From patchwork Thu Jan 24 10:30:36 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lv Zheng X-Patchwork-Id: 2027681 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id CDA7AE00CF for ; Thu, 24 Jan 2013 02:30:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753135Ab3AXCam (ORCPT ); Wed, 23 Jan 2013 21:30:42 -0500 Received: from mga14.intel.com ([143.182.124.37]:9281 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753071Ab3AXCal (ORCPT ); Wed, 23 Jan 2013 21:30:41 -0500 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 23 Jan 2013 18:30:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,525,1355126400"; d="scan'208";a="247728606" Received: from unknown (HELO z530.sh.intel.com) ([10.239.36.152]) by azsmga001.ch.intel.com with ESMTP; 23 Jan 2013 18:30:38 -0800 From: Lv Zheng To: Greg Kroah-Hartman , Alan Cox , Rafael J Wysocki , Len Brown , Mika Westerberg Cc: linux-acpi@vger.kernel.org, linux-serial@vger.kernel.org, Lv Zheng Subject: [PATCH v5 2/2] ACPI / UART: Add ACPI enumeration support for UART Date: Thu, 24 Jan 2013 18:30:36 +0800 Message-Id: X-Mailer: git-send-email 1.7.10 In-Reply-To: References: Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org ACPI 5.0 specification introduces mechanisms of enumerating the slave devices connected on the serial buses. This patch follows the specification, implementing such UART enumeration machanism for Linux. In order to use this UART device enumeration mechanism, driver writers are required to call the following API: Call acpi_tty_register_devices _after_ the creation of the tty ports: tty_port_register_device(port, driver, i, parent); acpi_uart_register_devices(port); Where: port: the registered tty port. parent: the physical device of the UART ports. driver and index: required parameters for tty_port_register_device. In this patch, only SERIAL_CORE drivers are enabled to use this ACPI UART enumeration mechanism. This can be changed if there are needs updated in the future. Signed-off-by: Lv Zheng --- drivers/acpi/Kconfig | 6 ++ drivers/acpi/Makefile | 1 + drivers/acpi/acpi_uart.c | 215 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/tty/tty_enum.c | 1 + include/linux/tty.h | 8 ++ 5 files changed, 231 insertions(+) create mode 100644 drivers/acpi/acpi_uart.c diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 38c5078..98e2d4e 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -187,6 +187,12 @@ config ACPI_I2C help ACPI I2C enumeration support. +config ACPI_UART + def_tristate TTY_ENUM + depends on TTY_ENUM + help + ACPI UART enumeration support. + config ACPI_PROCESSOR tristate "Processor" select THERMAL diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 2a4502b..784f332 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -71,6 +71,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o obj-$(CONFIG_ACPI_I2C) += acpi_i2c.o +obj-$(CONFIG_ACPI_UART) += acpi_uart.o # processor has its own "processor." module_param namespace processor-y := processor_driver.o processor_throttling.o diff --git a/drivers/acpi/acpi_uart.c b/drivers/acpi/acpi_uart.c new file mode 100644 index 0000000..6b1842a --- /dev/null +++ b/drivers/acpi/acpi_uart.c @@ -0,0 +1,215 @@ +/* + * acpi_uart.c - ACPI UART enumeration support + * + * Copyright (c) 2012, Intel Corporation + * Author: Lv Zheng + * + * 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; version 2 of the License. + */ + +#include +#include +#include +#include +#include +#include + + +static int acpi_uart_add_resources(struct acpi_resource *ares, void *context) +{ + struct tty_board_info *info = context; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_uart_serialbus *sb; + + sb = &ares->data.uart_serial_bus; + if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART) + return 1; + + /* baud rate */ + info->baud = sb->default_baud_rate; + + /* data bits */ + info->cflag &= ~CSIZE; + switch (sb->data_bits) { + case ACPI_UART_5_DATA_BITS: + info->cflag |= CS5; + break; + case ACPI_UART_6_DATA_BITS: + info->cflag |= CS6; + break; + case ACPI_UART_7_DATA_BITS: + info->cflag |= CS7; + break; + case ACPI_UART_8_DATA_BITS: + default: + info->cflag |= CS8; + break; + } + + /* parity */ + info->cflag &= ~(PARENB | PARODD); + if (sb->parity == ACPI_UART_PARITY_EVEN) + info->cflag |= PARENB; + else if (sb->parity == ACPI_UART_PARITY_ODD) + info->cflag |= (PARENB | PARODD); + + /* stop bits */ + if (sb->stop_bits == ACPI_UART_2_STOP_BITS) + info->cflag |= CSTOPB; + else + info->cflag &= ~CSTOPB; + + /* HW control */ + if (sb->flow_control & ACPI_UART_FLOW_CONTROL_HW) + info->cflag |= CRTSCTS; + else + info->cflag &= ~CRTSCTS; + + /* SW control */ + if (sb->flow_control & ACPI_UART_FLOW_CONTROL_XON_XOFF) + info->iflag |= (IXON | IXOFF); + else + info->iflag &= ~(IXON|IXOFF|IXANY); + + /* endianess */ + if (sb->endian == ACPI_UART_LITTLE_ENDIAN) + info->mctrl |= TIOCM_LE; + else + info->mctrl &= ~TIOCM_LE; + + /* terminal lines */ + if (sb->lines_enabled & ACPI_UART_DATA_TERMINAL_READY) + info->mctrl |= TIOCM_DTR; + else + info->mctrl &= ~TIOCM_DTR; + if (sb->lines_enabled & ACPI_UART_REQUEST_TO_SEND) + info->mctrl |= TIOCM_RTS; + else + info->mctrl &= ~TIOCM_RTS; + + /* modem lines */ + if (sb->lines_enabled & ACPI_UART_CLEAR_TO_SEND) + info->mctrl |= TIOCM_CTS; + else + info->mctrl &= ~TIOCM_CTS; + if (sb->lines_enabled & ACPI_UART_CARRIER_DETECT) + info->mctrl |= TIOCM_CAR; + else + info->mctrl &= ~TIOCM_CAR; + if (sb->lines_enabled & ACPI_UART_RING_INDICATOR) + info->mctrl |= TIOCM_RNG; + else + info->mctrl &= ~TIOCM_RNG; + if (sb->lines_enabled & ACPI_UART_DATA_SET_READY) + info->mctrl |= TIOCM_DSR; + else + info->mctrl &= ~TIOCM_DSR; + } else if (info->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + info->irq = r.start; + } + + return 1; +} + +static acpi_status acpi_uart_add_device(acpi_handle handle, u32 level, + void *context, void **return_value) +{ + struct tty_port *port = context; + struct tty_board_info *board_info; + struct acpi_device *adev; + struct list_head resource_list; + int ret; + struct tty_slave *tts; + int nr_ids, i; + size_t info_size; + struct acpi_hardware_id *id; + char node_name[5]; + struct acpi_buffer buffer = { sizeof(node_name), node_name }; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + /* Allocate board info structure. */ + nr_ids = 0; + list_for_each_entry(id, &adev->pnp.ids, list) + nr_ids++; + info_size = sizeof(struct tty_board_info) + (TTY_NAME_SIZE * nr_ids); + board_info = kzalloc(info_size, GFP_KERNEL); + if (!board_info) + return AE_OK; + + /* Enumerate resources. */ + board_info->acpi_node.handle = handle; + board_info->irq = -1; + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_uart_add_resources, board_info); + acpi_dev_free_resource_list(&resource_list); + if (ret < 0 || !board_info->baud) + goto fail; + + /* Use ACPI node name as device name. */ + acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); + strlcpy(board_info->type, node_name, TTY_NAME_SIZE); + + /* Store PnP IDs. */ + i = 0; + list_for_each_entry(id, &adev->pnp.ids, list) { + if (i >= nr_ids) + break; + strlcpy(board_info->ids[i], id->id, TTY_NAME_SIZE); + i++; + } + board_info->nr_ids = nr_ids; + + tts = tty_bus_register_slave(port, board_info); + if (!tts) + dev_err(&adev->dev, "failed to add %s UART device from ACPI\n", + dev_name(&adev->dev)); + +fail: + kfree(board_info); + return AE_OK; +} + +static struct device *acpi_uart_port_parent(struct tty_port *port) +{ + return port->dev ? port->dev->parent : NULL; +} + +/** + * acpi_uart_register_devices - register the uart slave devices behind the + * tty port + * @port: the host tty port + * + * Enumerate all tty slave devices behind the host device by walking the + * ACPI namespace. When a device is found, it will be added to the Linux + * device model and bound to the corresponding ACPI handle. + */ +void acpi_uart_register_devices(struct tty_port *port) +{ + acpi_handle handle; + acpi_status status; + struct device *dev; + + dev = acpi_uart_port_parent(port); + if (!dev) + return; + handle = ACPI_HANDLE(dev); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_uart_add_device, NULL, port, NULL); + if (ACPI_FAILURE(status)) + dev_warn(dev, "failed to enumerate UART slaves\n"); +} +EXPORT_SYMBOL_GPL(acpi_uart_register_devices); diff --git a/drivers/tty/tty_enum.c b/drivers/tty/tty_enum.c index 7947f47..2218629 100644 --- a/drivers/tty/tty_enum.c +++ b/drivers/tty/tty_enum.c @@ -260,6 +260,7 @@ struct tty_slave *tty_bus_register_slave(struct tty_port *port, tts->dev.parent = dev; tts->dev.bus = &tty_enum_bus; tts->dev.type = &tty_slave_type; + ACPI_HANDLE_SET(&tts->dev, info->acpi_node.handle); tts->dev.platform_data = info->platform_data; if (info->archdata) diff --git a/include/linux/tty.h b/include/linux/tty.h index b8d5dfb..8b60e47 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -172,6 +172,7 @@ struct tty_board_info; * @irq: stored in tty_slave.irq * @platform_data: stored in tty_slave.dev.platform_data * @archdata: copied into tty_slave.dev.archdata + * @acpi_node: ACPI device node * @nr_ids: number of IDs * @ids: ID strings * @@ -189,6 +190,7 @@ struct tty_board_info { int irq; void *platform_data; struct dev_archdata *archdata; + struct acpi_dev_node acpi_node; int nr_ids; /* This must be the last member of tty_board_info */ @@ -763,4 +765,10 @@ do { \ } while (0) +#if IS_ENABLED(CONFIG_ACPI_UART) +void acpi_uart_register_devices(struct tty_port *port); +#else +static inline void acpi_uart_register_devices(struct tty_port *port) {} +#endif + #endif