From patchwork Tue Mar 28 05:44:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Stanley X-Patchwork-Id: 96101 Delivered-To: patch@linaro.org Received: by 10.140.89.233 with SMTP id v96csp1552945qgd; Mon, 27 Mar 2017 22:47:46 -0700 (PDT) X-Received: by 10.84.129.67 with SMTP id 61mr34461032plb.16.1490680066621; Mon, 27 Mar 2017 22:47:46 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id q18si3037213pgd.282.2017.03.27.22.47.46; Mon, 27 Mar 2017 22:47:46 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-serial-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 linux-serial-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-serial-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753072AbdC1Fqf (ORCPT + 2 others); Tue, 28 Mar 2017 01:46:35 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:35974 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753708AbdC1Fqd (ORCPT ); Tue, 28 Mar 2017 01:46:33 -0400 Received: by mail-pg0-f67.google.com with SMTP id 81so18578004pgh.3; Mon, 27 Mar 2017 22:45:55 -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=4MoiCsF4Grq2ddfz1ON5cp/phNOUjVqaIs8DzwtaVOo=; b=hTuCXSko/F3RIeq/BsCiQzFUBji0dGYcPpX9x5fPFTVkpUgnk3Z5+7TG0lTDMjDnik t9zVbLwE8MMR3VdNuK/V/OVHyMMh8cclsLgwL4cOTGx9Cn3rXtUVrtMiowj70KOumRK8 vqvw1S0iUcSmFvZ2DLlYWhS/Fhzzqj3M3mkIT4FGhiw3EO/InZjZPAvMG0Nt3KBARXEk kbLHghr8EOmnfDLXkSz19PVKR3j3slOWdte3N0Qnc5T8Ys27CybiouL6eef+lIkdI4UU 7DkE0HXvqKdh2l4jIUmtegwTO2XXJnu/0jUbm39PWOqKtw22PToOPzeqpZU19PKtcLU7 sbiQ== 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=4MoiCsF4Grq2ddfz1ON5cp/phNOUjVqaIs8DzwtaVOo=; b=ri9Ts3x7+CRvsRHdWDysMM/ZnarVa/4VEpZwPC1TvtV4CEQg9ix6ZP87IFu/Vf8x+m QIjV64m/YMxC4MlFDeeuTGXujur6uU19/mDYIc/s0DCNJEKlh4ynTZwt4MZDtrOzA3Sb hJa+rzX9Sb6yOpDHcdjbtKg/GlCoYXJ52BRQecLSoaOMaqC74v6uTqwWxChgU1OBi5Jc 4lb32kaVgP1RNl+efPXsASTpUFHExdPQawofd/41D72vXnMdI3mGzDVob5+qVQxTE11j E2FF0vJvfZFgiPOKi/vS3O9VFuoMBuVJRKZYTlWsv0d++3yCILQkFKlCoyZVl+2bhHyQ OlIg== X-Gm-Message-State: AFeK/H3LPNZQrizsJvOuL46Qy0JgpBBtirZdGkxL5oOveGixgNjrUca0pigIAgWx65Cd0Q== X-Received: by 10.98.206.78 with SMTP id y75mr30135419pfg.108.1490679955049; Mon, 27 Mar 2017 22:45:55 -0700 (PDT) Received: from aurora.jms.id.au ([203.0.153.9]) by smtp.gmail.com with ESMTPSA id 11sm4451710pgf.28.2017.03.27.22.45.45 (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 27 Mar 2017 22:45:54 -0700 (PDT) Received: by aurora.jms.id.au (sSMTP sendmail emulation); Tue, 28 Mar 2017 16:15:39 +1030 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, openbmc@lists.ozlabs.org, devicetree@vger.kernel.org, Benjamin Herrenschmidt Subject: [PATCH 2/2] drivers/serial: Add driver for Aspeed virtual UART Date: Tue, 28 Mar 2017 16:14:58 +1030 Message-Id: <20170328054458.29341-3-joel@jms.id.au> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170328054458.29341-1-joel@jms.id.au> References: <20170328054458.29341-1-joel@jms.id.au> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@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. 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 --- Documentation/devicetree/bindings/serial/8250.txt | 2 + drivers/tty/serial/Kconfig | 10 + drivers/tty/serial/Makefile | 1 + drivers/tty/serial/aspeed-vuart.c | 335 ++++++++++++++++++++++ 4 files changed, 348 insertions(+) create mode 100644 drivers/tty/serial/aspeed-vuart.c -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" 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/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt index f86bb06c39e9..a12e9277ac5d 100644 --- a/Documentation/devicetree/bindings/serial/8250.txt +++ b/Documentation/devicetree/bindings/serial/8250.txt @@ -19,6 +19,8 @@ Required properties: - "altr,16550-FIFO128" - "fsl,16550-FIFO64" - "fsl,ns16550" + - "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/Kconfig b/drivers/tty/serial/Kconfig index e9cf5b67f1b7..758b69a51078 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1129,6 +1129,16 @@ config SERIAL_NETX_CONSOLE If you have enabled the serial port on the Hilscher NetX SoC you can make it the console by answering Y to this option. +config SERIAL_ASPEED_VUART + tristate "Aspeed Virtual UART" + depends on OF + depends on SERIAL_8250 + 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_OMAP tristate "OMAP serial port support" depends on ARCH_OMAP2PLUS diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 2d6288bc4554..5b97b0fa29e2 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250/ obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o +obj-$(CONFIG_SERIAL_ASPEED_VUART) += aspeed-vuart.o obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o obj-$(CONFIG_SERIAL_PXA_NON8250) += pxa.o obj-$(CONFIG_SERIAL_PNX8XXX) += pnx8xxx_uart.o diff --git a/drivers/tty/serial/aspeed-vuart.c b/drivers/tty/serial/aspeed-vuart.c new file mode 100644 index 000000000000..fc6fa6d243c8 --- /dev/null +++ b/drivers/tty/serial/aspeed-vuart.c @@ -0,0 +1,335 @@ +/* + * 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 "8250/8250.h" + +#define AST_VUART_GCRA 0x20 +#define AST_VUART_GCRA_VUART_EN 0x01 +#define AST_VUART_GCRA_HOST_TX_DISCARD 0x20 +#define AST_VUART_GCRB 0x24 +#define AST_VUART_GCRB_HOST_SIRQ_MASK 0xf0 +#define AST_VUART_GCRB_HOST_SIRQ_SHIFT 4 +#define AST_VUART_ADDRL 0x28 +#define AST_VUART_ADDRH 0x2c + +struct ast_vuart { + struct platform_device *pdev; + void __iomem *regs; + struct clk *clk; + int line; +}; + +static ssize_t ast_vuart_show_addr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ast_vuart *vuart = dev_get_drvdata(dev); + u16 addr; + + addr = (readb(vuart->regs + AST_VUART_ADDRH) << 8) | + (readb(vuart->regs + AST_VUART_ADDRL)); + + return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr); +} + +static ssize_t ast_vuart_set_addr(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ast_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + writeb((val >> 8) & 0xff, vuart->regs + AST_VUART_ADDRH); + writeb((val >> 0) & 0xff, vuart->regs + AST_VUART_ADDRL); + + return count; +} + +static DEVICE_ATTR(lpc_address, 0664, + ast_vuart_show_addr, ast_vuart_set_addr); + +static ssize_t ast_vuart_show_sirq(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ast_vuart *vuart = dev_get_drvdata(dev); + u8 reg; + + reg = readb(vuart->regs + AST_VUART_GCRB); + reg &= AST_VUART_GCRB_HOST_SIRQ_MASK; + reg >>= AST_VUART_GCRB_HOST_SIRQ_SHIFT; + + return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg); +} + +static ssize_t ast_vuart_set_sirq(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ast_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + u8 reg; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + val <<= AST_VUART_GCRB_HOST_SIRQ_SHIFT; + val &= AST_VUART_GCRB_HOST_SIRQ_MASK; + + reg = readb(vuart->regs + AST_VUART_GCRB); + reg &= ~AST_VUART_GCRB_HOST_SIRQ_MASK; + reg |= val; + writeb(reg, vuart->regs + AST_VUART_GCRB); + + return count; +} + +static DEVICE_ATTR(sirq, 0664, + ast_vuart_show_sirq, ast_vuart_set_sirq); + +static void ast_vuart_set_enabled(struct ast_vuart *vuart, bool enabled) +{ + u8 reg; + + reg = readb(vuart->regs + AST_VUART_GCRA); + reg &= ~AST_VUART_GCRA_VUART_EN; + if (enabled) + reg |= AST_VUART_GCRA_VUART_EN; + writeb(reg, vuart->regs + AST_VUART_GCRA); +} + +static void ast_vuart_set_host_tx_discard(struct ast_vuart *vuart, bool discard) +{ + u8 reg; + + reg = readb(vuart->regs + AST_VUART_GCRA); + + /* if the HOST_TX_DISCARD bit is set, discard is *disabled* */ + reg &= ~AST_VUART_GCRA_HOST_TX_DISCARD; + if (!discard) + reg |= AST_VUART_GCRA_HOST_TX_DISCARD; + + writeb(reg, vuart->regs + AST_VUART_GCRA); +} + +static int ast_vuart_startup(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct ast_vuart *vuart = uart_8250_port->port.private_data; + int rc; + + rc = serial8250_do_startup(uart_port); + if (rc) + return rc; + + ast_vuart_set_host_tx_discard(vuart, false); + + return 0; +} + +static void ast_vuart_shutdown(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct ast_vuart *vuart = uart_8250_port->port.private_data; + + ast_vuart_set_host_tx_discard(vuart, true); + + serial8250_do_shutdown(uart_port); +} + + +/** + * The device tree parsing code here is heavily based on that of the of_serial + * driver, but we have a few core differences, as we need to use our own + * ioremapping for extra register support + */ +static int ast_vuart_probe(struct platform_device *pdev) +{ + struct uart_8250_port port; + struct resource resource; + struct ast_vuart *vuart; + struct device_node *np; + u32 clk, prop; + int rc; + + np = pdev->dev.of_node; + + vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL); + if (!vuart) + return -ENOMEM; + + vuart->pdev = pdev; + rc = of_address_to_resource(np, 0, &resource); + if (rc) { + dev_warn(&pdev->dev, "invalid address\n"); + return rc; + } + + /* create our own mapping for VUART-specific registers */ + vuart->regs = devm_ioremap_resource(&pdev->dev, &resource); + if (IS_ERR(vuart->regs)) { + dev_warn(&pdev->dev, "failed to map registers\n"); + return PTR_ERR(vuart->regs); + } + + memset(&port, 0, sizeof(port)); + port.port.private_data = vuart; + port.port.membase = vuart->regs; + port.port.mapbase = resource.start; + port.port.mapsize = resource_size(&resource); + port.port.startup = ast_vuart_startup; + port.port.shutdown = ast_vuart_shutdown; + + 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; + if (of_property_read_u32(np, "reg-io-width", &prop) == 0) { + switch (prop) { + case 1: + port.port.iotype = UPIO_MEM; + break; + case 4: + port.port.iotype = of_device_is_big_endian(np) ? + UPIO_MEM32BE : UPIO_MEM32; + break; + default: + dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n", + prop); + rc = -EINVAL; + goto err_clk_disable; + } + } + + 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_find_property(np, "no-loopback-test", NULL)) + port.port.flags |= UPF_SKIP_TEST; + + port.port.dev = &pdev->dev; + + if (port.port.fifosize) + port.capabilities = UART_CAP_FIFO; + + if (of_property_read_bool(pdev->dev.of_node, + "auto-flow-control")) + port.capabilities |= UART_CAP_AFE; + + rc = serial8250_register_8250_port(&port); + if (rc < 0) + goto err_clk_disable; + + + vuart->line = rc; + ast_vuart_set_enabled(vuart, true); + ast_vuart_set_host_tx_discard(vuart, true); + platform_set_drvdata(pdev, vuart); + + /* extra sysfs control */ + rc = device_create_file(&pdev->dev, &dev_attr_lpc_address); + if (rc) + dev_warn(&pdev->dev, "can't create lpc_address file\n"); + rc = device_create_file(&pdev->dev, &dev_attr_sirq); + if (rc) + dev_warn(&pdev->dev, "can't create sirq file\n"); + + return 0; + +err_clk_disable: + if (vuart->clk) + clk_disable_unprepare(vuart->clk); + + irq_dispose_mapping(port.port.irq); + return rc; +} + +static int ast_vuart_remove(struct platform_device *pdev) +{ + struct ast_vuart *vuart = platform_get_drvdata(pdev); + + ast_vuart_set_enabled(vuart, false); + + if (vuart->clk) + clk_disable_unprepare(vuart->clk); + return 0; +} + +static const struct of_device_id ast_vuart_table[] = { + { .compatible = "aspeed,ast2400-vuart" }, + { .compatible = "aspeed,ast2500-vuart" }, + { }, +}; + +static struct platform_driver ast_vuart_driver = { + .driver = { + .name = "aspeed-vuart", + .of_match_table = ast_vuart_table, + }, + .probe = ast_vuart_probe, + .remove = ast_vuart_remove, +}; + +module_platform_driver(ast_vuart_driver); + +MODULE_AUTHOR("Jeremy Kerr "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Driver for Aspeed VUART device");