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:
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>;
+ };
*/
static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE;
-module_param(cfag12864b_rate, uint, S_IRUGO);
+module_param(cfag12864b_rate, uint, 0444);
MODULE_PARM_DESC(cfag12864b_rate,
"Refresh rate (hertz)");
}
static struct notifier_block panel_notifier = {
- panel_notify_sys,
- NULL,
- 0
+ .notifier_call = panel_notify_sys,
};
int charlcd_register(struct charlcd *lcd)
{
struct charlcd *lcd = platform_get_drvdata(pdev);
- kfree(lcd->drvdata);
charlcd_unregister(lcd);
+ kfree(lcd->drvdata);
kfree(lcd);
return 0;
*/
static unsigned int ks0108_port = CONFIG_KS0108_PORT;
-module_param(ks0108_port, uint, S_IRUGO);
+module_param(ks0108_port, uint, 0444);
MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
-module_param(ks0108_delay, uint, S_IRUGO);
+module_param(ks0108_delay, uint, 0444);
MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
/*
.detach = ks0108_parport_detach,
.devmodel = true,
};
-
-static int __init ks0108_init(void)
-{
- return parport_register_driver(&ks0108_parport_driver);
-}
-
-static void __exit ks0108_exit(void)
-{
- parport_unregister_driver(&ks0108_parport_driver);
-}
-
-module_init(ks0108_init);
-module_exit(ks0108_exit);
+module_parport_driver(ks0108_parport_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");