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[209.132.180.67]) by mx.google.com with ESMTP id z66si16370664pfb.297.2017.05.02.00.46.39; Tue, 02 May 2017 00:46:39 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752067AbdEBHq0 (ORCPT + 25 others); Tue, 2 May 2017 03:46:26 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:33640 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751135AbdEBHqS (ORCPT ); Tue, 2 May 2017 03:46:18 -0400 Received: by mail-pf0-f195.google.com with SMTP id b23so15356451pfc.0; Tue, 02 May 2017 00:46:18 -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=ROK1TT3XXNJuHmApA/A05vHjG+MwhZGsU7Yl7P6oXJA=; b=YNHcYYt1cbbOOtgHa/quS7Njx25mBI6ATnGuzCgDB7s0uvXQAC34WupyxJ9Mih1cFP 5aDkR2kfmhMFr2mMXv9jLbDvmZScO89BSKwQWVMG/9F7OBKqQ2GTkV+EGN5cLiKPNXkK uAYgWY18ZwgZAwbs3mPTlOVzbDffuDKtRz7t5tMdoFh30swghzrCzHZ6vVot7cl4M+r2 8e/FZTJ3V/mCm52O+QEVA7pTYRuzI6DkMR8Wwe99WV5t+yvT0iR62PskTqWYOjqgDZKZ dedCLmrz3RGx9ZxliSaSujC68atM5RGg5kx2H8ftr2s1i3nlYLec3oMbFnL9tWbZfAbU px3Q== 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=ROK1TT3XXNJuHmApA/A05vHjG+MwhZGsU7Yl7P6oXJA=; b=Rrd7M507AT+x4CfjW2qLzBawk68cBMAQooJMEKm4oWZmtk7Kxoy733bZy1uGjvvkr5 f6UaAhDDlEJcvrf2A/qGgYu/R/Fw1uBkBDFN6nLzeoXnFi0YLQqwEeUMHaSSaAex0+WD 5zf+TBjI+r+5IM3tK4cOucviMNPxXThyc8UkeXoWAU0Nk6Yj8UPJH/6OqEPNQ+0nnDCW 0mkF2y2tzk9HD2Z5oK3MX53TkcA8vYASXu9Ohk1iw2kgTPdyUfN/E6J77WE4qTODVLTe 6vZcpFI5rWiO+JfUFzoJQ5MCvS4nZFprxGQanTsVudqd6OExWs0YU8r4V8K2nSsTDPsW qkFQ== X-Gm-Message-State: AN3rC/69mncU//v1UDPVEQFEEmtDYpwY1ddFqtbKlW5lTJMPz23RRBuD D7bd32k2lNujzQ== X-Received: by 10.98.88.4 with SMTP id m4mr31304556pfb.41.1493711172494; Tue, 02 May 2017 00:46:12 -0700 (PDT) Received: from aurora.jms.id.au ([203.0.153.9]) by smtp.gmail.com with ESMTPSA id j125sm20826022pgc.53.2017.05.02.00.46.06 (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 02 May 2017 00:46:11 -0700 (PDT) Received: by aurora.jms.id.au (sSMTP sendmail emulation); Tue, 02 May 2017 17:16:04 +0930 From: Joel Stanley To: Greg Kroah-Hartman , Jiri Slaby Cc: Jeremy Kerr , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , Benjamin Herrenschmidt , Mark Rutland , Rob Herring , openbmc@lists.ozlabs.org Subject: [PATCH v4 2/2] drivers/serial: Add driver for Aspeed virtual UART Date: Tue, 2 May 2017 17:15:43 +0930 Message-Id: <20170502074543.1380-3-joel@jms.id.au> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170502074543.1380-1-joel@jms.id.au> References: <20170502074543.1380-1-joel@jms.id.au> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 --- v4: - Reorder if statements - Remove uncessary comment 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 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..822be4906763 --- /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 = readb(vuart->regs + ASPEED_VUART_GCRA); + + if (enabled) + reg |= ASPEED_VUART_GCRA_VUART_EN; + else + 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 */ + if (!discard) + reg |= ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD; + else + 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; + + 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 0e3f529d50e9..a1161ec0256f 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -224,6 +224,16 @@ 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