xref: /openbmc/u-boot/arch/arm/mach-mvebu/mbus.c (revision 95de1e2f)
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 <asm/errno.h>
52 #include <asm/io.h>
53 #include <asm/arch/cpu.h>
54 #include <asm/arch/soc.h>
55 #include <linux/mbus.h>
56 
57 #define BIT(nr)			(1UL << (nr))
58 
59 /* DDR target is the same on all platforms */
60 #define TARGET_DDR		0
61 
62 /* CPU Address Decode Windows registers */
63 #define WIN_CTRL_OFF		0x0000
64 #define   WIN_CTRL_ENABLE       BIT(0)
65 #define   WIN_CTRL_TGT_MASK     0xf0
66 #define   WIN_CTRL_TGT_SHIFT    4
67 #define   WIN_CTRL_ATTR_MASK    0xff00
68 #define   WIN_CTRL_ATTR_SHIFT   8
69 #define   WIN_CTRL_SIZE_MASK    0xffff0000
70 #define   WIN_CTRL_SIZE_SHIFT   16
71 #define WIN_BASE_OFF		0x0004
72 #define   WIN_BASE_LOW          0xffff0000
73 #define   WIN_BASE_HIGH         0xf
74 #define WIN_REMAP_LO_OFF	0x0008
75 #define   WIN_REMAP_LOW         0xffff0000
76 #define WIN_REMAP_HI_OFF	0x000c
77 
78 #define ATTR_HW_COHERENCY	(0x1 << 4)
79 
80 #define DDR_BASE_CS_OFF(n)	(0x0000 + ((n) << 3))
81 #define  DDR_BASE_CS_HIGH_MASK  0xf
82 #define  DDR_BASE_CS_LOW_MASK   0xff000000
83 #define DDR_SIZE_CS_OFF(n)	(0x0004 + ((n) << 3))
84 #define  DDR_SIZE_ENABLED       BIT(0)
85 #define  DDR_SIZE_CS_MASK       0x1c
86 #define  DDR_SIZE_CS_SHIFT      2
87 #define  DDR_SIZE_MASK          0xff000000
88 
89 #define DOVE_DDR_BASE_CS_OFF(n) ((n) << 4)
90 
91 struct mvebu_mbus_state;
92 
93 struct mvebu_mbus_soc_data {
94 	unsigned int num_wins;
95 	unsigned int num_remappable_wins;
96 	unsigned int (*win_cfg_offset)(const int win);
97 	void (*setup_cpu_target)(struct mvebu_mbus_state *s);
98 };
99 
100 struct mvebu_mbus_state mbus_state
101 	__attribute__ ((section(".data")));
102 static struct mbus_dram_target_info mbus_dram_info
103 	__attribute__ ((section(".data")));
104 
105 /*
106  * Functions to manipulate the address decoding windows
107  */
108 
109 static void mvebu_mbus_read_window(struct mvebu_mbus_state *mbus,
110 				   int win, int *enabled, u64 *base,
111 				   u32 *size, u8 *target, u8 *attr,
112 				   u64 *remap)
113 {
114 	void __iomem *addr = mbus->mbuswins_base +
115 		mbus->soc->win_cfg_offset(win);
116 	u32 basereg = readl(addr + WIN_BASE_OFF);
117 	u32 ctrlreg = readl(addr + WIN_CTRL_OFF);
118 
119 	if (!(ctrlreg & WIN_CTRL_ENABLE)) {
120 		*enabled = 0;
121 		return;
122 	}
123 
124 	*enabled = 1;
125 	*base = ((u64)basereg & WIN_BASE_HIGH) << 32;
126 	*base |= (basereg & WIN_BASE_LOW);
127 	*size = (ctrlreg | ~WIN_CTRL_SIZE_MASK) + 1;
128 
129 	if (target)
130 		*target = (ctrlreg & WIN_CTRL_TGT_MASK) >> WIN_CTRL_TGT_SHIFT;
131 
132 	if (attr)
133 		*attr = (ctrlreg & WIN_CTRL_ATTR_MASK) >> WIN_CTRL_ATTR_SHIFT;
134 
135 	if (remap) {
136 		if (win < mbus->soc->num_remappable_wins) {
137 			u32 remap_low = readl(addr + WIN_REMAP_LO_OFF);
138 			u32 remap_hi  = readl(addr + WIN_REMAP_HI_OFF);
139 			*remap = ((u64)remap_hi << 32) | remap_low;
140 		} else {
141 			*remap = 0;
142 		}
143 	}
144 }
145 
146 static void mvebu_mbus_disable_window(struct mvebu_mbus_state *mbus,
147 				      int win)
148 {
149 	void __iomem *addr;
150 
151 	addr = mbus->mbuswins_base + mbus->soc->win_cfg_offset(win);
152 
153 	writel(0, addr + WIN_BASE_OFF);
154 	writel(0, addr + WIN_CTRL_OFF);
155 	if (win < mbus->soc->num_remappable_wins) {
156 		writel(0, addr + WIN_REMAP_LO_OFF);
157 		writel(0, addr + WIN_REMAP_HI_OFF);
158 	}
159 }
160 
161 /* Checks whether the given window number is available */
162 static int mvebu_mbus_window_is_free(struct mvebu_mbus_state *mbus,
163 				     const int win)
164 {
165 	void __iomem *addr = mbus->mbuswins_base +
166 		mbus->soc->win_cfg_offset(win);
167 	u32 ctrl = readl(addr + WIN_CTRL_OFF);
168 	return !(ctrl & WIN_CTRL_ENABLE);
169 }
170 
171 /*
172  * Checks whether the given (base, base+size) area doesn't overlap an
173  * existing region
174  */
175 static int mvebu_mbus_window_conflicts(struct mvebu_mbus_state *mbus,
176 				       phys_addr_t base, size_t size,
177 				       u8 target, u8 attr)
178 {
179 	u64 end = (u64)base + size;
180 	int win;
181 
182 	for (win = 0; win < mbus->soc->num_wins; win++) {
183 		u64 wbase, wend;
184 		u32 wsize;
185 		u8 wtarget, wattr;
186 		int enabled;
187 
188 		mvebu_mbus_read_window(mbus, win,
189 				       &enabled, &wbase, &wsize,
190 				       &wtarget, &wattr, NULL);
191 
192 		if (!enabled)
193 			continue;
194 
195 		wend = wbase + wsize;
196 
197 		/*
198 		 * Check if the current window overlaps with the
199 		 * proposed physical range
200 		 */
201 		if ((u64)base < wend && end > wbase)
202 			return 0;
203 
204 		/*
205 		 * Check if target/attribute conflicts
206 		 */
207 		if (target == wtarget && attr == wattr)
208 			return 0;
209 	}
210 
211 	return 1;
212 }
213 
214 static int mvebu_mbus_find_window(struct mvebu_mbus_state *mbus,
215 				  phys_addr_t base, size_t size)
216 {
217 	int win;
218 
219 	for (win = 0; win < mbus->soc->num_wins; win++) {
220 		u64 wbase;
221 		u32 wsize;
222 		int enabled;
223 
224 		mvebu_mbus_read_window(mbus, win,
225 				       &enabled, &wbase, &wsize,
226 				       NULL, NULL, NULL);
227 
228 		if (!enabled)
229 			continue;
230 
231 		if (base == wbase && size == wsize)
232 			return win;
233 	}
234 
235 	return -ENODEV;
236 }
237 
238 static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus,
239 				   int win, phys_addr_t base, size_t size,
240 				   phys_addr_t remap, u8 target,
241 				   u8 attr)
242 {
243 	void __iomem *addr = mbus->mbuswins_base +
244 		mbus->soc->win_cfg_offset(win);
245 	u32 ctrl, remap_addr;
246 
247 	ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
248 		(attr << WIN_CTRL_ATTR_SHIFT)    |
249 		(target << WIN_CTRL_TGT_SHIFT)   |
250 		WIN_CTRL_ENABLE;
251 
252 	writel(base & WIN_BASE_LOW, addr + WIN_BASE_OFF);
253 	writel(ctrl, addr + WIN_CTRL_OFF);
254 	if (win < mbus->soc->num_remappable_wins) {
255 		if (remap == MVEBU_MBUS_NO_REMAP)
256 			remap_addr = base;
257 		else
258 			remap_addr = remap;
259 		writel(remap_addr & WIN_REMAP_LOW, addr + WIN_REMAP_LO_OFF);
260 		writel(0, addr + WIN_REMAP_HI_OFF);
261 	}
262 
263 	return 0;
264 }
265 
266 static int mvebu_mbus_alloc_window(struct mvebu_mbus_state *mbus,
267 				   phys_addr_t base, size_t size,
268 				   phys_addr_t remap, u8 target,
269 				   u8 attr)
270 {
271 	int win;
272 
273 	if (remap == MVEBU_MBUS_NO_REMAP) {
274 		for (win = mbus->soc->num_remappable_wins;
275 		     win < mbus->soc->num_wins; win++)
276 			if (mvebu_mbus_window_is_free(mbus, win))
277 				return mvebu_mbus_setup_window(mbus, win, base,
278 							       size, remap,
279 							       target, attr);
280 	}
281 
282 
283 	for (win = 0; win < mbus->soc->num_wins; win++)
284 		if (mvebu_mbus_window_is_free(mbus, win))
285 			return mvebu_mbus_setup_window(mbus, win, base, size,
286 						       remap, target, attr);
287 
288 	return -ENOMEM;
289 }
290 
291 /*
292  * SoC-specific functions and definitions
293  */
294 
295 static unsigned int armada_370_xp_mbus_win_offset(int win)
296 {
297 	/* The register layout is a bit annoying and the below code
298 	 * tries to cope with it.
299 	 * - At offset 0x0, there are the registers for the first 8
300 	 *   windows, with 4 registers of 32 bits per window (ctrl,
301 	 *   base, remap low, remap high)
302 	 * - Then at offset 0x80, there is a hole of 0x10 bytes for
303 	 *   the internal registers base address and internal units
304 	 *   sync barrier register.
305 	 * - Then at offset 0x90, there the registers for 12
306 	 *   windows, with only 2 registers of 32 bits per window
307 	 *   (ctrl, base).
308 	 */
309 	if (win < 8)
310 		return win << 4;
311 	else
312 		return 0x90 + ((win - 8) << 3);
313 }
314 
315 static unsigned int orion5x_mbus_win_offset(int win)
316 {
317 	return win << 4;
318 }
319 
320 static void mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus)
321 {
322 	int i;
323 	int cs;
324 
325 	mbus_dram_info.mbus_dram_target_id = TARGET_DDR;
326 
327 	for (i = 0, cs = 0; i < 4; i++) {
328 		u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));
329 		u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));
330 
331 		/*
332 		 * We only take care of entries for which the chip
333 		 * select is enabled, and that don't have high base
334 		 * address bits set (devices can only access the first
335 		 * 32 bits of the memory).
336 		 */
337 		if ((size & DDR_SIZE_ENABLED) &&
338 		    !(base & DDR_BASE_CS_HIGH_MASK)) {
339 			struct mbus_dram_window *w;
340 
341 			w = &mbus_dram_info.cs[cs++];
342 			w->cs_index = i;
343 			w->mbus_attr = 0xf & ~(1 << i);
344 			w->base = base & DDR_BASE_CS_LOW_MASK;
345 			w->size = (size | ~DDR_SIZE_MASK) + 1;
346 		}
347 	}
348 	mbus_dram_info.num_cs = cs;
349 }
350 
351 static const struct mvebu_mbus_soc_data
352 armada_370_xp_mbus_data __maybe_unused = {
353 	.num_wins            = 20,
354 	.num_remappable_wins = 8,
355 	.win_cfg_offset      = armada_370_xp_mbus_win_offset,
356 	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
357 };
358 
359 static const struct mvebu_mbus_soc_data
360 kirkwood_mbus_data __maybe_unused = {
361 	.num_wins            = 8,
362 	.num_remappable_wins = 4,
363 	.win_cfg_offset      = orion5x_mbus_win_offset,
364 	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
365 };
366 
367 /*
368  * Public API of the driver
369  */
370 const struct mbus_dram_target_info *mvebu_mbus_dram_info(void)
371 {
372 	return &mbus_dram_info;
373 }
374 
375 int mvebu_mbus_add_window_remap_by_id(unsigned int target,
376 				      unsigned int attribute,
377 				      phys_addr_t base, size_t size,
378 				      phys_addr_t remap)
379 {
380 	struct mvebu_mbus_state *s = &mbus_state;
381 
382 	if (!mvebu_mbus_window_conflicts(s, base, size, target, attribute)) {
383 		printf("Cannot add window '%x:%x', conflicts with another window\n",
384 		       target, attribute);
385 		return -EINVAL;
386 	}
387 
388 	return mvebu_mbus_alloc_window(s, base, size, remap, target, attribute);
389 }
390 
391 int mvebu_mbus_add_window_by_id(unsigned int target, unsigned int attribute,
392 				phys_addr_t base, size_t size)
393 {
394 	return mvebu_mbus_add_window_remap_by_id(target, attribute, base,
395 						 size, MVEBU_MBUS_NO_REMAP);
396 }
397 
398 int mvebu_mbus_del_window(phys_addr_t base, size_t size)
399 {
400 	int win;
401 
402 	win = mvebu_mbus_find_window(&mbus_state, base, size);
403 	if (win < 0)
404 		return win;
405 
406 	mvebu_mbus_disable_window(&mbus_state, win);
407 	return 0;
408 }
409 
410 int mbus_dt_setup_win(struct mvebu_mbus_state *mbus,
411 		      u32 base, u32 size, u8 target, u8 attr)
412 {
413 	if (!mvebu_mbus_window_conflicts(mbus, base, size, target, attr)) {
414 		printf("Cannot add window '%04x:%04x', conflicts with another window\n",
415 		       target, attr);
416 		return -EBUSY;
417 	}
418 
419 	/*
420 	 * In U-Boot we first try to add the mbus window to the remap windows.
421 	 * If this fails, lets try to add the windows to the non-remap windows.
422 	 */
423 	if (mvebu_mbus_alloc_window(mbus, base, size, base, target, attr)) {
424 		if (mvebu_mbus_alloc_window(mbus, base, size,
425 					    MVEBU_MBUS_NO_REMAP, target, attr))
426 			return -ENOMEM;
427 	}
428 
429 	return 0;
430 }
431 
432 int mvebu_mbus_probe(struct mbus_win windows[], int count)
433 {
434 	int win;
435 	int ret;
436 	int i;
437 
438 #if defined(CONFIG_KIRKWOOD)
439 	mbus_state.soc = &kirkwood_mbus_data;
440 #endif
441 #if defined(CONFIG_ARMADA_XP)
442 	mbus_state.soc = &armada_370_xp_mbus_data;
443 #endif
444 
445 	mbus_state.mbuswins_base = (void __iomem *)MVEBU_CPU_WIN_BASE;
446 	mbus_state.sdramwins_base = (void __iomem *)MVEBU_SDRAM_BASE;
447 
448 	for (win = 0; win < mbus_state.soc->num_wins; win++)
449 		mvebu_mbus_disable_window(&mbus_state, win);
450 
451 	mbus_state.soc->setup_cpu_target(&mbus_state);
452 
453 	/* Setup statically declared windows in the DT */
454 	for (i = 0; i < count; i++) {
455 		u32 base, size;
456 		u8 target, attr;
457 
458 		target = windows[i].target;
459 		attr = windows[i].attr;
460 		base = windows[i].base;
461 		size = windows[i].size;
462 		ret = mbus_dt_setup_win(&mbus_state, base, size, target, attr);
463 		if (ret < 0)
464 			return ret;
465 	}
466 
467 	return 0;
468 }
469