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1 #ifndef _GPXE_SPI_H
2 #define _GPXE_SPI_H
3 
4 /** @file
5  *
6  * SPI interface
7  *
8  */
9 
10 FILE_LICENCE ( GPL2_OR_LATER );
11 
12 #include <gpxe/nvs.h>
13 
14 /**
15  * @defgroup spicmds SPI commands
16  * @{
17  */
18 
19 /** Write status register */
20 #define SPI_WRSR 0x01
21 
22 /** Write data to memory array */
23 #define SPI_WRITE 0x02
24 
25 /** Read data from memory array */
26 #define SPI_READ 0x03
27 
28 /** Reset write enable latch */
29 #define SPI_WRDI 0x04
30 
31 /** Read status register */
32 #define SPI_RDSR 0x05
33 
34 /** Set write enable latch */
35 #define SPI_WREN 0x06
36 
37 /**
38  * @defgroup atmelcmds Atmel-specific SPI commands
39  * @{
40  */
41 
42 /** Erase one sector in memory array (Not supported on all devices) */
43 #define ATMEL_SECTOR_ERASE 0x52
44 
45 /** Erase all sections in memory array (Not supported on all devices) */
46 #define ATMEL_CHIP_ERASE 0x62
47 
48 /** Read manufacturer and product ID (Not supported on all devices) */
49 #define ATMEL_RDID 0x15
50 
51 /** @} */
52 
53 /** @} */
54 
55 /**
56  * @defgroup spistatus SPI status register bits (not present on all devices)
57  * @{
58  */
59 
60 /** Write-protect pin enabled */
61 #define SPI_STATUS_WPEN 0x80
62 
63 /** Block protection bit 2 */
64 #define SPI_STATUS_BP2 0x10
65 
66 /** Block protection bit 1 */
67 #define SPI_STATUS_BP1 0x08
68 
69 /** Block protection bit 0 */
70 #define SPI_STATUS_BP0 0x04
71 
72 /** State of the write enable latch */
73 #define SPI_STATUS_WEN 0x02
74 
75 /** Device busy flag */
76 #define SPI_STATUS_NRDY 0x01
77 
78 /** @} */
79 
80 /**
81  * An SPI device
82  *
83  * This data structure represents a physical SPI device attached to an
84  * SPI bus.
85  */
86 struct spi_device {
87 	/** NVS device */
88 	struct nvs_device nvs;
89 	/** SPI bus to which device is attached */
90 	struct spi_bus *bus;
91 	/** Slave number */
92 	unsigned int slave;
93 	/** Command length, in bits */
94 	unsigned int command_len;
95 	/** Address length, in bits */
96 	unsigned int address_len;
97 	/** Address is munged
98 	 *
99 	 * Some devices with 9-bit addresses (e.g. AT25040A EEPROM)
100 	 * use bit 3 of the command byte as address bit A8, rather
101 	 * than having a two-byte address.  If this flag is set, then
102 	 * commands should be munged in this way.
103 	 */
104 	unsigned int munge_address : 1;
105 };
106 
107 /**
108  * SPI magic autodetection address length
109  *
110  * Set @c spi_device::address_len to @c SPI_AUTODETECT_ADDRESS_LEN if
111  * the address length should be autodetected.
112  */
113 #define SPI_AUTODETECT_ADDRESS_LEN 0
114 
115 static inline __attribute__ (( always_inline )) struct spi_device *
nvs_to_spi(struct nvs_device * nvs)116 nvs_to_spi ( struct nvs_device *nvs ) {
117 	return container_of ( nvs, struct spi_device, nvs );
118 }
119 
120 /**
121  * An SPI bus
122  *
123  * This data structure represents an SPI bus controller capable of
124  * issuing commands to attached SPI devices.
125  */
126 struct spi_bus {
127 	/** SPI interface mode
128 	 *
129 	 * This is the bitwise OR of zero or more of @c SPI_MODE_CPHA
130 	 * and @c SPI_MODE_CPOL.  It is also the number conventionally
131 	 * used to describe the SPI interface mode.  For example, SPI
132 	 * mode 1 is the mode in which CPOL=0 and CPHA=1, which
133 	 * therefore corresponds to a mode value of (0|SPI_MODE_CPHA)
134 	 * which, happily, equals 1.
135 	 */
136 	unsigned int mode;
137 	/**
138 	 * Read/write data via SPI bus
139 	 *
140 	 * @v bus		SPI bus
141 	 * @v device		SPI device
142 	 * @v command		Command
143 	 * @v address		Address to read/write (<0 for no address)
144 	 * @v data_out		TX data buffer (or NULL)
145 	 * @v data_in		RX data buffer (or NULL)
146 	 * @v len		Length of data buffer(s)
147 	 *
148 	 * This issues the specified command and optional address to
149 	 * the SPI device, then reads and/or writes data to/from the
150 	 * data buffers.
151 	 */
152 	int ( * rw ) ( struct spi_bus *bus, struct spi_device *device,
153 		       unsigned int command, int address,
154 		       const void *data_out, void *data_in, size_t len );
155 };
156 
157 /** Clock phase (CPHA) mode bit
158  *
159  * Phase 0 is sample on rising edge, shift data on falling edge.
160  *
161  * Phase 1 is shift data on rising edge, sample data on falling edge.
162  */
163 #define SPI_MODE_CPHA 0x01
164 
165 /** Clock polarity (CPOL) mode bit
166  *
167  * This bit reflects the idle state of the clock line (SCLK).
168  */
169 #define SPI_MODE_CPOL 0x02
170 
171 /** Slave select polarity mode bit
172  *
173  * This bit reflects that active state of the slave select lines.  It
174  * is not part of the normal SPI mode number (which covers only @c
175  * SPI_MODE_CPOL and @c SPI_MODE_CPHA), but is included here for
176  * convenience.
177  */
178 #define SPI_MODE_SSPOL 0x10
179 
180 /** Microwire-compatible mode
181  *
182  * This is SPI mode 1 (i.e. CPOL=0, CPHA=1), and is compatible with
183  * the original Microwire protocol.
184  */
185 #define SPI_MODE_MICROWIRE 1
186 
187 /** Microwire/Plus-compatible mode
188  *
189  * This is SPI mode 0 (i.e. CPOL=0, CPHA=0), and is compatible with
190  * the Microwire/Plus protocol
191  */
192 #define SPI_MODE_MICROWIRE_PLUS 0
193 
194 /** Threewire-compatible mode
195  *
196  * This mode is compatible with Atmel's series of "three-wire"
197  * interfaces.
198  */
199 #define SPI_MODE_THREEWIRE ( SPI_MODE_MICROWIRE_PLUS | SPI_MODE_SSPOL )
200 
201 extern int spi_read ( struct nvs_device *nvs, unsigned int address,
202 		      void *data, size_t len );
203 extern int spi_write ( struct nvs_device *nvs, unsigned int address,
204 		       const void *data, size_t len );
205 
206 /**
207  * @defgroup spidevs SPI device types
208  * @{
209  */
210 
211 static inline __attribute__ (( always_inline )) void
init_spi(struct spi_device * device)212 init_spi ( struct spi_device *device ) {
213 	device->nvs.word_len_log2 = 0;
214 	device->command_len = 8,
215 	device->nvs.read = spi_read;
216 	device->nvs.write = spi_write;
217 }
218 
219 /** Atmel AT25F1024 serial flash */
220 static inline __attribute__ (( always_inline )) void
init_at25f1024(struct spi_device * device)221 init_at25f1024 ( struct spi_device *device ) {
222 	device->address_len = 24;
223 	device->nvs.size = ( 128 * 1024 );
224 	device->nvs.block_size = 256;
225 	init_spi ( device );
226 }
227 
228 /** Atmel 25040 serial EEPROM */
229 static inline __attribute__ (( always_inline )) void
init_at25040(struct spi_device * device)230 init_at25040 ( struct spi_device *device ) {
231 	device->address_len = 8;
232 	device->munge_address = 1;
233 	device->nvs.size = 512;
234 	device->nvs.block_size = 8;
235 	init_spi ( device );
236 }
237 
238 /** ST M25P32 serial flash */
239 static inline __attribute__ (( always_inline )) void
init_m25p32(struct spi_device * device)240 init_m25p32 ( struct spi_device *device ) {
241 	device->address_len = 24;
242 	device->nvs.size = ( 4 * 1024 * 1024 );
243 	device->nvs.block_size = 256;
244 	init_spi ( device );
245 }
246 
247 /** Microchip 25XX640 serial EEPROM */
248 static inline __attribute__ (( always_inline )) void
init_mc25xx640(struct spi_device * device)249 init_mc25xx640 ( struct spi_device *device ) {
250 	device->address_len = 16;
251 	device->nvs.size = ( 8 * 1024 );
252 	device->nvs.block_size = 32;
253 	init_spi ( device );
254 }
255 
256 /** @} */
257 
258 #endif /* _GPXE_SPI_H */
259