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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-12 16:00:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-12 16:00:49 -0700 |
commit | d41adc4e22c62640fa7de93f713a3c5b3638ab2e (patch) | |
tree | 6510e7f3d1226e602c28701110ea169991cb3e8b /Documentation | |
parent | f306b90c69ce3994bb8046b54374a90a27f66be6 (diff) | |
parent | 24ebc044c72ee6e88dc902a0041bac672f012537 (diff) | |
download | lwn-d41adc4e22c62640fa7de93f713a3c5b3638ab2e.tar.gz lwn-d41adc4e22c62640fa7de93f713a3c5b3638ab2e.zip |
Merge tag 'auxdisplay-for-linus-v5.15-rc1' of git://github.com/ojeda/linux
Pull auxdisplay updates from Miguel Ojeda:
"An assortment of improvements for auxdisplay:
- Replace symbolic permissions with octal permissions (Jinchao Wang)
- ks0108: Switch to use module_parport_driver() (Andy Shevchenko)
- charlcd: Drop unneeded initializers and switch to C99 style (Andy
Shevchenko)
- hd44780: Fix oops on module unloading (Lars Poeschel)
- Add I2C gpio expander example (Ralf Schlatterbeck)"
* tag 'auxdisplay-for-linus-v5.15-rc1' of git://github.com/ojeda/linux:
auxdisplay: Replace symbolic permissions with octal permissions
auxdisplay: ks0108: Switch to use module_parport_driver()
auxdisplay: charlcd: Drop unneeded initializers and switch to C99 style
auxdisplay: hd44780: Fix oops on module unloading
auxdisplay: Add I2C gpio expander example
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml index 9222b06e93a0..fde07e4b119d 100644 --- a/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml +++ b/Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml @@ -12,7 +12,10 @@ maintainers: description: The Hitachi HD44780 Character LCD Controller is commonly used on character LCDs that can display one or more lines of text. It exposes an M6800 bus - interface, which can be used in either 4-bit or 8-bit mode. + interface, which can be used in either 4-bit or 8-bit mode. By using a + GPIO expander it is possible to use the driver with one of the popular I2C + expander boards based on the PCF8574 available for these displays. For + an example see below. properties: compatible: @@ -94,3 +97,29 @@ examples: display-height-chars = <2>; display-width-chars = <16>; }; + - | + #include <dt-bindings/gpio/gpio.h> + i2c { + #address-cells = <1>; + #size-cells = <0>; + + pcf8574: pcf8574@27 { + compatible = "nxp,pcf8574"; + reg = <0x27>; + gpio-controller; + #gpio-cells = <2>; + }; + }; + hd44780 { + compatible = "hit,hd44780"; + display-height-chars = <2>; + display-width-chars = <16>; + data-gpios = <&pcf8574 4 0>, + <&pcf8574 5 0>, + <&pcf8574 6 0>, + <&pcf8574 7 0>; + enable-gpios = <&pcf8574 2 0>; + rs-gpios = <&pcf8574 0 0>; + rw-gpios = <&pcf8574 1 0>; + backlight-gpios = <&pcf8574 3 0>; + }; |