From patchwork Tue Jul 27 14:04:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 488151 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C75FAC4338F for ; Tue, 27 Jul 2021 14:06:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFDF561A87 for ; Tue, 27 Jul 2021 14:06:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236962AbhG0OF6 (ORCPT ); Tue, 27 Jul 2021 10:05:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236907AbhG0OFQ (ORCPT ); Tue, 27 Jul 2021 10:05:16 -0400 Received: from newton.telenet-ops.be (newton.telenet-ops.be [IPv6:2a02:1800:120:4::f00:d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 705FBC061765 for ; Tue, 27 Jul 2021 07:05:13 -0700 (PDT) Received: from baptiste.telenet-ops.be (baptiste.telenet-ops.be [IPv6:2a02:1800:120:4::f00:13]) by newton.telenet-ops.be (Postfix) with ESMTPS id 4GYz862xwTzMqr2M for ; Tue, 27 Jul 2021 16:05:10 +0200 (CEST) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:b0a9:7e88:5ca4:551a]) by baptiste.telenet-ops.be with bizsmtp id aE572500c1fSPfK01E575t; Tue, 27 Jul 2021 16:05:10 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1m8Nhj-001PuO-5q; Tue, 27 Jul 2021 16:05:07 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m8Nhh-00FoCX-G8; Tue, 27 Jul 2021 16:05:05 +0200 From: Geert Uytterhoeven To: Robin van der Gracht , Rob Herring , Miguel Ojeda , Paul Burton , Greg Kroah-Hartman , Pavel Machek , Marek Behun Cc: devicetree@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v4 06/19] auxdisplay: Extract character line display core support Date: Tue, 27 Jul 2021 16:04:46 +0200 Message-Id: <20210727140459.3767788-7-geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210727140459.3767788-1-geert@linux-m68k.org> References: <20210727140459.3767788-1-geert@linux-m68k.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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 --- Changes to img-ascii-lcd.c are untested due to lack of hardware. The backwards compatibility symlink has been tested by adding similar code to drivers/auxdisplay/ht16k33.c. v4: - No changes, v3: - Use compat_only_sysfs_link_entry_to_kobj() instead of cooking our own helper on top of kernfs_create_link(), v2: - Drop "select LINEDISP" from HT16K33 symbol, - Add backwards compatibility symlink. --- drivers/auxdisplay/Kconfig | 7 + drivers/auxdisplay/Makefile | 1 + drivers/auxdisplay/img-ascii-lcd.c | 204 ++++--------------------- drivers/auxdisplay/line-display.c | 231 +++++++++++++++++++++++++++++ drivers/auxdisplay/line-display.h | 43 ++++++ 5 files changed, 312 insertions(+), 174 deletions(-) create mode 100644 drivers/auxdisplay/line-display.c create mode 100644 drivers/auxdisplay/line-display.h diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig index 1509cb74705a30ad..b41fdc5f7bf72a1b 100644 --- a/drivers/auxdisplay/Kconfig +++ b/drivers/auxdisplay/Kconfig @@ -25,6 +25,12 @@ config CHARLCD This is some character LCD core interface that multiple drivers can use. +config LINEDISP + tristate "Character line display core support" if COMPILE_TEST + help + This is the core support for single-line character displays, to be + selected by drivers that use it. + config HD44780_COMMON tristate "Common functions for HD44780 (and compatibles) LCD displays" if COMPILE_TEST select CHARLCD @@ -155,6 +161,7 @@ config IMG_ASCII_LCD depends on HAS_IOMEM default y if MIPS_MALTA select MFD_SYSCON + select LINEDISP help Enable this to support the simple ASCII LCD displays found on development boards such as the MIPS Boston, MIPS Malta & MIPS SEAD3 diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile index 307771027c893a5b..6968ed4d3f0a8930 100644 --- a/drivers/auxdisplay/Makefile +++ b/drivers/auxdisplay/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_HD44780) += hd44780.o obj-$(CONFIG_HT16K33) += ht16k33.o obj-$(CONFIG_PARPORT_PANEL) += panel.o obj-$(CONFIG_LCD2S) += lcd2s.o +obj-$(CONFIG_LINEDISP) += line-display.o diff --git a/drivers/auxdisplay/img-ascii-lcd.c b/drivers/auxdisplay/img-ascii-lcd.c index 2b5640b638900a90..fa23e415f260ec56 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; } diff --git a/drivers/auxdisplay/line-display.c b/drivers/auxdisplay/line-display.c new file mode 100644 index 0000000000000000..4b97c20ac0b381ee --- /dev/null +++ b/drivers/auxdisplay/line-display.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Character line display core support + * + * Copyright (C) 2016 Imagination Technologies + * Author: Paul Burton + * + * Copyright (C) 2021 Glider bv + */ + +#include + +#include +#include +#include +#include +#include +#include + +#include "line-display.h" + +/** + * linedisp_scroll() - scroll the display by a character + * @t: really a pointer to the private data structure + * + * Scroll the current message along the display by one character, rearming the + * timer if required. + */ +static void linedisp_scroll(struct timer_list *t) +{ + struct linedisp *linedisp = from_timer(linedisp, t, timer); + unsigned int i, ch = linedisp->scroll_pos; + unsigned int num_chars = linedisp->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 < linedisp->message_len; i++, ch++) + linedisp->buf[i] = linedisp->message[ch]; + + /* wrap around to the start of the string */ + ch = 0; + } + + /* update the display */ + linedisp->update(linedisp); + + /* move on to the next character */ + linedisp->scroll_pos++; + linedisp->scroll_pos %= linedisp->message_len; + + /* rearm the timer */ + if (linedisp->message_len > num_chars) + mod_timer(&linedisp->timer, jiffies + linedisp->scroll_rate); +} + +/** + * linedisp_display() - set the message to be displayed + * @linedisp: pointer to the private data structure + * @msg: the message to display + * @count: length of msg, or -1 + * + * Display a new message @msg on the display. @msg can be longer than the + * number of characters the display can display, in which case it will begin + * scrolling across the display. + * + * Return: 0 on success, -ENOMEM on memory allocation failure + */ +static int linedisp_display(struct linedisp *linedisp, const char *msg, + ssize_t count) +{ + char *new_msg; + + /* stop the scroll timer */ + del_timer_sync(&linedisp->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 display */ + kfree(linedisp->message); + linedisp->message = NULL; + linedisp->message_len = 0; + memset(linedisp->buf, ' ', linedisp->num_chars); + linedisp->update(linedisp); + return 0; + } + + new_msg = kmalloc(count + 1, GFP_KERNEL); + if (!new_msg) + return -ENOMEM; + + memcpy(new_msg, msg, count); + new_msg[count] = 0; + + kfree(linedisp->message); + + linedisp->message = new_msg; + linedisp->message_len = count; + linedisp->scroll_pos = 0; + + /* update the display */ + linedisp_scroll(&linedisp->timer); + + return 0; +} + +/** + * message_show() - read message via sysfs + * @dev: the display device + * @attr: the display message attribute + * @buf: the buffer to read the message into + * + * Read the current message being displayed or scrolled across the 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 linedisp *linedisp = container_of(dev, struct linedisp, dev); + + return sysfs_emit(buf, "%s\n", linedisp->message); +} + +/** + * message_store() - write a new message via sysfs + * @dev: the display device + * @attr: the display 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 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 linedisp *linedisp = container_of(dev, struct linedisp, dev); + int err; + + err = linedisp_display(linedisp, buf, count); + return err ?: count; +} + +static DEVICE_ATTR_RW(message); + +static struct attribute *linedisp_attrs[] = { + &dev_attr_message.attr, + NULL, +}; +ATTRIBUTE_GROUPS(linedisp); + +static const struct device_type linedisp_type = { + .groups = linedisp_groups, +}; + +/** + * 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! + * + * 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)) +{ + 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->num_chars = num_chars; + linedisp->scroll_rate = HZ / 2; + + device_initialize(&linedisp->dev); + dev_set_name(&linedisp->dev, "linedisp.%lu", + (unsigned long)atomic_inc_return(&linedisp_id)); + + /* initialise a timer for scrolling the message */ + timer_setup(&linedisp->timer, linedisp_scroll, 0); + + err = device_add(&linedisp->dev); + if (err) + goto out_del_timer; + + /* display a default message */ + err = linedisp_display(linedisp, "Linux " UTS_RELEASE " ", -1); + if (err) + goto out_del_dev; + + return 0; + +out_del_dev: + device_del(&linedisp->dev); +out_del_timer: + del_timer_sync(&linedisp->timer); + put_device(&linedisp->dev); + return err; +} +EXPORT_SYMBOL_GPL(linedisp_register); + +/** + * linedisp_unregister - unregister a character line display + * @linedisp: pointer to character line display structure registered previously + * with linedisp_register() + */ +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); + +MODULE_LICENSE("GPL"); diff --git a/drivers/auxdisplay/line-display.h b/drivers/auxdisplay/line-display.h new file mode 100644 index 0000000000000000..0f5891d34c485871 --- /dev/null +++ b/drivers/auxdisplay/line-display.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Character line display core support + * + * Copyright (C) 2016 Imagination Technologies + * Author: Paul Burton + * + * Copyright (C) 2021 Glider bv + */ + +#ifndef _LINEDISP_H +#define _LINEDISP_H + +/** + * 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 + * @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 + */ +struct linedisp { + struct device dev; + struct timer_list timer; + void (*update)(struct linedisp *linedisp); + char *buf; + char *message; + unsigned int num_chars; + unsigned int message_len; + unsigned int scroll_pos; + unsigned int scroll_rate; +}; + +int linedisp_register(struct linedisp *linedisp, struct device *parent, + unsigned int num_chars, char *buf, + void (*update)(struct linedisp *linedisp)); +void linedisp_unregister(struct linedisp *linedisp); + +#endif /* LINEDISP_H */