From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B738B8489 for ; Fri, 10 Mar 2023 14:17:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A1CCC433EF; Fri, 10 Mar 2023 14:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678457842; bh=VE4MHrucOyK2W8f1KtIu+LxGm3Ke51nXPM+xQIEg2WA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R8IgEcZ5aw+lQsnovLfZw4PaY/5FflEw7rTSqAvL63ypMHXMzUYRmoGXh5OWXOWX4 OCU7VomW+GYykMCcsQSLGjqM5oGoZdrd8F08rtUowwZ/5h0qKnY+sDXXeUI19wndv3 rsnJJVaS7Xq18cov/2896bbMmvP9sbh4pyoWwTnY= 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 4.19 076/252] drm/mipi-dsi: Fix byte order of 16-bit DCS set/get brightness Date: Fri, 10 Mar 2023 14:37:26 +0100 Message-Id: <20230310133721.131658514@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133718.803482157@linuxfoundation.org> References: <20230310133718.803482157@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 c8c9daecd00da..81923442b42d0 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -1096,6 +1096,58 @@ 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 4fef19064b0f1..689f615471ab1 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -274,6 +274,10 @@ 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