1 #ifndef _GPXE_THREEWIRE_H
2 #define _GPXE_THREEWIRE_H
3
4 /** @file
5 *
6 * Three-wire serial interface
7 *
8 * The Atmel three-wire interface is a subset of the (newer) SPI
9 * interface, and is implemented here as a layer on top of the SPI
10 * support.
11 */
12
13 FILE_LICENCE ( GPL2_OR_LATER );
14
15 #include <gpxe/spi.h>
16 #include <limits.h>
17
18 /**
19 * @defgroup tcmds Three-wire commands
20 * @{
21 */
22
23 /** Read data from memory array */
24 #define THREEWIRE_READ 0x6
25
26 /** Write data to memory array */
27 #define THREEWIRE_WRITE 0x5
28
29 /** Write enable */
30 #define THREEWIRE_EWEN 0x4
31
32 /** Address to be used for write enable command */
33 #define THREEWIRE_EWEN_ADDRESS INT_MAX
34
35 /** Time to wait for write cycles to complete
36 *
37 * This is sufficient for AT93C46/AT93C56 devices, but may need to be
38 * increased in future when other devices are added.
39 */
40 #define THREEWIRE_WRITE_MDELAY 10
41
42 /** @} */
43
44 extern int threewire_read ( struct nvs_device *nvs, unsigned int address,
45 void *data, size_t len );
46 extern int threewire_write ( struct nvs_device *nvs, unsigned int address,
47 const void *data, size_t len );
48 extern int threewire_detect_address_len ( struct spi_device *device );
49
50 /**
51 * @defgroup tdevs Three-wire device types
52 * @{
53 */
54
55 static inline __attribute__ (( always_inline )) void
init_at93cx6(struct spi_device * device,unsigned int organisation)56 init_at93cx6 ( struct spi_device *device, unsigned int organisation ) {
57 device->nvs.word_len_log2 = ( ( organisation == 8 ) ? 0 : 1 );
58 device->nvs.block_size = 1;
59 device->command_len = 3,
60 device->nvs.read = threewire_read;
61 device->nvs.write = threewire_write;
62 }
63
64 /**
65 * Initialise Atmel AT93C46 serial EEPROM
66 *
67 * @v device SPI device
68 * @v organisation Word organisation (8 or 16)
69 */
70 static inline __attribute__ (( always_inline )) void
init_at93c46(struct spi_device * device,unsigned int organisation)71 init_at93c46 ( struct spi_device *device, unsigned int organisation ) {
72 device->nvs.size = ( 1024 / organisation );
73 device->address_len = ( ( organisation == 8 ) ? 7 : 6 );
74 init_at93cx6 ( device, organisation );
75 }
76
77 /**
78 * Initialise Atmel AT93C56 serial EEPROM
79 *
80 * @v device SPI device
81 * @v organisation Word organisation (8 or 16)
82 */
83 static inline __attribute__ (( always_inline )) void
init_at93c56(struct spi_device * device,unsigned int organisation)84 init_at93c56 ( struct spi_device *device, unsigned int organisation ) {
85 device->nvs.size = ( 2048 / organisation );
86 device->address_len = ( ( organisation == 8 ) ? 9 : 8 );
87 init_at93cx6 ( device, organisation );
88 }
89
90 /**
91 * Initialise Atmel AT93C66 serial EEPROM
92 *
93 * @v device SPI device
94 * @v organisation Word organisation (8 or 16)
95 */
96 static inline __attribute__ (( always_inline )) void
init_at93c66(struct spi_device * device,unsigned int organisation)97 init_at93c66 ( struct spi_device *device, unsigned int organisation ) {
98 device->nvs.size = ( 4096 / organisation );
99 device->address_len = ( ( organisation == 8 ) ? 9 : 8 );
100 init_at93cx6 ( device, organisation );
101 }
102
103 /** @} */
104
105 #endif /* _GPXE_THREEWIRE_H */
106