wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 1 | /* |
Jagannadha Sutradharudu Teki | 469146c | 2013-10-10 22:14:09 +0530 | [diff] [blame] | 2 | * Common SPI Interface: Controller-specific definitions |
| 3 | * |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 4 | * (C) Copyright 2001 |
| 5 | * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. |
| 6 | * |
Wolfgang Denk | 1a45966 | 2013-07-08 09:37:19 +0200 | [diff] [blame] | 7 | * SPDX-License-Identifier: GPL-2.0+ |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #ifndef _SPI_H_ |
| 11 | #define _SPI_H_ |
| 12 | |
Guennadi Liakhovetski | 38254f4 | 2008-04-15 14:14:25 +0200 | [diff] [blame] | 13 | /* 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 Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 20 | #define SPI_CS_HIGH 0x04 /* CS active high */ |
Guennadi Liakhovetski | 38254f4 | 2008-04-15 14:14:25 +0200 | [diff] [blame] | 21 | #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 Shinde | bb786b8 | 2013-05-28 20:10:37 +0000 | [diff] [blame] | 24 | #define SPI_SLAVE 0x40 /* slave mode */ |
| 25 | #define SPI_PREAMBLE 0x80 /* Skip preamble bytes */ |
Guennadi Liakhovetski | 38254f4 | 2008-04-15 14:14:25 +0200 | [diff] [blame] | 26 | |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 27 | /* SPI transfer flags */ |
Jagannadha Sutradharudu Teki | ce22b92 | 2013-10-07 19:34:56 +0530 | [diff] [blame] | 28 | #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 */ |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 32 | |
Rajeshwari Shinde | bb786b8 | 2013-05-28 20:10:37 +0000 | [diff] [blame] | 33 | /* Header byte that marks the start of the message */ |
Jagannadha Sutradharudu Teki | ce22b92 | 2013-10-07 19:34:56 +0530 | [diff] [blame] | 34 | #define SPI_PREAMBLE_END_BYTE 0xec |
Rajeshwari Shinde | bb786b8 | 2013-05-28 20:10:37 +0000 | [diff] [blame] | 35 | |
Nikita Kiryanov | 5753d09 | 2013-10-16 17:23:25 +0300 | [diff] [blame^] | 36 | #define SPI_DEFAULT_WORDLEN 8 |
| 37 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 38 | /** |
Jagannadha Sutradharudu Teki | ce22b92 | 2013-10-07 19:34:56 +0530 | [diff] [blame] | 39 | * struct spi_slave - Representation of a SPI slave |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 40 | * |
| 41 | * Drivers are expected to extend this with controller-specific data. |
| 42 | * |
Jagannadha Sutradharudu Teki | ce22b92 | 2013-10-07 19:34:56 +0530 | [diff] [blame] | 43 | * @bus: ID of the bus that the slave is attached to. |
| 44 | * @cs: ID of the chip select connected to the slave. |
Nikita Kiryanov | 5753d09 | 2013-10-16 17:23:25 +0300 | [diff] [blame^] | 45 | * @wordlen: Size of SPI word in number of bits |
Jagannadha Sutradharudu Teki | ce22b92 | 2013-10-07 19:34:56 +0530 | [diff] [blame] | 46 | * @max_write_size: If non-zero, the maximum number of bytes which can |
| 47 | * be written at once, excluding command bytes. |
| 48 | * @memory_map: Address of read-only SPI flash access. |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 49 | */ |
| 50 | struct spi_slave { |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 51 | unsigned int bus; |
| 52 | unsigned int cs; |
Nikita Kiryanov | 5753d09 | 2013-10-16 17:23:25 +0300 | [diff] [blame^] | 53 | unsigned int wordlen; |
Simon Glass | 0c456ce | 2013-03-11 06:08:05 +0000 | [diff] [blame] | 54 | unsigned int max_write_size; |
Poddar, Sourav | 004f15b | 2013-10-07 15:53:01 +0530 | [diff] [blame] | 55 | void *memory_map; |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 56 | }; |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 57 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 58 | /** |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 59 | * Initialization, must be called once on start up. |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 60 | * |
| 61 | * TODO: I don't think we really need this. |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 62 | */ |
| 63 | void spi_init(void); |
| 64 | |
Simon Glass | ba6c3ce | 2013-03-11 06:08:00 +0000 | [diff] [blame] | 65 | /** |
| 66 | * spi_do_alloc_slave - Allocate a new SPI slave (internal) |
| 67 | * |
| 68 | * Allocate and zero all fields in the spi slave, and set the bus/chip |
| 69 | * select. Use the helper macro spi_alloc_slave() to call this. |
| 70 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 71 | * @offset: Offset of struct spi_slave within slave structure. |
| 72 | * @size: Size of slave structure. |
| 73 | * @bus: Bus ID of the slave chip. |
| 74 | * @cs: Chip select ID of the slave chip on the specified bus. |
Simon Glass | ba6c3ce | 2013-03-11 06:08:00 +0000 | [diff] [blame] | 75 | */ |
| 76 | void *spi_do_alloc_slave(int offset, int size, unsigned int bus, |
| 77 | unsigned int cs); |
| 78 | |
| 79 | /** |
| 80 | * spi_alloc_slave - Allocate a new SPI slave |
| 81 | * |
| 82 | * Allocate and zero all fields in the spi slave, and set the bus/chip |
| 83 | * select. |
| 84 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 85 | * @_struct: Name of structure to allocate (e.g. struct tegra_spi). |
| 86 | * This structure must contain a member 'struct spi_slave *slave'. |
| 87 | * @bus: Bus ID of the slave chip. |
| 88 | * @cs: Chip select ID of the slave chip on the specified bus. |
Simon Glass | ba6c3ce | 2013-03-11 06:08:00 +0000 | [diff] [blame] | 89 | */ |
| 90 | #define spi_alloc_slave(_struct, bus, cs) \ |
| 91 | spi_do_alloc_slave(offsetof(_struct, slave), \ |
| 92 | sizeof(_struct), bus, cs) |
| 93 | |
| 94 | /** |
| 95 | * spi_alloc_slave_base - Allocate a new SPI slave with no private data |
| 96 | * |
| 97 | * Allocate and zero all fields in the spi slave, and set the bus/chip |
| 98 | * select. |
| 99 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 100 | * @bus: Bus ID of the slave chip. |
| 101 | * @cs: Chip select ID of the slave chip on the specified bus. |
Simon Glass | ba6c3ce | 2013-03-11 06:08:00 +0000 | [diff] [blame] | 102 | */ |
| 103 | #define spi_alloc_slave_base(bus, cs) \ |
| 104 | spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs) |
| 105 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 106 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 107 | * Set up communications parameters for a SPI slave. |
| 108 | * |
| 109 | * This must be called once for each slave. Note that this function |
| 110 | * usually doesn't touch any actual hardware, it only initializes the |
| 111 | * contents of spi_slave so that the hardware can be easily |
| 112 | * initialized later. |
| 113 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 114 | * @bus: Bus ID of the slave chip. |
| 115 | * @cs: Chip select ID of the slave chip on the specified bus. |
| 116 | * @max_hz: Maximum SCK rate in Hz. |
| 117 | * @mode: Clock polarity, clock phase and other parameters. |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 118 | * |
| 119 | * Returns: A spi_slave reference that can be used in subsequent SPI |
| 120 | * calls, or NULL if one or more of the parameters are not supported. |
| 121 | */ |
| 122 | struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, |
| 123 | unsigned int max_hz, unsigned int mode); |
| 124 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 125 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 126 | * Free any memory associated with a SPI slave. |
| 127 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 128 | * @slave: The SPI slave |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 129 | */ |
| 130 | void spi_free_slave(struct spi_slave *slave); |
| 131 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 132 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 133 | * Claim the bus and prepare it for communication with a given slave. |
| 134 | * |
| 135 | * This must be called before doing any transfers with a SPI slave. It |
| 136 | * will enable and initialize any SPI hardware as necessary, and make |
| 137 | * sure that the SCK line is in the correct idle state. It is not |
| 138 | * allowed to claim the same bus for several slaves without releasing |
| 139 | * the bus in between. |
| 140 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 141 | * @slave: The SPI slave |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 142 | * |
| 143 | * Returns: 0 if the bus was claimed successfully, or a negative value |
| 144 | * if it wasn't. |
| 145 | */ |
| 146 | int spi_claim_bus(struct spi_slave *slave); |
| 147 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 148 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 149 | * Release the SPI bus |
| 150 | * |
| 151 | * This must be called once for every call to spi_claim_bus() after |
| 152 | * all transfers have finished. It may disable any SPI hardware as |
| 153 | * appropriate. |
| 154 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 155 | * @slave: The SPI slave |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 156 | */ |
| 157 | void spi_release_bus(struct spi_slave *slave); |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 158 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 159 | /** |
Nikita Kiryanov | 5753d09 | 2013-10-16 17:23:25 +0300 | [diff] [blame^] | 160 | * Set the word length for SPI transactions |
| 161 | * |
| 162 | * Set the word length (number of bits per word) for SPI transactions. |
| 163 | * |
| 164 | * @slave: The SPI slave |
| 165 | * @wordlen: The number of bits in a word |
| 166 | * |
| 167 | * Returns: 0 on success, -1 on failure. |
| 168 | */ |
| 169 | int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen); |
| 170 | |
| 171 | /** |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 172 | * SPI transfer |
| 173 | * |
| 174 | * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks |
| 175 | * "bitlen" bits in the SPI MISO port. That's just the way SPI works. |
| 176 | * |
| 177 | * The source of the outgoing bits is the "dout" parameter and the |
| 178 | * destination of the input bits is the "din" parameter. Note that "dout" |
| 179 | * and "din" can point to the same memory location, in which case the |
| 180 | * input data overwrites the output data (since both are buffered by |
| 181 | * temporary variables, this is OK). |
| 182 | * |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 183 | * spi_xfer() interface: |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 184 | * @slave: The SPI slave which will be sending/receiving the data. |
| 185 | * @bitlen: How many bits to write and read. |
| 186 | * @dout: Pointer to a string of bits to send out. The bits are |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 187 | * held in a byte array and are sent MSB first. |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 188 | * @din: Pointer to a string of bits that will be filled in. |
| 189 | * @flags: A bitwise combination of SPI_XFER_* flags. |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 190 | * |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 191 | * Returns: 0 on success, not 0 on failure |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 192 | */ |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 193 | int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, |
| 194 | void *din, unsigned long flags); |
Guennadi Liakhovetski | 38254f4 | 2008-04-15 14:14:25 +0200 | [diff] [blame] | 195 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 196 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 197 | * Determine if a SPI chipselect is valid. |
| 198 | * This function is provided by the board if the low-level SPI driver |
| 199 | * needs it to determine if a given chipselect is actually valid. |
| 200 | * |
| 201 | * Returns: 1 if bus:cs identifies a valid chip on this board, 0 |
| 202 | * otherwise. |
| 203 | */ |
| 204 | int spi_cs_is_valid(unsigned int bus, unsigned int cs); |
| 205 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 206 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 207 | * Activate a SPI chipselect. |
| 208 | * This function is provided by the board code when using a driver |
| 209 | * that can't control its chipselects automatically (e.g. |
| 210 | * common/soft_spi.c). When called, it should activate the chip select |
| 211 | * to the device identified by "slave". |
| 212 | */ |
| 213 | void spi_cs_activate(struct spi_slave *slave); |
| 214 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 215 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 216 | * Deactivate a SPI chipselect. |
| 217 | * This function is provided by the board code when using a driver |
| 218 | * that can't control its chipselects automatically (e.g. |
| 219 | * common/soft_spi.c). When called, it should deactivate the chip |
| 220 | * select to the device identified by "slave". |
| 221 | */ |
| 222 | void spi_cs_deactivate(struct spi_slave *slave); |
| 223 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 224 | /** |
Thomas Chou | fa1423e | 2010-12-24 15:16:07 +0800 | [diff] [blame] | 225 | * Set transfer speed. |
| 226 | * This sets a new speed to be applied for next spi_xfer(). |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 227 | * @slave: The SPI slave |
| 228 | * @hz: The transfer speed |
Thomas Chou | fa1423e | 2010-12-24 15:16:07 +0800 | [diff] [blame] | 229 | */ |
| 230 | void spi_set_speed(struct spi_slave *slave, uint hz); |
| 231 | |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 232 | /** |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 233 | * Write 8 bits, then read 8 bits. |
Jagannadha Sutradharudu Teki | 1b1bd9a | 2013-09-25 15:47:36 +0530 | [diff] [blame] | 234 | * @slave: The SPI slave we're communicating with |
| 235 | * @byte: Byte to be written |
Haavard Skinnemoen | d255bb0 | 2008-05-16 11:10:31 +0200 | [diff] [blame] | 236 | * |
| 237 | * Returns: The value that was read, or a negative value on error. |
| 238 | * |
| 239 | * TODO: This function probably shouldn't be inlined. |
| 240 | */ |
| 241 | static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte) |
| 242 | { |
| 243 | unsigned char dout[2]; |
| 244 | unsigned char din[2]; |
| 245 | int ret; |
| 246 | |
| 247 | dout[0] = byte; |
| 248 | dout[1] = 0; |
| 249 | |
| 250 | ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END); |
| 251 | return ret < 0 ? ret : din[1]; |
| 252 | } |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 253 | |
Hung-ying Tyan | f3424c5 | 2013-05-15 18:27:30 +0800 | [diff] [blame] | 254 | /** |
| 255 | * Set up a SPI slave for a particular device tree node |
| 256 | * |
| 257 | * This calls spi_setup_slave() with the correct bus number. Call |
| 258 | * spi_free_slave() to free it later. |
| 259 | * |
Jagannadha Sutradharudu Teki | 469146c | 2013-10-10 22:14:09 +0530 | [diff] [blame] | 260 | * @param blob: Device tree blob |
| 261 | * @param node: SPI peripheral node to use |
| 262 | * @param cs: Chip select to use |
| 263 | * @param max_hz: Maximum SCK rate in Hz (0 for default) |
| 264 | * @param mode: Clock polarity, clock phase and other parameters |
Hung-ying Tyan | f3424c5 | 2013-05-15 18:27:30 +0800 | [diff] [blame] | 265 | * @return pointer to new spi_slave structure |
| 266 | */ |
| 267 | struct spi_slave *spi_setup_slave_fdt(const void *blob, int node, |
| 268 | unsigned int cs, unsigned int max_hz, unsigned int mode); |
| 269 | |
wdenk | 77f8558 | 2002-09-26 02:01:47 +0000 | [diff] [blame] | 270 | #endif /* _SPI_H_ */ |