From nobody Fri Jun 19 06:14:03 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 1A7A2C433EF for ; Thu, 7 Apr 2022 08:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243028AbiDGIdB (ORCPT ); Thu, 7 Apr 2022 04:33:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243036AbiDGIc2 (ORCPT ); Thu, 7 Apr 2022 04:32:28 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 181B3152823; Thu, 7 Apr 2022 01:30:28 -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; Thu, 7 Apr 2022 16:15:22 +0800 From: Yu Tu To: , , , , Neil Armstrong , Kevin Hilman , Jerome Brunet CC: Greg Kroah-Hartman , Jiri Slaby , Martin Blumenstingl , Yu Tu Subject: [PATCH 1/3] tty: serial: meson: Use DIV_ROUND_CLOSEST to calculate baud rates Date: Thu, 7 Apr 2022 16:13:53 +0800 Message-ID: <20220407081355.13602-2-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220407081355.13602-1-yu.tu@amlogic.com> References: <20220407081355.13602-1-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" Due to chip process differences, chip designers recommend using baud rates as close to and larger as possible in order to reduce clock errors. Signed-off-by: Yu Tu Reviewed-by: Neil Armstrong --- drivers/tty/serial/meson_uart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uar= t.c index 2bf1c57e0981..8e59624935af 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -299,10 +299,10 @@ static void meson_uart_change_speed(struct uart_port = *port, unsigned long baud) cpu_relax(); =20 if (port->uartclk =3D=3D 24000000) { - val =3D ((port->uartclk / 3) / baud) - 1; + val =3D DIV_ROUND_CLOSEST(port->uartclk / 3, baud) - 1; val |=3D AML_UART_BAUD_XTAL; } else { - val =3D ((port->uartclk * 10 / (baud * 4) + 5) / 10) - 1; + val =3D DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1; } val |=3D AML_UART_BAUD_USE; writel(val, port->membase + AML_UART_REG5); --=20 2.33.1 From nobody Fri Jun 19 06:14:03 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 E90D7C433EF for ; Thu, 7 Apr 2022 08:30:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243058AbiDGIcz (ORCPT ); Thu, 7 Apr 2022 04:32:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243028AbiDGIca (ORCPT ); Thu, 7 Apr 2022 04:32:30 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D97A3156088; Thu, 7 Apr 2022 01:30:30 -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; Thu, 7 Apr 2022 16:15:26 +0800 From: Yu Tu To: , , , , Neil Armstrong , Kevin Hilman , Jerome Brunet CC: Greg Kroah-Hartman , Jiri Slaby , Martin Blumenstingl , Yu Tu Subject: [PATCH 2/3] tty: serial: meson: Added 12Mhz as the clock source for calculating baud rate Date: Thu, 7 Apr 2022 16:13:54 +0800 Message-ID: <20220407081355.13602-3-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220407081355.13602-1-yu.tu@amlogic.com> References: <20220407081355.13602-1-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" Starting with the g12A chip, add a 12Mhz clock to calculate the baud rate, since 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 | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uar= t.c index 8e59624935af..7e77693a1318 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; + 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->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; @@ -691,6 +703,7 @@ static int meson_uart_probe_clocks(struct platform_devi= ce *pdev, =20 static int meson_uart_probe(struct platform_device *pdev) { + struct meson_uart_data *private_data; struct resource *res_mem; struct uart_port *port; u32 fifosize =3D 64; /* Default is 64, 128 for EE UART_0 */ @@ -733,6 +746,13 @@ static int meson_uart_probe(struct platform_device *pd= ev) if (!port) return -ENOMEM; =20 + private_data =3D devm_kzalloc(&pdev->dev, sizeof(struct meson_uart_data),= GFP_KERNEL); + if (!private_data) + return -ENOMEM; + + if ((bool)device_get_match_data(&pdev->dev)) + private_data->has_xtal_div2 =3D true; + ret =3D meson_uart_probe_clocks(pdev, port); if (ret) return ret; @@ -749,6 +769,7 @@ 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 private_data; =20 meson_ports[pdev->id] =3D port; platform_set_drvdata(pdev, port); --=20 2.33.1 From nobody Fri Jun 19 06:14:03 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 C6DBBC433EF for ; Thu, 7 Apr 2022 08:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243104AbiDGIdk (ORCPT ); Thu, 7 Apr 2022 04:33:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243091AbiDGIdh (ORCPT ); Thu, 7 Apr 2022 04:33:37 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16E9C1B6959; Thu, 7 Apr 2022 01:31:34 -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; Thu, 7 Apr 2022 16:15:28 +0800 From: Yu Tu To: , , , , Neil Armstrong , Kevin Hilman , Jerome Brunet CC: Greg Kroah-Hartman , Jiri Slaby , Martin Blumenstingl , Yu Tu Subject: [PATCH 3/3] tty: serial: meson: Added S4 SOC compatibility Date: Thu, 7 Apr 2022 16:13:55 +0800 Message-ID: <20220407081355.13602-4-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220407081355.13602-1-yu.tu@amlogic.com> References: <20220407081355.13602-1-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 | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uar= t.c index 7e77693a1318..03c9a305d805 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -803,6 +803,10 @@ static const struct of_device_id meson_uart_dt_match[]= =3D { { .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 *)true, + }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, meson_uart_dt_match); --=20 2.33.1