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From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Robin van der Gracht <robin@protonic.nl>,
	Rob Herring <robh+dt@kernel.org>, Miguel Ojeda <ojeda@kernel.org>,
	Paul Burton <paulburton@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devicetree@vger.kernel.org, linux-mips@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH 17/17] auxdisplay: ht16k33: Add segment display LED support
Date: Mon, 22 Mar 2021 15:48:48 +0100	[thread overview]
Message-ID: <20210322144848.1065067-18-geert@linux-m68k.org> (raw)
In-Reply-To: <20210322144848.1065067-1-geert@linux-m68k.org>

Instantiate a single LED for a segment display.  This allows the user to
control display brightness and blinking through the LED class API and
triggers, and exposes the display color.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
For setting display brightness, this could use the existing backlight
support for frame buffer devices instantiated for dot-matrix displays.
However, using the leds subsystem instead has the advantage that the
driver can make use of the HT16K33's hardware blinking support, and can
expose the display color.
---
 drivers/auxdisplay/ht16k33.c | 81 ++++++++++++++++++++++++++++++++++--
 1 file changed, 77 insertions(+), 4 deletions(-)

diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
index 0b502a6039f89c6b..5821addd9aec5633 100644
--- a/drivers/auxdisplay/ht16k33.c
+++ b/drivers/auxdisplay/ht16k33.c
@@ -29,6 +29,7 @@
 #include <asm/unaligned.h>
 
 #include "line-display.h"
+#include "../leds/leds.h"		/* for led_colors[] */
 
 /* Registers */
 #define REG_SYSTEM_SETUP		0x20
@@ -36,6 +37,10 @@
 
 #define REG_DISPLAY_SETUP		0x80
 #define REG_DISPLAY_SETUP_ON		BIT(0)
+#define REG_DISPLAY_SETUP_BLINK_OFF	(0 << 1)
+#define REG_DISPLAY_SETUP_BLINK_2HZ	(1 << 1)
+#define REG_DISPLAY_SETUP_BLINK_1HZ	(2 << 1)
+#define REG_DISPLAY_SETUP_BLINK_0HZ5	(3 << 1)
 
 #define REG_ROWINT_SET			0xA0
 #define REG_ROWINT_SET_INT_EN		BIT(0)
@@ -57,6 +62,8 @@
 #define BYTES_PER_ROW		(HT16K33_MATRIX_LED_MAX_ROWS / 8)
 #define HT16K33_FB_SIZE		(HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
 
+#define COLOR_DEFAULT		LED_COLOR_ID_RED
+
 enum display_type {
 	DISP_MATRIX = 0,
 	DISP_QUAD_7SEG,
@@ -85,6 +92,7 @@ struct ht16k33_fbdev {
 
 struct ht16k33_seg {
 	struct linedisp linedisp;
+	struct led_classdev led;
 	union {
 		struct seg7_conversion_map seg7;
 		struct seg14_conversion_map seg14;
@@ -102,6 +110,7 @@ struct ht16k33_priv {
 		struct ht16k33_seg seg;
 	};
 	enum display_type type;
+	uint8_t blink;
 };
 
 static const struct fb_fix_screeninfo ht16k33_fb_fix = {
@@ -160,7 +169,7 @@ static DEVICE_ATTR(map_seg14, 0644, map_seg_show, map_seg_store);
 
 static int ht16k33_display_on(struct ht16k33_priv *priv)
 {
-	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
+	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON | priv->blink;
 
 	return i2c_smbus_write_byte(priv->client, data);
 }
@@ -175,8 +184,11 @@ static int ht16k33_brightness_set(struct ht16k33_priv *priv,
 {
 	int error;
 
-	if (brightness == 0)
+	if (brightness == 0) {
+		// Disable blink mode
+		priv->blink = REG_DISPLAY_SETUP_BLINK_OFF;
 		return ht16k33_display_off(priv);
+	}
 
 	error = ht16k33_display_on(priv);
 	if (error)
@@ -186,6 +198,49 @@ static int ht16k33_brightness_set(struct ht16k33_priv *priv,
 				    REG_BRIGHTNESS | (brightness - 1));
 }
 
+static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
+					   enum led_brightness brightness)
+{
+	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
+						 seg.led);
+
+	return ht16k33_brightness_set(priv, brightness);
+}
+
+static int ht16k33_blink_set(struct led_classdev *led_cdev,
+			     unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
+						 seg.led);
+	unsigned int delay;
+	uint8_t blink;
+	int error;
+
+	if (!*delay_on && !*delay_off) {
+		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
+		delay = 1000;
+	} else if (*delay_on <= 750) {
+		blink = REG_DISPLAY_SETUP_BLINK_2HZ;
+		delay = 500;
+	} else if (*delay_on <= 1500) {
+		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
+		delay = 1000;
+	} else {
+		blink = REG_DISPLAY_SETUP_BLINK_0HZ5;
+		delay = 2000;
+	}
+
+	error = i2c_smbus_write_byte(priv->client,
+				     REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON |
+				     blink);
+	if (error)
+		return error;
+
+	priv->blink = blink;
+	*delay_on = *delay_off = delay;
+	return 0;
+}
+
 static void ht16k33_fb_queue(struct ht16k33_priv *priv)
 {
 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
@@ -578,11 +633,29 @@ static int ht16k33_fbdev_probe(struct i2c_client *client,
 static int ht16k33_seg_probe(struct i2c_client *client,
 			     struct ht16k33_priv *priv, uint32_t brightness)
 {
-	struct ht16k33_seg *seg = &priv->seg;
 	struct device *dev = &client->dev;
+	struct device_node *node = dev->of_node;
+	struct ht16k33_seg *seg = &priv->seg;
+	u32 color = COLOR_DEFAULT;
 	int err;
 
-	err = ht16k33_brightness_set(priv, MAX_BRIGHTNESS);
+	of_property_read_u32(node, "color", &color);
+	seg->led.name = devm_kasprintf(dev, GFP_KERNEL,
+			DRIVER_NAME ":%s:" LED_FUNCTION_BACKLIGHT,
+			color < LED_COLOR_ID_MAX ? led_colors[color] : "");
+	seg->led.brightness_set_blocking = ht16k33_brightness_set_blocking;
+	seg->led.blink_set = ht16k33_blink_set;
+	seg->led.flags = LED_CORE_SUSPENDRESUME;
+	seg->led.brightness = brightness;
+	seg->led.max_brightness = MAX_BRIGHTNESS;
+
+	err = devm_led_classdev_register(dev, &seg->led);
+	if (err) {
+		dev_err(dev, "Failed to register LED\n");
+		return err;
+	}
+
+	err = ht16k33_brightness_set(priv, seg->led.brightness);
 	if (err)
 		return err;
 
-- 
2.25.1


  parent reply	other threads:[~2021-03-22 14:49 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 14:48 [PATCH 00/17] auxdisplay: ht16k33: Add character display support Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 01/17] uapi: Add <linux/map_to_14segment.h> Geert Uytterhoeven
2021-03-22 17:05   ` Miguel Ojeda
2021-03-22 17:51     ` Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 02/17] dt-bindings: auxdisplay: ht16k33: Document Adafruit segment displays Geert Uytterhoeven
2021-03-22 17:38   ` Rob Herring
2021-03-23  9:12   ` robin
2021-05-18 14:35     ` Geert Uytterhoeven
2021-05-19 10:37       ` Robin van der Gracht
2021-05-19 11:02         ` Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 03/17] auxdisplay: img-ascii-lcd: Fix lock-up when displaying empty string Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 04/17] auxdisplay: img-ascii-lcd: Add helper variable dev Geert Uytterhoeven
2021-03-22 16:59   ` Miguel Ojeda
2021-03-22 17:53     ` Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 05/17] auxdisplay: img-ascii-lcd: Convert device attribute to sysfs_emit() Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 06/17] auxdisplay: Extract character line display core support Geert Uytterhoeven
2021-03-23  8:18   ` robin
2021-03-23  8:52     ` Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 07/17] auxdisplay: linedisp: Use kmemdup_nul() helper Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 08/17] auxdisplay: linedisp: Add support for changing scroll rate Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 09/17] auxdisplay: ht16k33: Use HT16K33_FB_SIZE in ht16k33_initialize() Geert Uytterhoeven
2021-03-23  7:59   ` robin
2021-03-22 14:48 ` [PATCH 10/17] auxdisplay: ht16k33: Remove unneeded error check in keypad probe() Geert Uytterhoeven
2021-03-23  8:08   ` robin
2021-03-22 14:48 ` [PATCH 11/17] auxdisplay: ht16k33: Convert to simple i2c probe function Geert Uytterhoeven
2021-03-23  8:31   ` robin
2021-03-22 14:48 ` [PATCH 12/17] auxdisplay: ht16k33: Add helper variable dev Geert Uytterhoeven
2021-03-23  8:57   ` robin
2021-03-22 14:48 ` [PATCH 13/17] auxdisplay: ht16k33: Move delayed work Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 14/17] auxdisplay: ht16k33: Extract ht16k33_brightness_set() Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 15/17] auxdisplay: ht16k33: Extract frame buffer probing Geert Uytterhoeven
2021-03-22 14:48 ` [PATCH 16/17] auxdisplay: ht16k33: Add support for segment displays Geert Uytterhoeven
2021-03-29  7:08   ` Robin van der Gracht
2021-03-29  7:15     ` Geert Uytterhoeven
2021-03-29  7:30       ` Robin van der Gracht
2021-03-22 14:48 ` Geert Uytterhoeven [this message]
2021-03-23 10:08   ` [PATCH 17/17] auxdisplay: ht16k33: Add segment display LED support Robin van der Gracht
2021-03-23 12:32     ` Geert Uytterhoeven
2021-03-23 20:40       ` Pavel Machek
2021-03-24  8:31         ` Geert Uytterhoeven
2021-03-27 22:19           ` Pavel Machek
2021-06-25 12:39           ` Geert Uytterhoeven
2021-03-22 17:03 ` [PATCH 00/17] auxdisplay: ht16k33: Add character display support Miguel Ojeda

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