From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9CCD8C433E1 for ; Tue, 23 Mar 2021 10:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 615D66157E for ; Tue, 23 Mar 2021 10:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230159AbhCWKIc (ORCPT ); Tue, 23 Mar 2021 06:08:32 -0400 Received: from protonic.xs4all.nl ([83.163.252.89]:32902 "EHLO protonic.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229693AbhCWKIR (ORCPT ); Tue, 23 Mar 2021 06:08:17 -0400 Received: from fiber.protonic.nl (edge2.prtnl [192.168.1.170]) by sparta.prtnl (Postfix) with ESMTP id 8611044A022C; Tue, 23 Mar 2021 11:08:15 +0100 (CET) MIME-Version: 1.0 Date: Tue, 23 Mar 2021 11:08:15 +0100 From: Robin van der Gracht To: Geert Uytterhoeven Cc: Rob Herring , Miguel Ojeda , Paul Burton , Greg Kroah-Hartman , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 17/17] auxdisplay: ht16k33: Add segment display LED support Reply-To: robin@protonic.nl In-Reply-To: <20210322144848.1065067-18-geert@linux-m68k.org> References: <20210322144848.1065067-1-geert@linux-m68k.org> <20210322144848.1065067-18-geert@linux-m68k.org> User-Agent: Roundcube Webmail/1.4.8 Message-ID: <543ec200931af3192541fef51bc8e96a@protonic.nl> X-Sender: robin@protonic.nl Organization: Protonic Holland Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-03-22 15:48, Geert Uytterhoeven wrote: > 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 > --- > 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 > > #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; The LED class can pretty much do what the backlight class can and more. Maybe we can stop registering a backlight device in the fbdev case and register a led device for both. This makes the code cleaner and drops a dependency but will break backwards compatibility. I'd prefer a single solution that covers both use cases, but I'm not sure about the 'breaking backwards compatibility' consequence... Groetjes / Kind regards, Robin van der Gracht