From patchwork Mon Jul 17 15:24:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ulrich Hecht X-Patchwork-Id: 789572 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xB6Y62DXBz9sxR for ; Tue, 18 Jul 2017 01:24:58 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="EKPQOYhm"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751357AbdGQPY4 (ORCPT ); Mon, 17 Jul 2017 11:24:56 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35034 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751343AbdGQPYy (ORCPT ); Mon, 17 Jul 2017 11:24:54 -0400 Received: by mail-wm0-f68.google.com with SMTP id u23so23732389wma.2; Mon, 17 Jul 2017 08:24:53 -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=osoxWFSUreGpo5xQOO93Vl189No3LM/CVlvkyI9T2Qs=; b=EKPQOYhmoPW7f6xOe1u6kX1ciQwx9RvwgQoDPTl+aSWMhe3XpgT0t9UObNDMI7Iimz lgfFg0BDXmU7dAdgYQBOLwDOZ62YxOP7iEpnz0XN66PbfF70miBTGTk100yZeLnMSQly kgf8CpbNmWWU5NrJBjvGvatKQfgUgYpajK9LehT4kQnFKu3wOINIjJcNCghSrpufzn4O KGUTje+UDU1bMi0kkudsISQ4yR3CVb3Ou42EJQYc0t8L1CPGGPxw1ph1vQGK82i4uWuY dLpqo7P+yxU5l756p9g0BLQ7R/AZe2kJPaXogLI9jR6op2PJTQw4MB8NLHA8lCWT7Icx elzA== 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=osoxWFSUreGpo5xQOO93Vl189No3LM/CVlvkyI9T2Qs=; b=gfpFn1fLapE8hQaXhRKfUqeBC0VVy4dcbUS3UH3lhAtpueFjw7jXgin3CDwOahinZE qLncMki0EPtRx9QzD/gsbok4evnI7LlYW4p0HZoeLFgAOKzzhk9PqpxNoZKCIvFkqpBc 1/8EYJGTJarbvJoBkdwaJvqG0C14HcqTvBvqTx2uPgo9czLXnGHsPzCJkVnRXbsHD8Yc XtqUc5vHN/PNmZlEHqbQVO9Py9N5MQmGxpFtutJz+d1EDweQX3ZBVBowGubzqN4NdYd/ HMqnP+RvDEq+DJe+sdRYp3W3X5HEcTVNcHorDKwsNWKwAQOrQBwqPRLiBceEhg8y6SlF NcYw== X-Gm-Message-State: AIVw112/1dbTobtev4zDydtpYEGUHF+PeVaJL5hmUiFJXE0diZbsprRl 3J4AwaxZjNqHLQLE/04= X-Received: by 10.28.98.66 with SMTP id w63mr4524156wmb.34.1500305092506; Mon, 17 Jul 2017 08:24:52 -0700 (PDT) Received: from groucho.site (ipbcc169a0.dynamic.kabel-deutschland.de. [188.193.105.160]) by smtp.gmail.com with ESMTPSA id 13sm10802102wrl.57.2017.07.17.08.24.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 17 Jul 2017 08:24:51 -0700 (PDT) From: Ulrich Hecht To: linux-serial@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, magnus.damm@gmail.com, laurent.pinchart@ideasonboard.com, wsa@the-dreams.de, robh@kernel.org, peda@axentia.se, geert@linux-m68k.org, linux-i2c@vger.kernel.org, Ulrich Hecht Subject: [RFC v2 3/6] serdev: add multiplexer support Date: Mon, 17 Jul 2017 17:24:33 +0200 Message-Id: <1500305076-15570-4-git-send-email-ulrich.hecht+renesas@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1500305076-15570-1-git-send-email-ulrich.hecht+renesas@gmail.com> References: <1500305076-15570-1-git-send-email-ulrich.hecht+renesas@gmail.com> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Adds an interface for slave device multiplexing using the mux subsystem. Signed-off-by: Ulrich Hecht --- drivers/tty/serdev/Kconfig | 3 +++ drivers/tty/serdev/Makefile | 1 + drivers/tty/serdev/core.c | 14 +++++++++- drivers/tty/serdev/mux.c | 66 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/serdev.h | 16 ++++++++--- 5 files changed, 96 insertions(+), 4 deletions(-) create mode 100644 drivers/tty/serdev/mux.c diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig index cdc6b82..9096b71 100644 --- a/drivers/tty/serdev/Kconfig +++ b/drivers/tty/serdev/Kconfig @@ -13,4 +13,7 @@ config SERIAL_DEV_CTRL_TTYPORT depends on TTY depends on SERIAL_DEV_BUS != m +config SERIAL_DEV_MUX + bool "Serial device multiplexer support" + endif diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile index 0cbdb94..d713381 100644 --- a/drivers/tty/serdev/Makefile +++ b/drivers/tty/serdev/Makefile @@ -1,5 +1,6 @@ serdev-objs := core.o obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o +obj-$(CONFIG_SERIAL_DEV_MUX) += mux.o obj-$(CONFIG_SERIAL_DEV_CTRL_TTYPORT) += serdev-ttyport.o diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index 1fbaa4c..92c5bfa 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -305,7 +305,8 @@ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) return NULL; serdev->ctrl = ctrl; - ctrl->serdev = serdev; + if (!ctrl->serdev) + ctrl->serdev = serdev; device_initialize(&serdev->dev); serdev->dev.parent = &ctrl->dev; serdev->dev.bus = &serdev_bus_type; @@ -368,6 +369,8 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl) struct serdev_device *serdev = NULL; int err; bool found = false; + int nr = 0; + u32 reg; for_each_available_child_of_node(ctrl->dev.of_node, node) { if (!of_get_property(node, "compatible", NULL)) @@ -380,6 +383,10 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl) continue; serdev->dev.of_node = node; + serdev->nr = nr++; + + if (!of_property_read_u32(node, "reg", ®)) + serdev->mux_addr = reg; err = serdev_device_add(serdev); if (err) { @@ -414,6 +421,11 @@ int serdev_controller_add(struct serdev_controller *ctrl) if (ret) return ret; +#ifdef CONFIG_SERIAL_DEV_MUX + if (of_serdev_register_mux(ctrl) == -EPROBE_DEFER) + return -EPROBE_DEFER; +#endif + ret = of_serdev_register_devices(ctrl); if (ret) goto out_dev_del; diff --git a/drivers/tty/serdev/mux.c b/drivers/tty/serdev/mux.c new file mode 100644 index 0000000..fc9405b --- /dev/null +++ b/drivers/tty/serdev/mux.c @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2017 Ulrich Hecht + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include + +int serdev_device_mux_select(struct serdev_device *serdev) +{ + struct mux_control *mux = serdev->ctrl->mux; + int ret; + + if (!mux) + return -EINVAL; + + ret = mux_control_select(mux, serdev->mux_addr); + serdev->ctrl->mux_do_not_deselect = ret < 0; + + serdev->ctrl->serdev = serdev; + + return ret; +} + +int serdev_device_mux_deselect(struct serdev_device *serdev) +{ + struct mux_control *mux = serdev->ctrl->mux; + + if (!mux) + return -EINVAL; + + if (!serdev->ctrl->mux_do_not_deselect) + return mux_control_deselect(mux); + else + return 0; +} + +int of_serdev_register_mux(struct serdev_controller *ctrl) +{ + struct mux_control *mux; + struct device *dev = &ctrl->dev; + + mux = devm_mux_control_get(dev, NULL); + + if (IS_ERR(mux)) { + if (PTR_ERR(mux) != -EPROBE_DEFER) + dev_err(dev, "failed to get control mux\n"); + return PTR_ERR(mux); + } + + ctrl->mux = mux; + + return 0; +} + diff --git a/include/linux/serdev.h b/include/linux/serdev.h index 8b67fcd..26d5994 100644 --- a/include/linux/serdev.h +++ b/include/linux/serdev.h @@ -17,6 +17,7 @@ #include #include #include +#include struct serdev_controller; struct serdev_device; @@ -51,6 +52,7 @@ struct serdev_device { const struct serdev_device_ops *ops; struct completion write_comp; struct mutex write_lock; + int mux_addr; }; static inline struct serdev_device *to_serdev_device(struct device *d) @@ -76,6 +78,8 @@ static inline struct serdev_device_driver *to_serdev_device_driver(struct device return container_of(d, struct serdev_device_driver, driver); } +int of_serdev_register_mux(struct serdev_controller *ctrl); + /* * serdev controller structures */ @@ -97,14 +101,18 @@ struct serdev_controller_ops { * struct serdev_controller - interface to the serdev controller * @dev: Driver model representation of the device. * @nr: number identifier for this controller/bus. - * @serdev: Pointer to slave device for this controller. + * @serdev: Pointer to active slave device for this controller. * @ops: Controller operations. + * @mux: Slave multiplexer control. + * @mux_do_not_deselect: Set if slave selection failed. */ struct serdev_controller { struct device dev; unsigned int nr; struct serdev_device *serdev; const struct serdev_controller_ops *ops; + struct mux_control *mux; + int mux_do_not_deselect; }; static inline struct serdev_controller *to_serdev_controller(struct device *d) @@ -172,7 +180,7 @@ static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl { struct serdev_device *serdev = ctrl->serdev; - if (!serdev || !serdev->ops->write_wakeup) + if (!serdev || !serdev->ops || !serdev->ops->write_wakeup) return; serdev->ops->write_wakeup(serdev); @@ -184,7 +192,7 @@ static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl, { struct serdev_device *serdev = ctrl->serdev; - if (!serdev || !serdev->ops->receive_buf) + if (!serdev || !serdev->ops || !serdev->ops->receive_buf) return -EINVAL; return serdev->ops->receive_buf(serdev, data, count); @@ -204,6 +212,8 @@ void serdev_device_write_wakeup(struct serdev_device *); int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long); void serdev_device_write_flush(struct serdev_device *); int serdev_device_write_room(struct serdev_device *); +int serdev_device_mux_select(struct serdev_device *); +int serdev_device_mux_deselect(struct serdev_device *); /* * serdev device driver functions