From patchwork Fri Apr 29 20:40:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 569268 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 E47B5C433F5 for ; Fri, 29 Apr 2022 20:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380942AbiD2Unl (ORCPT ); Fri, 29 Apr 2022 16:43:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359728AbiD2Uni (ORCPT ); Fri, 29 Apr 2022 16:43:38 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5C0B315719; Fri, 29 Apr 2022 13:40:19 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id A56B192009D; Fri, 29 Apr 2022 22:40:18 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 9F1A892009B; Fri, 29 Apr 2022 21:40:18 +0100 (BST) Date: Fri, 29 Apr 2022 21:40:18 +0100 (BST) From: "Maciej W. Rozycki" To: Greg Kroah-Hartman , Jiri Slaby , Palmer Dabbelt , Paul Walmsley cc: Damien Le Moal , linux-serial@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] serial: sifive: Report actual baud base rather than fixed 115200 In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The base baud value reported is supposed to be the highest baud rate that can be set for a serial port. The SiFive FU740-C000 SOC's on-chip UART supports baud rates of up to 1/16 of the input clock rate, which is the bus clock `tlclk'[1], often at 130MHz in the case of the HiFive Unmatched board. However the sifive UART driver reports a fixed value of 115200 instead: 10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 115200) is a SiFive UART v0 10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 115200) is a SiFive UART v0 even though we already support setting higher baud rates, e.g.: $ tty /dev/ttySIF1 $ stty speed 230400 The baud base value is computed by the serial core by dividing the UART clock recorded in `struct uart_port' by 16, which is also the minimum value of the clock divider supported, so correct the baud base value reported by setting the UART clock recorded to the input clock rate rather than 115200: 10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 8125000) is a SiFive UART v0 10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 8125000) is a SiFive UART v0 References: [1] "SiFive FU740-C000 Manual", v1p3, SiFive, Inc., August 13, 2021, Section 16.9 "Baud Rate Divisor Register (div)", pp.143-144 Signed-off-by: Maciej W. Rozycki Fixes: 1f1496a923b6 ("riscv: Fix sifive serial driver") --- drivers/tty/serial/sifive.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) linux-serial-sifive-base-baud.diff Index: linux-macro/drivers/tty/serial/sifive.c =================================================================== --- linux-macro.orig/drivers/tty/serial/sifive.c +++ linux-macro/drivers/tty/serial/sifive.c @@ -998,7 +998,7 @@ static int sifive_serial_probe(struct pl /* Set up clock divider */ ssp->clkin_rate = clk_get_rate(ssp->clk); ssp->baud_rate = SIFIVE_DEFAULT_BAUD_RATE; - ssp->port.uartclk = ssp->baud_rate * 16; + ssp->port.uartclk = ssp->clkin_rate; __ssp_update_div(ssp); platform_set_drvdata(pdev, ssp); From patchwork Fri Apr 29 20:40:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 567674 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 48126C433F5 for ; Fri, 29 Apr 2022 20:40:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381001AbiD2UoB (ORCPT ); Fri, 29 Apr 2022 16:44:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1380993AbiD2Uns (ORCPT ); Fri, 29 Apr 2022 16:43:48 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DE11065404; Fri, 29 Apr 2022 13:40:26 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id 1D9FD92009C; Fri, 29 Apr 2022 22:40:26 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 169AD92009B; Fri, 29 Apr 2022 21:40:26 +0100 (BST) Date: Fri, 29 Apr 2022 21:40:26 +0100 (BST) From: "Maciej W. Rozycki" To: Greg Kroah-Hartman , Jiri Slaby , Palmer Dabbelt , Paul Walmsley cc: Damien Le Moal , linux-serial@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] serial: sifive: Remove duplicate `clkin_rate' setting In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The `clkin_rate' member of `struct sifive_serial_port' now duplicates `uartclk' from nested `struct uart_port', so use `uartclk' throughout and remove `clkin_rate'. Signed-off-by: Maciej W. Rozycki --- drivers/tty/serial/sifive.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) linux-serial-sifive-uartclk.diff Index: linux-macro/drivers/tty/serial/sifive.c =================================================================== --- linux-macro.orig/drivers/tty/serial/sifive.c +++ linux-macro/drivers/tty/serial/sifive.c @@ -148,7 +148,6 @@ * @port: struct uart_port embedded in this struct * @dev: struct device * * @ier: shadowed copy of the interrupt enable register - * @clkin_rate: input clock to the UART IP block. * @baud_rate: UART serial line rate (e.g., 115200 baud) * @clk: reference to this device's clock * @clk_notifier: clock rate change notifier for upstream clock changes @@ -159,7 +158,6 @@ struct sifive_serial_port { struct uart_port port; struct device *dev; unsigned char ier; - unsigned long clkin_rate; unsigned long baud_rate; struct clk *clk; struct notifier_block clk_notifier; @@ -463,7 +461,7 @@ static void __ssp_update_div(struct sifi { u16 div; - div = DIV_ROUND_UP(ssp->clkin_rate, ssp->baud_rate) - 1; + div = DIV_ROUND_UP(ssp->port.uartclk, ssp->baud_rate) - 1; __ssp_writel(div, SIFIVE_SERIAL_DIV_OFFS, ssp); } @@ -648,8 +646,8 @@ static int sifive_serial_clk_notifier(st udelay(DIV_ROUND_UP(12 * 1000 * 1000, ssp->baud_rate)); } - if (event == POST_RATE_CHANGE && ssp->clkin_rate != cnd->new_rate) { - ssp->clkin_rate = cnd->new_rate; + if (event == POST_RATE_CHANGE && ssp->port.uartclk != cnd->new_rate) { + ssp->port.uartclk = cnd->new_rate; __ssp_update_div(ssp); } @@ -678,7 +676,8 @@ static void sifive_serial_set_termios(st __ssp_set_stop_bits(ssp, nstop); /* Set line rate */ - rate = uart_get_baud_rate(port, termios, old, 0, ssp->clkin_rate / 16); + rate = uart_get_baud_rate(port, termios, old, 0, + ssp->port.uartclk / 16); __ssp_update_baud_rate(ssp, rate); spin_lock_irqsave(&ssp->port.lock, flags); @@ -996,9 +995,8 @@ static int sifive_serial_probe(struct pl } /* Set up clock divider */ - ssp->clkin_rate = clk_get_rate(ssp->clk); + ssp->port.uartclk = clk_get_rate(ssp->clk); ssp->baud_rate = SIFIVE_DEFAULT_BAUD_RATE; - ssp->port.uartclk = ssp->clkin_rate; __ssp_update_div(ssp); platform_set_drvdata(pdev, ssp);