From patchwork Tue Dec 21 07:16:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Tu X-Patchwork-Id: 12689185 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 502BBC433F5 for ; Tue, 21 Dec 2021 07:18:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IVCTNG0fOA5KMpM4vvoz58ARNkeeIjwuFxfgSseHYQ4=; b=SEEW7lZ5ob8LuH 6x2zv1cs+3BmorIHPd5vYCtJjD/zDUQABo4ZAFTMV2fwAY6D9l6Mesl3lV8bEqIkfJlJuymJPZaUe wDfJX2aqYWS6XauNW71VJQTGW20klBO19RAD3BYbbbCjK346cH/TXzr1xsz7GbmIkzea8qfgDC7BP 9t/A6nYjn0vb7HlYhe0PVIadKmxhcyXMTd5KEoJjApBX/rqpfxJJqMcuqQ5nl4mabE1+N2purOT9g xZGyXxg2011xcqYcRZ25Bxy+P/bIwJvo6nGF7wJleUgiXI+tQFqFdLLnXkbYMTkXt7AM3HN7B6jLP lZqPhDqCZc+9zAFp/71g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mzZPc-005k4g-Jx; Tue, 21 Dec 2021 07:18:16 +0000 Received: from mail-sh.amlogic.com ([58.32.228.43]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mzZOf-005jgE-IJ; Tue, 21 Dec 2021 07:17:19 +0000 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 X-Originating-IP: [10.18.11.248] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211220_231717_652035_00061C1E X-CRM114-Status: GOOD ( 16.43 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.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);