From fecf27a373f5a6b393e93b14f8460299b8abd6f9 Mon Sep 17 00:00:00 2001 From: Peter Hung Date: Tue, 28 Jul 2015 11:59:24 +0800 Subject: [PATCH] serial: 8250_pci: add RS485 for F81504/508/512 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 low with idle & RX, high with TX. When it set with 0x31, it's configured with RS485 mode. RTS is controlled by H/W, RTS high with idle & RX, low with TX. We will force 0x01 on pci_fintek_setup(). Signed-off-by: Peter Hung Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 61 ++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index e55f18b93fe7..df2e61e206fa 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1685,11 +1685,60 @@ pci_brcm_trumanage_setup(struct serial_private *priv, return ret; } +/* RTS will control by MCR if this bit is 0 */ +#define FINTEK_RTS_CONTROL_BY_HW BIT(4) +/* only worked with FINTEK_RTS_CONTROL_BY_HW on */ +#define FINTEK_RTS_INVERT BIT(5) + +/* We should do proper H/W transceiver setting before change to RS485 mode */ +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) + memset(rs485->padding, 0, sizeof(rs485->padding)); + else + memset(rs485, 0, sizeof(*rs485)); + + /* F81504/508/512 not support RTS delay before or after send */ + rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND; + + if (rs485->flags & SER_RS485_ENABLED) { + /* Enable RTS H/W control mode */ + setting |= FINTEK_RTS_CONTROL_BY_HW; + + if (rs485->flags & SER_RS485_RTS_ON_SEND) { + /* RTS driving high on TX */ + setting &= ~FINTEK_RTS_INVERT; + } else { + /* RTS driving low on TX */ + setting |= FINTEK_RTS_INVERT; + } + + rs485->delay_rts_after_send = 0; + rs485->delay_rts_before_send = 0; + } else { + /* Disable RTS H/W control mode */ + setting &= ~(FINTEK_RTS_CONTROL_BY_HW | FINTEK_RTS_INVERT); + } + + 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 +1751,15 @@ 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 +1810,9 @@ 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; -- 2.39.2