commit bc42fb0f36591c8109cfd95d4731fbbc9f4ae3db
author Steve Markgraf <steve@steve-m.de> Mon Jan 09 23:06:52 2023 +0100
committer Nico Huber <nico.h@gmx.de> Fri Mar 03 17:47:30 2023 +0000
tree b3c77af7b08a48be68fc2c619a11c00e3e989520
parent 537985c977bfb329441fe7fee517389fde3391eb

programmer: Add bitbanging programmer driver for Linux libgpiod

With this driver, any single board computer, old smartphone, etc. with
a few spare GPIOs can be used for flashrom.

Tested by reading of a 2048 kB flash chip on a Qualcomm MSM8916 SoC
@800 MHz, ran the following command:

time flashrom -p linux_gpiod:gpiochip=0,cs=18,sck=19,mosi=13,miso=56 -r test.bin

This command uses /dev/gpiochip0 with the specified GPIO numbers for the
SPI lines. All arguments are mandatory.

Output:
[...]
Found GigaDevice flash chip "GD25LQ16" (2048 kB, SPI) on linux_gpiod.
[...]
real    1m 33.96s

Change-Id: Icad3eb7764f28feaea51bda3a7893da724c86d06
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Signed-off-by: Nico Huber <nico.h@gmx.de>

Documentation/building_meson.md

diff --git a/Documentation/building_meson.md b/Documentation/building_meson.md
index 21d400e..74dc65b 100644
--- a/Documentation/building_meson.md
+++ b/Documentation/building_meson.md
@@ -11,6 +11,7 @@
   * libusb1 >=1.0.9 ***
   * libftdi1 ***
   * libjaylink ***
+  * libgpiod (Linux only) ***
 
 \*   Compile time dependency
 \*** Runtime / Programmer specific
@@ -46,14 +47,14 @@
 ```
 apt-get install -y gcc meson ninja-build pkg-config \
 	linux-headers-generic libpci-dev libusb-1.0-0-dev libftdi1-dev \
-	libjaylink-dev
+	libjaylink-dev libgpiod-dev
 ```
 
 ### ArchLinux / Manjaro
   * __libjaylink__ is not available through the package manager
 ```
 pacman -S --noconfirm gcc meson ninja pkg-config \
-	pciutils libusb libftdi
+	pciutils libusb libftdi libgpiod
 ```
 
 ### NixOS / Nixpkgs
@@ -62,20 +63,20 @@
 ```
 or
 ```
-nix-shell -p meson ninja pkg-config pciutils libusb1 libftdi1 libjaylink
+nix-shell -p meson ninja pkg-config pciutils libusb1 libftdi1 libjaylink libgpiod
 ```
 
 ### OpenSUSE
 ```
 zypper install -y gcc meson ninja pkg-config \
 	pciutils-devel libusb-1_0-devel libftdi1-devel \
-	libjaylink-devel
+	libjaylink-devel libgpiod-devel
 ```
 
 ### Alpine
 ```
 apk add build-base meson ninja pkgconf pciutils-dev libusb-dev \
-	libftdi1-dev libjaylink-dev linux-headers
+	libftdi1-dev libjaylink-dev linux-headers libgpiod-dev
 ```
 
 ### Freebsd / DragonFly BSD