From mboxrd@z Thu Jan 1 00:00:00 1970 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 DF084C433F5 for ; Tue, 8 Feb 2022 07:18:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348018AbiBHHSe (ORCPT ); Tue, 8 Feb 2022 02:18:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235298AbiBHHSW (ORCPT ); Tue, 8 Feb 2022 02:18:22 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4F6B4C0401F2; Mon, 7 Feb 2022 23:18:19 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D5BFD2B; Mon, 7 Feb 2022 23:18:18 -0800 (PST) Received: from [192.168.122.164] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 63F4E3F73B; Mon, 7 Feb 2022 23:18:18 -0800 (PST) Message-ID: <827f3c8b-b89a-018f-a5af-3984c7bc8492@arm.com> Date: Tue, 8 Feb 2022 01:18:09 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCH v3] serial: 8250_bcm2835aux: Add ACPI support Content-Language: en-US To: Adrien Thierry , linux-serial@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Jiri Slaby , Nicolas Saenz Julienne , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com References: <20220207232129.402882-1-athierry@redhat.com> From: Jeremy Linton In-Reply-To: <20220207232129.402882-1-athierry@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2/7/22 17:21, Adrien Thierry wrote: > Add ACPI support to 8250_bcm2835aux driver. This makes it possible to > use the miniuart on the Raspberry Pi with the tianocore/edk2 UEFI > firmware. I merged this to 5.17rc3, switched the console to this device and it now works in linux! Thanks for doing this! Tested-by: Jeremy Linton > > Signed-off-by: Adrien Thierry > --- > V1 -> V2: Refactored code to remove unnecessary conditional paths and > intermediate variables > V2 -> V3: Cleaned up coding style and addressed review comments > > drivers/tty/serial/8250/8250_bcm2835aux.c | 52 ++++++++++++++++++++--- > 1 file changed, 46 insertions(+), 6 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c > index fd95860cd661..2a1226a78a0c 100644 > --- a/drivers/tty/serial/8250/8250_bcm2835aux.c > +++ b/drivers/tty/serial/8250/8250_bcm2835aux.c > @@ -17,6 +17,7 @@ > #include > #include > #include > +#include > > #include "8250.h" > > @@ -44,6 +45,10 @@ struct bcm2835aux_data { > u32 cntl; > }; > > +struct bcm2835_aux_serial_driver_data { > + resource_size_t offset; > +}; > + > static void bcm2835aux_rs485_start_tx(struct uart_8250_port *up) > { > if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) { > @@ -80,9 +85,12 @@ static void bcm2835aux_rs485_stop_tx(struct uart_8250_port *up) > > static int bcm2835aux_serial_probe(struct platform_device *pdev) > { > + const struct bcm2835_aux_serial_driver_data *bcm_data; > struct uart_8250_port up = { }; > struct bcm2835aux_data *data; > + resource_size_t offset = 0; > struct resource *res; > + unsigned int uartclk; > int ret; > > /* allocate the custom structure */ > @@ -109,9 +117,7 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev) > platform_set_drvdata(pdev, data); > > /* get the clock - this also enables the HW */ > - data->clk = devm_clk_get(&pdev->dev, NULL); > - if (IS_ERR(data->clk)) > - return dev_err_probe(&pdev->dev, PTR_ERR(data->clk), "could not get clk\n"); > + data->clk = devm_clk_get_optional(&pdev->dev, NULL); > > /* get the interrupt */ > ret = platform_get_irq(pdev, 0); > @@ -125,8 +131,24 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev) > dev_err(&pdev->dev, "memory resource not found"); > return -EINVAL; > } > - up.port.mapbase = res->start; > - up.port.mapsize = resource_size(res); > + > + bcm_data = device_get_match_data(&pdev->dev); > + > + /* Some UEFI implementations (e.g. tianocore/edk2 for the Raspberry Pi) > + * describe the miniuart with a base address that encompasses the auxiliary > + * registers shared between the miniuart and spi. > + * > + * This is due to historical reasons, see discussion here : > + * https://edk2.groups.io/g/devel/topic/87501357#84349 > + * > + * We need to add the offset between the miniuart and auxiliary > + * registers to get the real miniuart base address. > + */ > + if (bcm_data) > + offset = bcm_data->offset; > + > + up.port.mapbase = res->start + offset; > + up.port.mapsize = resource_size(res) - offset; > > /* Check for a fixed line number */ > ret = of_alias_get_id(pdev->dev.of_node, "serial"); > @@ -141,12 +163,19 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev) > return ret; > } > > + uartclk = clk_get_rate(data->clk); > + if (!uartclk) { > + ret = device_property_read_u32(&pdev->dev, "clock-frequency", &uartclk); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "could not get clk rate\n"); > + } > + > /* the HW-clock divider for bcm2835aux is 8, > * but 8250 expects a divider of 16, > * so we have to multiply the actual clock by 2 > * to get identical baudrates. > */ > - up.port.uartclk = clk_get_rate(data->clk) * 2; > + up.port.uartclk = uartclk * 2; > > /* register the port */ > ret = serial8250_register_8250_port(&up); > @@ -173,16 +202,27 @@ static int bcm2835aux_serial_remove(struct platform_device *pdev) > return 0; > } > > +static const struct bcm2835_aux_serial_driver_data bcm2835_acpi_data = { > + .offset = 0x40, > +}; > + > static const struct of_device_id bcm2835aux_serial_match[] = { > { .compatible = "brcm,bcm2835-aux-uart" }, > { }, > }; > MODULE_DEVICE_TABLE(of, bcm2835aux_serial_match); > > +static const struct acpi_device_id bcm2835aux_serial_acpi_match[] = { > + { "BCM2836", (kernel_ulong_t)&bcm2835_acpi_data }, > + { } > +}; > +MODULE_DEVICE_TABLE(acpi, bcm2835aux_serial_acpi_match); > + > static struct platform_driver bcm2835aux_serial_driver = { > .driver = { > .name = "bcm2835-aux-uart", > .of_match_table = bcm2835aux_serial_match, > + .acpi_match_table = bcm2835aux_serial_acpi_match, > }, > .probe = bcm2835aux_serial_probe, > .remove = bcm2835aux_serial_remove, > > base-commit: 2ade8eef993c37a2a43e51a9b1f6c25509a2acce >