From 7e76aece6f036cb7ada4858d6aa73825bfe22983 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 19 Oct 2021 16:45:05 +0200 Subject: 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 Signed-off-by: Miguel Ojeda --- drivers/auxdisplay/img-ascii-lcd.c | 204 ++++++------------------------------- 1 file changed, 30 insertions(+), 174 deletions(-) (limited to 'drivers/auxdisplay/img-ascii-lcd.c') diff --git a/drivers/auxdisplay/img-ascii-lcd.c b/drivers/auxdisplay/img-ascii-lcd.c index 2b5640b63890..fa23e415f260 100644 --- a/drivers/auxdisplay/img-ascii-lcd.c +++ b/drivers/auxdisplay/img-ascii-lcd.c @@ -4,7 +4,6 @@ * Author: Paul Burton */ -#include #include #include #include @@ -14,7 +13,8 @@ #include #include #include -#include + +#include "line-display.h" struct img_ascii_lcd_ctx; @@ -27,36 +27,26 @@ 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); }; /** * 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); }; @@ -64,8 +54,10 @@ struct img_ascii_lcd_ctx { * MIPS Boston development board */ -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; #if BITS_PER_LONG == 64 @@ -90,12 +82,14 @@ static struct img_ascii_lcd_config boston_config = { * MIPS Malta development board */ -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; - 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; } -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; - 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); -/** - * 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; - - /* 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]; - - /* wrap around to the start of the string */ - ch = 0; - } - - /* update the LCD */ - ctx->cfg->update(ctx); - - /* move on to the next character */ - ctx->scroll_pos++; - ctx->scroll_pos %= ctx->message_len; - - /* rearm the timer */ - if (ctx->message_len > ctx->cfg->num_chars) - mod_timer(&ctx->timer, jiffies + ctx->scroll_rate); -} - -/** - * 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; - - /* stop the scroll timer */ - del_timer_sync(&ctx->timer); - - if (count == -1) - count = strlen(msg); - - /* if the string ends with a newline, trim it */ - if (msg[count - 1] == '\n') - count--; - - 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; - } - - new_msg = devm_kmalloc(&ctx->pdev->dev, count + 1, GFP_KERNEL); - if (!new_msg) - return -ENOMEM; - - memcpy(new_msg, msg, count); - new_msg[count] = 0; - - if (ctx->message) - devm_kfree(&ctx->pdev->dev, ctx->message); - - ctx->message = new_msg; - ctx->message_len = count; - ctx->scroll_pos = 0; - - /* update the LCD */ - img_ascii_lcd_scroll(&ctx->timer); - - return 0; -} - -/** - * 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); - - return sysfs_emit(buf, "%s\n", ctx->message); -} - -/** - * 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; - - err = img_ascii_lcd_display(ctx, buf, count); - return err ?: count; -} - -static DEVICE_ATTR_RW(message); - /** * img_ascii_lcd_probe() - probe an LCD display device * @pdev: the LCD platform device @@ -391,29 +253,23 @@ static int img_ascii_lcd_probe(struct platform_device *pdev) return PTR_ERR(ctx->base); } - ctx->pdev = pdev; - ctx->cfg = cfg; - ctx->message = NULL; - ctx->scroll_pos = 0; - ctx->scroll_rate = HZ / 2; - - /* initialise a timer for scrolling the message */ - timer_setup(&ctx->timer, img_ascii_lcd_scroll, 0); - - platform_set_drvdata(pdev, ctx); - - /* 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; - 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; + platform_set_drvdata(pdev, ctx); return 0; -out_del_timer: - del_timer_sync(&ctx->timer); + +err_unregister: + linedisp_unregister(&ctx->linedisp); return err; } @@ -430,8 +286,8 @@ static int img_ascii_lcd_remove(struct platform_device *pdev) { struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev); - 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; } -- cgit