Merge tag 'auxdisplay-v6.9-1' of...

Merge tag 'auxdisplay-v6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-auxdisplay

Pull auxdisplay updates from Andy Shevchenko:

 - New driver for GPIO based 7-segment LED display (Chris Packham)

 - New driver for Maxim MAX6958/6959 I²C 7-segment LED display
   controller

 - Refactor linedisp library to make the above happen

 - Update Holtek HT16k33 driver to follow the linedisp refactoring

 - Convert .remove to return void in platform drivers (Uwe Kleine-König)

 - Fix DT schemas (Krzysztof Kozlowski)

 - Refresh MAINTAINERS database

* tag 'auxdisplay-v6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-auxdisplay: (27 commits)
  auxdisplay: img-ascii-lcd: Convert to platform remove callback returning void
  auxdisplay: hd44780: Convert to platform remove callback returning void
  auxdisplay: cfag12864bfb: Convert to platform remove callback returning void
  auxdisplay: seg-led-gpio: Import linedisp namespace
  dt-bindings: auxdisplay: Add bindings for generic 7-segment LED
  auxdisplay: Add 7-segment LED display driver
  auxdisplay: Add driver for MAX695x 7-segment LED controllers
  dt-bindings: auxdisplay: Add Maxim MAX6958/6959
  auxdisplay: ht16k33: Drop struct ht16k33_seg
  auxdisplay: ht16k33: Switch to use line display character mapping
  auxdisplay: ht16k33: Define a few helper macros
  auxdisplay: ht16k33: Move ht16k33_linedisp_ops down
  auxdisplay: ht16k33: Add default to switch-cases
  auxdisplay: linedisp: Allocate buffer for the string
  auxdisplay: linedisp: Add support for overriding character mapping
  auxdisplay: linedisp: Provide struct linedisp_ops for future extension
  auxdisplay: linedisp: Move exported symbols to a namespace
  auxdisplay: linedisp: Add missing header(s)
  auxdisplay: linedisp: Unshadow error codes in ->store()
  auxdisplay: linedisp: Use unique number for id
  ...

Documentation/devicetree/bindings/auxdisplay/arm,versatile-lcd.yaml

@@ -39,6 +39,6 @@ additionalProperties: false
 examples:
   - |
     lcd@10008000 {
-            compatible = "arm,versatile-lcd";
-            reg = <0x10008000 0x1000>;
+        compatible = "arm,versatile-lcd";
+        reg = <0x10008000 0x1000>;
     };

Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/gpio-7-segment.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO based LED segment display
+
+maintainers:
+  - Chris Packham <chris.packham@alliedtelesis.co.nz>
+
+properties:
+  compatible:
+    const: gpio-7-segment
+
+  segment-gpios:
+    description: |
+      An array of GPIOs one per segment. The first GPIO corresponds to the A
+      segment, the seventh GPIO corresponds to the G segment. Some LED blocks
+      also have a decimal point which can be specified as an optional eighth
+      segment.
+
+               -a-
+              |   |
+              f   b
+              |   |
+               -g-
+              |   |
+              e   c
+              |   |
+               -d-  dp
+
+    minItems: 7
+    maxItems: 8
+
+required:
+  - segment-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+
+    #include <dt-bindings/gpio/gpio.h>
+
+    led-7seg {
+        compatible = "gpio-7-segment";
+        segment-gpios = <&gpio 0 GPIO_ACTIVE_LOW>,
+                        <&gpio 1 GPIO_ACTIVE_LOW>,
+                        <&gpio 2 GPIO_ACTIVE_LOW>,
+                        <&gpio 3 GPIO_ACTIVE_LOW>,
+                        <&gpio 4 GPIO_ACTIVE_LOW>,
+                        <&gpio 5 GPIO_ACTIVE_LOW>,
+                        <&gpio 6 GPIO_ACTIVE_LOW>;
+    };

Documentation/devicetree/bindings/auxdisplay/hit,hd44780.yaml

@@ -84,42 +84,44 @@ additionalProperties: false
 examples:
   - |
     #include <dt-bindings/gpio/gpio.h>
-    auxdisplay {
-            compatible = "hit,hd44780";
-
-            data-gpios = <&hc595 0 GPIO_ACTIVE_HIGH>,
-                         <&hc595 1 GPIO_ACTIVE_HIGH>,
-                         <&hc595 2 GPIO_ACTIVE_HIGH>,
-                         <&hc595 3 GPIO_ACTIVE_HIGH>;
-            enable-gpios = <&hc595 4 GPIO_ACTIVE_HIGH>;
-            rs-gpios = <&hc595 5 GPIO_ACTIVE_HIGH>;
-
-            display-height-chars = <2>;
-            display-width-chars = <16>;
+    display-controller {
+        compatible = "hit,hd44780";
+
+        data-gpios = <&hc595 0 GPIO_ACTIVE_HIGH>,
+                     <&hc595 1 GPIO_ACTIVE_HIGH>,
+                     <&hc595 2 GPIO_ACTIVE_HIGH>,
+                     <&hc595 3 GPIO_ACTIVE_HIGH>;
+        enable-gpios = <&hc595 4 GPIO_ACTIVE_HIGH>;
+        rs-gpios = <&hc595 5 GPIO_ACTIVE_HIGH>;
+
+        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>;
-            };
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pcf8574: gpio-expander@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>;
+
+    display-controller {
+        compatible = "hit,hd44780";
+        display-height-chars = <2>;
+        display-width-chars = <16>;
+        data-gpios = <&pcf8574 4 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 5 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 6 GPIO_ACTIVE_HIGH>,
+                     <&pcf8574 7 GPIO_ACTIVE_HIGH>;
+        enable-gpios = <&pcf8574 2 GPIO_ACTIVE_HIGH>;
+        rs-gpios = <&pcf8574 0 GPIO_ACTIVE_HIGH>;
+        rw-gpios = <&pcf8574 1 GPIO_ACTIVE_HIGH>;
+        backlight-gpios = <&pcf8574 3 GPIO_ACTIVE_HIGH>;
     };

Documentation/devicetree/bindings/auxdisplay/holtek,ht16k33.yaml

@@ -74,31 +74,31 @@ examples:
     #include <dt-bindings/input/input.h>
     #include <dt-bindings/leds/common.h>
     i2c {
-            #address-cells = <1>;
-            #size-cells = <0>;
-
-            ht16k33: ht16k33@70 {
-                    compatible = "holtek,ht16k33";
-                    reg = <0x70>;
-                    refresh-rate-hz = <20>;
-                    interrupt-parent = <&gpio4>;
-                    interrupts = <5 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
-                    debounce-delay-ms = <50>;
-                    linux,keymap = <MATRIX_KEY(2, 0, KEY_F6)>,
-                                   <MATRIX_KEY(3, 0, KEY_F8)>,
-                                   <MATRIX_KEY(4, 0, KEY_F10)>,
-                                   <MATRIX_KEY(5, 0, KEY_F4)>,
-                                   <MATRIX_KEY(6, 0, KEY_F2)>,
-                                   <MATRIX_KEY(2, 1, KEY_F5)>,
-                                   <MATRIX_KEY(3, 1, KEY_F7)>,
-                                   <MATRIX_KEY(4, 1, KEY_F9)>,
-                                   <MATRIX_KEY(5, 1, KEY_F3)>,
-                                   <MATRIX_KEY(6, 1, KEY_F1)>;
-
-                    led {
-                            color = <LED_COLOR_ID_RED>;
-                            function = LED_FUNCTION_BACKLIGHT;
-                            linux,default-trigger = "backlight";
-                    };
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display-controller@70 {
+            compatible = "holtek,ht16k33";
+            reg = <0x70>;
+            refresh-rate-hz = <20>;
+            interrupt-parent = <&gpio4>;
+            interrupts = <5 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
+            debounce-delay-ms = <50>;
+            linux,keymap = <MATRIX_KEY(2, 0, KEY_F6)>,
+                           <MATRIX_KEY(3, 0, KEY_F8)>,
+                           <MATRIX_KEY(4, 0, KEY_F10)>,
+                           <MATRIX_KEY(5, 0, KEY_F4)>,
+                           <MATRIX_KEY(6, 0, KEY_F2)>,
+                           <MATRIX_KEY(2, 1, KEY_F5)>,
+                           <MATRIX_KEY(3, 1, KEY_F7)>,
+                           <MATRIX_KEY(4, 1, KEY_F9)>,
+                           <MATRIX_KEY(5, 1, KEY_F3)>,
+                           <MATRIX_KEY(6, 1, KEY_F1)>;
+
+            led {
+                color = <LED_COLOR_ID_RED>;
+                function = LED_FUNCTION_BACKLIGHT;
+                linux,default-trigger = "backlight";
             };
-      };
+        };
+    };

Documentation/devicetree/bindings/auxdisplay/img,ascii-lcd.yaml

@@ -50,6 +50,6 @@ additionalProperties: false
 examples:
   - |
     lcd: lcd@17fff000 {
-            compatible = "img,boston-lcd";
-            reg = <0x17fff000 0x8>;
+        compatible = "img,boston-lcd";
+        reg = <0x17fff000 0x8>;
     };

Documentation/devicetree/bindings/auxdisplay/maxim,max6959.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/maxim,max6959.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MAX6958/6959 7-segment LED display controller
+
+maintainers:
+  - Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+
+description:
+  The Maxim MAX6958/6959 7-segment LED display controller provides
+  an I2C interface to up to four 7-segment LED digits. The MAX6959,
+  in comparison to MAX6958, adds input support. Type of the chip can
+  be autodetected via specific register read, and hence the features
+  may be enabled in the driver at run-time, in case they are requested
+  via Device Tree. A given hardware is simple and does not provide
+  any additional pins, such as reset or power enable.
+
+properties:
+  compatible:
+    const: maxim,max6959
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display-controller@38 {
+            compatible = "maxim,max6959";
+            reg = <0x38>;
+        };
+    };

MAINTAINERS

@@ -3389,11 +3389,15 @@ F:	drivers/base/auxiliary.c
 F:	include/linux/auxiliary_bus.h
 
 AUXILIARY DISPLAY DRIVERS
-M:	Miguel Ojeda <ojeda@kernel.org>
-S:	Maintained
+M:	Andy Shevchenko <andy@kernel.org>
+R:	Geert Uytterhoeven <geert@linux-m68k.org>
+S:	Odd Fixes
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-auxdisplay.git
 F:	Documentation/devicetree/bindings/auxdisplay/
 F:	drivers/auxdisplay/
 F:	include/linux/cfag12864b.h
+F:	include/uapi/linux/map_to_14segment.h
+F:	include/uapi/linux/map_to_7segment.h
 
 AVIA HX711 ANALOG DIGITAL CONVERTER IIO DRIVER
 M:	Andreas Klinger <ak@it-klinger.de>

drivers/auxdisplay/Kconfig

@@ -177,6 +177,20 @@ config HT16K33
 	  Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
 	  LED controller driver with keyscan.
 
+config MAX6959
+	tristate "Maxim MAX6958/6959 7-segment LED controller"
+	depends on I2C
+	select REGMAP_I2C
+	select LINEDISP
+	help
+	  If you say yes here you get support for the following Maxim chips
+	  (I2C 7-segment LED display controller):
+	  - MAX6958
+	  - MAX6959 (input support)
+
+	  This driver can also be built as a module. If so, the module
+	  will be called max6959.
+
 config LCD2S
 	tristate "lcd2s 20x4 character display over I2C console"
 	depends on I2C
@@ -197,6 +211,17 @@ config ARM_CHARLCD
 	  line and the Linux version on the second line, but that's
 	  still useful.
 
+config SEG_LED_GPIO
+	tristate "Generic 7-segment LED display"
+	depends on GPIOLIB || COMPILE_TEST
+	select LINEDISP
+	help
+	  This driver supports a generic 7-segment LED display made up
+	  of GPIO pins connected to the individual segments.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called seg-led-gpio.
+
 menuconfig PARPORT_PANEL
 	tristate "Parallel port LCD/Keypad Panel support"
 	depends on PARPORT

drivers/auxdisplay/Makefile

@@ -14,3 +14,5 @@ obj-$(CONFIG_HT16K33)		+= ht16k33.o
 obj-$(CONFIG_PARPORT_PANEL)	+= panel.o
 obj-$(CONFIG_LCD2S)		+= lcd2s.o
 obj-$(CONFIG_LINEDISP)		+= line-display.o
+obj-$(CONFIG_MAX6959)		+= max6959.o
+obj-$(CONFIG_SEG_LED_GPIO)	+= seg-led-gpio.o

drivers/auxdisplay/cfag12864bfb.c

@@ -96,7 +96,7 @@ static int cfag12864bfb_probe(struct platform_device *device)
 	return ret;
 }
 
-static int cfag12864bfb_remove(struct platform_device *device)
+static void cfag12864bfb_remove(struct platform_device *device)
 {
 	struct fb_info *info = platform_get_drvdata(device);
 
@@ -104,13 +104,11 @@ static int cfag12864bfb_remove(struct platform_device *device)
 		unregister_framebuffer(info);
 		framebuffer_release(info);
 	}
-
-	return 0;
 }
 
 static struct platform_driver cfag12864bfb_driver = {
 	.probe	= cfag12864bfb_probe,
-	.remove = cfag12864bfb_remove,
+	.remove_new = cfag12864bfb_remove,
 	.driver = {
 		.name	= CFAG12864BFB_NAME,
 	},

drivers/auxdisplay/hd44780.c

@@ -319,7 +319,7 @@ static int hd44780_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int hd44780_remove(struct platform_device *pdev)
+static void hd44780_remove(struct platform_device *pdev)
 {
 	struct charlcd *lcd = platform_get_drvdata(pdev);
 	struct hd44780_common *hdc = lcd->drvdata;
@@ -329,7 +329,6 @@ static int hd44780_remove(struct platform_device *pdev)
 	kfree(lcd->drvdata);
 
 	kfree(lcd);
-	return 0;
 }
 
 static const struct of_device_id hd44780_of_match[] = {
@@ -340,7 +339,7 @@ MODULE_DEVICE_TABLE(of, hd44780_of_match);
 
 static struct platform_driver hd44780_driver = {
 	.probe = hd44780_probe,
-	.remove = hd44780_remove,
+	.remove_new = hd44780_remove,
 	.driver		= {
 		.name	= "hd44780",
 		.of_match_table = hd44780_of_match,

drivers/auxdisplay/ht16k33.c

@@ -15,6 +15,7 @@
 #include <linux/property.h>
 #include <linux/fb.h>
 #include <linux/backlight.h>
+#include <linux/container_of.h>
 #include <linux/input.h>
 #include <linux/input/matrix_keypad.h>
 #include <linux/leds.h>
@@ -85,16 +86,6 @@ struct ht16k33_fbdev {
 	uint8_t *cache;
 };
 
-struct ht16k33_seg {
-	struct linedisp linedisp;
-	union {
-		struct seg7_conversion_map seg7;
-		struct seg14_conversion_map seg14;
-	} map;
-	unsigned int map_size;
-	char curr[4];
-};
-
 struct ht16k33_priv {
 	struct i2c_client *client;
 	struct delayed_work work;
@@ -102,12 +93,21 @@ struct ht16k33_priv {
 	struct ht16k33_keypad keypad;
 	union {
 		struct ht16k33_fbdev fbdev;
-		struct ht16k33_seg seg;
+		struct linedisp linedisp;
 	};
 	enum display_type type;
 	uint8_t blink;
 };
 
+#define ht16k33_work_to_priv(p)				\
+	container_of(p, struct ht16k33_priv, work.work)
+
+#define ht16k33_led_to_priv(p)				\
+	container_of(p, struct ht16k33_priv, led)
+
+#define ht16k33_linedisp_to_priv(p)			\
+	container_of(p, struct ht16k33_priv, linedisp)
+
 static const struct fb_fix_screeninfo ht16k33_fb_fix = {
 	.id		= DRIVER_NAME,
 	.type		= FB_TYPE_PACKED_PIXELS,
@@ -135,33 +135,6 @@ static const struct fb_var_screeninfo ht16k33_fb_var = {
 	.vmode = FB_VMODE_NONINTERLACED,
 };
 
-static const SEG7_DEFAULT_MAP(initial_map_seg7);
-static const SEG14_DEFAULT_MAP(initial_map_seg14);
-
-static ssize_t map_seg_show(struct device *dev, struct device_attribute *attr,
-			    char *buf)
-{
-	struct ht16k33_priv *priv = dev_get_drvdata(dev);
-
-	memcpy(buf, &priv->seg.map, priv->seg.map_size);
-	return priv->seg.map_size;
-}
-
-static ssize_t map_seg_store(struct device *dev, struct device_attribute *attr,
-			     const char *buf, size_t cnt)
-{
-	struct ht16k33_priv *priv = dev_get_drvdata(dev);
-
-	if (cnt != priv->seg.map_size)
-		return -EINVAL;
-
-	memcpy(&priv->seg.map, buf, cnt);
-	return cnt;
-}
-
-static DEVICE_ATTR(map_seg7, 0644, map_seg_show, map_seg_store);
-static DEVICE_ATTR(map_seg14, 0644, map_seg_show, map_seg_store);
-
 static int ht16k33_display_on(struct ht16k33_priv *priv)
 {
 	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON | priv->blink;
@@ -195,8 +168,7 @@ static int ht16k33_brightness_set(struct ht16k33_priv *priv,
 static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
 					   enum led_brightness brightness)
 {
-	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
-						 led);
+	struct ht16k33_priv *priv = ht16k33_led_to_priv(led_cdev);
 
 	return ht16k33_brightness_set(priv, brightness);
 }
@@ -204,8 +176,7 @@ static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
 static int ht16k33_blink_set(struct led_classdev *led_cdev,
 			     unsigned long *delay_on, unsigned long *delay_off)
 {
-	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
-						 led);
+	struct ht16k33_priv *priv = ht16k33_led_to_priv(led_cdev);
 	unsigned int delay;
 	uint8_t blink;
 	int err;
@@ -247,8 +218,7 @@ static void ht16k33_fb_queue(struct ht16k33_priv *priv)
  */
 static void ht16k33_fb_update(struct work_struct *work)
 {
-	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
-						 work.work);
+	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
 
 	uint8_t *p1, *p2;
@@ -440,51 +410,71 @@ static void ht16k33_keypad_stop(struct input_dev *dev)
 	disable_irq(keypad->client->irq);
 }
 
-static void ht16k33_linedisp_update(struct linedisp *linedisp)
-{
-	struct ht16k33_priv *priv = container_of(linedisp, struct ht16k33_priv,
-						 seg.linedisp);
-
-	schedule_delayed_work(&priv->work, 0);
-}
-
 static void ht16k33_seg7_update(struct work_struct *work)
 {
-	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
-						 work.work);
-	struct ht16k33_seg *seg = &priv->seg;
-	char *s = seg->curr;
+	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
+	struct linedisp_map *map = priv->linedisp.map;
+	char *s = priv->linedisp.buf;
 	uint8_t buf[9];
 
-	buf[0] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[0] = map_to_seg7(&map->map.seg7, *s++);
 	buf[1] = 0;
-	buf[2] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[2] = map_to_seg7(&map->map.seg7, *s++);
 	buf[3] = 0;
 	buf[4] = 0;
 	buf[5] = 0;
-	buf[6] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[6] = map_to_seg7(&map->map.seg7, *s++);
 	buf[7] = 0;
-	buf[8] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[8] = map_to_seg7(&map->map.seg7, *s++);
 
 	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
 }
 
 static void ht16k33_seg14_update(struct work_struct *work)
 {
-	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
-						 work.work);
-	struct ht16k33_seg *seg = &priv->seg;
-	char *s = seg->curr;
+	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
+	struct linedisp_map *map = priv->linedisp.map;
+	char *s = priv->linedisp.buf;
 	uint8_t buf[8];
 
-	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf);
-	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 2);
-	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 4);
-	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 6);
+	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 0);
+	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 2);
+	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 4);
+	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 6);
 
 	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
 }
 
+static int ht16k33_linedisp_get_map_type(struct linedisp *linedisp)
+{
+	struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
+
+	switch (priv->type) {
+	case DISP_QUAD_7SEG:
+		INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
+		return LINEDISP_MAP_SEG7;
+
+	case DISP_QUAD_14SEG:
+		INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
+		return LINEDISP_MAP_SEG14;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static void ht16k33_linedisp_update(struct linedisp *linedisp)
+{
+	struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
+
+	schedule_delayed_work(&priv->work, 0);
+}
+
+static const struct linedisp_ops ht16k33_linedisp_ops = {
+	.get_map_type = ht16k33_linedisp_get_map_type,
+	.update = ht16k33_linedisp_update,
+};
+
 static int ht16k33_led_probe(struct device *dev, struct led_classdev *led,
 			     unsigned int brightness)
 {
@@ -666,47 +656,14 @@ static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
 static int ht16k33_seg_probe(struct device *dev, struct ht16k33_priv *priv,
 			     uint32_t brightness)
 {
-	struct ht16k33_seg *seg = &priv->seg;
+	struct linedisp *linedisp = &priv->linedisp;
 	int err;
 
 	err = ht16k33_brightness_set(priv, brightness);
 	if (err)
 		return err;
 
-	switch (priv->type) {
-	case DISP_MATRIX:
-		/* not handled here */
-		err = -EINVAL;
-		break;
-
-	case DISP_QUAD_7SEG:
-		INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
-		seg->map.seg7 = initial_map_seg7;
-		seg->map_size = sizeof(seg->map.seg7);
-		err = device_create_file(dev, &dev_attr_map_seg7);
-		break;
-
-	case DISP_QUAD_14SEG:
-		INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
-		seg->map.seg14 = initial_map_seg14;
-		seg->map_size = sizeof(seg->map.seg14);
-		err = device_create_file(dev, &dev_attr_map_seg14);
-		break;
-	}
-	if (err)
-		return err;
-
-	err = linedisp_register(&seg->linedisp, dev, 4, seg->curr,
-				ht16k33_linedisp_update);
-	if (err)
-		goto err_remove_map_file;
-
-	return 0;
-
-err_remove_map_file:
-	device_remove_file(dev, &dev_attr_map_seg7);
-	device_remove_file(dev, &dev_attr_map_seg14);
-	return err;
+	return linedisp_register(linedisp, dev, 4, &ht16k33_linedisp_ops);
 }
 
 static int ht16k33_probe(struct i2c_client *client)
@@ -770,6 +727,9 @@ static int ht16k33_probe(struct i2c_client *client)
 		/* Segment Display */
 		err = ht16k33_seg_probe(dev, priv, dft_brightness);
 		break;
+
+	default:
+		return -EINVAL;
 	}
 	return err;
 }
@@ -790,9 +750,10 @@ static void ht16k33_remove(struct i2c_client *client)
 
 	case DISP_QUAD_7SEG:
 	case DISP_QUAD_14SEG:
-		linedisp_unregister(&priv->seg.linedisp);
-		device_remove_file(&client->dev, &dev_attr_map_seg7);
-		device_remove_file(&client->dev, &dev_attr_map_seg14);
+		linedisp_unregister(&priv->linedisp);
+		break;
+
+	default:
 		break;
 	}
 }
@@ -831,4 +792,5 @@ module_i2c_driver(ht16k33_driver);
 
 MODULE_DESCRIPTION("Holtek HT16K33 driver");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);
 MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");

drivers/auxdisplay/img-ascii-lcd.c

@@ -22,32 +22,30 @@ struct img_ascii_lcd_ctx;
  * struct img_ascii_lcd_config - Configuration information about an LCD model
  * @num_chars: the number of characters the LCD can display
  * @external_regmap: true if registers are in a system controller, else false
- * @update: function called to update the LCD
+ * @ops: character line display operations
  */
 struct img_ascii_lcd_config {
 	unsigned int num_chars;
 	bool external_regmap;
-	void (*update)(struct linedisp *linedisp);
+	const struct linedisp_ops ops;
 };
 
 /**
  * struct img_ascii_lcd_ctx - Private data structure
+ * @linedisp: line display structure
  * @base: the base address of the LCD registers
  * @regmap: the regmap through which LCD registers are accessed
  * @offset: the offset within regmap to the start of the LCD registers
  * @cfg: pointer to the LCD model configuration
- * @linedisp: line display structure
- * @curr: the string currently displayed on the LCD
  */
 struct img_ascii_lcd_ctx {
+	struct linedisp linedisp;
 	union {
 		void __iomem *base;
 		struct regmap *regmap;
 	};
 	u32 offset;
 	const struct img_ascii_lcd_config *cfg;
-	struct linedisp linedisp;
-	char curr[] __aligned(8);
 };
 
 /*
@@ -61,12 +59,12 @@ static void boston_update(struct linedisp *linedisp)
 	ulong val;
 
 #if BITS_PER_LONG == 64
-	val = *((u64 *)&ctx->curr[0]);
+	val = *((u64 *)&linedisp->buf[0]);
 	__raw_writeq(val, ctx->base);
 #elif BITS_PER_LONG == 32
-	val = *((u32 *)&ctx->curr[0]);
+	val = *((u32 *)&linedisp->buf[0]);
 	__raw_writel(val, ctx->base);
-	val = *((u32 *)&ctx->curr[4]);
+	val = *((u32 *)&linedisp->buf[4]);
 	__raw_writel(val, ctx->base + 4);
 #else
 # error Not 32 or 64 bit
@@ -75,7 +73,9 @@ static void boston_update(struct linedisp *linedisp)
 
 static struct img_ascii_lcd_config boston_config = {
 	.num_chars = 8,
-	.update = boston_update,
+	.ops = {
+		.update = boston_update,
+	},
 };
 
 /*
@@ -91,7 +91,7 @@ static void malta_update(struct linedisp *linedisp)
 
 	for (i = 0; i < linedisp->num_chars; i++) {
 		err = regmap_write(ctx->regmap,
-				   ctx->offset + (i * 8), ctx->curr[i]);
+				   ctx->offset + (i * 8), linedisp->buf[i]);
 		if (err)
 			break;
 	}
@@ -103,7 +103,9 @@ static void malta_update(struct linedisp *linedisp)
 static struct img_ascii_lcd_config malta_config = {
 	.num_chars = 8,
 	.external_regmap = true,
-	.update = malta_update,
+	.ops = {
+		.update = malta_update,
+	},
 };
 
 /*
@@ -191,7 +193,7 @@ static void sead3_update(struct linedisp *linedisp)
 
 		err = regmap_write(ctx->regmap,
 				   ctx->offset + SEAD3_REG_LCD_DATA,
-				   ctx->curr[i]);
+				   linedisp->buf[i]);
 		if (err)
 			break;
 	}
@@ -203,7 +205,9 @@ static void sead3_update(struct linedisp *linedisp)
 static struct img_ascii_lcd_config sead3_config = {
 	.num_chars = 16,
 	.external_regmap = true,
-	.update = sead3_update,
+	.ops = {
+		.update = sead3_update,
+	},
 };
 
 static const struct of_device_id img_ascii_lcd_matches[] = {
@@ -230,7 +234,7 @@ static int img_ascii_lcd_probe(struct platform_device *pdev)
 	struct img_ascii_lcd_ctx *ctx;
 	int err;
 
-	ctx = devm_kzalloc(dev, sizeof(*ctx) + cfg->num_chars, GFP_KERNEL);
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
 
@@ -247,8 +251,7 @@ static int img_ascii_lcd_probe(struct platform_device *pdev)
 			return PTR_ERR(ctx->base);
 	}
 
-	err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, ctx->curr,
-				cfg->update);
+	err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, &cfg->ops);
 	if (err)
 		return err;
 
@@ -273,16 +276,13 @@ static int img_ascii_lcd_probe(struct platform_device *pdev)
  *
  * Remove an LCD display device, freeing private resources & ensuring that the
  * driver stops using the LCD display registers.
- *
- * Return: 0
  */
-static int img_ascii_lcd_remove(struct platform_device *pdev)
+static void img_ascii_lcd_remove(struct platform_device *pdev)
 {
 	struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev);
 
 	sysfs_remove_link(&pdev->dev.kobj, "message");
 	linedisp_unregister(&ctx->linedisp);
-	return 0;
 }
 
 static struct platform_driver img_ascii_lcd_driver = {
@@ -291,10 +291,11 @@ static struct platform_driver img_ascii_lcd_driver = {
 		.of_match_table	= img_ascii_lcd_matches,
 	},
 	.probe	= img_ascii_lcd_probe,
-	.remove	= img_ascii_lcd_remove,
+	.remove_new = img_ascii_lcd_remove,
 };
 module_platform_driver(img_ascii_lcd_driver);
 
 MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display");
 MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);

drivers/auxdisplay/line-display.c

@@ -10,13 +10,21 @@
 
 #include <generated/utsrelease.h>
 
+#include <linux/container_of.h>
 #include <linux/device.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/jiffies.h>
+#include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/sysfs.h>
 #include <linux/timer.h>
 
+#include <linux/map_to_7segment.h>
+#include <linux/map_to_14segment.h>
+
 #include "line-display.h"
 
 #define DEFAULT_SCROLL_RATE	(HZ / 2)
@@ -45,7 +53,7 @@ static void linedisp_scroll(struct timer_list *t)
 	}
 
 	/* update the display */
-	linedisp->update(linedisp);
+	linedisp->ops->update(linedisp);
 
 	/* move on to the next character */
 	linedisp->scroll_pos++;
@@ -89,7 +97,7 @@ static int linedisp_display(struct linedisp *linedisp, const char *msg,
 		linedisp->message = NULL;
 		linedisp->message_len = 0;
 		memset(linedisp->buf, ' ', linedisp->num_chars);
-		linedisp->update(linedisp);
+		linedisp->ops->update(linedisp);
 		return 0;
 	}
 
@@ -165,9 +173,11 @@ static ssize_t scroll_step_ms_store(struct device *dev,
 {
 	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
 	unsigned int ms;
+	int err;
 
-	if (kstrtouint(buf, 10, &ms) != 0)
-		return -EINVAL;
+	err = kstrtouint(buf, 10, &ms);
+	if (err)
+		return err;
 
 	linedisp->scroll_rate = msecs_to_jiffies(ms);
 	if (linedisp->message && linedisp->message_len > linedisp->num_chars) {
@@ -181,45 +191,165 @@ static ssize_t scroll_step_ms_store(struct device *dev,
 
 static DEVICE_ATTR_RW(scroll_step_ms);
 
+static ssize_t map_seg_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+	struct linedisp_map *map = linedisp->map;
+
+	memcpy(buf, &map->map, map->size);
+	return map->size;
+}
+
+static ssize_t map_seg_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+	struct linedisp_map *map = linedisp->map;
+
+	if (count != map->size)
+		return -EINVAL;
+
+	memcpy(&map->map, buf, count);
+	return count;
+}
+
+static const SEG7_DEFAULT_MAP(initial_map_seg7);
+static DEVICE_ATTR(map_seg7, 0644, map_seg_show, map_seg_store);
+
+static const SEG14_DEFAULT_MAP(initial_map_seg14);
+static DEVICE_ATTR(map_seg14, 0644, map_seg_show, map_seg_store);
+
 static struct attribute *linedisp_attrs[] = {
 	&dev_attr_message.attr,
 	&dev_attr_scroll_step_ms.attr,
-	NULL,
+	&dev_attr_map_seg7.attr,
+	&dev_attr_map_seg14.attr,
+	NULL
+};
+
+static umode_t linedisp_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+	struct linedisp_map *map = linedisp->map;
+	umode_t mode = attr->mode;
+
+	if (attr == &dev_attr_map_seg7.attr) {
+		if (!map)
+			return 0;
+		if (map->type != LINEDISP_MAP_SEG7)
+			return 0;
+	}
+
+	if (attr == &dev_attr_map_seg14.attr) {
+		if (!map)
+			return 0;
+		if (map->type != LINEDISP_MAP_SEG14)
+			return 0;
+	}
+
+	return mode;
 };
-ATTRIBUTE_GROUPS(linedisp);
+
+static const struct attribute_group linedisp_group = {
+	.is_visible	= linedisp_attr_is_visible,
+	.attrs		= linedisp_attrs,
+};
+__ATTRIBUTE_GROUPS(linedisp);
+
+static DEFINE_IDA(linedisp_id);
+
+static void linedisp_release(struct device *dev)
+{
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+
+	kfree(linedisp->map);
+	kfree(linedisp->message);
+	kfree(linedisp->buf);
+	ida_free(&linedisp_id, linedisp->id);
+}
 
 static const struct device_type linedisp_type = {
 	.groups	= linedisp_groups,
+	.release = linedisp_release,
 };
 
+static int linedisp_init_map(struct linedisp *linedisp)
+{
+	struct linedisp_map *map;
+	int err;
+
+	if (!linedisp->ops->get_map_type)
+		return 0;
+
+	err = linedisp->ops->get_map_type(linedisp);
+	if (err < 0)
+		return err;
+
+	map = kmalloc(sizeof(*map), GFP_KERNEL);
+	if (!map)
+		return -ENOMEM;
+
+	map->type = err;
+
+	/* assign initial mapping */
+	switch (map->type) {
+	case LINEDISP_MAP_SEG7:
+		map->map.seg7 = initial_map_seg7;
+		map->size = sizeof(map->map.seg7);
+		break;
+	case LINEDISP_MAP_SEG14:
+		map->map.seg14 = initial_map_seg14;
+		map->size = sizeof(map->map.seg14);
+		break;
+	default:
+		kfree(map);
+		return -EINVAL;
+	}
+
+	linedisp->map = map;
+
+	return 0;
+}
+
 /**
  * linedisp_register - register a character line display
  * @linedisp: pointer to character line display structure
  * @parent: parent device
  * @num_chars: the number of characters that can be displayed
- * @buf: pointer to a buffer that can hold @num_chars characters
- * @update: Function called to update the display.  This must not sleep!
+ * @ops: character line display operations
  *
  * Return: zero on success, else a negative error code.
  */
 int linedisp_register(struct linedisp *linedisp, struct device *parent,
-		      unsigned int num_chars, char *buf,
-		      void (*update)(struct linedisp *linedisp))
+		      unsigned int num_chars, const struct linedisp_ops *ops)
 {
-	static atomic_t linedisp_id = ATOMIC_INIT(-1);
 	int err;
 
 	memset(linedisp, 0, sizeof(*linedisp));
 	linedisp->dev.parent = parent;
 	linedisp->dev.type = &linedisp_type;
-	linedisp->update = update;
-	linedisp->buf = buf;
+	linedisp->ops = ops;
 	linedisp->num_chars = num_chars;
 	linedisp->scroll_rate = DEFAULT_SCROLL_RATE;
 
+	err = ida_alloc(&linedisp_id, GFP_KERNEL);
+	if (err < 0)
+		return err;
+	linedisp->id = err;
+
 	device_initialize(&linedisp->dev);
-	dev_set_name(&linedisp->dev, "linedisp.%lu",
-		     (unsigned long)atomic_inc_return(&linedisp_id));
+	dev_set_name(&linedisp->dev, "linedisp.%u", linedisp->id);
+
+	err = -ENOMEM;
+	linedisp->buf = kzalloc(linedisp->num_chars, GFP_KERNEL);
+	if (!linedisp->buf)
+		goto out_put_device;
+
+	/* initialise a character mapping, if required */
+	err = linedisp_init_map(linedisp);
+	if (err)
+		goto out_put_device;
 
 	/* initialise a timer for scrolling the message */
 	timer_setup(&linedisp->timer, linedisp_scroll, 0);
@@ -239,10 +369,11 @@ int linedisp_register(struct linedisp *linedisp, struct device *parent,
 	device_del(&linedisp->dev);
 out_del_timer:
 	del_timer_sync(&linedisp->timer);
+out_put_device:
 	put_device(&linedisp->dev);
 	return err;
 }
-EXPORT_SYMBOL_GPL(linedisp_register);
+EXPORT_SYMBOL_NS_GPL(linedisp_register, LINEDISP);
 
 /**
  * linedisp_unregister - unregister a character line display
@@ -253,9 +384,8 @@ void linedisp_unregister(struct linedisp *linedisp)
 {
 	device_del(&linedisp->dev);
 	del_timer_sync(&linedisp->timer);
-	kfree(linedisp->message);
 	put_device(&linedisp->dev);
 }
-EXPORT_SYMBOL_GPL(linedisp_unregister);
+EXPORT_SYMBOL_NS_GPL(linedisp_unregister, LINEDISP);
 
 MODULE_LICENSE("GPL");

drivers/auxdisplay/line-display.h

@@ -11,33 +11,78 @@
 #ifndef _LINEDISP_H
 #define _LINEDISP_H
 
+#include <linux/device.h>
+#include <linux/timer_types.h>
+
+#include <linux/map_to_7segment.h>
+#include <linux/map_to_14segment.h>
+
+struct linedisp;
+
+/**
+ * enum linedisp_map_type - type of the character mapping
+ * @LINEDISP_MAP_SEG7: Map characters to 7 segment display
+ * @LINEDISP_MAP_SEG14: Map characters to 14 segment display
+ */
+enum linedisp_map_type {
+	LINEDISP_MAP_SEG7,
+	LINEDISP_MAP_SEG14,
+};
+
+/**
+ * struct linedisp_map - character mapping
+ * @type: type of the character mapping
+ * @map: conversion character mapping
+ * @size: size of the @map
+ */
+struct linedisp_map {
+	enum linedisp_map_type type;
+	union {
+		struct seg7_conversion_map seg7;
+		struct seg14_conversion_map seg14;
+	} map;
+	unsigned int size;
+};
+
+/**
+ * struct linedisp_ops - character line display operations
+ * @get_map_type: Function called to get the character mapping, if required
+ * @update: Function called to update the display. This must not sleep!
+ */
+struct linedisp_ops {
+	int (*get_map_type)(struct linedisp *linedisp);
+	void (*update)(struct linedisp *linedisp);
+};
+
 /**
  * struct linedisp - character line display private data structure
  * @dev: the line display device
  * @timer: timer used to implement scrolling
- * @update: function called to update the display
+ * @ops: character line display operations
  * @buf: pointer to the buffer for the string currently displayed
  * @message: the full message to display or scroll on the display
  * @num_chars: the number of characters that can be displayed
  * @message_len: the length of the @message string
  * @scroll_pos: index of the first character of @message currently displayed
  * @scroll_rate: scroll interval in jiffies
+ * @id: instance id of this display
  */
 struct linedisp {
 	struct device dev;
 	struct timer_list timer;
-	void (*update)(struct linedisp *linedisp);
+	const struct linedisp_ops *ops;
+	struct linedisp_map *map;
 	char *buf;
 	char *message;
 	unsigned int num_chars;
 	unsigned int message_len;
 	unsigned int scroll_pos;
 	unsigned int scroll_rate;
+	unsigned int id;
 };
 
 int linedisp_register(struct linedisp *linedisp, struct device *parent,
-		      unsigned int num_chars, char *buf,
-		      void (*update)(struct linedisp *linedisp));
+		      unsigned int num_chars, const struct linedisp_ops *ops);
 void linedisp_unregister(struct linedisp *linedisp);
 
 #endif /* LINEDISP_H */

drivers/auxdisplay/max6959.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MAX6958/6959 7-segment LED display controller
+ * Datasheet:
+ * https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6958-MAX6959.pdf
+ *
+ * Copyright (c) 2024, Intel Corporation.
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+#include <linux/array_size.h>
+#include <linux/bitrev.h>
+#include <linux/bits.h>
+#include <linux/container_of.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include <linux/map_to_7segment.h>
+
+#include "line-display.h"
+
+/* Registers */
+#define REG_DECODE_MODE			0x01
+#define REG_INTENSITY			0x02
+#define REG_SCAN_LIMIT			0x03
+#define REG_CONFIGURATION		0x04
+#define REG_CONFIGURATION_S_BIT		BIT(0)
+
+#define REG_DIGIT(x)			(0x20 + (x))
+#define REG_DIGIT0			0x20
+#define REG_DIGIT1			0x21
+#define REG_DIGIT2			0x22
+#define REG_DIGIT3			0x23
+
+#define REG_SEGMENTS			0x24
+#define REG_MAX				REG_SEGMENTS
+
+struct max6959_priv {
+	struct linedisp linedisp;
+	struct delayed_work work;
+	struct regmap *regmap;
+};
+
+static void max6959_disp_update(struct work_struct *work)
+{
+	struct max6959_priv *priv = container_of(work, struct max6959_priv, work.work);
+	struct linedisp *linedisp = &priv->linedisp;
+	struct linedisp_map *map = linedisp->map;
+	char *s = linedisp->buf;
+	u8 buf[4];
+
+	/* Map segments according to datasheet */
+	buf[0] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+	buf[1] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+	buf[2] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+	buf[3] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
+
+	regmap_bulk_write(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
+}
+
+static int max6959_linedisp_get_map_type(struct linedisp *linedisp)
+{
+	struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
+
+	INIT_DELAYED_WORK(&priv->work, max6959_disp_update);
+	return LINEDISP_MAP_SEG7;
+}
+
+static void max6959_linedisp_update(struct linedisp *linedisp)
+{
+	struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
+
+	schedule_delayed_work(&priv->work, 0);
+}
+
+static const struct linedisp_ops max6959_linedisp_ops = {
+	.get_map_type = max6959_linedisp_get_map_type,
+	.update = max6959_linedisp_update,
+};
+
+static int max6959_enable(struct max6959_priv *priv, bool enable)
+{
+	u8 mask = REG_CONFIGURATION_S_BIT;
+	u8 value = enable ? mask : 0;
+
+	return regmap_update_bits(priv->regmap, REG_CONFIGURATION, mask, value);
+}
+
+static void max6959_power_off(void *priv)
+{
+	max6959_enable(priv, false);
+}
+
+static int max6959_power_on(struct max6959_priv *priv)
+{
+	struct device *dev = regmap_get_device(priv->regmap);
+	int ret;
+
+	ret = max6959_enable(priv, true);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, max6959_power_off, priv);
+}
+
+static const struct regmap_config max6959_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = REG_MAX,
+	.cache_type = REGCACHE_MAPLE,
+};
+
+static int max6959_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max6959_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = devm_regmap_init_i2c(client, &max6959_regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	ret = max6959_power_on(priv);
+	if (ret)
+		return ret;
+
+	ret = linedisp_register(&priv->linedisp, dev, 4, &max6959_linedisp_ops);
+	if (ret)
+		return ret;
+
+	i2c_set_clientdata(client, priv);
+
+	return 0;
+}
+
+static void max6959_i2c_remove(struct i2c_client *client)
+{
+	struct max6959_priv *priv = i2c_get_clientdata(client);
+
+	cancel_delayed_work_sync(&priv->work);
+	linedisp_unregister(&priv->linedisp);
+}
+
+static int max6959_suspend(struct device *dev)
+{
+	return max6959_enable(dev_get_drvdata(dev), false);
+}
+
+static int max6959_resume(struct device *dev)
+{
+	return max6959_enable(dev_get_drvdata(dev), true);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
+
+static const struct i2c_device_id max6959_i2c_id[] = {
+	{ "max6959" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
+
+static const struct of_device_id max6959_of_table[] = {
+	{ .compatible = "maxim,max6959" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max6959_of_table);
+
+static struct i2c_driver max6959_i2c_driver = {
+	.driver = {
+		.name = "max6959",
+		.pm = pm_sleep_ptr(&max6959_pm_ops),
+		.of_match_table = max6959_of_table,
+	},
+	.probe = max6959_i2c_probe,
+	.remove = max6959_i2c_remove,
+	.id_table = max6959_i2c_id,
+};
+module_i2c_driver(max6959_i2c_driver);
+
+MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller");
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);

drivers/auxdisplay/panel.c

@@ -1519,106 +1519,9 @@ static void keypad_init(void)
 
 static void panel_attach(struct parport *port)
 {
+	int selected_keypad_type = NOT_SET;
 	struct pardev_cb panel_cb;
 
-	if (port->number != parport)
-		return;
-
-	if (pprt) {
-		pr_err("%s: port->number=%d parport=%d, already registered!\n",
-		       __func__, port->number, parport);
-		return;
-	}
-
-	memset(&panel_cb, 0, sizeof(panel_cb));
-	panel_cb.private = &pprt;
-	/* panel_cb.flags = 0 should be PARPORT_DEV_EXCL? */
-
-	pprt = parport_register_dev_model(port, "panel", &panel_cb, 0);
-	if (!pprt) {
-		pr_err("%s: port->number=%d parport=%d, parport_register_device() failed\n",
-		       __func__, port->number, parport);
-		return;
-	}
-
-	if (parport_claim(pprt)) {
-		pr_err("could not claim access to parport%d. Aborting.\n",
-		       parport);
-		goto err_unreg_device;
-	}
-
-	/* must init LCD first, just in case an IRQ from the keypad is
-	 * generated at keypad init
-	 */
-	if (lcd.enabled) {
-		lcd_init();
-		if (!lcd.charlcd || charlcd_register(lcd.charlcd))
-			goto err_unreg_device;
-	}
-
-	if (keypad.enabled) {
-		keypad_init();
-		if (misc_register(&keypad_dev))
-			goto err_lcd_unreg;
-	}
-	return;
-
-err_lcd_unreg:
-	if (scan_timer.function)
-		del_timer_sync(&scan_timer);
-	if (lcd.enabled)
-		charlcd_unregister(lcd.charlcd);
-err_unreg_device:
-	kfree(lcd.charlcd);
-	lcd.charlcd = NULL;
-	parport_unregister_device(pprt);
-	pprt = NULL;
-}
-
-static void panel_detach(struct parport *port)
-{
-	if (port->number != parport)
-		return;
-
-	if (!pprt) {
-		pr_err("%s: port->number=%d parport=%d, nothing to unregister.\n",
-		       __func__, port->number, parport);
-		return;
-	}
-	if (scan_timer.function)
-		del_timer_sync(&scan_timer);
-
-	if (keypad.enabled) {
-		misc_deregister(&keypad_dev);
-		keypad_initialized = 0;
-	}
-
-	if (lcd.enabled) {
-		charlcd_unregister(lcd.charlcd);
-		lcd.initialized = false;
-		kfree(lcd.charlcd->drvdata);
-		kfree(lcd.charlcd);
-		lcd.charlcd = NULL;
-	}
-
-	/* TODO: free all input signals */
-	parport_release(pprt);
-	parport_unregister_device(pprt);
-	pprt = NULL;
-}
-
-static struct parport_driver panel_driver = {
-	.name = "panel",
-	.match_port = panel_attach,
-	.detach = panel_detach,
-	.devmodel = true,
-};
-
-/* init function */
-static int __init panel_init_module(void)
-{
-	int selected_keypad_type = NOT_SET, err;
-
 	/* take care of an eventual profile */
 	switch (profile) {
 	case PANEL_PROFILE_CUSTOM:
@@ -1710,29 +1613,102 @@ static int __init panel_init_module(void)
 	if (!lcd.enabled && !keypad.enabled) {
 		/* no device enabled, let's exit */
 		pr_err("panel driver disabled.\n");
-		return -ENODEV;
+		return;
 	}
 
-	err = parport_register_driver(&panel_driver);
-	if (err) {
-		pr_err("could not register with parport. Aborting.\n");
-		return err;
+	if (port->number != parport)
+		return;
+
+	if (pprt) {
+		pr_err("%s: port->number=%d parport=%d, already registered!\n",
+		       __func__, port->number, parport);
+		return;
 	}
 
-	if (pprt)
-		pr_info("panel driver registered on parport%d (io=0x%lx).\n",
-			parport, pprt->port->base);
-	else
-		pr_info("panel driver not yet registered\n");
-	return 0;
+	memset(&panel_cb, 0, sizeof(panel_cb));
+	panel_cb.private = &pprt;
+	/* panel_cb.flags = 0 should be PARPORT_DEV_EXCL? */
+
+	pprt = parport_register_dev_model(port, "panel", &panel_cb, 0);
+	if (!pprt) {
+		pr_err("%s: port->number=%d parport=%d, parport_register_device() failed\n",
+		       __func__, port->number, parport);
+		return;
+	}
+
+	if (parport_claim(pprt)) {
+		pr_err("could not claim access to parport%d. Aborting.\n",
+		       parport);
+		goto err_unreg_device;
+	}
+
+	/* must init LCD first, just in case an IRQ from the keypad is
+	 * generated at keypad init
+	 */
+	if (lcd.enabled) {
+		lcd_init();
+		if (!lcd.charlcd || charlcd_register(lcd.charlcd))
+			goto err_unreg_device;
+	}
+
+	if (keypad.enabled) {
+		keypad_init();
+		if (misc_register(&keypad_dev))
+			goto err_lcd_unreg;
+	}
+	return;
+
+err_lcd_unreg:
+	if (scan_timer.function)
+		del_timer_sync(&scan_timer);
+	if (lcd.enabled)
+		charlcd_unregister(lcd.charlcd);
+err_unreg_device:
+	kfree(lcd.charlcd);
+	lcd.charlcd = NULL;
+	parport_unregister_device(pprt);
+	pprt = NULL;
 }
 
-static void __exit panel_cleanup_module(void)
+static void panel_detach(struct parport *port)
 {
-	parport_unregister_driver(&panel_driver);
+	if (port->number != parport)
+		return;
+
+	if (!pprt) {
+		pr_err("%s: port->number=%d parport=%d, nothing to unregister.\n",
+		       __func__, port->number, parport);
+		return;
+	}
+	if (scan_timer.function)
+		del_timer_sync(&scan_timer);
+
+	if (keypad.enabled) {
+		misc_deregister(&keypad_dev);
+		keypad_initialized = 0;
+	}
+
+	if (lcd.enabled) {
+		charlcd_unregister(lcd.charlcd);
+		lcd.initialized = false;
+		kfree(lcd.charlcd->drvdata);
+		kfree(lcd.charlcd);
+		lcd.charlcd = NULL;
+	}
+
+	/* TODO: free all input signals */
+	parport_release(pprt);
+	parport_unregister_device(pprt);
+	pprt = NULL;
 }
 
-module_init(panel_init_module);
-module_exit(panel_cleanup_module);
+static struct parport_driver panel_driver = {
+	.name = "panel",
+	.match_port = panel_attach,
+	.detach = panel_detach,
+	.devmodel = true,
+};
+module_parport_driver(panel_driver);
+
 MODULE_AUTHOR("Willy Tarreau");
 MODULE_LICENSE("GPL");

drivers/auxdisplay/seg-led-gpio.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for a 7-segment LED display
+ *
+ * The decimal point LED present on some devices is currently not
+ * supported.
+ *
+ * Copyright (C) Allied Telesis Labs
+ */
+
+#include <linux/bitmap.h>
+#include <linux/container_of.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/map_to_7segment.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "line-display.h"
+
+struct seg_led_priv {
+	struct linedisp linedisp;
+	struct delayed_work work;
+	struct gpio_descs *segment_gpios;
+};
+
+static void seg_led_update(struct work_struct *work)
+{
+	struct seg_led_priv *priv = container_of(work, struct seg_led_priv, work.work);
+	struct linedisp *linedisp = &priv->linedisp;
+	struct linedisp_map *map = linedisp->map;
+	DECLARE_BITMAP(values, 8) = { };
+
+	bitmap_set_value8(values, map_to_seg7(&map->map.seg7, linedisp->buf[0]), 0);
+
+	gpiod_set_array_value_cansleep(priv->segment_gpios->ndescs, priv->segment_gpios->desc,
+				       priv->segment_gpios->info, values);
+}
+
+static int seg_led_linedisp_get_map_type(struct linedisp *linedisp)
+{
+	struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
+
+	INIT_DELAYED_WORK(&priv->work, seg_led_update);
+	return LINEDISP_MAP_SEG7;
+}
+
+static void seg_led_linedisp_update(struct linedisp *linedisp)
+{
+	struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
+
+	schedule_delayed_work(&priv->work, 0);
+}
+
+static const struct linedisp_ops seg_led_linedisp_ops = {
+	.get_map_type = seg_led_linedisp_get_map_type,
+	.update = seg_led_linedisp_update,
+};
+
+static int seg_led_probe(struct platform_device *pdev)
+{
+	struct seg_led_priv *priv;
+	struct device *dev = &pdev->dev;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->segment_gpios = devm_gpiod_get_array(dev, "segment", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->segment_gpios))
+		return PTR_ERR(priv->segment_gpios);
+
+	if (priv->segment_gpios->ndescs < 7 || priv->segment_gpios->ndescs > 8)
+		return -EINVAL;
+
+	return linedisp_register(&priv->linedisp, dev, 1, &seg_led_linedisp_ops);
+}
+
+static int seg_led_remove(struct platform_device *pdev)
+{
+	struct seg_led_priv *priv = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&priv->work);
+	linedisp_unregister(&priv->linedisp);
+
+	return 0;
+}
+
+static const struct of_device_id seg_led_of_match[] = {
+	{ .compatible = "gpio-7-segment"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, seg_led_of_match);
+
+static struct platform_driver seg_led_driver = {
+	.probe = seg_led_probe,
+	.remove = seg_led_remove,
+	.driver = {
+		.name = "seg-led-gpio",
+		.of_match_table = seg_led_of_match,
+	},
+};
+module_platform_driver(seg_led_driver);
+
+MODULE_AUTHOR("Chris Packham <chris.packham@alliedtelesis.co.nz>");
+MODULE_DESCRIPTION("7 segment LED driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LINEDISP);