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From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Robin van der Gracht <robin@protonic.nl>,
	Miguel Ojeda <ojeda@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Paul Burton <paulburton@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Pavel Machek <pavel@ucw.cz>, Marek Behun <marek.behun@nic.cz>,
	devicetree@vger.kernel.org, linux-leds@vger.kernel.org,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH v5 08/19] auxdisplay: linedisp: Add support for changing scroll rate
Date: Wed, 11 Aug 2021 11:57:48 +0200	[thread overview]
Message-ID: <20210811095759.1281480-9-geert@linux-m68k.org> (raw)
In-Reply-To: <20210811095759.1281480-1-geert@linux-m68k.org>

If the message to display is longer than the number of characters that
the display can show, the message will be scrolled.  Currently the
scroll rate is fixed, moving every 500 ms.

Add support for changing the scroll rate through a "scroll_step_ms"
device attribute in sysfs.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
v5:
  - No changes,

v4:
  - No changes,

v3:
  - No changes,

v2:
  - No changes.
---
 drivers/auxdisplay/line-display.c | 37 +++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/auxdisplay/line-display.c b/drivers/auxdisplay/line-display.c
index 3f35199bc39f511f..03e7f104aa1add32 100644
--- a/drivers/auxdisplay/line-display.c
+++ b/drivers/auxdisplay/line-display.c
@@ -19,6 +19,8 @@
 
 #include "line-display.h"
 
+#define DEFAULT_SCROLL_RATE	(HZ / 2)
+
 /**
  * linedisp_scroll() - scroll the display by a character
  * @t: really a pointer to the private data structure
@@ -50,7 +52,7 @@ static void linedisp_scroll(struct timer_list *t)
 	linedisp->scroll_pos %= linedisp->message_len;
 
 	/* rearm the timer */
-	if (linedisp->message_len > num_chars)
+	if (linedisp->message_len > num_chars && linedisp->scroll_rate)
 		mod_timer(&linedisp->timer, jiffies + linedisp->scroll_rate);
 }
 
@@ -149,8 +151,39 @@ static ssize_t message_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR_RW(message);
 
+static ssize_t scroll_step_ms_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+
+	return sysfs_emit(buf, "%u\n", jiffies_to_msecs(linedisp->scroll_rate));
+}
+
+static ssize_t scroll_step_ms_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct linedisp *linedisp = container_of(dev, struct linedisp, dev);
+	unsigned int ms;
+
+	if (kstrtouint(buf, 10, &ms) != 0)
+		return -EINVAL;
+
+	linedisp->scroll_rate = msecs_to_jiffies(ms);
+	if (linedisp->message && linedisp->message_len > linedisp->num_chars) {
+		del_timer_sync(&linedisp->timer);
+		if (linedisp->scroll_rate)
+			linedisp_scroll(&linedisp->timer);
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(scroll_step_ms);
+
 static struct attribute *linedisp_attrs[] = {
 	&dev_attr_message.attr,
+	&dev_attr_scroll_step_ms.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(linedisp);
@@ -182,7 +215,7 @@ int linedisp_register(struct linedisp *linedisp, struct device *parent,
 	linedisp->update = update;
 	linedisp->buf = buf;
 	linedisp->num_chars = num_chars;
-	linedisp->scroll_rate = HZ / 2;
+	linedisp->scroll_rate = DEFAULT_SCROLL_RATE;
 
 	device_initialize(&linedisp->dev);
 	dev_set_name(&linedisp->dev, "linedisp.%lu",
-- 
2.25.1


  parent reply	other threads:[~2021-08-11  9:59 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-11  9:57 [PATCH v5 00/19] auxdisplay: ht16k33: Add character display support Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 01/19] uapi: Add <linux/map_to_14segment.h> Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 02/19] dt-bindings: auxdisplay: ht16k33: Document Adafruit segment displays Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 03/19] auxdisplay: img-ascii-lcd: Fix lock-up when displaying empty string Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 04/19] auxdisplay: img-ascii-lcd: Add helper variable dev Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 05/19] auxdisplay: img-ascii-lcd: Convert device attribute to sysfs_emit() Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 06/19] auxdisplay: Extract character line display core support Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 07/19] auxdisplay: linedisp: Use kmemdup_nul() helper Geert Uytterhoeven
2021-08-11  9:57 ` Geert Uytterhoeven [this message]
2021-08-11  9:57 ` [PATCH v5 09/19] auxdisplay: ht16k33: Connect backlight to fbdev Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 10/19] auxdisplay: ht16k33: Use HT16K33_FB_SIZE in ht16k33_initialize() Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 11/19] auxdisplay: ht16k33: Remove unneeded error check in keypad probe() Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 12/19] auxdisplay: ht16k33: Convert to simple i2c probe function Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 13/19] auxdisplay: ht16k33: Add helper variable dev Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 14/19] auxdisplay: ht16k33: Move delayed work Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 15/19] auxdisplay: ht16k33: Extract ht16k33_brightness_set() Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 16/19] auxdisplay: ht16k33: Extract frame buffer probing Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 17/19] auxdisplay: ht16k33: Add support for segment displays Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 18/19] dt-bindings: auxdisplay: ht16k33: Document LED subnode Geert Uytterhoeven
2021-08-11  9:57 ` [PATCH v5 19/19] auxdisplay: ht16k33: Add LED support Geert Uytterhoeven
2021-08-11 10:47   ` Marek Behún
2021-08-11 11:29     ` Geert Uytterhoeven
     [not found]       ` <CAHp75VeNyHUmcU7GPnP8woRcDErDNQ5M3FHQGpLnhUoL5qTnLQ@mail.gmail.com>
2021-08-13 12:52         ` Geert Uytterhoeven
2021-08-13 13:59           ` Andy Shevchenko

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