From nobody Mon May 11 02:55:52 2026 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 5FC62C433EF for ; Mon, 18 Apr 2022 05:33:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236675AbiDRFgF (ORCPT ); Mon, 18 Apr 2022 01:36:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230337AbiDRFgD (ORCPT ); Mon, 18 Apr 2022 01:36:03 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86D9B13E22; Sun, 17 Apr 2022 22:33:25 -0700 (PDT) Received: from droid06.amlogic.com (10.18.11.248) by mail-sh.amlogic.com (10.18.11.5) with Microsoft SMTP Server id 15.1.2176.14; Mon, 18 Apr 2022 13:33:23 +0800 From: Yu Tu To: , , , , Greg Kroah-Hartman , Neil Armstrong , Kevin Hilman , Jerome Brunet CC: Jiri Slaby , Martin Blumenstingl , Yu Tu Subject: [PATCH V2 1/2] tty: serial: meson: Add a 12MHz internal clock rate to calculate baud rate in order to meet the baud rate requirements of special BT modules Date: Mon, 18 Apr 2022 13:32:01 +0800 Message-ID: <20220418053202.24528-2-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220418053202.24528-1-yu.tu@amlogic.com> References: <20220418053202.24528-1-yu.tu@amlogic.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.18.11.248] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" A /2 divider over XTAL was introduced since G12A, and is preferred to be used over the still present /3 divider since it provides much closer frequencies vs the request baudrate.Especially the BT module uses 3Mhz baud rate. 8Mhz calculations can lead to baud rate bias, causing some problems. Signed-off-by: Yu Tu --- drivers/tty/serial/meson_uart.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uar= t.c index 8e59624935af..58bd2723c004 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -68,6 +68,7 @@ #define AML_UART_BAUD_MASK 0x7fffff #define AML_UART_BAUD_USE BIT(23) #define AML_UART_BAUD_XTAL BIT(24) +#define AML_UART_BAUD_XTAL_DIV2 BIT(27) =20 #define AML_UART_PORT_NUM 12 #define AML_UART_PORT_OFFSET 6 @@ -80,6 +81,10 @@ static struct uart_driver meson_uart_driver; =20 static struct uart_port *meson_ports[AML_UART_PORT_NUM]; =20 +struct meson_uart_data { + bool has_xtal_div2; +}; + static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctr= l) { } @@ -293,13 +298,20 @@ static int meson_uart_startup(struct uart_port *port) =20 static void meson_uart_change_speed(struct uart_port *port, unsigned long = baud) { - u32 val; + const struct meson_uart_data *private_data =3D port->private_data; + u32 val =3D 0; =20 while (!meson_uart_tx_empty(port)) cpu_relax(); =20 if (port->uartclk =3D=3D 24000000) { - val =3D DIV_ROUND_CLOSEST(port->uartclk / 3, baud) - 1; + unsigned int xtal_div =3D 3; + + if (private_data && private_data->has_xtal_div2) { + xtal_div =3D 2; + val |=3D AML_UART_BAUD_XTAL_DIV2; + } + val |=3D DIV_ROUND_CLOSEST(port->uartclk / xtal_div, baud) - 1; val |=3D AML_UART_BAUD_XTAL; } else { val =3D DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1; @@ -749,6 +761,7 @@ static int meson_uart_probe(struct platform_device *pde= v) port->x_char =3D 0; port->ops =3D &meson_uart_ops; port->fifosize =3D fifosize; + port->private_data =3D (void *)device_get_match_data(&pdev->dev); =20 meson_ports[pdev->id] =3D port; platform_set_drvdata(pdev, port); --=20 2.33.1 From nobody Mon May 11 02:55:52 2026 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 2A30CC433EF for ; Mon, 18 Apr 2022 05:33:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236674AbiDRFgO (ORCPT ); Mon, 18 Apr 2022 01:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236672AbiDRFgF (ORCPT ); Mon, 18 Apr 2022 01:36:05 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68B1A13E12; Sun, 17 Apr 2022 22:33:27 -0700 (PDT) Received: from droid06.amlogic.com (10.18.11.248) by mail-sh.amlogic.com (10.18.11.5) with Microsoft SMTP Server id 15.1.2176.14; Mon, 18 Apr 2022 13:33:26 +0800 From: Yu Tu To: , , , , Greg Kroah-Hartman , Neil Armstrong , Kevin Hilman , Jerome Brunet CC: Jiri Slaby , Martin Blumenstingl , Yu Tu Subject: [PATCH V2 2/2] tty: serial: meson: Added S4 SOC compatibility Date: Mon, 18 Apr 2022 13:32:02 +0800 Message-ID: <20220418053202.24528-3-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220418053202.24528-1-yu.tu@amlogic.com> References: <20220418053202.24528-1-yu.tu@amlogic.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.18.11.248] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Make UART driver compatible with S4 SOC UART. Meanwhile, the S4 SOC UART uses 12MHz as the clock source for baud rate calculations. Signed-off-by: Yu Tu --- drivers/tty/serial/meson_uart.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uar= t.c index 58bd2723c004..43941f21735f 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -790,11 +790,19 @@ static int meson_uart_remove(struct platform_device *= pdev) return 0; } =20 +static struct meson_uart_data s4_uart_date =3D { + .has_xtal_div2 =3D true, +}; + static const struct of_device_id meson_uart_dt_match[] =3D { { .compatible =3D "amlogic,meson6-uart" }, { .compatible =3D "amlogic,meson8-uart" }, { .compatible =3D "amlogic,meson8b-uart" }, { .compatible =3D "amlogic,meson-gx-uart" }, + { + .compatible =3D "amlogic,meson-s4-uart", + .data =3D (void *)&s4_uart_date, + }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, meson_uart_dt_match); --=20 2.33.1