blob: 5164d437b9fd75819f0aca4a9394fd1532c50bdd [file] [log] [blame]
wdenk77f85582002-09-26 02:01:47 +00001/*
2 * (C) Copyright 2001
3 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
wdenk77f85582002-09-26 02:01:47 +00006 */
7
8#ifndef _SPI_H_
9#define _SPI_H_
10
Ben Warrenf8cc3122008-06-08 23:28:33 -070011/* Controller-specific definitions: */
12
Guennadi Liakhovetski38254f42008-04-15 14:14:25 +020013/* SPI mode flags */
14#define SPI_CPHA 0x01 /* clock phase */
15#define SPI_CPOL 0x02 /* clock polarity */
16#define SPI_MODE_0 (0|0) /* (original MicroWire) */
17#define SPI_MODE_1 (0|SPI_CPHA)
18#define SPI_MODE_2 (SPI_CPOL|0)
19#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020020#define SPI_CS_HIGH 0x04 /* CS active high */
Guennadi Liakhovetski38254f42008-04-15 14:14:25 +020021#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
22#define SPI_3WIRE 0x10 /* SI/SO signals shared */
23#define SPI_LOOP 0x20 /* loopback mode */
Rajeshwari Shindebb786b82013-05-28 20:10:37 +000024#define SPI_SLAVE 0x40 /* slave mode */
25#define SPI_PREAMBLE 0x80 /* Skip preamble bytes */
Guennadi Liakhovetski38254f42008-04-15 14:14:25 +020026
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020027/* SPI transfer flags */
Jagannadha Sutradharudu Tekice22b922013-10-07 19:34:56 +053028#define SPI_XFER_BEGIN 0x01 /* Assert CS before transfer */
29#define SPI_XFER_END 0x02 /* Deassert CS after transfer */
30#define SPI_XFER_MMAP 0x08 /* Memory Mapped start */
31#define SPI_XFER_MMAP_END 0x10 /* Memory Mapped End */
wdenk77f85582002-09-26 02:01:47 +000032
Rajeshwari Shindebb786b82013-05-28 20:10:37 +000033/* Header byte that marks the start of the message */
Jagannadha Sutradharudu Tekice22b922013-10-07 19:34:56 +053034#define SPI_PREAMBLE_END_BYTE 0xec
Rajeshwari Shindebb786b82013-05-28 20:10:37 +000035
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053036/**
Jagannadha Sutradharudu Tekice22b922013-10-07 19:34:56 +053037 * struct spi_slave - Representation of a SPI slave
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020038 *
39 * Drivers are expected to extend this with controller-specific data.
40 *
Jagannadha Sutradharudu Tekice22b922013-10-07 19:34:56 +053041 * @bus: ID of the bus that the slave is attached to.
42 * @cs: ID of the chip select connected to the slave.
43 * @max_write_size: If non-zero, the maximum number of bytes which can
44 * be written at once, excluding command bytes.
45 * @memory_map: Address of read-only SPI flash access.
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020046 */
47struct spi_slave {
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053048 unsigned int bus;
49 unsigned int cs;
Simon Glass0c456ce2013-03-11 06:08:05 +000050 unsigned int max_write_size;
Poddar, Sourav004f15b2013-10-07 15:53:01 +053051 void *memory_map;
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020052};
wdenk77f85582002-09-26 02:01:47 +000053
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053054/**
wdenk77f85582002-09-26 02:01:47 +000055 * Initialization, must be called once on start up.
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020056 *
57 * TODO: I don't think we really need this.
wdenk77f85582002-09-26 02:01:47 +000058 */
59void spi_init(void);
60
Simon Glassba6c3ce2013-03-11 06:08:00 +000061/**
62 * spi_do_alloc_slave - Allocate a new SPI slave (internal)
63 *
64 * Allocate and zero all fields in the spi slave, and set the bus/chip
65 * select. Use the helper macro spi_alloc_slave() to call this.
66 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053067 * @offset: Offset of struct spi_slave within slave structure.
68 * @size: Size of slave structure.
69 * @bus: Bus ID of the slave chip.
70 * @cs: Chip select ID of the slave chip on the specified bus.
Simon Glassba6c3ce2013-03-11 06:08:00 +000071 */
72void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
73 unsigned int cs);
74
75/**
76 * spi_alloc_slave - Allocate a new SPI slave
77 *
78 * Allocate and zero all fields in the spi slave, and set the bus/chip
79 * select.
80 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053081 * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
82 * This structure must contain a member 'struct spi_slave *slave'.
83 * @bus: Bus ID of the slave chip.
84 * @cs: Chip select ID of the slave chip on the specified bus.
Simon Glassba6c3ce2013-03-11 06:08:00 +000085 */
86#define spi_alloc_slave(_struct, bus, cs) \
87 spi_do_alloc_slave(offsetof(_struct, slave), \
88 sizeof(_struct), bus, cs)
89
90/**
91 * spi_alloc_slave_base - Allocate a new SPI slave with no private data
92 *
93 * Allocate and zero all fields in the spi slave, and set the bus/chip
94 * select.
95 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +053096 * @bus: Bus ID of the slave chip.
97 * @cs: Chip select ID of the slave chip on the specified bus.
Simon Glassba6c3ce2013-03-11 06:08:00 +000098 */
99#define spi_alloc_slave_base(bus, cs) \
100 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
101
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530102/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200103 * Set up communications parameters for a SPI slave.
104 *
105 * This must be called once for each slave. Note that this function
106 * usually doesn't touch any actual hardware, it only initializes the
107 * contents of spi_slave so that the hardware can be easily
108 * initialized later.
109 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530110 * @bus: Bus ID of the slave chip.
111 * @cs: Chip select ID of the slave chip on the specified bus.
112 * @max_hz: Maximum SCK rate in Hz.
113 * @mode: Clock polarity, clock phase and other parameters.
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200114 *
115 * Returns: A spi_slave reference that can be used in subsequent SPI
116 * calls, or NULL if one or more of the parameters are not supported.
117 */
118struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
119 unsigned int max_hz, unsigned int mode);
120
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530121/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200122 * Free any memory associated with a SPI slave.
123 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530124 * @slave: The SPI slave
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200125 */
126void spi_free_slave(struct spi_slave *slave);
127
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530128/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200129 * Claim the bus and prepare it for communication with a given slave.
130 *
131 * This must be called before doing any transfers with a SPI slave. It
132 * will enable and initialize any SPI hardware as necessary, and make
133 * sure that the SCK line is in the correct idle state. It is not
134 * allowed to claim the same bus for several slaves without releasing
135 * the bus in between.
136 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530137 * @slave: The SPI slave
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200138 *
139 * Returns: 0 if the bus was claimed successfully, or a negative value
140 * if it wasn't.
141 */
142int spi_claim_bus(struct spi_slave *slave);
143
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530144/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200145 * Release the SPI bus
146 *
147 * This must be called once for every call to spi_claim_bus() after
148 * all transfers have finished. It may disable any SPI hardware as
149 * appropriate.
150 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530151 * @slave: The SPI slave
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200152 */
153void spi_release_bus(struct spi_slave *slave);
wdenk77f85582002-09-26 02:01:47 +0000154
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530155/**
wdenk77f85582002-09-26 02:01:47 +0000156 * SPI transfer
157 *
158 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
159 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
160 *
161 * The source of the outgoing bits is the "dout" parameter and the
162 * destination of the input bits is the "din" parameter. Note that "dout"
163 * and "din" can point to the same memory location, in which case the
164 * input data overwrites the output data (since both are buffered by
165 * temporary variables, this is OK).
166 *
wdenk77f85582002-09-26 02:01:47 +0000167 * spi_xfer() interface:
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530168 * @slave: The SPI slave which will be sending/receiving the data.
169 * @bitlen: How many bits to write and read.
170 * @dout: Pointer to a string of bits to send out. The bits are
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200171 * held in a byte array and are sent MSB first.
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530172 * @din: Pointer to a string of bits that will be filled in.
173 * @flags: A bitwise combination of SPI_XFER_* flags.
wdenk77f85582002-09-26 02:01:47 +0000174 *
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530175 * Returns: 0 on success, not 0 on failure
wdenk77f85582002-09-26 02:01:47 +0000176 */
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200177int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
178 void *din, unsigned long flags);
Guennadi Liakhovetski38254f42008-04-15 14:14:25 +0200179
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530180/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200181 * Determine if a SPI chipselect is valid.
182 * This function is provided by the board if the low-level SPI driver
183 * needs it to determine if a given chipselect is actually valid.
184 *
185 * Returns: 1 if bus:cs identifies a valid chip on this board, 0
186 * otherwise.
187 */
188int spi_cs_is_valid(unsigned int bus, unsigned int cs);
189
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530190/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200191 * Activate a SPI chipselect.
192 * This function is provided by the board code when using a driver
193 * that can't control its chipselects automatically (e.g.
194 * common/soft_spi.c). When called, it should activate the chip select
195 * to the device identified by "slave".
196 */
197void spi_cs_activate(struct spi_slave *slave);
198
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530199/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200200 * Deactivate a SPI chipselect.
201 * This function is provided by the board code when using a driver
202 * that can't control its chipselects automatically (e.g.
203 * common/soft_spi.c). When called, it should deactivate the chip
204 * select to the device identified by "slave".
205 */
206void spi_cs_deactivate(struct spi_slave *slave);
207
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530208/**
Thomas Choufa1423e2010-12-24 15:16:07 +0800209 * Set transfer speed.
210 * This sets a new speed to be applied for next spi_xfer().
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530211 * @slave: The SPI slave
212 * @hz: The transfer speed
Thomas Choufa1423e2010-12-24 15:16:07 +0800213 */
214void spi_set_speed(struct spi_slave *slave, uint hz);
215
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530216/**
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200217 * Write 8 bits, then read 8 bits.
Jagannadha Sutradharudu Teki1b1bd9a2013-09-25 15:47:36 +0530218 * @slave: The SPI slave we're communicating with
219 * @byte: Byte to be written
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200220 *
221 * Returns: The value that was read, or a negative value on error.
222 *
223 * TODO: This function probably shouldn't be inlined.
224 */
225static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
226{
227 unsigned char dout[2];
228 unsigned char din[2];
229 int ret;
230
231 dout[0] = byte;
232 dout[1] = 0;
233
234 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
235 return ret < 0 ? ret : din[1];
236}
wdenk77f85582002-09-26 02:01:47 +0000237
Hung-ying Tyanf3424c52013-05-15 18:27:30 +0800238/**
239 * Set up a SPI slave for a particular device tree node
240 *
241 * This calls spi_setup_slave() with the correct bus number. Call
242 * spi_free_slave() to free it later.
243 *
244 * @param blob Device tree blob
245 * @param node SPI peripheral node to use
246 * @param cs Chip select to use
247 * @param max_hz Maximum SCK rate in Hz (0 for default)
248 * @param mode Clock polarity, clock phase and other parameters
249 * @return pointer to new spi_slave structure
250 */
251struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
252 unsigned int cs, unsigned int max_hz, unsigned int mode);
253
wdenk77f85582002-09-26 02:01:47 +0000254#endif /* _SPI_H_ */