README: document the CONFIG_GPIO_LED symbol

[karo-tx-uboot.git] / README

diff --git a/README b/README
index 91c3ac0fa729fcb011a8faaf51713c550e1ecc3c..7b393b79b34c8ffcaf272f23c7259f15a75585a9 100644 (file)
--- a/README
+++ b/README
@@ -848,6 +848,7 @@ The following options need to be configured:
                CONFIG_CMD_ELF          * bootelf, bootvx
                CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
                CONFIG_CMD_ENV_FLAGS    * display details about env flags
+               CONFIG_CMD_ENV_EXISTS   * check existence of env variable
                CONFIG_CMD_EXPORTENV    * export the environment
                CONFIG_CMD_EXT2         * ext2 command support
                CONFIG_CMD_EXT4         * ext4 command support
@@ -1032,7 +1033,6 @@ The following options need to be configured:
 
 - GPIO Support:
                CONFIG_PCA953X          - use NXP's PCA953X series I2C GPIO
-               CONFIG_PCA953X_INFO     - enable pca953x info command
 
                The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
                chip-ngpio pairs that tell the PCA953X driver the number of
@@ -1367,6 +1367,13 @@ The following options need to be configured:
                        for your device
                        - CONFIG_USBD_PRODUCTID 0xFFFF
 
+               Some USB device drivers may need to check USB cable attachment.
+               In this case you can enable following config in BoardName.h:
+                       CONFIG_USB_CABLE_CHECK
+                       This enables function definition:
+                       - usb_cable_connected() in include/usb.h
+                       Implementation of this function is board-specific.
+
 - ULPI Layer Support:
                The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
                the generic ULPI layer. The generic layer accesses the ULPI PHY
@@ -1956,6 +1963,14 @@ CBFS (Coreboot Filesystem) support
                kernel). Defining CONFIG_STATUS_LED enables this
                feature in U-Boot.
 
+               Additional options:
+
+               CONFIG_GPIO_LED
+               The status LED can be connected to a GPIO pin.
+               In such cases, the gpio_led driver can be used as a
+               status LED backend implementation. Define CONFIG_GPIO_LED
+               to include the gpio_led driver in the U-Boot binary.
+
 - CAN Support: CONFIG_CAN_DRIVER
 
                Defining CONFIG_CAN_DRIVER enables CAN driver support
@@ -2033,6 +2048,42 @@ CBFS (Coreboot Filesystem) support
                  - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
                  - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
 
+               - drivers/i2c/sh_i2c.c:
+                 - activate this driver with CONFIG_SYS_I2C_SH
+                 - This driver adds from 2 to 5 i2c buses
+
+                 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
+                 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
+                 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
+                 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
+                 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
+                 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
+                 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
+                 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
+                 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
+                 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
+                 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
+                 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
+                 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
+
+               - drivers/i2c/omap24xx_i2c.c
+                 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
+                 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
+                 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
+                 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
+                 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
+                 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
+                 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
+                 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
+                 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
+                 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
+                 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
+
+               - drivers/i2c/zynq_i2c.c
+                 - activate this driver with CONFIG_SYS_I2C_ZYNQ
+                 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
+                 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
+
                additional defines:
 
                CONFIG_SYS_NUM_I2C_BUSES