Lines Matching +full:two +full:- +full:wire
27 /* AT24CM02 and M24M02-R have a 256-byte write page size.
31 #define EEPROM_PAGE_MASK (EEPROM_PAGE_SIZE - 1)
35 /* EEPROM memory addresses are 19-bits long, which can
37 * The upper 3 bits are sent as part of the 7-bit
38 * "Device Type Identifier"--an I2C concept, which for EEPROM devices
39 * is hard-coded as 1010b, indicating that it is an EEPROM
40 * device--this is the wire format, followed by the upper
41 * 3 bits of the 19-bit address, followed by the direction,
42 * followed by two bytes holding the rest of the 16-bits of
43 * the EEPROM memory address. The format on the wire for EEPROM
47 * These bits are compared to how pins 1-3 of the part are connected,
50 * Note that of this wire format, a client is in control
55 * For instance, a 2-Mbit I2C EEPROM part, addresses all its bytes,
56 * using an 18-bit address, bit 17 to 0 and thus would use all but one bit of
59 * either Vcc or GND. This would allow for up to two 2-Mbit parts on
63 * For a 2-Mbit part, bit 18 is usually known as the "Chip Enable" or
66 * device responds to the command. This way, you can connect two
67 * 2-Mbit EEPROM devices on the same bus, but see one contiguous
72 * This addressing you encode in the 32-bit "eeprom_addr" below,
73 * namely the 19-bits "XYZ,A15:A0", as a single 19-bit address. For
83 * (M24M02-DR device only, which we do not use), change the "7" to
109 buf_size -= len, eeprom_addr += len, eeprom_buf += len) { in __amdgpu_eeprom_xfer()
130 * condition, so that the self-timed write in __amdgpu_eeprom_xfer()
134 len = min(EEPROM_PAGE_SIZE - (eeprom_addr & in __amdgpu_eeprom_xfer()
140 * device--they are simply sequenced out. in __amdgpu_eeprom_xfer()
147 /* This constitutes a START-STOP transaction. in __amdgpu_eeprom_xfer()
155 * self-writing cycle, tWR (tW), is 10 ms. in __amdgpu_eeprom_xfer()
166 return r < 0 ? r : eeprom_buf - p; in __amdgpu_eeprom_xfer()
170 * amdgpu_eeprom_xfer -- Read/write from/to an I2C EEPROM device
177 * Returns the number of bytes read/written; -errno on error.
182 const struct i2c_adapter_quirks *quirks = i2c_adap->quirks; in amdgpu_eeprom_xfer()
188 limit = quirks->max_read_len; in amdgpu_eeprom_xfer()
190 limit = quirks->max_write_len; in amdgpu_eeprom_xfer()
196 dev_err_ratelimited(&i2c_adap->dev, in amdgpu_eeprom_xfer()
200 return -EINVAL; in amdgpu_eeprom_xfer()
209 limit -= EEPROM_OFFSET_SIZE; in amdgpu_eeprom_xfer()
211 buf_size -= ps, eeprom_addr += ps, eeprom_buf += ps) { in amdgpu_eeprom_xfer()