From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752147AbbKGMWh (ORCPT ); Sat, 7 Nov 2015 07:22:37 -0500 Received: from mail-ig0-f175.google.com ([209.85.213.175]:34907 "EHLO mail-ig0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbbKGMWe (ORCPT ); Sat, 7 Nov 2015 07:22:34 -0500 Subject: Re: [PATCH v2 1/3] tty: Introduce UART_CAP_HW485 To: "Matwey V. Kornilov" References: <1446890976-1817-1-git-send-email-matwey@sai.msu.ru> Cc: gregkh@linuxfoundation.org, jslaby@suse.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, matwey.kornilov@gmail.com From: Peter Hurley Message-ID: <563DED05.9010004@hurleysoftware.com> Date: Sat, 7 Nov 2015 07:22:29 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1446890976-1817-1-git-send-email-matwey@sai.msu.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/07/2015 05:09 AM, Matwey V. Kornilov wrote: > Introduce new capability UART_CAP_HW485 to mark 8250 UARTs which have > hardware support of line direction control. Since capabilities are not exported to user-space, how will user-space know if the port only provides emulated 485 (eg., where only HW485 is acceptable)? Regards, Peter Hurley > Signed-off-by: Matwey V. Kornilov > --- > Changes since v1: > - Commit message has been wrapped > > drivers/tty/serial/8250/8250.h | 1 + > drivers/tty/serial/8250/8250_fintek.c | 1 + > drivers/tty/serial/8250/8250_lpc18xx.c | 1 + > drivers/tty/serial/8250/8250_pci.c | 1 + > 4 files changed, 4 insertions(+) > > diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h > index d54dcd8..92a4f47 100644 > --- a/drivers/tty/serial/8250/8250.h > +++ b/drivers/tty/serial/8250/8250.h > @@ -69,6 +69,7 @@ struct serial8250_config { > unsigned int flags; > }; > > +#define UART_CAP_HW485 (1 << 7) /* UART has hardware direction control for RS485 */ > #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */ > #define UART_CAP_EFR (1 << 9) /* UART has EFR */ > #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */ > diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c > index 8947439..f2831a8 100644 > --- a/drivers/tty/serial/8250/8250_fintek.c > +++ b/drivers/tty/serial/8250/8250_fintek.c > @@ -208,6 +208,7 @@ fintek_8250_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id) > uart.port.iobase = pnp_port_start(dev, 0); > uart.port.iotype = UPIO_PORT; > uart.port.rs485_config = fintek_8250_rs485_config; > + uart.capabilities = UART_CAP_HW485; > > uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF; > if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE) > diff --git a/drivers/tty/serial/8250/8250_lpc18xx.c b/drivers/tty/serial/8250/8250_lpc18xx.c > index 99cd478..9d30276 100644 > --- a/drivers/tty/serial/8250/8250_lpc18xx.c > +++ b/drivers/tty/serial/8250/8250_lpc18xx.c > @@ -175,6 +175,7 @@ static int lpc18xx_serial_probe(struct platform_device *pdev) > uart.port.private_data = data; > uart.port.rs485_config = lpc18xx_rs485_config; > uart.port.serial_out = lpc18xx_uart_serial_out; > + uart.capabilities = UART_CAP_HW485; > > uart.dma = &data->dma; > uart.dma->rxconf.src_maxburst = 1; > diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c > index 4097f3f..c7c0ae9 100644 > --- a/drivers/tty/serial/8250/8250_pci.c > +++ b/drivers/tty/serial/8250/8250_pci.c > @@ -1599,6 +1599,7 @@ static int pci_fintek_setup(struct serial_private *priv, > port->port.iotype = UPIO_PORT; > port->port.iobase = iobase; > port->port.rs485_config = pci_fintek_rs485_config; > + port->capabilities = UART_CAP_HW485; > > data = devm_kzalloc(&pdev->dev, sizeof(u8), GFP_KERNEL); > if (!data) >