diff options
Diffstat (limited to 'README')
| -rw-r--r-- | README | 74 |
1 files changed, 71 insertions, 3 deletions
@@ -1944,9 +1944,77 @@ CBFS (Coreboot Filesystem) support on those systems that support this (optional) feature, like the TQM8xxL modules. -- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C - - These enable I2C serial bus commands. Defining either of +- I2C Support: CONFIG_SYS_I2C + + This enable the NEW i2c subsystem, and will allow you to use + i2c commands at the u-boot command line (as long as you set + CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c + based realtime clock chips or other i2c devices. See + common/cmd_i2c.c for a description of the command line + interface. + + ported i2c driver to the new framework: + + additional defines: + + CONFIG_SYS_NUM_I2C_BUSES + Hold the number of i2c busses you want to use. If you + don't use/have i2c muxes on your i2c bus, this + is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can + omit this define. + + CONFIG_SYS_I2C_DIRECT_BUS + define this, if you don't use i2c muxes on your hardware. + if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can + omit this define. + + CONFIG_SYS_I2C_MAX_HOPS + define how many muxes are maximal consecutively connected + on one i2c bus. If you not use i2c muxes, omit this + define. + + CONFIG_SYS_I2C_BUSES + hold a list of busses you want to use, only used if + CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example + a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and + CONFIG_SYS_NUM_I2C_BUSES = 9: + + CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ + {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ + {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ + {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ + {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ + {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ + {1, {I2C_NULL_HOP}}, \ + {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ + {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ + } + + which defines + bus 0 on adapter 0 without a mux + bus 1 on adapter 0 without a PCA9547 on address 0x70 port 1 + bus 2 on adapter 0 without a PCA9547 on address 0x70 port 2 + bus 3 on adapter 0 without a PCA9547 on address 0x70 port 3 + bus 4 on adapter 0 without a PCA9547 on address 0x70 port 4 + bus 5 on adapter 0 without a PCA9547 on address 0x70 port 5 + bus 6 on adapter 1 without a mux + bus 7 on adapter 1 without a PCA9544 on address 0x72 port 1 + bus 8 on adapter 1 without a PCA9544 on address 0x72 port 2 + + If you do not have i2c muxes on your board, omit this define. + +- Legacy I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C + + NOTE: It is intended to move drivers to CONFIG_SYS_I2C which + provides the following compelling advantages: + + - more than one i2c adapter is usable + - approved multibus support + - better i2c mux support + + ** Please consider updating your I2C driver now. ** + + These enable legacy I2C serial bus commands. Defining either of (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will include the appropriate I2C driver for the selected CPU. |