From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hung Subject: [PATCH 1/1] serial: 8250_pci: add RS485 for F81504/508/512 Date: Fri, 24 Jul 2015 13:55:39 +0800 Message-ID: <1437717339-28881-1-git-send-email-hpeter+linux_kernel@gmail.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: gregkh@linuxfoundation.org Cc: jslaby@suse.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, tom_tsai@fintek.com.tw, peter_hong@fintek.com.tw, Peter Hung List-Id: linux-serial@vger.kernel.org Add RS485 control for Fintek F81504/508/512 F81504/508/512 can control their RTS with H/W mode. PCI configuration space for each port is 0x40 + idx * 8 + 7. When it set with 0x01, it's configured with RS232 mode. RTS is controlled by MCR. When it set with 0x11, it's configured with RS485 mode. RTS is controlled by H/W, RTS high with idle & RX, low with TX. When it set with 0x31, it's configured with RS485 mode. RTS is controlled by H/W, RTS low with idle & RX, high with TX. We will force 0x01 on pci_fintek_setup(). Signed-off-by: Peter Hung --- drivers/tty/serial/8250/8250_pci.c | 44 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index e55f18b..36280fa 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1685,11 +1685,43 @@ pci_brcm_trumanage_setup(struct serial_private *priv, return ret; } +static int pci_fintek_rs485_config(struct uart_port *port, + struct serial_rs485 *rs485) +{ + u8 setting; + u8 *index = (u8 *) port->private_data; + struct pci_dev *pci_dev = container_of(port->dev, struct pci_dev, + dev); + + pci_read_config_byte(pci_dev, 0x40 + 8 * *index + 7, &setting); + + if (rs485->flags & SER_RS485_ENABLED) { + /* Enable RTS H/W control mode */ + setting |= BIT(4); + + if (rs485->flags & SER_RS485_RTS_ON_SEND) { + /* RTS driving high on TX */ + setting |= BIT(5); + } else { + /* RTS driving low on TX */ + setting &= ~BIT(5); + } + } else { + /* Disable RTS H/W control mode */ + setting &= ~(BIT(4) | BIT(5)); + } + + pci_write_config_byte(pci_dev, 0x40 + 8 * *index + 7, setting); + port->rs485 = *rs485; + return 0; +} + static int pci_fintek_setup(struct serial_private *priv, const struct pciserial_board *board, struct uart_8250_port *port, int idx) { struct pci_dev *pdev = priv->dev; + u8 *data; u8 config_base; u16 iobase; @@ -1702,6 +1734,15 @@ 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; + + data = devm_kzalloc(&pdev->dev, sizeof(u8), GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* preserve index in PCI configuration space */ + *data = idx; + port->port.private_data = data; return 0; } @@ -1752,6 +1793,9 @@ static int pci_fintek_init(struct pci_dev *dev) (u8)((iobase & 0xff00) >> 8)); pci_write_config_byte(dev, config_base + 0x06, dev->irq); + + /* force init to RS232 Mode */ + pci_write_config_byte(dev, config_base + 0x07, 0x01); } return max_port; -- 1.9.1