diff options
Diffstat (limited to 'README')
| -rw-r--r-- | README | 195 |
1 files changed, 113 insertions, 82 deletions
@@ -1,24 +1,8 @@ # -# (C) Copyright 2000 - 2012 +# (C) Copyright 2000 - 2013 # Wolfgang Denk, DENX Software Engineering, wd@denx.de. # -# See file CREDITS for list of people who contributed to this -# project. -# -# This program is free software; you can redistribute it and/or -# modify it under the terms of the GNU General Public License as -# published by the Free Software Foundation; either version 2 of -# the License, or (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program; if not, write to the Free Software -# Foundation, Inc., 59 Temple Place, Suite 330, Boston, -# MA 02111-1307 USA +# SPDX-License-Identifier: GPL-2.0+ # Summary: @@ -1944,11 +1928,114 @@ 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 - (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will - include the appropriate I2C driver for the selected CPU. +- 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: + - drivers/i2c/soft_i2c.c: + - activate first bus with CONFIG_SYS_I2C_SOFT define + CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE + for defining speed and slave address + - activate second bus with I2C_SOFT_DECLARATIONS2 define + CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 + for defining speed and slave address + - activate third bus with I2C_SOFT_DECLARATIONS3 define + CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 + for defining speed and slave address + - activate fourth bus with I2C_SOFT_DECLARATIONS4 define + CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 + for defining speed and slave address + + - drivers/i2c/fsl_i2c.c: + - activate i2c driver with CONFIG_SYS_I2C_FSL + define CONFIG_SYS_FSL_I2C_OFFSET for setting the register + offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and + CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first + bus. + - If your board supports a second fsl i2c bus, define + CONFIG_SYS_FSL_I2C2_OFFSET for the register offset + CONFIG_SYS_FSL_I2C2_SPEED for the speed and + CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the + second bus. + + - drivers/i2c/tegra_i2c.c: + - activate this driver with CONFIG_SYS_I2C_TEGRA + - This driver adds 4 i2c buses with a fix speed from + 100000 and the slave addr 0! + + - drivers/i2c/ppc4xx_i2c.c + - activate this driver with CONFIG_SYS_I2C_PPC4XX + - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 + - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 + + 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 with a PCA9547 on address 0x70 port 1 + bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 + bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 + bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 + bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 + bus 6 on adapter 1 without a mux + bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 + bus 8 on adapter 1 with 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 + + 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 + CONFIG_HARD_I2C will include the appropriate I2C driver + for the selected CPU. This will allow you to use i2c commands at the u-boot command line (as long as you set CONFIG_CMD_I2C in @@ -1958,12 +2045,8 @@ CBFS (Coreboot Filesystem) support CONFIG_HARD_I2C selects a hardware I2C controller. - CONFIG_SOFT_I2C configures u-boot to use a software (aka - bit-banging) driver instead of CPM or similar hardware - support for I2C. - There are several other quantities that must also be - defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. + defined when you define CONFIG_HARD_I2C. In both cases you will need to define CONFIG_SYS_I2C_SPEED to be the frequency (in Hz) at which you wish your i2c bus @@ -1985,7 +2068,7 @@ CBFS (Coreboot Filesystem) support That's all that's required for CONFIG_HARD_I2C. - If you use the software i2c interface (CONFIG_SOFT_I2C) + If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) then the following macros need to be defined (examples are from include/configs/lwmon.h): @@ -2136,58 +2219,6 @@ CBFS (Coreboot Filesystem) support If not defined, then U-Boot uses predefined value for specified DTT device. - CONFIG_FSL_I2C - - Define this option if you want to use Freescale's I2C driver in - drivers/i2c/fsl_i2c.c. - - CONFIG_I2C_MUX - - Define this option if you have I2C devices reached over 1 .. n - I2C Muxes like the pca9544a. This option addes a new I2C - Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a - new I2C Bus to the existing I2C Busses. If you select the - new Bus with "i2c dev", u-bbot sends first the commandos for - the muxes to activate this new "bus". - - CONFIG_I2C_MULTI_BUS must be also defined, to use this - feature! - - Example: - Adding a new I2C Bus reached over 2 pca9544a muxes - The First mux with address 70 and channel 6 - The Second mux with address 71 and channel 4 - - => i2c bus pca9544a:70:6:pca9544a:71:4 - - Use the "i2c bus" command without parameter, to get a list - of I2C Busses with muxes: - - => i2c bus - Busses reached over muxes: - Bus ID: 2 - reached over Mux(es): - pca9544a@70 ch: 4 - Bus ID: 3 - reached over Mux(es): - pca9544a@70 ch: 6 - pca9544a@71 ch: 4 - => - - If you now switch to the new I2C Bus 3 with "i2c dev 3" - u-boot first sends the command to the mux@70 to enable - channel 6, and then the command to the mux@71 to enable - the channel 4. - - After that, you can use the "normal" i2c commands as - usual to communicate with your I2C devices behind - the 2 muxes. - - This option is actually implemented for the bitbanging - algorithm in common/soft_i2c.c and for the Hardware I2C - Bus on the MPC8260. But it should be not so difficult - to add this option to other architectures. - CONFIG_SOFT_I2C_READ_REPEATED_START defining this will force the i2c_read() function in @@ -3619,7 +3650,7 @@ to save the current settings. I2C muxes, you can define here, how to reach this EEPROM. For example: - #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0" + #define CONFIG_I2C_ENV_EEPROM_BUS 1 EEPROM which holds the environment, is reached over a pca9547 i2c mux with address 0x70, channel 3. |