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

5 files changed, 36 insertions, 21 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>;
+    };
diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c
index fd430e6866a1..6526aa51fb1d 100644
--- a/drivers/auxdisplay/cfag12864b.c
+++ b/drivers/auxdisplay/cfag12864b.c
@@ -33,7 +33,7 @@
  */
 
 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)");
 
diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 24fd6f369ebe..304accde365c 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -637,9 +637,7 @@ static int panel_notify_sys(struct notifier_block *this, unsigned long code,
 }
 
 static struct notifier_block panel_notifier = {
-	panel_notify_sys,
-	NULL,
-	0
+	.notifier_call = panel_notify_sys,
 };
 
 int charlcd_register(struct charlcd *lcd)
diff --git a/drivers/auxdisplay/hd44780.c b/drivers/auxdisplay/hd44780.c
index 2e5e7c993933..8b2a0eb3f32a 100644
--- a/drivers/auxdisplay/hd44780.c
+++ b/drivers/auxdisplay/hd44780.c
@@ -323,8 +323,8 @@ static int hd44780_remove(struct platform_device *pdev)
 {
 	struct charlcd *lcd = platform_get_drvdata(pdev);
 
-	kfree(lcd->drvdata);
 	charlcd_unregister(lcd);
+	kfree(lcd->drvdata);
 
 	kfree(lcd);
 	return 0;
diff --git a/drivers/auxdisplay/ks0108.c b/drivers/auxdisplay/ks0108.c
index 03c95ad4216c..e871b94a1911 100644
--- a/drivers/auxdisplay/ks0108.c
+++ b/drivers/auxdisplay/ks0108.c
@@ -28,11 +28,11 @@
  */
 
 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)");
 
 /*
@@ -167,19 +167,7 @@ static struct parport_driver ks0108_parport_driver = {
 	.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>");