int num_remappable_wins;
95 	unsigned int (*win_cfg_offset)(const int win);
96 	void (*setup_cpu_target)(struct mvebu_mbus_state *s);
97 };
98 
99 struct mvebu_mbus_state mbus_state
100 	__attribute__ ((section(".data")));
101 static struct mbus_dram_target_info mbus_dram_info
102 	__attribute__ ((section(".data")));
103 
104 /*
105  * Functions to manipulate the address decoding windows
106  */
107 
108 static void mvebu_mbus_read_window(struct mvebu_mbus_state *mbus,
109 				   int win, int *enabled, u64 *base,
110 				   u32 *size, u8 *target, u8 *attr,
111 				   u64 *remap)
112 {
113 	void __iomem *addr = mbus->mbuswins_base +
114 		mbus->soc->win_cfg_offset(win);
115 	u32 basereg = readl(addr + WIN_BASE_OFF);
116 	u32 ctrlreg = readl(addr + WIN_CTRL_OFF);
117 
118 	if (!(ctrlreg & WIN_CTRL_ENABLE)) {
119 		*enabled = 0;
120 		return;
121 	}
122 
123 	*enabled = 1;
124 	*base = ((u64)basereg & WIN_BASE_HIGH) << 32;
125 	*base |= (basereg & WIN_BASE_LOW);
126 	*size = (ctrlreg | ~WIN_CTRL_SIZE_MASK) + 1;
127 
128 	if (target)
129 		*target = (ctrlreg & WIN_CTRL_TGT_MASK) >> WIN_CTRL_TGT_SHIFT;
130 
131 	if (attr)
132 		*attr = (ctrlreg & WIN_CTRL_ATTR_MASK) >> WIN_CTRL_ATTR_SHIFT;
133 
134 	if (remap) {
135 		if (win < mbus->soc->num_remappable_wins) {
136 			u32 remap_low = readl(addr + WIN_REMAP_LO_OFF);
137 			u32 remap_hi  = readl(addr + WIN_REMAP_HI_OFF);
138 			*remap = ((u64)remap_hi << 32) | remap_low;
139 		} else {
140 			*remap = 0;
141 		}
142 	}
143 }
144 
145 static void mvebu_mbus_disable_window(struct mvebu_mbus_state *mbus,
146 				      int win)
147 {
148 	void __iomem *addr;
149 
150 	addr = mbus->mbuswins_base + mbus->soc->win_cfg_offset(win);
151 
152 	writel(0, addr + WIN_BASE_OFF);
153 	writel(0, addr + WIN_CTRL_OFF);
154 	if (win < mbus->soc->num_remappable_wins) {
155 		writel(0, addr + WIN_REMAP_LO_OFF);
156 		writel(0, addr + WIN_REMAP_HI_OFF);
157 	}
158 }
159 
160 /* Checks whether the given window number is available */
161 static int mvebu_mbus_window_is_free(struct mvebu_mbus_state *mbus,
162 				     const int win)
163 {
164 	void __iomem *addr = mbus->mbuswins_base +
165 		mbus->soc->win_cfg_offset(win);
166 	u32 ctrl = readl(addr + WIN_CTRL_OFF);
167 	return !(ctrl & WIN_CTRL_ENABLE);
168 }
169 
170 /*
171  * Checks whether the given (base, base+size) area doesn't overlap an
172  * existing region
173  */
174 static int mvebu_mbus_window_conflicts(struct mvebu_mbus_state *mbus,
175 				       phys_addr_t base, size_t size,
176 				       u8 target, u8 attr)
177 {
178 	u64 end = (u64)base + size;
179 	int win;
180 
181 	for (win = 0; win < mbus->soc->num_wins; win++) {
182 		u64 wbase, wend;
183 		u32 wsize;
184 		u8 wtarget, wattr;
185 		int enabled;
186 
187 		mvebu_mbus_read_window(mbus, win,
188 				       &enabled, &wbase, &wsize,
189 				       &wtarget, &wattr, NULL);
190 
191 		if (!enabled)
192 			continue;
193 
194 		wend = wbase + wsize;
195 
196 		/*
197 		 * Check if the current window overlaps with the
198 		 * proposed physical range
199 		 */
200 		if ((u64)base < wend && end > wbase)
201 			return 0;
202 
203 		/*
204 		 * Check if target/attribute conflicts
205 		 */
206 		if (target == wtarget && attr == wattr)
207 			return 0;
208 	}
209 
210 	return 1;
211 }
212 
213 static int mvebu_mbus_find_window(struct mvebu_mbus_state *mbus,
214 				  phys_addr_t base, size_t size)
215 {
216 	int win;
217 
218 	for (win = 0; win < mbus->soc->num_wins; win++) {
219 		u64 wbase;
220 		u32 wsize;
221 		int enabled;
222 
223 		mvebu_mbus_read_window(mbus, win,
224 				       &enabled, &wbase, &wsize,
225 				       NULL, NULL, NULL);
226 
227 		if (!enabled)
228 			continue;
229 
230 		if (base == wbase && size == wsize)
231 			return win;
232 	}
233 
234 	return -ENODEV;
235 }
236 
237 static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus,
238 				   int win, phys_addr_t base, size_t size,
239 				   phys_addr_t remap, u8 target,
240 				   u8 attr)
241 {
242 	void __iomem *addr = mbus->mbuswins_base +
243 		mbus->soc->win_cfg_offset(win);
244 	u32 ctrl, remap_addr;
245 
246 	ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
247 		(attr << WIN_CTRL_ATTR_SHIFT)    |
248 		(target << WIN_CTRL_TGT_SHIFT)   |
249 		WIN_CTRL_ENABLE;
250 
251 	writel(base & WIN_BASE_LOW, addr + WIN_BASE_OFF);
252 	writel(ctrl, addr + WIN_CTRL_OFF);
253 	if (win < mbus->soc->num_remappable_wins) {
254 		if (remap == MVEBU_MBUS_NO_REMAP)
255 			remap_addr = base;
256 		else
257 			remap_addr = remap;
258 		writel(remap_addr & WIN_REMAP_LOW, addr + WIN_REMAP_LO_OFF);
259 		writel(0, addr + WIN_REMAP_HI_OFF);
260 	}
261 
262 	return 0;
263 }
264 
265 static int mvebu_mbus_alloc_window(struct mvebu_mbus_state *mbus,
266 				   phys_addr_t base, size_t size,
267 				   phys_addr_t remap, u8 target,
268 				   u8 attr)
269 {
270 	int win;
271 
272 	if (remap == MVEBU_MBUS_NO_REMAP) {
273 		for (win = mbus->soc->num_remappable_wins;
274 		     win < mbus->soc->num_wins; win++)
275 			if (mvebu_mbus_window_is_free(mbus, win))
276 				return mvebu_mbus_setup_window(mbus, win, base,
277 							       size, remap,
278 							       target, attr);
279 	}
280 
281 
282 	for (win = 0; win < mbus->soc->num_wins; win++)
283 		if (mvebu_mbus_window_is_free(mbus, win))
284 			return mvebu_mbus_setup_window(mbus, win, base, size,
285 						       remap, target, attr);
286 
287 	return -ENOMEM;
288 }
289 
290 /*
291  * SoC-specific functions and definitions
292  */
293 
294 static unsigned int armada_370_xp_mbus_win_offset(int win)
295 {
296 	/* The register layout is a bit annoying and the below code
297 	 * tries to cope with it.
298 	 * - At offset 0x0, there are the registers for the first 8
299 	 *   windows, with 4 registers of 32 bits per window (ctrl,
300 	 *   base, remap low, remap high)
301 	 * - Then at offset 0x80, there is a hole of 0x10 bytes for
302 	 *   the internal registers base address and internal units
303 	 *   sync barrier register.
304 	 * - Then at offset 0x90, there the registers for 12
305 	 *   windows, with only 2 registers of 32 bits per window
306 	 *   (ctrl, base).
307 	 */
308 	if (win < 8)
309 		return win << 4;
310 	else
311 		return 0x90 + ((win - 8) << 3);
312 }
313 
314 static unsigned int orion5x_mbus_win_offset(int win)
315 {
316 	return win << 4;
317 }
318 
319 static void mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus)
320 {
321 	int i;
322 	int cs;
323 
324 	mbus_dram_info.mbus_dram_target_id = TARGET_DDR;
325 
326 	for (i = 0, cs = 0; i < 4; i++) {
327 		u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));
328 		u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));
329 
330 		/*
331 		 * We only take care of entries for which the chip
332 		 * select is enabled, and that don't have high base
333 		 * address bits set (devices can only access the first
334 		 * 32 bits of the memory).
335 		 */
336 		if ((size & DDR_SIZE_ENABLED) &&
337 		    !(base & DDR_BASE_CS_HIGH_MASK)) {
338 			struct mbus_dram_window *w;
339 
340 			w = &mbus_dram_info.cs[cs++];
341 			w->cs_index = i;
342 			w->mbus_attr = 0xf & ~(1 << i);
343 			w->base = base & DDR_BASE_CS_LOW_MASK;
344 			w->size = (size | ~DDR_SIZE_MASK) + 1;
345 		}
346 	}
347 	mbus_dram_info.num_cs = cs;
348 }
349 
350 static const struct mvebu_mbus_soc_data
351 armada_370_xp_mbus_data __maybe_unused = {
352 	.num_wins            = 20,
353 	.num_remappable_wins = 8,
354 	.win_cfg_offset      = armada_370_xp_mbus_win_offset,
355 	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
356 };
357 
358 static const struct mvebu_mbus_soc_data
359 kirkwood_mbus_data __maybe_unused = {
360 	.num_wins            = 8,
361 	.num_remappable_wins = 4,
362 	.win_cfg_offset      = orion5x_mbus_win_offset,
363 	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
364 };
365 
366 /*
367  * Public API of the driver
368  */
369 const struct mbus_dram_target_info *mvebu_mbus_dram_info(void)
370 {
371 	return &mbus_dram_info;
372 }
373 
374 int mvebu_mbus_add_window_remap_by_id(unsigned int target,
375 				      unsigned int attribute,
376 				      phys_addr_t base, size_t size,
377 				      phys_addr_t remap)
378 {
379 	struct mvebu_mbus_state *s = &mbus_state;
380 
381 	if (!mvebu_mbus_window_conflicts(s, base, size, target, attribute)) {
382 		printf("Cannot add window '%x:%x', conflicts with another window\n",
383 		       target, attribute);
384 		return -EINVAL;
385 	}
386 
387 	return mvebu_mbus_alloc_window(s, base, size, remap, target, attribute);
388 }
389 
390 int mvebu_mbus_add_window_by_id(unsigned int target, unsigned int attribute,
391 				phys_addr_t base, size_t size)
392 {
393 	return mvebu_mbus_add_window_remap_by_id(target, attribute, base,
394 						 size, MVEBU_MBUS_NO_REMAP);
395 }
396 
397 int mvebu_mbus_del_window(phys_addr_t base, size_t size)
398 {
399 	int win;
400 
401 	win = mvebu_mbus_find_window(&mbus_state, base, size);
402 	if (win < 0)
403 		return win;
404 
405 	mvebu_mbus_disable_window(&mbus_state, win);
406 	return 0;
407 }
408 
409 static void mvebu_mbus_get_lowest_base(struct mvebu_mbus_state *mbus,
410 				       phys_addr_t *base)
411 {
412 	int win;
413 	*base = 0xffffffff;
414 
415 	for (win = 0; win < mbus->soc->num_wins; win++) {
416 		u64 wbase;
417 		u32 wsize;
418 		u8 wtarget, wattr;
419 		int enabled;
420 
421 		mvebu_mbus_read_window(mbus, win,
422 				       &enabled, &wbase, &wsize,
423 				       &wtarget, &wattr, NULL);
424 
425 		if (!enabled)
426 			continue;
427 
428 		if (wbase < *base)
429 			*base = wbase;
430 	}
431 }
432 
433 static void mvebu_config_mbus_bridge(struct mvebu_mbus_state *mbus)
434 {
435 	phys_addr_t base;
436 	u32 val;
437 	u32 size;
438 
439 	/* Set MBUS bridge base/ctrl */
440 	mvebu_mbus_get_lowest_base(&mbus_state, &base);
441 
442 	size = 0xffffffff - base + 1;
443 	if (!is_power_of_2(size)) {
444 		/* Round up to next power of 2 */
445 		size = 1 << (ffs(base) + 1);
446 		base = 0xffffffff - size + 1;
447 	}
448 
449 	/* Now write base and size */
450 	writel(base, MBUS_BRIDGE_WIN_BASE_REG);
451 	/* Align window size to 64KiB */
452 	val = (size / (64 << 10)) - 1;
453 	writel((val << 16) | 0x1, MBUS_BRIDGE_WIN_CTRL_REG);
454 }
455 
456 int mbus_dt_setup_win(struct mvebu_mbus_state *mbus,
457 		      u32 base, u32 size, u8 target, u8 attr)
458 {
459 	if (!mvebu_mbus_window_conflicts(mbus, base, size, target, attr)) {
460 		printf("Cannot add window '%04x:%04x', conflicts with another window\n",
461 		       target, attr);
462 		return -EBUSY;
463 	}
464 
465 	/*
466 	 * In U-Boot we first try to add the mbus window to the remap windows.
467 	 * If this fails, lets try to add the windows to the non-remap windows.
468 	 */
469 	if (mvebu_mbus_alloc_window(mbus, base, size, base, target, attr)) {
470 		if (mvebu_mbus_alloc_window(mbus, base, size,
471 					    MVEBU_MBUS_NO_REMAP, target, attr))
472 			return -ENOMEM;
473 	}
474 
475 	/*
476 	 * Re-configure the mbus bridge registers each time this function
477 	 * is called. Since it may get called from the board code in
478 	 * later boot stages as well.
479 	 */
480 	mvebu_config_mbus_bridge(mbus);
481 
482 	return 0;
483 }
484 
485 int mvebu_mbus_probe(struct mbus_win windows[], int count)
486 {
487 	int win;
488 	int ret;
489 	int i;
490 
491 #if defined(CONFIG_KIRKWOOD)
492 	mbus_state.soc = &kirkwood_mbus_data;
493 #endif
494 #if defined(CONFIG_ARCH_MVEBU)
495 	mbus_state.soc = &armada_370_xp_mbus_data;
496 #endif
497 
498 	mbus_state.mbuswins_base = (void __iomem *)MVEBU_CPU_WIN_BASE;
499 	mbus_state.sdramwins_base = (void __iomem *)MVEBU_SDRAM_BASE;
500 
501 	for (win = 0; win < mbus_state.soc->num_wins; win++)
502 		mvebu_mbus_disable_window(&mbus_state, win);
503 
504 	mbus_state.soc->setup_cpu_target(&mbus_state);
505 
506 	/* Setup statically declared windows in the DT */
507 	for (i = 0; i < count; i++) {
508 		u32 base, size;
509 		u8 target, attr;
510 
511 		target = windows[i].target;
512 		attr = windows[i].attr;
513 		base = windows[i].base;
514 		size = windows[i].size;
515 		ret = mbus_dt_setup_win(&mbus_state, base, size, target, attr);
516 		if (ret < 0)
517 			return ret;
518 	}
519 
520 	return 0;
521 }
522