auxdisplay: linedisp: Add support for overriding character mapping

There is already the driver using character mapping table for
7 or 14 segment display. It is possible to override it. Make
the similar in the line display library to allow other drivers
to utilise the same functionality.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/auxdisplay/line-display.c b/drivers/auxdisplay/line-display.c
index 8bb15bd166dd2bdff1d3dbb384586ef0b211de02..13be7c2f6bc362d1655f1dcb88f2358218886d93 100644 (file)
--- a/drivers/auxdisplay/line-display.c
+++ b/drivers/auxdisplay/line-display.c
@@ -22,6 +22,9 @@
 #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)
@@ -188,12 +191,71 @@ 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;
+};
+
+static const struct attribute_group linedisp_group = {
+       .is_visible     = linedisp_attr_is_visible,
+       .attrs          = linedisp_attrs,
 };
-ATTRIBUTE_GROUPS(linedisp);
+__ATTRIBUTE_GROUPS(linedisp);
 
 static DEFINE_IDA(linedisp_id);
 
@@ -201,6 +263,7 @@ static void linedisp_release(struct device *dev)
 {
        struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
 
+       kfree(linedisp->map);
        kfree(linedisp->message);
        ida_free(&linedisp_id, linedisp->id);
 }
@@ -210,6 +273,44 @@ static const struct device_type linedisp_type = {
        .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
@@ -242,6 +343,11 @@ int linedisp_register(struct linedisp *linedisp, struct device *parent,
        device_initialize(&linedisp->dev);
        dev_set_name(&linedisp->dev, "linedisp.%u", linedisp->id);
 
+       /* 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);
 
@@ -260,6 +366,7 @@ out_del_dev:
        device_del(&linedisp->dev);
 out_del_timer:
        del_timer_sync(&linedisp->timer);
+out_put_device:
        put_device(&linedisp->dev);
        return err;
 }

diff --git a/drivers/auxdisplay/line-display.h b/drivers/auxdisplay/line-display.h
index 88d05144559915662326019af0608fb589d06157..4e310b0e611efde81f29a7185205a5266148970e 100644 (file)
--- a/drivers/auxdisplay/line-display.h
+++ b/drivers/auxdisplay/line-display.h
@@ -14,13 +14,43 @@
 #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);
 };
 
@@ -41,6 +71,7 @@ struct linedisp {
        struct device dev;
        struct timer_list timer;
        const struct linedisp_ops *ops;
+       struct linedisp_map *map;
        char *buf;
        char *message;
        unsigned int num_chars;