xref: /openbmc/u-boot/include/fdtdec.h (revision dc288431)
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 #ifdef CONFIG_PHYS_64BIT
25 typedef u64 fdt_addr_t;
26 typedef u64 fdt_size_t;
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 typedef u32 fdt_addr_t;
32 typedef u32 fdt_size_t;
33 #define FDT_ADDR_T_NONE (-1U)
34 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
35 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
36 #endif
37 
38 /* Information obtained about memory from the FDT */
39 struct fdt_memory {
40 	fdt_addr_t start;
41 	fdt_addr_t end;
42 };
43 
44 /*
45  * Information about a resource. start is the first address of the resource
46  * and end is the last address (inclusive). The length of the resource will
47  * be equal to: end - start + 1.
48  */
49 struct fdt_resource {
50 	fdt_addr_t start;
51 	fdt_addr_t end;
52 };
53 
54 enum fdt_pci_space {
55 	FDT_PCI_SPACE_CONFIG = 0,
56 	FDT_PCI_SPACE_IO = 0x01000000,
57 	FDT_PCI_SPACE_MEM32 = 0x02000000,
58 	FDT_PCI_SPACE_MEM64 = 0x03000000,
59 	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
60 	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
61 };
62 
63 #define FDT_PCI_ADDR_CELLS	3
64 #define FDT_PCI_SIZE_CELLS	2
65 #define FDT_PCI_REG_SIZE	\
66 	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
67 
68 /*
69  * The Open Firmware spec defines PCI physical address as follows:
70  *
71  *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
72  *
73  * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
74  * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
75  * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
76  *
77  * where:
78  *
79  * n:        is 0 if the address is relocatable, 1 otherwise
80  * p:        is 1 if addressable region is prefetchable, 0 otherwise
81  * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
82  *           (for Memory), or below 64KB (for relocatable I/O)
83  * ss:       is the space code, denoting the address space
84  * bbbbbbbb: is the 8-bit Bus Number
85  * ddddd:    is the 5-bit Device Number
86  * fff:      is the 3-bit Function Number
87  * rrrrrrrr: is the 8-bit Register Number
88  * hhhhhhhh: is a 32-bit unsigned number
89  * llllllll: is a 32-bit unsigned number
90  */
91 struct fdt_pci_addr {
92 	u32	phys_hi;
93 	u32	phys_mid;
94 	u32	phys_lo;
95 };
96 
97 /**
98  * Compute the size of a resource.
99  *
100  * @param res	the resource to operate on
101  * @return the size of the resource
102  */
103 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
104 {
105 	return res->end - res->start + 1;
106 }
107 
108 /**
109  * Compat types that we know about and for which we might have drivers.
110  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
111  * within drivers.
112  */
113 enum fdt_compat_id {
114 	COMPAT_UNKNOWN,
115 	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
116 	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
117 	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */
118 	COMPAT_NVIDIA_TEGRA114_I2C,	/* Tegra114 I2C w/single clock source */
119 	COMPAT_NVIDIA_TEGRA20_I2C,	/* Tegra20 i2c */
120 	COMPAT_NVIDIA_TEGRA20_DVC,	/* Tegra20 dvc (really just i2c) */
121 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
122 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
123 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
124 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
125 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
126 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
127 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
128 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
129 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
130 	COMPAT_NVIDIA_TEGRA20_SFLASH,	/* Tegra 2 SPI flash controller */
131 	COMPAT_NVIDIA_TEGRA20_SLINK,	/* Tegra 2 SPI SLINK controller */
132 	COMPAT_NVIDIA_TEGRA114_SPI,	/* Tegra 114 SPI controller */
133 	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
134 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
135 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
136 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
137 					/* Tegra124 XUSB pad controller */
138 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
139 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
140 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
141 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
142 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
143 	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */
144 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
145 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
146 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
147 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
148 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
149 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
150 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
151 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
152 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
153 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
154 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
155 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
156 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
157 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
158 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
159 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
160 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
161 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
162 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
163 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
164 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
165 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
166 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
167 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
168 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
169 	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
170 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
171 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
172 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
173 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
174 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
175 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
176 	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
177 
178 	COMPAT_COUNT,
179 };
180 
181 /* GPIOs are numbered from 0 */
182 enum {
183 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
184 
185 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
186 };
187 
188 /* This is the state of a GPIO pin as defined by the fdt */
189 struct fdt_gpio_state {
190 	const char *name;	/* name of the fdt property defining this */
191 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
192 	u8 flags;		/* FDT_GPIO_... flags */
193 };
194 
195 /* This tells us whether a fdt_gpio_state record is valid or not */
196 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
197 
198 /**
199  * Read the GPIO taking into account the polarity of the pin.
200  *
201  * @param gpio		pointer to the decoded gpio
202  * @return value of the gpio if successful, < 0 if unsuccessful
203  */
204 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
205 
206 /**
207  * Write the GPIO taking into account the polarity of the pin.
208  *
209  * @param gpio		pointer to the decoded gpio
210  * @return 0 if successful
211  */
212 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
213 
214 /**
215  * Find the next numbered alias for a peripheral. This is used to enumerate
216  * all the peripherals of a certain type.
217  *
218  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
219  * this function will return a pointer to the node the alias points to, and
220  * then update *upto to 1. Next time you call this function, the next node
221  * will be returned.
222  *
223  * All nodes returned will match the compatible ID, as it is assumed that
224  * all peripherals use the same driver.
225  *
226  * @param blob		FDT blob to use
227  * @param name		Root name of alias to search for
228  * @param id		Compatible ID to look for
229  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
230  */
231 int fdtdec_next_alias(const void *blob, const char *name,
232 		enum fdt_compat_id id, int *upto);
233 
234 /**
235  * Find the compatible ID for a given node.
236  *
237  * Generally each node has at least one compatible string attached to it.
238  * This function looks through our list of known compatible strings and
239  * returns the corresponding ID which matches the compatible string.
240  *
241  * @param blob		FDT blob to use
242  * @param node		Node containing compatible string to find
243  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
244  */
245 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
246 
247 /**
248  * Find the next compatible node for a peripheral.
249  *
250  * Do the first call with node = 0. This function will return a pointer to
251  * the next compatible node. Next time you call this function, pass the
252  * value returned, and the next node will be provided.
253  *
254  * @param blob		FDT blob to use
255  * @param node		Start node for search
256  * @param id		Compatible ID to look for (enum fdt_compat_id)
257  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
258  */
259 int fdtdec_next_compatible(const void *blob, int node,
260 		enum fdt_compat_id id);
261 
262 /**
263  * Find the next compatible subnode for a peripheral.
264  *
265  * Do the first call with node set to the parent and depth = 0. This
266  * function will return the offset of the next compatible node. Next time
267  * you call this function, pass the node value returned last time, with
268  * depth unchanged, and the next node will be provided.
269  *
270  * @param blob		FDT blob to use
271  * @param node		Start node for search
272  * @param id		Compatible ID to look for (enum fdt_compat_id)
273  * @param depthp	Current depth (set to 0 before first call)
274  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
275  */
276 int fdtdec_next_compatible_subnode(const void *blob, int node,
277 		enum fdt_compat_id id, int *depthp);
278 
279 /**
280  * Look up an address property in a node and return it as an address.
281  * The property must hold either one address with no trailing data or
282  * one address with a length. This is only tested on 32-bit machines.
283  *
284  * @param blob	FDT blob
285  * @param node	node to examine
286  * @param prop_name	name of property to find
287  * @return address, if found, or FDT_ADDR_T_NONE if not
288  */
289 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
290 		const char *prop_name);
291 
292 /**
293  * Look up an address property in a node and return it as an address.
294  * The property must hold one address with a length. This is only tested
295  * on 32-bit machines.
296  *
297  * @param blob	FDT blob
298  * @param node	node to examine
299  * @param prop_name	name of property to find
300  * @return address, if found, or FDT_ADDR_T_NONE if not
301  */
302 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
303 		const char *prop_name, fdt_size_t *sizep);
304 
305 /**
306  * Look at an address property in a node and return the pci address which
307  * corresponds to the given type in the form of fdt_pci_addr.
308  * The property must hold one fdt_pci_addr with a lengh.
309  *
310  * @param blob		FDT blob
311  * @param node		node to examine
312  * @param type		pci address type (FDT_PCI_SPACE_xxx)
313  * @param prop_name	name of property to find
314  * @param addr		returns pci address in the form of fdt_pci_addr
315  * @return 0 if ok, negative on error
316  */
317 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
318 		const char *prop_name, struct fdt_pci_addr *addr);
319 
320 /**
321  * Look at the compatible property of a device node that represents a PCI
322  * device and extract pci vendor id and device id from it.
323  *
324  * @param blob		FDT blob
325  * @param node		node to examine
326  * @param vendor	vendor id of the pci device
327  * @param device	device id of the pci device
328  * @return 0 if ok, negative on error
329  */
330 int fdtdec_get_pci_vendev(const void *blob, int node,
331 		u16 *vendor, u16 *device);
332 
333 /**
334  * Look at the pci address of a device node that represents a PCI device
335  * and parse the bus, device and function number from it.
336  *
337  * @param blob		FDT blob
338  * @param node		node to examine
339  * @param addr		pci address in the form of fdt_pci_addr
340  * @param bdf		returns bus, device, function triplet
341  * @return 0 if ok, negative on error
342  */
343 int fdtdec_get_pci_bdf(const void *blob, int node,
344 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
345 
346 /**
347  * Look at the pci address of a device node that represents a PCI device
348  * and return base address of the pci device's registers.
349  *
350  * @param blob		FDT blob
351  * @param node		node to examine
352  * @param addr		pci address in the form of fdt_pci_addr
353  * @param bar		returns base address of the pci device's registers
354  * @return 0 if ok, negative on error
355  */
356 int fdtdec_get_pci_bar32(const void *blob, int node,
357 		struct fdt_pci_addr *addr, u32 *bar);
358 
359 /**
360  * Look up a 32-bit integer property in a node and return it. The property
361  * must have at least 4 bytes of data. The value of the first cell is
362  * returned.
363  *
364  * @param blob	FDT blob
365  * @param node	node to examine
366  * @param prop_name	name of property to find
367  * @param default_val	default value to return if the property is not found
368  * @return integer value, if found, or default_val if not
369  */
370 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
371 		s32 default_val);
372 
373 /**
374  * Look up a 64-bit integer property in a node and return it. The property
375  * must have at least 8 bytes of data (2 cells). The first two cells are
376  * concatenated to form a 8 bytes value, where the first cell is top half and
377  * the second cell is bottom half.
378  *
379  * @param blob	FDT blob
380  * @param node	node to examine
381  * @param prop_name	name of property to find
382  * @param default_val	default value to return if the property is not found
383  * @return integer value, if found, or default_val if not
384  */
385 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
386 		uint64_t default_val);
387 
388 /**
389  * Checks whether a node is enabled.
390  * This looks for a 'status' property. If this exists, then returns 1 if
391  * the status is 'ok' and 0 otherwise. If there is no status property,
392  * it returns 1 on the assumption that anything mentioned should be enabled
393  * by default.
394  *
395  * @param blob	FDT blob
396  * @param node	node to examine
397  * @return integer value 0 (not enabled) or 1 (enabled)
398  */
399 int fdtdec_get_is_enabled(const void *blob, int node);
400 
401 /**
402  * Make sure we have a valid fdt available to control U-Boot.
403  *
404  * If not, a message is printed to the console if the console is ready.
405  *
406  * @return 0 if all ok, -1 if not
407  */
408 int fdtdec_prepare_fdt(void);
409 
410 /**
411  * Checks that we have a valid fdt available to control U-Boot.
412 
413  * However, if not then for the moment nothing is done, since this function
414  * is called too early to panic().
415  *
416  * @returns 0
417  */
418 int fdtdec_check_fdt(void);
419 
420 /**
421  * Find the nodes for a peripheral and return a list of them in the correct
422  * order. This is used to enumerate all the peripherals of a certain type.
423  *
424  * To use this, optionally set up a /aliases node with alias properties for
425  * a peripheral. For example, for usb you could have:
426  *
427  * aliases {
428  *		usb0 = "/ehci@c5008000";
429  *		usb1 = "/ehci@c5000000";
430  * };
431  *
432  * Pass "usb" as the name to this function and will return a list of two
433  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
434  *
435  * All nodes returned will match the compatible ID, as it is assumed that
436  * all peripherals use the same driver.
437  *
438  * If no alias node is found, then the node list will be returned in the
439  * order found in the fdt. If the aliases mention a node which doesn't
440  * exist, then this will be ignored. If nodes are found with no aliases,
441  * they will be added in any order.
442  *
443  * If there is a gap in the aliases, then this function return a 0 node at
444  * that position. The return value will also count these gaps.
445  *
446  * This function checks node properties and will not return nodes which are
447  * marked disabled (status = "disabled").
448  *
449  * @param blob		FDT blob to use
450  * @param name		Root name of alias to search for
451  * @param id		Compatible ID to look for
452  * @param node_list	Place to put list of found nodes
453  * @param maxcount	Maximum number of nodes to find
454  * @return number of nodes found on success, FTD_ERR_... on error
455  */
456 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
457 			enum fdt_compat_id id, int *node_list, int maxcount);
458 
459 /*
460  * This function is similar to fdtdec_find_aliases_for_id() except that it
461  * adds to the node_list that is passed in. Any 0 elements are considered
462  * available for allocation - others are considered already used and are
463  * skipped.
464  *
465  * You can use this by calling fdtdec_find_aliases_for_id() with an
466  * uninitialised array, then setting the elements that are returned to -1,
467  * say, then calling this function, perhaps with a different compat id.
468  * Any elements you get back that are >0 are new nodes added by the call
469  * to this function.
470  *
471  * Note that if you have some nodes with aliases and some without, you are
472  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
473  * one compat_id may fill in positions for which you have aliases defined
474  * for another compat_id. When you later call *this* function with the second
475  * compat_id, the alias positions may already be used. A debug warning may
476  * be generated in this case, but it is safest to define aliases for all
477  * nodes when you care about the ordering.
478  */
479 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
480 			enum fdt_compat_id id, int *node_list, int maxcount);
481 
482 /**
483  * Get the alias sequence number of a node
484  *
485  * This works out whether a node is pointed to by an alias, and if so, the
486  * sequence number of that alias. Aliases are of the form <base><num> where
487  * <num> is the sequence number. For example spi2 would be sequence number
488  * 2.
489  *
490  * @param blob		Device tree blob (if NULL, then error is returned)
491  * @param base		Base name for alias (before the underscore)
492  * @param node		Node to look up
493  * @param seqp		This is set to the sequence number if one is found,
494  *			but otherwise the value is left alone
495  * @return 0 if a sequence was found, -ve if not
496  */
497 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
498 			 int *seqp);
499 
500 /**
501  * Get the offset of the given chosen node
502  *
503  * This looks up a property in /chosen containing the path to another node,
504  * then finds the offset of that node.
505  *
506  * @param blob		Device tree blob (if NULL, then error is returned)
507  * @param name		Property name, e.g. "stdout-path"
508  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
509  */
510 int fdtdec_get_chosen_node(const void *blob, const char *name);
511 
512 /*
513  * Get the name for a compatible ID
514  *
515  * @param id		Compatible ID to look for
516  * @return compatible string for that id
517  */
518 const char *fdtdec_get_compatible(enum fdt_compat_id id);
519 
520 /* Look up a phandle and follow it to its node. Then return the offset
521  * of that node.
522  *
523  * @param blob		FDT blob
524  * @param node		node to examine
525  * @param prop_name	name of property to find
526  * @return node offset if found, -ve error code on error
527  */
528 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
529 
530 /**
531  * Look up a property in a node and return its contents in an integer
532  * array of given length. The property must have at least enough data for
533  * the array (4*count bytes). It may have more, but this will be ignored.
534  *
535  * @param blob		FDT blob
536  * @param node		node to examine
537  * @param prop_name	name of property to find
538  * @param array		array to fill with data
539  * @param count		number of array elements
540  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
541  *		or -FDT_ERR_BADLAYOUT if not enough data
542  */
543 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
544 		u32 *array, int count);
545 
546 /**
547  * Look up a property in a node and return its contents in an integer
548  * array of given length. The property must exist but may have less data that
549  * expected (4*count bytes). It may have more, but this will be ignored.
550  *
551  * @param blob		FDT blob
552  * @param node		node to examine
553  * @param prop_name	name of property to find
554  * @param array		array to fill with data
555  * @param count		number of array elements
556  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
557  *		property is not found
558  */
559 int fdtdec_get_int_array_count(const void *blob, int node,
560 			       const char *prop_name, u32 *array, int count);
561 
562 /**
563  * Look up a property in a node and return a pointer to its contents as a
564  * unsigned int array of given length. The property must have at least enough
565  * data for the array ('count' cells). It may have more, but this will be
566  * ignored. The data is not copied.
567  *
568  * Note that you must access elements of the array with fdt32_to_cpu(),
569  * since the elements will be big endian even on a little endian machine.
570  *
571  * @param blob		FDT blob
572  * @param node		node to examine
573  * @param prop_name	name of property to find
574  * @param count		number of array elements
575  * @return pointer to array if found, or NULL if the property is not
576  *		found or there is not enough data
577  */
578 const u32 *fdtdec_locate_array(const void *blob, int node,
579 			       const char *prop_name, int count);
580 
581 /**
582  * Look up a boolean property in a node and return it.
583  *
584  * A boolean properly is true if present in the device tree and false if not
585  * present, regardless of its value.
586  *
587  * @param blob	FDT blob
588  * @param node	node to examine
589  * @param prop_name	name of property to find
590  * @return 1 if the properly is present; 0 if it isn't present
591  */
592 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
593 
594 /**
595  * Decode a single GPIOs from an FDT.
596  *
597  * If the property is not found, then the GPIO structure will still be
598  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
599  * provide optional GPIOs.
600  *
601  * @param blob		FDT blob to use
602  * @param node		Node to look at
603  * @param prop_name	Node property name
604  * @param gpio		gpio elements to fill from FDT
605  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
606  */
607 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
608 		struct fdt_gpio_state *gpio);
609 
610 /**
611  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
612  * terminating item.
613  *
614  * @param blob         FDT blob to use
615  * @param node         Node to look at
616  * @param prop_name    Node property name
617  * @param gpio         Array of gpio elements to fill from FDT. This will be
618  *                     untouched if either 0 or an error is returned
619  * @param max_count    Maximum number of elements allowed
620  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
621  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
622  */
623 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
624 		struct fdt_gpio_state *gpio, int max_count);
625 
626 /**
627  * Set up a GPIO pin according to the provided gpio information. At present this
628  * just requests the GPIO.
629  *
630  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
631  * deal with optional GPIOs.
632  *
633  * @param gpio		GPIO info to use for set up
634  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
635  */
636 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
637 
638 /**
639  * Look in the FDT for a config item with the given name and return its value
640  * as a 32-bit integer. The property must have at least 4 bytes of data. The
641  * value of the first cell is returned.
642  *
643  * @param blob		FDT blob to use
644  * @param prop_name	Node property name
645  * @param default_val	default value to return if the property is not found
646  * @return integer value, if found, or default_val if not
647  */
648 int fdtdec_get_config_int(const void *blob, const char *prop_name,
649 		int default_val);
650 
651 /**
652  * Look in the FDT for a config item with the given name
653  * and return whether it exists.
654  *
655  * @param blob		FDT blob
656  * @param prop_name	property name to look up
657  * @return 1, if it exists, or 0 if not
658  */
659 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
660 
661 /**
662  * Look in the FDT for a config item with the given name and return its value
663  * as a string.
664  *
665  * @param blob          FDT blob
666  * @param prop_name     property name to look up
667  * @returns property string, NULL on error.
668  */
669 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
670 
671 /*
672  * Look up a property in a node and return its contents in a byte
673  * array of given length. The property must have at least enough data for
674  * the array (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 0 if ok, or -FDT_ERR_MISSING if the property is not found,
682  *		or -FDT_ERR_BADLAYOUT if not enough data
683  */
684 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
685 		u8 *array, int count);
686 
687 /**
688  * Look up a property in a node and return a pointer to its contents as a
689  * byte array of given length. The property must have at least enough data
690  * for the array (count bytes). It may have more, but this will be ignored.
691  * The data is not copied.
692  *
693  * @param blob		FDT blob
694  * @param node		node to examine
695  * @param prop_name	name of property to find
696  * @param count		number of array elements
697  * @return pointer to byte array if found, or NULL if the property is not
698  *		found or there is not enough data
699  */
700 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
701 			     const char *prop_name, int count);
702 
703 /**
704  * Look up a property in a node which contains a memory region address and
705  * size. Then return a pointer to this address.
706  *
707  * The property must hold one address with a length. This is only tested on
708  * 32-bit machines.
709  *
710  * @param blob		FDT blob
711  * @param node		node to examine
712  * @param prop_name	name of property to find
713  * @param basep		Returns base address of region
714  * @param size		Returns size of region
715  * @return 0 if ok, -1 on error (property not found)
716  */
717 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
718 			 fdt_addr_t *basep, fdt_size_t *sizep);
719 
720 enum fmap_compress_t {
721 	FMAP_COMPRESS_NONE,
722 	FMAP_COMPRESS_LZO,
723 };
724 
725 enum fmap_hash_t {
726 	FMAP_HASH_NONE,
727 	FMAP_HASH_SHA1,
728 	FMAP_HASH_SHA256,
729 };
730 
731 /* A flash map entry, containing an offset and length */
732 struct fmap_entry {
733 	uint32_t offset;
734 	uint32_t length;
735 	uint32_t used;			/* Number of bytes used in region */
736 	enum fmap_compress_t compress_algo;	/* Compression type */
737 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
738 	const uint8_t *hash;			/* Hash value */
739 	int hash_size;				/* Hash size */
740 };
741 
742 /**
743  * Read a flash entry from the fdt
744  *
745  * @param blob		FDT blob
746  * @param node		Offset of node to read
747  * @param name		Name of node being read
748  * @param entry		Place to put offset and size of this node
749  * @return 0 if ok, -ve on error
750  */
751 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
752 			   struct fmap_entry *entry);
753 
754 /**
755  * Obtain an indexed resource from a device property.
756  *
757  * @param fdt		FDT blob
758  * @param node		node to examine
759  * @param property	name of the property to parse
760  * @param index		index of the resource to retrieve
761  * @param res		returns the resource
762  * @return 0 if ok, negative on error
763  */
764 int fdt_get_resource(const void *fdt, int node, const char *property,
765 		     unsigned int index, struct fdt_resource *res);
766 
767 /**
768  * Obtain a named resource from a device property.
769  *
770  * Look up the index of the name in a list of strings and return the resource
771  * at that index.
772  *
773  * @param fdt		FDT blob
774  * @param node		node to examine
775  * @param property	name of the property to parse
776  * @param prop_names	name of the property containing the list of names
777  * @param name		the name of the entry to look up
778  * @param res		returns the resource
779  */
780 int fdt_get_named_resource(const void *fdt, int node, const char *property,
781 			   const char *prop_names, const char *name,
782 			   struct fdt_resource *res);
783 
784 /**
785  * Decode a named region within a memory bank of a given type.
786  *
787  * This function handles selection of a memory region. The region is
788  * specified as an offset/size within a particular type of memory.
789  *
790  * The properties used are:
791  *
792  *	<mem_type>-memory<suffix> for the name of the memory bank
793  *	<mem_type>-offset<suffix> for the offset in that bank
794  *
795  * The property value must have an offset and a size. The function checks
796  * that the region is entirely within the memory bank.5
797  *
798  * @param blob		FDT blob
799  * @param node		Node containing the properties (-1 for /config)
800  * @param mem_type	Type of memory to use, which is a name, such as
801  *			"u-boot" or "kernel".
802  * @param suffix	String to append to the memory/offset
803  *			property names
804  * @param basep		Returns base of region
805  * @param sizep		Returns size of region
806  * @return 0 if OK, -ive on error
807  */
808 int fdtdec_decode_memory_region(const void *blob, int node,
809 				const char *mem_type, const char *suffix,
810 				fdt_addr_t *basep, fdt_size_t *sizep);
811 #endif
812