1STRUCT SPI_DEVICE(9) Serial Peripheral Interface (S STRUCT SPI_DEVICE(9)
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6 struct_spi_device - Master side proxy for an SPI slave device
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9 struct spi_device {
10 struct device dev;
11 struct spi_master * master;
12 u32 max_speed_hz;
13 u8 chip_select;
14 u8 mode;
15 #define SPI_CPHA 0x01
16 #define SPI_CPOL 0x02
17 #define SPI_MODE_0 (0|0)
18 #define SPI_MODE_1 (0|SPI_CPHA)
19 #define SPI_MODE_2 (SPI_CPOL|0)
20 #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
21 #define SPI_CS_HIGH 0x04
22 #define SPI_LSB_FIRST 0x08
23 #define SPI_3WIRE 0x10
24 #define SPI_LOOP 0x20
25 #define SPI_NO_CS 0x40
26 #define SPI_READY 0x80
27 u8 bits_per_word;
28 int irq;
29 void * controller_state;
30 void * controller_data;
31 char modalias[SPI_NAME_SIZE];
32 };
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35 dev
36 Driver model representation of the device.
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38 master
39 SPI controller used with the device.
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41 max_speed_hz
42 Maximum clock rate to be used with this chip (on this board); may
43 be changed by the device's driver. The spi_transfer.speed_hz can
44 override this for each transfer.
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46 chip_select
47 Chipselect, distinguishing chips handled by master.
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49 mode
50 The spi mode defines how data is clocked out and in. This may be
51 changed by the device's driver. The “active low” default for
52 chipselect mode can be overridden (by specifying SPI_CS_HIGH) as
53 can the “MSB first” default for each word in a transfer (by
54 specifying SPI_LSB_FIRST).
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56 bits_per_word
57 Data transfers involve one or more words; word sizes like eight or
58 12 bits are common. In-memory wordsizes are powers of two bytes
59 (e.g. 20 bit samples use 32 bits). This may be changed by the
60 device's driver, or left at the default (0) indicating protocol
61 words are eight bit bytes. The spi_transfer.bits_per_word can
62 override this for each transfer.
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64 irq
65 Negative, or the number passed to request_irq to receive interrupts
66 from this device.
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68 controller_state
69 Controller's runtime state
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71 controller_data
72 Board-specific definitions for controller, such as FIFO
73 initialization parameters; from board_info.controller_data
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75 modalias[SPI_NAME_SIZE]
76 Name of the driver to use with this device, or an alias for that
77 name. This appears in the sysfs “modalias” attribute for driver
78 coldplugging, and in uevents used for hotplugging
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81 A spi_device is used to interchange data between an SPI slave (usually
82 a discrete chip) and CPU memory.
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84 In dev, the platform_data is used to hold information about this device
85 that's meaningful to the device's protocol driver, but not to its
86 controller. One example might be an identifier for a chip variant with
87 slightly different functionality; another might be information about
88 how this particular board wires the chip's pins.
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91Kernel Hackers Manual 2.6. November 2011 STRUCT SPI_DEVICE(9)