Commit 34ddc83d authored by Andy Shevchenko's avatar Andy Shevchenko
Browse files

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: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent 70fb97c0

drivers/auxdisplay/line-display.c

+109 −2
Original line number Diff line number Diff line
@@ -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

};

ATTRIBUTE_GROUPS(linedisp);



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);



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 @@ 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;

}

drivers/auxdisplay/line-display.h

+31 −0
Original line number Diff line number Diff line
@@ -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;