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auxdisplay: Extract character line display core support
Extract the character line display core support from the simple ASCII LCD driver for the MIPS Boston, Malta & SEAD3 development boards into its own subdriver, so it can be reused for other displays. As this moves the "message" device attribute in sysfs in a "linedisp.N" subdirectory, a symlink is added to preserve backwards compatibility. Signed-off-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Miguel Ojeda <[email protected]>
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Original file line number | Diff line number | Diff line change |
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@@ -4,7 +4,6 @@ | |
* Author: Paul Burton <[email protected]> | ||
*/ | ||
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||
#include <generated/utsrelease.h> | ||
#include <linux/kernel.h> | ||
#include <linux/io.h> | ||
#include <linux/mfd/syscon.h> | ||
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@@ -14,7 +13,8 @@ | |
#include <linux/platform_device.h> | ||
#include <linux/regmap.h> | ||
#include <linux/slab.h> | ||
#include <linux/sysfs.h> | ||
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#include "line-display.h" | ||
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struct img_ascii_lcd_ctx; | ||
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@@ -27,45 +27,37 @@ struct img_ascii_lcd_ctx; | |
struct img_ascii_lcd_config { | ||
unsigned int num_chars; | ||
bool external_regmap; | ||
void (*update)(struct img_ascii_lcd_ctx *ctx); | ||
void (*update)(struct linedisp *linedisp); | ||
}; | ||
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/** | ||
* struct img_ascii_lcd_ctx - Private data structure | ||
* @pdev: the ASCII LCD platform device | ||
* @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 | ||
* @message: the full message to display or scroll on the LCD | ||
* @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 | ||
* @timer: timer used to implement scrolling | ||
* @linedisp: line display structure | ||
* @curr: the string currently displayed on the LCD | ||
*/ | ||
struct img_ascii_lcd_ctx { | ||
struct platform_device *pdev; | ||
union { | ||
void __iomem *base; | ||
struct regmap *regmap; | ||
}; | ||
u32 offset; | ||
const struct img_ascii_lcd_config *cfg; | ||
char *message; | ||
unsigned int message_len; | ||
unsigned int scroll_pos; | ||
unsigned int scroll_rate; | ||
struct timer_list timer; | ||
struct linedisp linedisp; | ||
char curr[] __aligned(8); | ||
}; | ||
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/* | ||
* MIPS Boston development board | ||
*/ | ||
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static void boston_update(struct img_ascii_lcd_ctx *ctx) | ||
static void boston_update(struct linedisp *linedisp) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = | ||
container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); | ||
ulong val; | ||
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#if BITS_PER_LONG == 64 | ||
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@@ -90,12 +82,14 @@ static struct img_ascii_lcd_config boston_config = { | |
* MIPS Malta development board | ||
*/ | ||
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static void malta_update(struct img_ascii_lcd_ctx *ctx) | ||
static void malta_update(struct linedisp *linedisp) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = | ||
container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); | ||
unsigned int i; | ||
int err = 0; | ||
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for (i = 0; i < ctx->cfg->num_chars; i++) { | ||
for (i = 0; i < linedisp->num_chars; i++) { | ||
err = regmap_write(ctx->regmap, | ||
ctx->offset + (i * 8), ctx->curr[i]); | ||
if (err) | ||
|
@@ -173,12 +167,14 @@ static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx) | |
return 0; | ||
} | ||
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||
static void sead3_update(struct img_ascii_lcd_ctx *ctx) | ||
static void sead3_update(struct linedisp *linedisp) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = | ||
container_of(linedisp, struct img_ascii_lcd_ctx, linedisp); | ||
unsigned int i; | ||
int err = 0; | ||
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||
for (i = 0; i < ctx->cfg->num_chars; i++) { | ||
for (i = 0; i < linedisp->num_chars; i++) { | ||
err = sead3_wait_lcd_idle(ctx); | ||
if (err) | ||
break; | ||
|
@@ -218,140 +214,6 @@ static const struct of_device_id img_ascii_lcd_matches[] = { | |
}; | ||
MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches); | ||
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||
/** | ||
* img_ascii_lcd_scroll() - scroll the display by a character | ||
* @t: really a pointer to the private data structure | ||
* | ||
* Scroll the current message along the LCD by one character, rearming the | ||
* timer if required. | ||
*/ | ||
static void img_ascii_lcd_scroll(struct timer_list *t) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = from_timer(ctx, t, timer); | ||
unsigned int i, ch = ctx->scroll_pos; | ||
unsigned int num_chars = ctx->cfg->num_chars; | ||
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||
/* update the current message string */ | ||
for (i = 0; i < num_chars;) { | ||
/* copy as many characters from the string as possible */ | ||
for (; i < num_chars && ch < ctx->message_len; i++, ch++) | ||
ctx->curr[i] = ctx->message[ch]; | ||
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||
/* wrap around to the start of the string */ | ||
ch = 0; | ||
} | ||
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/* update the LCD */ | ||
ctx->cfg->update(ctx); | ||
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/* move on to the next character */ | ||
ctx->scroll_pos++; | ||
ctx->scroll_pos %= ctx->message_len; | ||
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/* rearm the timer */ | ||
if (ctx->message_len > ctx->cfg->num_chars) | ||
mod_timer(&ctx->timer, jiffies + ctx->scroll_rate); | ||
} | ||
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||
/** | ||
* img_ascii_lcd_display() - set the message to be displayed | ||
* @ctx: pointer to the private data structure | ||
* @msg: the message to display | ||
* @count: length of msg, or -1 | ||
* | ||
* Display a new message @msg on the LCD. @msg can be longer than the number of | ||
* characters the LCD can display, in which case it will begin scrolling across | ||
* the LCD display. | ||
* | ||
* Return: 0 on success, -ENOMEM on memory allocation failure | ||
*/ | ||
static int img_ascii_lcd_display(struct img_ascii_lcd_ctx *ctx, | ||
const char *msg, ssize_t count) | ||
{ | ||
char *new_msg; | ||
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/* stop the scroll timer */ | ||
del_timer_sync(&ctx->timer); | ||
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if (count == -1) | ||
count = strlen(msg); | ||
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/* if the string ends with a newline, trim it */ | ||
if (msg[count - 1] == '\n') | ||
count--; | ||
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if (!count) { | ||
/* clear the LCD */ | ||
devm_kfree(&ctx->pdev->dev, ctx->message); | ||
ctx->message = NULL; | ||
ctx->message_len = 0; | ||
memset(ctx->curr, ' ', ctx->cfg->num_chars); | ||
ctx->cfg->update(ctx); | ||
return 0; | ||
} | ||
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new_msg = devm_kmalloc(&ctx->pdev->dev, count + 1, GFP_KERNEL); | ||
if (!new_msg) | ||
return -ENOMEM; | ||
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memcpy(new_msg, msg, count); | ||
new_msg[count] = 0; | ||
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if (ctx->message) | ||
devm_kfree(&ctx->pdev->dev, ctx->message); | ||
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ctx->message = new_msg; | ||
ctx->message_len = count; | ||
ctx->scroll_pos = 0; | ||
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/* update the LCD */ | ||
img_ascii_lcd_scroll(&ctx->timer); | ||
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return 0; | ||
} | ||
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/** | ||
* message_show() - read message via sysfs | ||
* @dev: the LCD device | ||
* @attr: the LCD message attribute | ||
* @buf: the buffer to read the message into | ||
* | ||
* Read the current message being displayed or scrolled across the LCD display | ||
* into @buf, for reads from sysfs. | ||
* | ||
* Return: the number of characters written to @buf | ||
*/ | ||
static ssize_t message_show(struct device *dev, struct device_attribute *attr, | ||
char *buf) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = dev_get_drvdata(dev); | ||
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return sysfs_emit(buf, "%s\n", ctx->message); | ||
} | ||
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/** | ||
* message_store() - write a new message via sysfs | ||
* @dev: the LCD device | ||
* @attr: the LCD message attribute | ||
* @buf: the buffer containing the new message | ||
* @count: the size of the message in @buf | ||
* | ||
* Write a new message to display or scroll across the LCD display from sysfs. | ||
* | ||
* Return: the size of the message on success, else -ERRNO | ||
*/ | ||
static ssize_t message_store(struct device *dev, struct device_attribute *attr, | ||
const char *buf, size_t count) | ||
{ | ||
struct img_ascii_lcd_ctx *ctx = dev_get_drvdata(dev); | ||
int err; | ||
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err = img_ascii_lcd_display(ctx, buf, count); | ||
return err ?: count; | ||
} | ||
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static DEVICE_ATTR_RW(message); | ||
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/** | ||
* img_ascii_lcd_probe() - probe an LCD display device | ||
* @pdev: the LCD platform device | ||
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@@ -391,29 +253,23 @@ static int img_ascii_lcd_probe(struct platform_device *pdev) | |
return PTR_ERR(ctx->base); | ||
} | ||
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ctx->pdev = pdev; | ||
ctx->cfg = cfg; | ||
ctx->message = NULL; | ||
ctx->scroll_pos = 0; | ||
ctx->scroll_rate = HZ / 2; | ||
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/* initialise a timer for scrolling the message */ | ||
timer_setup(&ctx->timer, img_ascii_lcd_scroll, 0); | ||
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platform_set_drvdata(pdev, ctx); | ||
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/* display a default message */ | ||
err = img_ascii_lcd_display(ctx, "Linux " UTS_RELEASE " ", -1); | ||
err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, ctx->curr, | ||
cfg->update); | ||
if (err) | ||
goto out_del_timer; | ||
return err; | ||
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err = device_create_file(dev, &dev_attr_message); | ||
/* for backwards compatibility */ | ||
err = compat_only_sysfs_link_entry_to_kobj(&dev->kobj, | ||
&ctx->linedisp.dev.kobj, | ||
"message", NULL); | ||
if (err) | ||
goto out_del_timer; | ||
goto err_unregister; | ||
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platform_set_drvdata(pdev, ctx); | ||
return 0; | ||
out_del_timer: | ||
del_timer_sync(&ctx->timer); | ||
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err_unregister: | ||
linedisp_unregister(&ctx->linedisp); | ||
return err; | ||
} | ||
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@@ -430,8 +286,8 @@ static int img_ascii_lcd_remove(struct platform_device *pdev) | |
{ | ||
struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev); | ||
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device_remove_file(&pdev->dev, &dev_attr_message); | ||
del_timer_sync(&ctx->timer); | ||
sysfs_remove_link(&pdev->dev.kobj, "message"); | ||
linedisp_unregister(&ctx->linedisp); | ||
return 0; | ||
} | ||
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