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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31F3FC678D5 for ; Tue, 7 Mar 2023 19:09:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233394AbjCGTJh (ORCPT ); Tue, 7 Mar 2023 14:09:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233676AbjCGTJK (ORCPT ); Tue, 7 Mar 2023 14:09:10 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7833B2561 for ; Tue, 7 Mar 2023 10:54:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D2ACE6150F for ; Tue, 7 Mar 2023 18:54:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C87B0C433D2; Tue, 7 Mar 2023 18:54:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678215246; bh=APftpHcCNkktIjqzc5rgCvJEkcdqPJZ2ffyRsKc48i4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wIIE6H7vEhsOxpZCdgtwF4fnRJwFL0tRlv3fyqeV8yh6h+3sCjETMTuuIBHTmcMCA nfbS3dMsTP7EXnO1lOMU9P7gezKTkC5yAZsP1JDA83/cd7vE+f1CVKzJBIVYc7P5XR D2Ryz8SWu9nIUVPRCw4AbaN52Mahb0RbQrSIyRiI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniel Mentz , Richard Acayan , Caleb Connolly , Neil Armstrong , Sam Ravnborg , Sasha Levin Subject: [PATCH 5.15 199/567] drm/mipi-dsi: Fix byte order of 16-bit DCS set/get brightness Date: Tue, 7 Mar 2023 17:58:55 +0100 Message-Id: <20230307165914.556023052@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307165905.838066027@linuxfoundation.org> References: <20230307165905.838066027@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Daniel Mentz [ Upstream commit c9d27c6be518b4ef2966d9564654ef99292ea1b3 ] The MIPI DCS specification demands that brightness values are sent in big endian byte order. It also states that one parameter (i.e. one byte) shall be sent/received for 8 bit wide values, and two parameters shall be used for values that are between 9 and 16 bits wide. Add new functions to properly handle 16-bit brightness in big endian, since the two 8- and 16-bit cases are distinct from each other. [richard: use separate functions instead of switch/case] [richard: split into 16-bit component] Fixes: 1a9d759331b8 ("drm/dsi: Implement DCS set/get display brightness") Signed-off-by: Daniel Mentz Link: https://android.googlesource.com/kernel/msm/+/754affd62d0ee268c686c53169b1dbb7deac8550 [richard: fix 16-bit brightness_get] Signed-off-by: Richard Acayan Tested-by: Caleb Connolly Reviewed-by: Neil Armstrong Reviewed-by: Sam Ravnborg Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20230116224909.23884-2-mailingradian@gmail.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_mipi_dsi.c | 52 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 4 +++ 2 files changed, 56 insertions(+) diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 2c43d54766f34..19fb1d93a4f07 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -1143,6 +1143,58 @@ int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness); +/** + * mipi_dsi_dcs_set_display_brightness_large() - sets the 16-bit brightness value + * of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi, + u16 brightness) +{ + u8 payload[2] = { brightness >> 8, brightness & 0xff }; + ssize_t err; + + err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, + payload, sizeof(payload)); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness_large); + +/** + * mipi_dsi_dcs_get_display_brightness_large() - gets the current 16-bit + * brightness value of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, + u16 *brightness) +{ + u8 brightness_be[2]; + ssize_t err; + + err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, + brightness_be, sizeof(brightness_be)); + if (err <= 0) { + if (err == 0) + err = -ENODATA; + + return err; + } + + *brightness = (brightness_be[0] << 8) | brightness_be[1]; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness_large); + static int mipi_dsi_drv_probe(struct device *dev) { struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver); diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index af7ba8071eb08..1d263eb0b2e12 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -288,6 +288,10 @@ int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi, u16 brightness); int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi, u16 *brightness); +int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi, + u16 brightness); +int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, + u16 *brightness); /** * struct mipi_dsi_driver - DSI driver -- 2.39.2