From patchwork Thu Apr 30 18:49:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 11521193 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F88A1392 for ; Thu, 30 Apr 2020 18:49:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F5892082E for ; Thu, 30 Apr 2020 18:49:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588272590; bh=Z6DECa7N8G4+bwjZsfqnOxuuzgQZyt8hmyoOawef5xs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EzkzpVzGs21BeQ6hgutLSZnhJKWvA2wx34CJAvZ81k/F/2vRCMPoyqiet3WqNSoMS tANLHVH59oVtdNNIZnQPz1sNZKAw8nVVasOChRabMJ96cq5+j/+eHPeiEeccVFg6tG cZ/2V31ea/0S5Js9vbXiad/dYAsx26qcsQFlpkvA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726778AbgD3Str (ORCPT ); Thu, 30 Apr 2020 14:49:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:33224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726520AbgD3Stq (ORCPT ); Thu, 30 Apr 2020 14:49:46 -0400 Received: from localhost.localdomain (unknown [157.46.61.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BC87F2082E; Thu, 30 Apr 2020 18:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588272585; bh=Z6DECa7N8G4+bwjZsfqnOxuuzgQZyt8hmyoOawef5xs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FpLxQ6NR39VtsF7sVE7koAHKegDdLo317LgxLx6dQHfz5lvwHPrTqQ3So9NUuLaSE 76TfWZBSHsdO4MfDUu0PZNOgir/Fy/OxSwocrA00jYrJlUEx5Oez0kDqcmPGu/9rLz 8S75MG8mWvu65KDHrBoipBMLFdVybMw6KUbstnaA= From: mani@kernel.org To: johan@kernel.org, gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, patong.mxl@gmail.com, Manivannan Sadhasivam , Linus Walleij , linux-gpio@vger.kernel.org Subject: [PATCH v3 2/2] usb: serial: xr_serial: Add gpiochip support Date: Fri, 1 May 2020 00:19:24 +0530 Message-Id: <20200430184924.31690-3-mani@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200430184924.31690-1-mani@kernel.org> References: <20200430184924.31690-1-mani@kernel.org> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Manivannan Sadhasivam Add gpiochip support for Maxlinear/Exar USB to serial converter for controlling the available gpios. Cc: Linus Walleij Cc: linux-gpio@vger.kernel.org Reviewed-by: Linus Walleij Signed-off-by: Manivannan Sadhasivam --- drivers/usb/serial/xr_serial.c | 199 ++++++++++++++++++++++++++++++++- 1 file changed, 198 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c index fdb9ddf8bd95..255a30540b52 100644 --- a/drivers/usb/serial/xr_serial.c +++ b/drivers/usb/serial/xr_serial.c @@ -7,6 +7,7 @@ * Copyright (c) 2020 Manivannan Sadhasivam */ +#include #include #include #include @@ -32,6 +33,11 @@ struct xr_uart_regs { }; struct xr_port_private { +#ifdef CONFIG_GPIOLIB + struct gpio_chip gc; + bool gpio_registered; + u8 gpio_altfunc; +#endif const struct xr_uart_regs *regs; }; @@ -562,6 +568,196 @@ static void xr_break_ctl(struct tty_struct *tty, int break_state) state); } +#ifdef CONFIG_GPIOLIB + +static int xr_gpio_request(struct gpio_chip *gc, unsigned int offset) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + /* Check if the requested GPIO is occupied */ + if (port_priv->gpio_altfunc & BIT(offset)) + return -ENODEV; + + return 0; +} + +static int xr_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u8 gpio_status; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_status, &gpio_status); + if (ret) + return ret; + + return !!(gpio_status & BIT(gpio)); +} + +static void xr_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + if (val) + xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_set, BIT(gpio)); + else + xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_clr, BIT(gpio)); +} + +static int xr_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u8 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + /* Logic 0 = input and Logic 1 = output */ + return !(gpio_dir & BIT(gpio)); +} + +static int xr_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u8 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + gpio_dir &= ~BIT(gpio); + + return xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, gpio_dir); +} + +static int xr_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio, + int val) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u8 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + gpio_dir |= BIT(gpio); + + ret = xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, gpio_dir); + if (ret) + return ret; + + xr_gpio_set(gc, gpio, val); + + return 0; +} + +static int xr21v141x_gpio_init(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u8 gpio_mode; + + port_priv->gc.ngpio = 6; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_mode, &gpio_mode); + if (ret) + return ret; + + /* Mark all pins which are not in GPIO mode */ + if (gpio_mode & UART_MODE_RTS_CTS) + port_priv->gpio_altfunc |= (BIT(4) | BIT(5)); + else if (gpio_mode & UART_MODE_DTR_DSR) + port_priv->gpio_altfunc |= (BIT(2) | BIT(3)); + else if (gpio_mode & UART_MODE_RS485) + port_priv->gpio_altfunc |= BIT(5); + else if (gpio_mode & UART_MODE_RS485_ADDR) + port_priv->gpio_altfunc |= BIT(5); + else + port_priv->gpio_altfunc = 0; /* All GPIOs are available */ + + return ret; +} + +static int xr_gpio_init(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + struct usb_serial *serial = port->serial; + int ret = 0; + u16 pid; + + /* Don't register gpiochip for interface 0 */ + if (port->minor == 0) + return ret; + + pid = le16_to_cpu(serial->dev->descriptor.idProduct); + + ret = xr21v141x_gpio_init(port); + if (ret < 0) + return ret; + + port_priv->gc.label = devm_kasprintf(&port->dev, GFP_KERNEL, "XR%04x", + pid); + port_priv->gc.request = xr_gpio_request; + port_priv->gc.get_direction = xr_gpio_direction_get; + port_priv->gc.direction_input = xr_gpio_direction_input; + port_priv->gc.direction_output = xr_gpio_direction_output; + port_priv->gc.get = xr_gpio_get; + port_priv->gc.set = xr_gpio_set; + port_priv->gc.owner = THIS_MODULE; + port_priv->gc.parent = &port->dev; + port_priv->gc.base = -1; + port_priv->gc.can_sleep = true; + + ret = gpiochip_add_data(&port_priv->gc, port); + if (!ret) + port_priv->gpio_registered = true; + + return ret; +} + +static void xr_gpio_remove(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + if (port_priv->gpio_registered) { + gpiochip_remove(&port_priv->gc); + port_priv->gpio_registered = false; + } +} + +#else + +static int xr_gpio_init(struct usb_serial_port *port) +{ + return 0; +} + +static void xr_gpio_remove(struct usb_serial_port *port) +{ + /* Nothing to do */ +} + +#endif + static int xr_port_probe(struct usb_serial_port *port) { struct xr_port_private *port_priv; @@ -575,13 +771,14 @@ static int xr_port_probe(struct usb_serial_port *port) usb_set_serial_port_data(port, port_priv); - return 0; + return xr_gpio_init(port); } static int xr_port_remove(struct usb_serial_port *port) { struct xr_port_private *port_priv = usb_get_serial_port_data(port); + xr_gpio_remove(port); kfree(port_priv); return 0;