xref: /openbmc/u-boot/include/fdtdec.h (revision d9b88d25)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * SPDX-License-Identifier:	GPL-2.0+
4  */
5 
6 #ifndef __fdtdec_h
7 #define __fdtdec_h
8 
9 /*
10  * This file contains convenience functions for decoding useful and
11  * enlightening information from FDTs. It is intended to be used by device
12  * drivers and board-specific code within U-Boot. It aims to reduce the
13  * amount of FDT munging required within U-Boot itself, so that driver code
14  * changes to support FDT are minimized.
15  */
16 
17 #include <libfdt.h>
18 #include <pci.h>
19 
20 /*
21  * A typedef for a physical address. Note that fdt data is always big
22  * endian even on a litle endian machine.
23  */
24 typedef phys_addr_t fdt_addr_t;
25 typedef phys_size_t fdt_size_t;
26 #ifdef CONFIG_PHYS_64BIT
27 #define FDT_ADDR_T_NONE (-1ULL)
28 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
29 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
30 #else
31 #define FDT_ADDR_T_NONE (-1U)
32 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
33 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
34 #endif
35 
36 /* Information obtained about memory from the FDT */
37 struct fdt_memory {
38 	fdt_addr_t start;
39 	fdt_addr_t end;
40 };
41 
42 #ifdef CONFIG_SPL_BUILD
43 #define SPL_BUILD	1
44 #else
45 #define SPL_BUILD	0
46 #endif
47 
48 /*
49  * Information about a resource. start is the first address of the resource
50  * and end is the last address (inclusive). The length of the resource will
51  * be equal to: end - start + 1.
52  */
53 struct fdt_resource {
54 	fdt_addr_t start;
55 	fdt_addr_t end;
56 };
57 
58 enum fdt_pci_space {
59 	FDT_PCI_SPACE_CONFIG = 0,
60 	FDT_PCI_SPACE_IO = 0x01000000,
61 	FDT_PCI_SPACE_MEM32 = 0x02000000,
62 	FDT_PCI_SPACE_MEM64 = 0x03000000,
63 	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
64 	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
65 };
66 
67 #define FDT_PCI_ADDR_CELLS	3
68 #define FDT_PCI_SIZE_CELLS	2
69 #define FDT_PCI_REG_SIZE	\
70 	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
71 
72 /*
73  * The Open Firmware spec defines PCI physical address as follows:
74  *
75  *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
76  *
77  * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
78  * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
79  * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
80  *
81  * where:
82  *
83  * n:        is 0 if the address is relocatable, 1 otherwise
84  * p:        is 1 if addressable region is prefetchable, 0 otherwise
85  * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
86  *           (for Memory), or below 64KB (for relocatable I/O)
87  * ss:       is the space code, denoting the address space
88  * bbbbbbbb: is the 8-bit Bus Number
89  * ddddd:    is the 5-bit Device Number
90  * fff:      is the 3-bit Function Number
91  * rrrrrrrr: is the 8-bit Register Number
92  * hhhhhhhh: is a 32-bit unsigned number
93  * llllllll: is a 32-bit unsigned number
94  */
95 struct fdt_pci_addr {
96 	u32	phys_hi;
97 	u32	phys_mid;
98 	u32	phys_lo;
99 };
100 
101 /**
102  * Compute the size of a resource.
103  *
104  * @param res	the resource to operate on
105  * @return the size of the resource
106  */
107 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
108 {
109 	return res->end - res->start + 1;
110 }
111 
112 /**
113  * Compat types that we know about and for which we might have drivers.
114  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
115  * within drivers.
116  */
117 enum fdt_compat_id {
118 	COMPAT_UNKNOWN,
119 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
120 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
121 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
122 	COMPAT_NVIDIA_TEGRA124_PMC,	/* Tegra 124 power mgmt controller */
123 	COMPAT_NVIDIA_TEGRA186_SDMMC,	/* Tegra186 SDMMC controller */
124 	COMPAT_NVIDIA_TEGRA210_SDMMC,	/* Tegra210 SDMMC controller */
125 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
126 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
127 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
128 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
129 					/* Tegra124 XUSB pad controller */
130 	COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
131 					/* Tegra210 XUSB pad controller */
132 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
133 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
134 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
135 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
136 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
137 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
138 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
139 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
140 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
141 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
142 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
143 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
144 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
145 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
146 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
147 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
148 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
149 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
150 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
151 	COMPAT_ALTERA_SOCFPGA_DWMAC,	/* SoCFPGA Ethernet controller */
152 	COMPAT_ALTERA_SOCFPGA_DWMMC,	/* SoCFPGA DWMMC controller */
153 	COMPAT_ALTERA_SOCFPGA_DWC2USB,	/* SoCFPGA DWC2 USB controller */
154 	COMPAT_INTEL_BAYTRAIL_FSP,	/* Intel Bay Trail FSP */
155 	COMPAT_INTEL_BAYTRAIL_FSP_MDP,	/* Intel FSP memory-down params */
156 	COMPAT_INTEL_IVYBRIDGE_FSP,	/* Intel Ivy Bridge FSP */
157 	COMPAT_SUNXI_NAND,		/* SUNXI NAND controller */
158 
159 	COMPAT_COUNT,
160 };
161 
162 #define MAX_PHANDLE_ARGS 16
163 struct fdtdec_phandle_args {
164 	int node;
165 	int args_count;
166 	uint32_t args[MAX_PHANDLE_ARGS];
167 };
168 
169 /**
170  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
171  *
172  * This function is useful to parse lists of phandles and their arguments.
173  *
174  * Example:
175  *
176  * phandle1: node1 {
177  *	#list-cells = <2>;
178  * }
179  *
180  * phandle2: node2 {
181  *	#list-cells = <1>;
182  * }
183  *
184  * node3 {
185  *	list = <&phandle1 1 2 &phandle2 3>;
186  * }
187  *
188  * To get a device_node of the `node2' node you may call this:
189  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
190  *				  &args);
191  *
192  * (This function is a modified version of __of_parse_phandle_with_args() from
193  * Linux 3.18)
194  *
195  * @blob:	Pointer to device tree
196  * @src_node:	Offset of device tree node containing a list
197  * @list_name:	property name that contains a list
198  * @cells_name:	property name that specifies the phandles' arguments count,
199  *		or NULL to use @cells_count
200  * @cells_count: Cell count to use if @cells_name is NULL
201  * @index:	index of a phandle to parse out
202  * @out_args:	optional pointer to output arguments structure (will be filled)
203  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
204  *	@list_name does not exist, a phandle was not found, @cells_name
205  *	could not be found, the arguments were truncated or there were too
206  *	many arguments.
207  *
208  */
209 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
210 				   const char *list_name,
211 				   const char *cells_name,
212 				   int cell_count, int index,
213 				   struct fdtdec_phandle_args *out_args);
214 
215 /**
216  * Find the next numbered alias for a peripheral. This is used to enumerate
217  * all the peripherals of a certain type.
218  *
219  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
220  * this function will return a pointer to the node the alias points to, and
221  * then update *upto to 1. Next time you call this function, the next node
222  * will be returned.
223  *
224  * All nodes returned will match the compatible ID, as it is assumed that
225  * all peripherals use the same driver.
226  *
227  * @param blob		FDT blob to use
228  * @param name		Root name of alias to search for
229  * @param id		Compatible ID to look for
230  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
231  */
232 int fdtdec_next_alias(const void *blob, const char *name,
233 		enum fdt_compat_id id, int *upto);
234 
235 /**
236  * Find the compatible ID for a given node.
237  *
238  * Generally each node has at least one compatible string attached to it.
239  * This function looks through our list of known compatible strings and
240  * returns the corresponding ID which matches the compatible string.
241  *
242  * @param blob		FDT blob to use
243  * @param node		Node containing compatible string to find
244  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
245  */
246 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
247 
248 /**
249  * Find the next compatible node for a peripheral.
250  *
251  * Do the first call with node = 0. This function will return a pointer to
252  * the next compatible node. Next time you call this function, pass the
253  * value returned, and the next node will be provided.
254  *
255  * @param blob		FDT blob to use
256  * @param node		Start node for search
257  * @param id		Compatible ID to look for (enum fdt_compat_id)
258  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
259  */
260 int fdtdec_next_compatible(const void *blob, int node,
261 		enum fdt_compat_id id);
262 
263 /**
264  * Find the next compatible subnode for a peripheral.
265  *
266  * Do the first call with node set to the parent and depth = 0. This
267  * function will return the offset of the next compatible node. Next time
268  * you call this function, pass the node value returned last time, with
269  * depth unchanged, and the next node will be provided.
270  *
271  * @param blob		FDT blob to use
272  * @param node		Start node for search
273  * @param id		Compatible ID to look for (enum fdt_compat_id)
274  * @param depthp	Current depth (set to 0 before first call)
275  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
276  */
277 int fdtdec_next_compatible_subnode(const void *blob, int node,
278 		enum fdt_compat_id id, int *depthp);
279 
280 /*
281  * Look up an address property in a node and return the parsed address, and
282  * optionally the parsed size.
283  *
284  * This variant assumes a known and fixed number of cells are used to
285  * represent the address and size.
286  *
287  * You probably don't want to use this function directly except to parse
288  * non-standard properties, and never to parse the "reg" property. Instead,
289  * use one of the "auto" variants below, which automatically honor the
290  * #address-cells and #size-cells properties in the parent node.
291  *
292  * @param blob	FDT blob
293  * @param node	node to examine
294  * @param prop_name	name of property to find
295  * @param index	which address to retrieve from a list of addresses. Often 0.
296  * @param na	the number of cells used to represent an address
297  * @param ns	the number of cells used to represent a size
298  * @param sizep	a pointer to store the size into. Use NULL if not required
299  * @param translate	Indicates whether to translate the returned value
300  *			using the parent node's ranges property.
301  * @return address, if found, or FDT_ADDR_T_NONE if not
302  */
303 fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
304 		const char *prop_name, int index, int na, int ns,
305 		fdt_size_t *sizep, bool translate);
306 
307 /*
308  * Look up an address property in a node and return the parsed address, and
309  * optionally the parsed size.
310  *
311  * This variant automatically determines the number of cells used to represent
312  * the address and size by parsing the provided parent node's #address-cells
313  * and #size-cells properties.
314  *
315  * @param blob	FDT blob
316  * @param parent	parent node of @node
317  * @param node	node to examine
318  * @param prop_name	name of property to find
319  * @param index	which address to retrieve from a list of addresses. Often 0.
320  * @param sizep	a pointer to store the size into. Use NULL if not required
321  * @param translate	Indicates whether to translate the returned value
322  *			using the parent node's ranges property.
323  * @return address, if found, or FDT_ADDR_T_NONE if not
324  */
325 fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
326 		int node, const char *prop_name, int index, fdt_size_t *sizep,
327 		bool translate);
328 
329 /*
330  * Look up an address property in a node and return the parsed address, and
331  * optionally the parsed size.
332  *
333  * This variant automatically determines the number of cells used to represent
334  * the address and size by parsing the parent node's #address-cells
335  * and #size-cells properties. The parent node is automatically found.
336  *
337  * The automatic parent lookup implemented by this function is slow.
338  * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
339  * possible.
340  *
341  * @param blob	FDT blob
342  * @param parent	parent node of @node
343  * @param node	node to examine
344  * @param prop_name	name of property to find
345  * @param index	which address to retrieve from a list of addresses. Often 0.
346  * @param sizep	a pointer to store the size into. Use NULL if not required
347  * @param translate	Indicates whether to translate the returned value
348  *			using the parent node's ranges property.
349  * @return address, if found, or FDT_ADDR_T_NONE if not
350  */
351 fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
352 		const char *prop_name, int index, fdt_size_t *sizep,
353 		bool translate);
354 
355 /*
356  * Look up an address property in a node and return the parsed address.
357  *
358  * This variant hard-codes the number of cells used to represent the address
359  * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
360  * always returns the first address value in the property (index 0).
361  *
362  * Use of this function is not recommended due to the hard-coding of cell
363  * counts. There is no programmatic validation that these hard-coded values
364  * actually match the device tree content in any way at all. This assumption
365  * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
366  * set in the U-Boot build and exercising strict control over DT content to
367  * ensure use of matching #address-cells/#size-cells properties. However, this
368  * approach is error-prone; those familiar with DT will not expect the
369  * assumption to exist, and could easily invalidate it. If the assumption is
370  * invalidated, this function will not report the issue, and debugging will
371  * be required. Instead, use fdtdec_get_addr_size_auto_parent().
372  *
373  * @param blob	FDT blob
374  * @param node	node to examine
375  * @param prop_name	name of property to find
376  * @return address, if found, or FDT_ADDR_T_NONE if not
377  */
378 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
379 		const char *prop_name);
380 
381 /*
382  * Look up an address property in a node and return the parsed address, and
383  * optionally the parsed size.
384  *
385  * This variant hard-codes the number of cells used to represent the address
386  * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
387  * always returns the first address value in the property (index 0).
388  *
389  * Use of this function is not recommended due to the hard-coding of cell
390  * counts. There is no programmatic validation that these hard-coded values
391  * actually match the device tree content in any way at all. This assumption
392  * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
393  * set in the U-Boot build and exercising strict control over DT content to
394  * ensure use of matching #address-cells/#size-cells properties. However, this
395  * approach is error-prone; those familiar with DT will not expect the
396  * assumption to exist, and could easily invalidate it. If the assumption is
397  * invalidated, this function will not report the issue, and debugging will
398  * be required. Instead, use fdtdec_get_addr_size_auto_parent().
399  *
400  * @param blob	FDT blob
401  * @param node	node to examine
402  * @param prop_name	name of property to find
403  * @param sizep	a pointer to store the size into. Use NULL if not required
404  * @return address, if found, or FDT_ADDR_T_NONE if not
405  */
406 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
407 		const char *prop_name, fdt_size_t *sizep);
408 
409 /**
410  * Look at an address property in a node and return the pci address which
411  * corresponds to the given type in the form of fdt_pci_addr.
412  * The property must hold one fdt_pci_addr with a lengh.
413  *
414  * @param blob		FDT blob
415  * @param node		node to examine
416  * @param type		pci address type (FDT_PCI_SPACE_xxx)
417  * @param prop_name	name of property to find
418  * @param addr		returns pci address in the form of fdt_pci_addr
419  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
420  *		format of the property was invalid, -ENXIO if the requested
421  *		address type was not found
422  */
423 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
424 		const char *prop_name, struct fdt_pci_addr *addr);
425 
426 /**
427  * Look at the compatible property of a device node that represents a PCI
428  * device and extract pci vendor id and device id from it.
429  *
430  * @param blob		FDT blob
431  * @param node		node to examine
432  * @param vendor	vendor id of the pci device
433  * @param device	device id of the pci device
434  * @return 0 if ok, negative on error
435  */
436 int fdtdec_get_pci_vendev(const void *blob, int node,
437 		u16 *vendor, u16 *device);
438 
439 /**
440  * Look at the pci address of a device node that represents a PCI device
441  * and return base address of the pci device's registers.
442  *
443  * @param dev		device to examine
444  * @param addr		pci address in the form of fdt_pci_addr
445  * @param bar		returns base address of the pci device's registers
446  * @return 0 if ok, negative on error
447  */
448 int fdtdec_get_pci_bar32(struct udevice *dev, struct fdt_pci_addr *addr,
449 			 u32 *bar);
450 
451 /**
452  * Look up a 32-bit integer property in a node and return it. The property
453  * must have at least 4 bytes of data. The value of the first cell is
454  * returned.
455  *
456  * @param blob	FDT blob
457  * @param node	node to examine
458  * @param prop_name	name of property to find
459  * @param default_val	default value to return if the property is not found
460  * @return integer value, if found, or default_val if not
461  */
462 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
463 		s32 default_val);
464 
465 /**
466  * Unsigned version of fdtdec_get_int. The property must have at least
467  * 4 bytes of data. The value of the first cell is returned.
468  *
469  * @param blob	FDT blob
470  * @param node	node to examine
471  * @param prop_name	name of property to find
472  * @param default_val	default value to return if the property is not found
473  * @return unsigned integer value, if found, or default_val if not
474  */
475 unsigned int fdtdec_get_uint(const void *blob, int node, const char *prop_name,
476 			unsigned int default_val);
477 
478 /**
479  * Get a variable-sized number from a property
480  *
481  * This reads a number from one or more cells.
482  *
483  * @param ptr	Pointer to property
484  * @param cells	Number of cells containing the number
485  * @return the value in the cells
486  */
487 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
488 
489 /**
490  * Look up a 64-bit integer property in a node and return it. The property
491  * must have at least 8 bytes of data (2 cells). The first two cells are
492  * concatenated to form a 8 bytes value, where the first cell is top half and
493  * the second cell is bottom half.
494  *
495  * @param blob	FDT blob
496  * @param node	node to examine
497  * @param prop_name	name of property to find
498  * @param default_val	default value to return if the property is not found
499  * @return integer value, if found, or default_val if not
500  */
501 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
502 		uint64_t default_val);
503 
504 /**
505  * Checks whether a node is enabled.
506  * This looks for a 'status' property. If this exists, then returns 1 if
507  * the status is 'ok' and 0 otherwise. If there is no status property,
508  * it returns 1 on the assumption that anything mentioned should be enabled
509  * by default.
510  *
511  * @param blob	FDT blob
512  * @param node	node to examine
513  * @return integer value 0 (not enabled) or 1 (enabled)
514  */
515 int fdtdec_get_is_enabled(const void *blob, int node);
516 
517 /**
518  * Make sure we have a valid fdt available to control U-Boot.
519  *
520  * If not, a message is printed to the console if the console is ready.
521  *
522  * @return 0 if all ok, -1 if not
523  */
524 int fdtdec_prepare_fdt(void);
525 
526 /**
527  * Checks that we have a valid fdt available to control U-Boot.
528 
529  * However, if not then for the moment nothing is done, since this function
530  * is called too early to panic().
531  *
532  * @returns 0
533  */
534 int fdtdec_check_fdt(void);
535 
536 /**
537  * Find the nodes for a peripheral and return a list of them in the correct
538  * order. This is used to enumerate all the peripherals of a certain type.
539  *
540  * To use this, optionally set up a /aliases node with alias properties for
541  * a peripheral. For example, for usb you could have:
542  *
543  * aliases {
544  *		usb0 = "/ehci@c5008000";
545  *		usb1 = "/ehci@c5000000";
546  * };
547  *
548  * Pass "usb" as the name to this function and will return a list of two
549  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
550  *
551  * All nodes returned will match the compatible ID, as it is assumed that
552  * all peripherals use the same driver.
553  *
554  * If no alias node is found, then the node list will be returned in the
555  * order found in the fdt. If the aliases mention a node which doesn't
556  * exist, then this will be ignored. If nodes are found with no aliases,
557  * they will be added in any order.
558  *
559  * If there is a gap in the aliases, then this function return a 0 node at
560  * that position. The return value will also count these gaps.
561  *
562  * This function checks node properties and will not return nodes which are
563  * marked disabled (status = "disabled").
564  *
565  * @param blob		FDT blob to use
566  * @param name		Root name of alias to search for
567  * @param id		Compatible ID to look for
568  * @param node_list	Place to put list of found nodes
569  * @param maxcount	Maximum number of nodes to find
570  * @return number of nodes found on success, FDT_ERR_... on error
571  */
572 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
573 			enum fdt_compat_id id, int *node_list, int maxcount);
574 
575 /*
576  * This function is similar to fdtdec_find_aliases_for_id() except that it
577  * adds to the node_list that is passed in. Any 0 elements are considered
578  * available for allocation - others are considered already used and are
579  * skipped.
580  *
581  * You can use this by calling fdtdec_find_aliases_for_id() with an
582  * uninitialised array, then setting the elements that are returned to -1,
583  * say, then calling this function, perhaps with a different compat id.
584  * Any elements you get back that are >0 are new nodes added by the call
585  * to this function.
586  *
587  * Note that if you have some nodes with aliases and some without, you are
588  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
589  * one compat_id may fill in positions for which you have aliases defined
590  * for another compat_id. When you later call *this* function with the second
591  * compat_id, the alias positions may already be used. A debug warning may
592  * be generated in this case, but it is safest to define aliases for all
593  * nodes when you care about the ordering.
594  */
595 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
596 			enum fdt_compat_id id, int *node_list, int maxcount);
597 
598 /**
599  * Get the alias sequence number of a node
600  *
601  * This works out whether a node is pointed to by an alias, and if so, the
602  * sequence number of that alias. Aliases are of the form <base><num> where
603  * <num> is the sequence number. For example spi2 would be sequence number
604  * 2.
605  *
606  * @param blob		Device tree blob (if NULL, then error is returned)
607  * @param base		Base name for alias (before the underscore)
608  * @param node		Node to look up
609  * @param seqp		This is set to the sequence number if one is found,
610  *			but otherwise the value is left alone
611  * @return 0 if a sequence was found, -ve if not
612  */
613 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
614 			 int *seqp);
615 
616 /**
617  * Get a property from the /chosen node
618  *
619  * @param blob		Device tree blob (if NULL, then NULL is returned)
620  * @param name		Property name to look up
621  * @return Value of property, or NULL if it does not exist
622  */
623 const char *fdtdec_get_chosen_prop(const void *blob, const char *name);
624 
625 /**
626  * Get the offset of the given /chosen node
627  *
628  * This looks up a property in /chosen containing the path to another node,
629  * then finds the offset of that node.
630  *
631  * @param blob		Device tree blob (if NULL, then error is returned)
632  * @param name		Property name, e.g. "stdout-path"
633  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
634  */
635 int fdtdec_get_chosen_node(const void *blob, const char *name);
636 
637 /*
638  * Get the name for a compatible ID
639  *
640  * @param id		Compatible ID to look for
641  * @return compatible string for that id
642  */
643 const char *fdtdec_get_compatible(enum fdt_compat_id id);
644 
645 /* Look up a phandle and follow it to its node. Then return the offset
646  * of that node.
647  *
648  * @param blob		FDT blob
649  * @param node		node to examine
650  * @param prop_name	name of property to find
651  * @return node offset if found, -ve error code on error
652  */
653 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
654 
655 /**
656  * Look up a property in a node and return its contents in an integer
657  * array of given length. The property must have at least enough data for
658  * the array (4*count bytes). It may have more, but this will be ignored.
659  *
660  * @param blob		FDT blob
661  * @param node		node to examine
662  * @param prop_name	name of property to find
663  * @param array		array to fill with data
664  * @param count		number of array elements
665  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
666  *		or -FDT_ERR_BADLAYOUT if not enough data
667  */
668 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
669 		u32 *array, int count);
670 
671 /**
672  * Look up a property in a node and return its contents in an integer
673  * array of given length. The property must exist but may have less data that
674  * expected (4*count bytes). It may have more, but this will be ignored.
675  *
676  * @param blob		FDT blob
677  * @param node		node to examine
678  * @param prop_name	name of property to find
679  * @param array		array to fill with data
680  * @param count		number of array elements
681  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
682  *		property is not found
683  */
684 int fdtdec_get_int_array_count(const void *blob, int node,
685 			       const char *prop_name, u32 *array, int count);
686 
687 /**
688  * Look up a property in a node and return a pointer to its contents as a
689  * unsigned int array of given length. The property must have at least enough
690  * data for the array ('count' cells). It may have more, but this will be
691  * ignored. The data is not copied.
692  *
693  * Note that you must access elements of the array with fdt32_to_cpu(),
694  * since the elements will be big endian even on a little endian machine.
695  *
696  * @param blob		FDT blob
697  * @param node		node to examine
698  * @param prop_name	name of property to find
699  * @param count		number of array elements
700  * @return pointer to array if found, or NULL if the property is not
701  *		found or there is not enough data
702  */
703 const u32 *fdtdec_locate_array(const void *blob, int node,
704 			       const char *prop_name, int count);
705 
706 /**
707  * Look up a boolean property in a node and return it.
708  *
709  * A boolean properly is true if present in the device tree and false if not
710  * present, regardless of its value.
711  *
712  * @param blob	FDT blob
713  * @param node	node to examine
714  * @param prop_name	name of property to find
715  * @return 1 if the properly is present; 0 if it isn't present
716  */
717 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
718 
719 /*
720  * Count child nodes of one parent node.
721  *
722  * @param blob	FDT blob
723  * @param node	parent node
724  * @return number of child node; 0 if there is not child node
725  */
726 int fdtdec_get_child_count(const void *blob, int node);
727 
728 /**
729  * Look in the FDT for a config item with the given name and return its value
730  * as a 32-bit integer. The property must have at least 4 bytes of data. The
731  * value of the first cell is returned.
732  *
733  * @param blob		FDT blob to use
734  * @param prop_name	Node property name
735  * @param default_val	default value to return if the property is not found
736  * @return integer value, if found, or default_val if not
737  */
738 int fdtdec_get_config_int(const void *blob, const char *prop_name,
739 		int default_val);
740 
741 /**
742  * Look in the FDT for a config item with the given name
743  * and return whether it exists.
744  *
745  * @param blob		FDT blob
746  * @param prop_name	property name to look up
747  * @return 1, if it exists, or 0 if not
748  */
749 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
750 
751 /**
752  * Look in the FDT for a config item with the given name and return its value
753  * as a string.
754  *
755  * @param blob          FDT blob
756  * @param prop_name     property name to look up
757  * @returns property string, NULL on error.
758  */
759 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
760 
761 /*
762  * Look up a property in a node and return its contents in a byte
763  * array of given length. The property must have at least enough data for
764  * the array (count bytes). It may have more, but this will be ignored.
765  *
766  * @param blob		FDT blob
767  * @param node		node to examine
768  * @param prop_name	name of property to find
769  * @param array		array to fill with data
770  * @param count		number of array elements
771  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
772  *		or -FDT_ERR_BADLAYOUT if not enough data
773  */
774 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
775 		u8 *array, int count);
776 
777 /**
778  * Look up a property in a node and return a pointer to its contents as a
779  * byte array of given length. The property must have at least enough data
780  * for the array (count bytes). It may have more, but this will be ignored.
781  * The data is not copied.
782  *
783  * @param blob		FDT blob
784  * @param node		node to examine
785  * @param prop_name	name of property to find
786  * @param count		number of array elements
787  * @return pointer to byte array if found, or NULL if the property is not
788  *		found or there is not enough data
789  */
790 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
791 			     const char *prop_name, int count);
792 
793 /**
794  * Look up a property in a node which contains a memory region address and
795  * size. Then return a pointer to this address.
796  *
797  * The property must hold one address with a length. This is only tested on
798  * 32-bit machines.
799  *
800  * @param blob		FDT blob
801  * @param node		node to examine
802  * @param prop_name	name of property to find
803  * @param basep		Returns base address of region
804  * @param size		Returns size of region
805  * @return 0 if ok, -1 on error (property not found)
806  */
807 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
808 			 fdt_addr_t *basep, fdt_size_t *sizep);
809 
810 enum fmap_compress_t {
811 	FMAP_COMPRESS_NONE,
812 	FMAP_COMPRESS_LZO,
813 };
814 
815 enum fmap_hash_t {
816 	FMAP_HASH_NONE,
817 	FMAP_HASH_SHA1,
818 	FMAP_HASH_SHA256,
819 };
820 
821 /* A flash map entry, containing an offset and length */
822 struct fmap_entry {
823 	uint32_t offset;
824 	uint32_t length;
825 	uint32_t used;			/* Number of bytes used in region */
826 	enum fmap_compress_t compress_algo;	/* Compression type */
827 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
828 	const uint8_t *hash;			/* Hash value */
829 	int hash_size;				/* Hash size */
830 };
831 
832 /**
833  * Read a flash entry from the fdt
834  *
835  * @param blob		FDT blob
836  * @param node		Offset of node to read
837  * @param name		Name of node being read
838  * @param entry		Place to put offset and size of this node
839  * @return 0 if ok, -ve on error
840  */
841 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
842 			   struct fmap_entry *entry);
843 
844 /**
845  * Obtain an indexed resource from a device property.
846  *
847  * @param fdt		FDT blob
848  * @param node		node to examine
849  * @param property	name of the property to parse
850  * @param index		index of the resource to retrieve
851  * @param res		returns the resource
852  * @return 0 if ok, negative on error
853  */
854 int fdt_get_resource(const void *fdt, int node, const char *property,
855 		     unsigned int index, struct fdt_resource *res);
856 
857 /**
858  * Obtain a named resource from a device property.
859  *
860  * Look up the index of the name in a list of strings and return the resource
861  * at that index.
862  *
863  * @param fdt		FDT blob
864  * @param node		node to examine
865  * @param property	name of the property to parse
866  * @param prop_names	name of the property containing the list of names
867  * @param name		the name of the entry to look up
868  * @param res		returns the resource
869  */
870 int fdt_get_named_resource(const void *fdt, int node, const char *property,
871 			   const char *prop_names, const char *name,
872 			   struct fdt_resource *res);
873 
874 /**
875  * Decode a named region within a memory bank of a given type.
876  *
877  * This function handles selection of a memory region. The region is
878  * specified as an offset/size within a particular type of memory.
879  *
880  * The properties used are:
881  *
882  *	<mem_type>-memory<suffix> for the name of the memory bank
883  *	<mem_type>-offset<suffix> for the offset in that bank
884  *
885  * The property value must have an offset and a size. The function checks
886  * that the region is entirely within the memory bank.5
887  *
888  * @param blob		FDT blob
889  * @param node		Node containing the properties (-1 for /config)
890  * @param mem_type	Type of memory to use, which is a name, such as
891  *			"u-boot" or "kernel".
892  * @param suffix	String to append to the memory/offset
893  *			property names
894  * @param basep		Returns base of region
895  * @param sizep		Returns size of region
896  * @return 0 if OK, -ive on error
897  */
898 int fdtdec_decode_memory_region(const void *blob, int node,
899 				const char *mem_type, const char *suffix,
900 				fdt_addr_t *basep, fdt_size_t *sizep);
901 
902 /* Display timings from linux include/video/display_timing.h */
903 enum display_flags {
904 	DISPLAY_FLAGS_HSYNC_LOW		= 1 << 0,
905 	DISPLAY_FLAGS_HSYNC_HIGH	= 1 << 1,
906 	DISPLAY_FLAGS_VSYNC_LOW		= 1 << 2,
907 	DISPLAY_FLAGS_VSYNC_HIGH	= 1 << 3,
908 
909 	/* data enable flag */
910 	DISPLAY_FLAGS_DE_LOW		= 1 << 4,
911 	DISPLAY_FLAGS_DE_HIGH		= 1 << 5,
912 	/* drive data on pos. edge */
913 	DISPLAY_FLAGS_PIXDATA_POSEDGE	= 1 << 6,
914 	/* drive data on neg. edge */
915 	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= 1 << 7,
916 	DISPLAY_FLAGS_INTERLACED	= 1 << 8,
917 	DISPLAY_FLAGS_DOUBLESCAN	= 1 << 9,
918 	DISPLAY_FLAGS_DOUBLECLK		= 1 << 10,
919 };
920 
921 /*
922  * A single signal can be specified via a range of minimal and maximal values
923  * with a typical value, that lies somewhere inbetween.
924  */
925 struct timing_entry {
926 	u32 min;
927 	u32 typ;
928 	u32 max;
929 };
930 
931 /*
932  * Single "mode" entry. This describes one set of signal timings a display can
933  * have in one setting. This struct can later be converted to struct videomode
934  * (see include/video/videomode.h). As each timing_entry can be defined as a
935  * range, one struct display_timing may become multiple struct videomodes.
936  *
937  * Example: hsync active high, vsync active low
938  *
939  *				    Active Video
940  * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
941  *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
942  *	  |	     |	 porch  |		     |	 porch	 |
943  *
944  * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
945  *
946  * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
947  */
948 struct display_timing {
949 	struct timing_entry pixelclock;
950 
951 	struct timing_entry hactive;		/* hor. active video */
952 	struct timing_entry hfront_porch;	/* hor. front porch */
953 	struct timing_entry hback_porch;	/* hor. back porch */
954 	struct timing_entry hsync_len;		/* hor. sync len */
955 
956 	struct timing_entry vactive;		/* ver. active video */
957 	struct timing_entry vfront_porch;	/* ver. front porch */
958 	struct timing_entry vback_porch;	/* ver. back porch */
959 	struct timing_entry vsync_len;		/* ver. sync len */
960 
961 	enum display_flags flags;		/* display flags */
962 };
963 
964 /**
965  * fdtdec_decode_display_timing() - decode display timings
966  *
967  * Decode display timings from the supplied 'display-timings' node.
968  * See doc/device-tree-bindings/video/display-timing.txt for binding
969  * information.
970  *
971  * @param blob		FDT blob
972  * @param node		'display-timing' node containing the timing subnodes
973  * @param index		Index number to read (0=first timing subnode)
974  * @param config	Place to put timings
975  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
976  */
977 int fdtdec_decode_display_timing(const void *blob, int node, int index,
978 				 struct display_timing *config);
979 
980 /**
981  * fdtdec_setup_memory_size() - decode and setup gd->ram_size
982  *
983  * Decode the /memory 'reg' property to determine the size of the first memory
984  * bank, populate the global data with the size of the first bank of memory.
985  *
986  * This function should be called from a boards dram_init(). This helper
987  * function allows for boards to query the device tree for DRAM size instead of
988  * hard coding the value in the case where the memory size cannot be detected
989  * automatically.
990  *
991  * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
992  * invalid
993  */
994 int fdtdec_setup_memory_size(void);
995 
996 /**
997  * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
998  *
999  * Decode the /memory 'reg' property to determine the address and size of the
1000  * memory banks. Use this data to populate the global data board info with the
1001  * phys address and size of memory banks.
1002  *
1003  * This function should be called from a boards dram_init_banksize(). This
1004  * helper function allows for boards to query the device tree for memory bank
1005  * information instead of hard coding the information in cases where it cannot
1006  * be detected automatically.
1007  *
1008  * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
1009  * invalid
1010  */
1011 int fdtdec_setup_memory_banksize(void);
1012 
1013 /**
1014  * Set up the device tree ready for use
1015  */
1016 int fdtdec_setup(void);
1017 
1018 #endif
1019