From patchwork Mon Apr 10 04:04:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Stanley X-Patchwork-Id: 97061 Delivered-To: patch@linaro.org Received: by 10.140.89.233 with SMTP id v96csp1200773qgd; Sun, 9 Apr 2017 21:04:45 -0700 (PDT) X-Received: by 10.98.81.132 with SMTP id f126mr53064662pfb.25.1491797085166; Sun, 09 Apr 2017 21:04:45 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id a124si12441523pgc.127.2017.04.09.21.04.44; Sun, 09 Apr 2017 21:04:45 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@gmail.com; spf=pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047AbdDJEEo (ORCPT + 7 others); Mon, 10 Apr 2017 00:04:44 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:34255 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752046AbdDJEEn (ORCPT ); Mon, 10 Apr 2017 00:04:43 -0400 Received: by mail-pg0-f65.google.com with SMTP id o123so24115934pga.1; Sun, 09 Apr 2017 21:04:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=MLbRYMyVXTrLcVoRtaD0+jXKrROkE/LwhIh9roJ10O4=; b=VKdmuaBf2bMW5VkqKvnK+QtQFJjaZEY5PH4pMd3xLJwZcmwHEQoo5AjX3hXw+LAYhO Qup7r01uruUrRs25PTQhc4yanhg/kzVWgNRwfL7agd33qrLoUr995zvLxbwlB+mMEA1y jvttpWkbzUrTjui5uVkwbj+9Wkgd2ZERn3cfL651Zds3xMkVXULHGHElzYzqgYoZQt2/ 4Qn+AVeLaFo3zglP/V9m195tGteBvsHuru8FZlyRoZwqhqbtVGa7l54d24w8kUk9G11H UqFDuVpOeIuAYda+TmfeY7jNV2WVpdV7GmjGPM75zbM6brvFR2Mb+vaq9wwpwwiuSEhE 3zfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=MLbRYMyVXTrLcVoRtaD0+jXKrROkE/LwhIh9roJ10O4=; b=Pr3RyNiKcSdypGC7jZUC9bgK+og3yFBldRdYCdTux10r8V8h9AmPCZBSmAUP0/eCFq gDBC+/mVWsnfm1eG23Nz/LKs1Dv3QjdrMZs5ir2vzTMCOR336N8wdV6fcEi6PeWLDiKn TOyIjYTXgf48gOrwsr9YIZ0FNiAltSXMr8IIeqTy5GgWrfbFCBKbD4RTS6X6TC7peGWe tPtGLraOx1+Ulbr/PKMT0yzIav479V/3wQeMXYJ0z2TQOAFnvvYCL6d9qe8vtNvp3QBw crgorkTc9Eblubjr6k/ceoVFFekdyYer/PbPfNQaMt8I1bPw8iHVnuKlFztv1VtOi43N bObA== X-Gm-Message-State: AN3rC/5UqJPJld/uyIK+hHPwAEEyHgEKCARrCOoRLqcNWehCIoTo7iUoJbioSBZwkflBUQ== X-Received: by 10.84.238.141 with SMTP id v13mr16714848plk.13.1491797076755; Sun, 09 Apr 2017 21:04:36 -0700 (PDT) Received: from aurora.jms.id.au ([203.0.153.9]) by smtp.gmail.com with ESMTPSA id u14sm6862027pfd.67.2017.04.09.21.04.31 (version=TLS1 cipher=AES128-SHA bits=128/128); Sun, 09 Apr 2017 21:04:36 -0700 (PDT) Received: by aurora.jms.id.au (sSMTP sendmail emulation); Mon, 10 Apr 2017 13:34:28 +0930 From: Joel Stanley To: Greg Kroah-Hartman , Jiri Slaby , Mark Rutland , Rob Herring Cc: Jeremy Kerr , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , Benjamin Herrenschmidt , openbmc@lists.ozlabs.org Subject: [PATCH v3 2/2] drivers/serial: Add driver for Aspeed virtual UART Date: Mon, 10 Apr 2017 13:34:00 +0930 Message-Id: <20170410040400.5509-3-joel@jms.id.au> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170410040400.5509-1-joel@jms.id.au> References: <20170410040400.5509-1-joel@jms.id.au> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Jeremy Kerr This change adds a driver for the 16550-based Aspeed virtual UART device. We use a similar process to the of_serial driver for device probe, but expose some VUART-specific functions through sysfs too. The VUART is two UART 'front ends' connected by their FIFO (no actual serial line in between). One is on the BMC side (management controller) and one is on the host CPU side. This driver is for the BMC side. The sysfs files allow the BMC userspace, which owns the system configuration policy, to specify at what IO port and interrupt number the host side will appear to the host on the Host <-> BMC LPC bus. It could be different on a different system (though most of them use 3f8/4). OpenPOWER host firmware doesn't like it when the host-side of the VUART's FIFO is not drained. This driver only disables host TX discard mode when the port is in use. We set the VUART enabled bit when we bind to the device, and clear it on unbind. We don't want to do this on open/release, as the host may be using this bit to configure serial output modes, which is independent of whether the devices has been opened by BMC userspace. Signed-off-by: Jeremy Kerr Signed-off-by: Joel Stanley Acked-by: Rob Herring --- v3: - remove whitespace in header - reformat comment - don't check for reg-io-width property; we don't need any special accessors for reading/writing bytes - move file to 8250_aspeed_vuart.c v2: - Use attribute groups and DEVICE_ATTR_RW - Use platform_get_resource/devm_ioremap_resource - of_find_property -> of_property_read_bool - Drop unncessary 0xff mask - Fix comment style - Use BIT and GENMASK where pssible - Move to 8250 directory - Rename ast -> aspeed to match other Aspeed drivers - Add documentation of sysfs file - Add detail to the commit message Documentation/ABI/stable/sysfs-driver-aspeed-vuart | 15 + Documentation/devicetree/bindings/serial/8250.txt | 2 + drivers/tty/serial/8250/8250_aspeed_vuart.c | 323 +++++++++++++++++++++ drivers/tty/serial/8250/Kconfig | 10 + drivers/tty/serial/8250/Makefile | 1 + 5 files changed, 351 insertions(+) create mode 100644 Documentation/ABI/stable/sysfs-driver-aspeed-vuart create mode 100644 drivers/tty/serial/8250/8250_aspeed_vuart.c -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Documentation/ABI/stable/sysfs-driver-aspeed-vuart b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart new file mode 100644 index 000000000000..8062953ce77b --- /dev/null +++ b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart @@ -0,0 +1,15 @@ +What: /sys/bus/platform/drivers/aspeed-vuart/*/lpc_address +Date: April 2017 +Contact: Jeremy Kerr +Description: Configures which IO port the host side of the UART + will appear on the host <-> BMC LPC bus. +Users: OpenBMC. Proposed changes should be mailed to + openbmc@lists.ozlabs.org + +What: /sys/bus/platform/drivers/aspeed-vuart*/sirq +Date: April 2017 +Contact: Jeremy Kerr +Description: Configures which interrupt number the host side of + the UART will appear on the host <-> BMC LPC bus. +Users: OpenBMC. Proposed changes should be mailed to + openbmc@lists.ozlabs.org diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt index 10276a46ecef..656733949309 100644 --- a/Documentation/devicetree/bindings/serial/8250.txt +++ b/Documentation/devicetree/bindings/serial/8250.txt @@ -20,6 +20,8 @@ Required properties: - "fsl,16550-FIFO64" - "fsl,ns16550" - "ti,da830-uart" + - "aspeed,ast2400-vuart" + - "aspeed,ast2500-vuart" - "serial" if the port type is unknown. - reg : offset and length of the register set for the device. - interrupts : should contain uart interrupt. diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c new file mode 100644 index 000000000000..5db0023e0225 --- /dev/null +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -0,0 +1,323 @@ +/* + * Serial Port driver for Aspeed VUART device + * + * Copyright (C) 2016 Jeremy Kerr , IBM Corp. + * Copyright (C) 2006 Arnd Bergmann , IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include + +#include "8250.h" + +#define ASPEED_VUART_GCRA 0x20 +#define ASPEED_VUART_GCRA_VUART_EN BIT(0) +#define ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD BIT(5) +#define ASPEED_VUART_GCRB 0x24 +#define ASPEED_VUART_GCRB_HOST_SIRQ_MASK GENMASK(7, 4) +#define ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT 4 +#define ASPEED_VUART_ADDRL 0x28 +#define ASPEED_VUART_ADDRH 0x2c + +struct aspeed_vuart { + struct device *dev; + void __iomem *regs; + struct clk *clk; + int line; +}; + +/* + * The VUART is basically two UART 'front ends' connected by their FIFO + * (no actual serial line in between). One is on the BMC side (management + * controller) and one is on the host CPU side. + * + * It allows the BMC to provide to the host a "UART" that pipes into + * the BMC itself and can then be turned by the BMC into a network console + * of some sort for example. + * + * This driver is for the BMC side. The sysfs files allow the BMC + * userspace which owns the system configuration policy, to specify + * at what IO port and interrupt number the host side will appear + * to the host on the Host <-> BMC LPC bus. It could be different on a + * different system (though most of them use 3f8/4). + */ + +static ssize_t lpc_address_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + u16 addr; + + addr = (readb(vuart->regs + ASPEED_VUART_ADDRH) << 8) | + (readb(vuart->regs + ASPEED_VUART_ADDRL)); + + return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr); +} + +static ssize_t lpc_address_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + writeb(val >> 8, vuart->regs + ASPEED_VUART_ADDRH); + writeb(val >> 0, vuart->regs + ASPEED_VUART_ADDRL); + + return count; +} + +static DEVICE_ATTR_RW(lpc_address); + +static ssize_t sirq_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRB); + reg &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + reg >>= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; + + return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg); +} + +static ssize_t sirq_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + u8 reg; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + val <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; + val &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + + reg = readb(vuart->regs + ASPEED_VUART_GCRB); + reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + reg |= val; + writeb(reg, vuart->regs + ASPEED_VUART_GCRB); + + return count; +} + +static DEVICE_ATTR_RW(sirq); + +static struct attribute *aspeed_vuart_attrs[] = { + &dev_attr_sirq.attr, + &dev_attr_lpc_address.attr, + NULL, +}; + +static const struct attribute_group aspeed_vuart_attr_group = { + .attrs = aspeed_vuart_attrs, +}; + +static void aspeed_vuart_set_enabled(struct aspeed_vuart *vuart, bool enabled) +{ + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRA); + reg &= ~ASPEED_VUART_GCRA_VUART_EN; + if (enabled) + reg |= ASPEED_VUART_GCRA_VUART_EN; + writeb(reg, vuart->regs + ASPEED_VUART_GCRA); +} + +static void aspeed_vuart_set_host_tx_discard(struct aspeed_vuart *vuart, + bool discard) +{ + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRA); + + /* If the DISABLE_HOST_TX_DISCARD bit is set, discard is disabled */ + reg &= ~ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD; + if (!discard) + reg |= ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD; + + writeb(reg, vuart->regs + ASPEED_VUART_GCRA); +} + +static int aspeed_vuart_startup(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct aspeed_vuart *vuart = uart_8250_port->port.private_data; + int rc; + + rc = serial8250_do_startup(uart_port); + if (rc) + return rc; + + aspeed_vuart_set_host_tx_discard(vuart, false); + + return 0; +} + +static void aspeed_vuart_shutdown(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct aspeed_vuart *vuart = uart_8250_port->port.private_data; + + aspeed_vuart_set_host_tx_discard(vuart, true); + + serial8250_do_shutdown(uart_port); +} + +static int aspeed_vuart_probe(struct platform_device *pdev) +{ + struct uart_8250_port port; + struct aspeed_vuart *vuart; + struct device_node *np; + struct resource *res; + u32 clk, prop; + int rc; + + np = pdev->dev.of_node; + + vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL); + if (!vuart) + return -ENOMEM; + + vuart->dev = &pdev->dev; + + /* The 8510 core creates the mapping, which we grab a reference to + * for VUART-specific registers */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + vuart->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(vuart->regs)) + return PTR_ERR(vuart->regs); + + memset(&port, 0, sizeof(port)); + port.port.private_data = vuart; + port.port.membase = vuart->regs; + port.port.mapbase = res->start; + port.port.mapsize = resource_size(res); + port.port.startup = aspeed_vuart_startup; + port.port.shutdown = aspeed_vuart_shutdown; + port.port.dev = &pdev->dev; + + rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group); + if (rc < 0) + return rc; + + if (of_property_read_u32(np, "clock-frequency", &clk)) { + vuart->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(vuart->clk)) { + dev_warn(&pdev->dev, + "clk or clock-frequency not defined\n"); + return PTR_ERR(vuart->clk); + } + + rc = clk_prepare_enable(vuart->clk); + if (rc < 0) + return rc; + + clk = clk_get_rate(vuart->clk); + } + + /* If current-speed was set, then try not to change it. */ + if (of_property_read_u32(np, "current-speed", &prop) == 0) + port.port.custom_divisor = clk / (16 * prop); + + /* Check for shifted address mapping */ + if (of_property_read_u32(np, "reg-offset", &prop) == 0) + port.port.mapbase += prop; + + /* Check for registers offset within the devices address range */ + if (of_property_read_u32(np, "reg-shift", &prop) == 0) + port.port.regshift = prop; + + /* Check for fifo size */ + if (of_property_read_u32(np, "fifo-size", &prop) == 0) + port.port.fifosize = prop; + + /* Check for a fixed line number */ + rc = of_alias_get_id(np, "serial"); + if (rc >= 0) + port.port.line = rc; + + port.port.irq = irq_of_parse_and_map(np, 0); + port.port.irqflags = IRQF_SHARED; + port.port.iotype = UPIO_MEM; + port.port.type = PORT_16550A; + port.port.uartclk = clk; + port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF + | UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST; + + if (of_property_read_bool(np, "no-loopback-test")) + port.port.flags |= UPF_SKIP_TEST; + + if (port.port.fifosize) + port.capabilities = UART_CAP_FIFO; + + if (of_property_read_bool(np, "auto-flow-control")) + port.capabilities |= UART_CAP_AFE; + + rc = serial8250_register_8250_port(&port); + if (rc < 0) + goto err_clk_disable; + + vuart->line = rc; + + aspeed_vuart_set_enabled(vuart, true); + aspeed_vuart_set_host_tx_discard(vuart, true); + platform_set_drvdata(pdev, vuart); + + return 0; + +err_clk_disable: + clk_disable_unprepare(vuart->clk); + irq_dispose_mapping(port.port.irq); + return rc; +} + +static int aspeed_vuart_remove(struct platform_device *pdev) +{ + struct aspeed_vuart *vuart = platform_get_drvdata(pdev); + + aspeed_vuart_set_enabled(vuart, false); + serial8250_unregister_port(vuart->line); + sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group); + clk_disable_unprepare(vuart->clk); + + return 0; +} + +static const struct of_device_id aspeed_vuart_table[] = { + { .compatible = "aspeed,ast2400-vuart" }, + { .compatible = "aspeed,ast2500-vuart" }, + { }, +}; + +static struct platform_driver aspeed_vuart_driver = { + .driver = { + .name = "aspeed-vuart", + .of_match_table = aspeed_vuart_table, + }, + .probe = aspeed_vuart_probe, + .remove = aspeed_vuart_remove, +}; + +module_platform_driver(aspeed_vuart_driver); + +MODULE_AUTHOR("Jeremy Kerr "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Driver for Aspeed VUART device"); diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index a65fb8197aec..fb217f02ec94 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -220,6 +220,16 @@ config SERIAL_8250_ACCENT To compile this driver as a module, choose M here: the module will be called 8250_accent. +config SERIAL_8250_ASPEED_VUART + tristate "Aspeed Virtual UART" + depends on SERIAL_8250 + depends on OF + help + If you want to use the virtual UART (VUART) device on Aspeed + BMC platforms, enable this option. This enables the 16550A- + compatible device on the local LPC bus, giving a UART device + with no physical RS232 connections. + config SERIAL_8250_BOCA tristate "Support Boca cards" depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index 2f30f9ecdb1b..a44a99a3e623 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_SERIAL_8250_EXAR) += 8250_exar.o obj-$(CONFIG_SERIAL_8250_HP300) += 8250_hp300.o obj-$(CONFIG_SERIAL_8250_CS) += serial_cs.o obj-$(CONFIG_SERIAL_8250_ACORN) += 8250_acorn.o +obj-$(CONFIG_SERIAL_8250_ASPEED_VUART) += 8250_aspeed_vuart.o obj-$(CONFIG_SERIAL_8250_BCM2835AUX) += 8250_bcm2835aux.o obj-$(CONFIG_SERIAL_8250_CONSOLE) += 8250_early.o obj-$(CONFIG_SERIAL_8250_FOURPORT) += 8250_fourport.o