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-rw-r--r--README195
1 files changed, 113 insertions, 82 deletions
diff --git a/README b/README
index bcfffc3..a5c3e8d 100644
--- a/README
+++ b/README
@@ -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
@@ -3604,7 +3635,7 @@ 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.