From f2c24ce7e03d059fa9f674d8ebf6286e8f0c38b6 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Wed, 5 Dec 2018 11:56:40 +0000 Subject: [PATCH] overlays: Update README with removal of lirc-rpi Signed-off-by: Phil Elwell --- arch/arm/boot/dts/overlays/README | 57 ++++++++++++------------------- 1 file changed, 21 insertions(+), 36 deletions(-) --- a/arch/arm/boot/dts/overlays/README +++ b/arch/arm/boot/dts/overlays/README @@ -56,23 +56,29 @@ have its contents deleted (or commented Using Overlays ============== -Overlays are loaded using the "dtoverlay" directive. As an example, consider -the popular lirc-rpi module, the Linux Infrared Remote Control driver. In the -pre-DT world this would be loaded from /etc/modules, with an explicit -"modprobe lirc-rpi" command, or programmatically by lircd. With DT enabled, -this becomes a line in config.txt: - - dtoverlay=lirc-rpi - -This causes the file /boot/overlays/lirc-rpi.dtbo to be loaded. By -default it will use GPIOs 17 (out) and 18 (in), but this can be modified using -DT parameters: - - dtoverlay=lirc-rpi,gpio_out_pin=17,gpio_in_pin=13 - -Parameters always have default values, although in some cases (e.g. "w1-gpio") -it is necessary to provided multiple overlays in order to get the desired -behaviour. See the list of overlays below for a description of the parameters +Overlays are loaded using the "dtoverlay" config.txt setting. As an example, +consider I2C Real Time Clock drivers. In the pre-DT world these would be loaded +by writing a magic string comprising a device identifier and an I2C address to +a special file in /sys/class/i2c-adapter, having first loaded the driver for +the I2C interface and the RTC device - something like this: + + modprobe i2c-bcm2835 + modprobe rtc-ds1307 + echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device + +With DT enabled, this becomes a line in config.txt: + + dtoverlay=i2c-rtc,ds1307 + +This causes the file /boot/overlays/i2c-rtc.dtbo to be loaded and a "node" +describing the DS1307 I2C device to be added to the Device Tree for the Pi. By +default it usees address 0x68, but this can be modified with an additional DT +parameter: + + dtoverlay=i2c-rtc,ds1307,addr=0x68 + +Parameters usually have default values, although certain parameters are +mandatory. See the list of overlays below for a description of the parameters and their defaults. The Overlay and Parameter Reference @@ -1135,29 +1141,8 @@ Params: Name: lirc-rpi -Info: Configures lirc-rpi (Linux Infrared Remote Control for Raspberry Pi) - Consult the module documentation for more details. -Load: dtoverlay=lirc-rpi,= -Params: gpio_out_pin GPIO for output (default "17") - - gpio_in_pin GPIO for input (default "18") - - gpio_in_pull Pull up/down/off on the input pin - (default "down") - - sense Override the IR receive auto-detection logic: - "0" = force active-high - "1" = force active-low - "-1" = use auto-detection - (default "-1") - - softcarrier Turn the software carrier "on" or "off" - (default "on") - - invert "on" = invert the output pin (default "off") - - debug "on" = enable additional debug messages - (default "off") +Info: This overlay has been deprecated and removed - see gpio-ir +Load: Name: ltc294x