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 81923C433EF for ; Tue, 21 Dec 2021 07:32:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235291AbhLUHcQ (ORCPT ); Tue, 21 Dec 2021 02:32:16 -0500 Received: from mail-sh.amlogic.com ([58.32.228.43]:61697 "EHLO mail-sh.amlogic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235258AbhLUHcP (ORCPT ); Tue, 21 Dec 2021 02:32:15 -0500 X-Greylist: delayed 902 seconds by postgrey-1.27 at vger.kernel.org; Tue, 21 Dec 2021 02:32:04 EST 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; Tue, 21 Dec 2021 15:17:03 +0800 From: Yu Tu To: , , , CC: Greg Kroah-Hartman , Jiri Slaby , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Yu Tu Subject: [PATCH 3/3] tty: serial: meson: add UART driver compatible with S4 SoC on-chip Date: Tue, 21 Dec 2021 15:16:34 +0800 Message-ID: <20211221071634.25980-4-yu.tu@amlogic.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211221071634.25980-1-yu.tu@amlogic.com> References: <20211221071634.25980-1-yu.tu@amlogic.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.18.11.248] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The S4 SoC on-chip UART uses a 12M clock as the clock source for calculating the baud rate of the UART. But previously, chips used 24M or other clock sources. So add this change. The specific clock source is determined by chip design. Signed-off-by: Yu Tu --- drivers/tty/serial/meson_uart.c | 62 +++++++++++++++++++++++++++++---- 1 file changed, 55 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index 69450a461c48..557c24d954a2 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -19,6 +19,7 @@ #include #include #include +#include /* Register offsets */ #define AML_UART_WFIFO 0x00 @@ -68,6 +69,8 @@ #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_TICK BIT(26) +#define AML_UART_BAUD_XTAL_DIV2 BIT(27) #define AML_UART_PORT_NUM 12 #define AML_UART_PORT_OFFSET 6 @@ -80,6 +83,11 @@ static struct uart_driver meson_uart_driver; static struct uart_port *meson_ports[AML_UART_PORT_NUM]; +struct meson_uart_data { + /*A clock source that calculates baud rates*/ + unsigned int xtal_tick_en; +}; + static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { } @@ -294,16 +302,29 @@ static int meson_uart_startup(struct uart_port *port) static void meson_uart_change_speed(struct uart_port *port, unsigned long baud) { + struct meson_uart_data *uart_data = port->private_data; u32 val; while (!meson_uart_tx_empty(port)) cpu_relax(); + val = readl_relaxed(port->membase + AML_UART_REG5); + val &= ~AML_UART_BAUD_MASK; + if (port->uartclk == 24000000) { - val = ((port->uartclk / 3) / baud) - 1; - val |= AML_UART_BAUD_XTAL; + if (uart_data->xtal_tick_en) { + val = (port->uartclk / 2 + baud / 2) / baud - 1; + val |= (AML_UART_BAUD_XTAL | AML_UART_BAUD_XTAL_DIV2); + } else { + val = ((port->uartclk / 3) + baud / 2) / baud - 1; + val &= (~(AML_UART_BAUD_XTAL_TICK | + AML_UART_BAUD_XTAL_DIV2)); + val |= AML_UART_BAUD_XTAL; + } } else { val = ((port->uartclk * 10 / (baud * 4) + 5) / 10) - 1; + val &= (~(AML_UART_BAUD_XTAL | AML_UART_BAUD_XTAL_TICK | + AML_UART_BAUD_XTAL_DIV2)); } val |= AML_UART_BAUD_USE; writel(val, port->membase + AML_UART_REG5); @@ -714,6 +735,7 @@ static int meson_uart_probe(struct platform_device *pdev) { struct resource *res_mem, *res_irq; struct uart_port *port; + struct meson_uart_data *uart_data; int ret = 0; int id = -1; @@ -729,6 +751,10 @@ static int meson_uart_probe(struct platform_device *pdev) } } + uart_data = of_device_get_match_data(&pdev->dev); + if (!uart_data) + return -EINVAL; + if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM) return -EINVAL; @@ -770,6 +796,7 @@ static int meson_uart_probe(struct platform_device *pdev) port->x_char = 0; port->ops = &meson_uart_ops; port->fifosize = 64; + port->private_data = uart_data; meson_ports[pdev->id] = port; platform_set_drvdata(pdev, port); @@ -798,14 +825,35 @@ static int meson_uart_remove(struct platform_device *pdev) return 0; } +static const struct meson_uart_data meson_uart_data = { + .xtal_tick_en = 0, +}; + +static const struct meson_uart_data s4_meson_uart_data = { + .xtal_tick_en = 1, +}; + static const struct of_device_id meson_uart_dt_match[] = { /* Legacy bindings, should be removed when no more used */ - { .compatible = "amlogic,meson-uart" }, + { .compatible = "amlogic,meson-uart", + .data = &meson_uart_data + }, /* Stable bindings */ - { .compatible = "amlogic,meson6-uart" }, - { .compatible = "amlogic,meson8-uart" }, - { .compatible = "amlogic,meson8b-uart" }, - { .compatible = "amlogic,meson-gx-uart" }, + { .compatible = "amlogic,meson6-uart", + .data = &meson_uart_data + }, + { .compatible = "amlogic,meson8-uart", + .data = &meson_uart_data + }, + { .compatible = "amlogic,meson8b-uart", + .data = &meson_uart_data + }, + { .compatible = "amlogic,meson-gx-uart", + .data = &meson_uart_data + }, + { .compatible = "amlogic,meson-s4-uart", + .data = &s4_meson_uart_data + }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, meson_uart_dt_match); -- 2.33.1