From nobody Tue Dec 16 16:01:47 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DD90C32772 for ; Tue, 23 Aug 2022 19:07:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231858AbiHWTHm (ORCPT ); Tue, 23 Aug 2022 15:07:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229643AbiHWTHV (ORCPT ); Tue, 23 Aug 2022 15:07:21 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DB8C13388F for ; Tue, 23 Aug 2022 10:45:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1661276572; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LUDgFDOop3oO9UdFTyjiH9Nq2FyB1TchayHNmf3+uok=; b=OYIZjHt8c+x6Ps2DdpwQ7lLZf4sGvlSR/GC9KS3SK3QYgy/G6j6PFMS9CgfrUhbq+jH1bT QOEv8LXFcHXAU/WsxYyoK2t1xdk91iPoYAZEH0t7xliQCGaLCNJk0k3duoS4GkIkMzYj2Y 6xhR125shBn5HAqN0tOPg3PUiov+Sac= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-359-cUEoGw5rPAeWW5Ffds_fvA-1; Tue, 23 Aug 2022 13:42:49 -0400 X-MC-Unique: cUEoGw5rPAeWW5Ffds_fvA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9FEEE3C0D1A2; Tue, 23 Aug 2022 17:42:48 +0000 (UTC) Received: from cmirabil.redhat.com (unknown [10.22.33.37]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2755D14152E0; Tue, 23 Aug 2022 17:42:48 +0000 (UTC) From: Charles Mirabile To: linux-kernel@vger.kernel.org Cc: Charles Mirabile , Peter Robinson , Serge Schneider , Stefan Wahren , Nicolas Saenz Julienne , Mattias Brugger , linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, rh-kdlp@googlegroups.com, Miguel Ojeda , Joel Savitz Subject: [PATCH 2/5] drivers/auxdisplay: sensehat: Raspberry Pi Sense HAT display driver Date: Tue, 23 Aug 2022 13:41:55 -0400 Message-Id: <20220823174158.45579-3-cmirabil@redhat.com> In-Reply-To: <20220823174158.45579-1-cmirabil@redhat.com> References: <20220823174158.45579-1-cmirabil@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This patch adds the driver for the 8x8 RGB LED matrix display on the Sense HAT. It appears as a character device named sense-hat in /dev/. That special file is 192 bytes large and contains 64 RGB triplets (3 bytes each) one for each pixel in row major order. Co-developed-by: Joel Savitz Signed-off-by: Joel Savitz Signed-off-by: Charles Mirabile Reviewed-by: Matthias Brugger --- drivers/auxdisplay/Kconfig | 8 + drivers/auxdisplay/Makefile | 1 + drivers/auxdisplay/sensehat-display.c | 205 ++++++++++++++++++++++++++ 3 files changed, 214 insertions(+) create mode 100644 drivers/auxdisplay/sensehat-display.c diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig index 64012cda4d12..9bad1aade7a0 100644 --- a/drivers/auxdisplay/Kconfig +++ b/drivers/auxdisplay/Kconfig @@ -203,6 +203,14 @@ config ARM_CHARLCD line and the Linux version on the second line, but that's still useful. =20 +config SENSEHAT_DISPLAY + tristate "Raspberry Pi Sense HAT display driver" + depends on I2C + select MFD_SIMPLE_MFD_I2C + help + This is a driver for the Raspberry Pi Sensehat 8x8 RBG-LED matrix + you can access it as a misc device at /dev/sense-hat + menuconfig PARPORT_PANEL tristate "Parallel port LCD/Keypad Panel support" depends on PARPORT diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile index 6968ed4d3f0a..30b2b7934046 100644 --- a/drivers/auxdisplay/Makefile +++ b/drivers/auxdisplay/Makefile @@ -14,3 +14,4 @@ obj-$(CONFIG_HT16K33) +=3D ht16k33.o obj-$(CONFIG_PARPORT_PANEL) +=3D panel.o obj-$(CONFIG_LCD2S) +=3D lcd2s.o obj-$(CONFIG_LINEDISP) +=3D line-display.o +obj-$(CONFIG_SENSEHAT_DISPLAY) +=3D sensehat-display.o diff --git a/drivers/auxdisplay/sensehat-display.c b/drivers/auxdisplay/sen= sehat-display.c new file mode 100644 index 000000000000..08c0c4338f3e --- /dev/null +++ b/drivers/auxdisplay/sensehat-display.c @@ -0,0 +1,205 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Raspberry Pi Sense HAT 8x8 LED matrix display driver + * http://raspberrypi.org + * + * Copyright (C) 2015 Raspberry Pi + * Copyright (C) 2021 Charles Mirabile, Joel Savitz + * + * Original Author: Serge Schneider + * Revised for upstream Linux by: Charles Mirabile, Joel Savitz + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DISPLAY_SMB_REG 0x00 +#define RGB_555_MASK 0x1f +#define NUM_LEDS 8 +#define NUM_CHANNELS 3 + +struct sensehat_display { + struct platform_device *pdev; + struct miscdevice mdev; + struct mutex rw_mtx; + u8 vmem[NUM_LEDS][NUM_LEDS][NUM_CHANNELS]; + struct regmap *regmap; +}; + +#define VMEM_SIZE sizeof_field(struct sensehat_display, vmem) + + +static int sensehat_update_display(struct sensehat_display *display) +{ + int i, j, k, ret; + u8 buff[NUM_LEDS][NUM_CHANNELS][NUM_LEDS]; + + for (i =3D 0; i < NUM_LEDS; ++i) + for (j =3D 0; j < NUM_LEDS; ++j) + for (k =3D 0; k < NUM_CHANNELS; ++k) + buff[i][k][j] =3D + display->vmem[i][j][k] & RGB_555_MASK; + + ret =3D regmap_bulk_write(display->regmap, DISPLAY_SMB_REG, buff, + VMEM_SIZE); + if (ret < 0) + dev_err(&display->pdev->dev, + "Update to 8x8 LED matrix display failed"); + return ret; +} + +static loff_t sensehat_display_llseek(struct file *filp, loff_t offset, + int whence) +{ + return fixed_size_llseek(filp, offset, whence, VMEM_SIZE); +} + +static ssize_t sensehat_display_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos) +{ + struct sensehat_display *sensehat_display =3D + container_of(filp->private_data, struct sensehat_display, mdev); + ssize_t ret =3D -EFAULT; + + if (*f_pos < 0 || *f_pos >=3D VMEM_SIZE) + return 0; + count =3D min_t(size_t, count, VMEM_SIZE - *f_pos); + + if (mutex_lock_interruptible(&sensehat_display->rw_mtx)) + return -ERESTARTSYS; + if (copy_to_user(buf, *f_pos + (u8 *)sensehat_display->vmem, count)) + goto out; + *f_pos +=3D count; + ret =3D count; +out: + mutex_unlock(&sensehat_display->rw_mtx); + return ret; +} + +static ssize_t sensehat_display_write(struct file *filp, const char __user= *buf, + size_t count, loff_t *f_pos) +{ + struct sensehat_display *sensehat_display =3D + container_of(filp->private_data, struct sensehat_display, mdev); + int ret =3D -EFAULT; + + if (*f_pos < 0 || *f_pos >=3D VMEM_SIZE) + return -EFBIG; + count =3D min_t(size_t, count, VMEM_SIZE - *f_pos); + + if (mutex_lock_interruptible(&sensehat_display->rw_mtx)) + return -ERESTARTSYS; + if (copy_from_user(*f_pos + (u8 *)sensehat_display->vmem, buf, count)) + goto out; + ret =3D sensehat_update_display(sensehat_display); + if (ret < 0) { + ret =3D -EIO; + goto out; + } + *f_pos +=3D count; + ret =3D count; +out: + mutex_unlock(&sensehat_display->rw_mtx); + return ret; +} + +static const struct file_operations sensehat_display_fops =3D { + .owner =3D THIS_MODULE, + .llseek =3D sensehat_display_llseek, + .read =3D sensehat_display_read, + .write =3D sensehat_display_write, +}; + +static int sensehat_display_probe(struct platform_device *pdev) +{ + int ret; + + struct sensehat_display *sensehat_display =3D + devm_kmalloc(&pdev->dev, sizeof(*sensehat_display), GFP_KERNEL); + if (!sensehat_display) + return -ENOMEM; + + sensehat_display->pdev =3D pdev; + + dev_set_drvdata(&pdev->dev, sensehat_display); + + sensehat_display->regmap =3D dev_get_regmap(pdev->dev.parent, NULL); + if (!sensehat_display->regmap) { + dev_err(&pdev->dev, + "unable to get sensehat regmap"); + return -ENODEV; + } + + memset(sensehat_display->vmem, 0, VMEM_SIZE); + + mutex_init(&sensehat_display->rw_mtx); + + ret =3D sensehat_update_display(sensehat_display); + if (ret < 0) { + dev_err(&pdev->dev, + "Could not communicate with sensehat"); + return ret; + } + + sensehat_display->mdev =3D (struct miscdevice){ + .minor =3D MISC_DYNAMIC_MINOR, + .name =3D "sense-hat", + .mode =3D 0666, + .fops =3D &sensehat_display_fops, + }; + + ret =3D misc_register(&sensehat_display->mdev); + if (ret < 0) { + dev_err(&pdev->dev, + "Could not register 8x8 LED matrix display."); + return ret; + } + + dev_info(&pdev->dev, + "8x8 LED matrix display registered with minor number %i", + sensehat_display->mdev.minor); + + return 0; +} + +static int sensehat_display_remove(struct platform_device *pdev) +{ + struct sensehat_display *sensehat_display =3D dev_get_drvdata(&pdev->dev); + + misc_deregister(&sensehat_display->mdev); + return 0; +} + +static const struct of_device_id sensehat_display_device_id[] =3D { + { .compatible =3D "raspberrypi,sensehat-display" }, + {}, +}; +MODULE_DEVICE_TABLE(of, sensehat_display_device_id); + +static struct platform_driver sensehat_display_driver =3D { + .probe =3D sensehat_display_probe, + .remove =3D sensehat_display_remove, + .driver =3D { + .name =3D "sensehat-display", + .of_match_table =3D sensehat_display_device_id, + }, +}; + +module_platform_driver(sensehat_display_driver); + +MODULE_DESCRIPTION("Raspberry Pi Sense HAT 8x8 LED matrix display driver"); +MODULE_AUTHOR("Charles Mirabile "); +MODULE_AUTHOR("Serge Schneider "); +MODULE_LICENSE("GPL"); --=20 2.31.1