2015-07-24 05:55:46

by Ji-Ze Hong (Peter Hong)

[permalink] [raw]
Subject: [PATCH 1/1] 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 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 <[email protected]>
---
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


2015-07-25 09:35:53

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH 1/1] serial: 8250_pci: add RS485 for F81504/508/512

On Fri, 24 Jul 2015 13:55:39 +0800, Peter Hung wrote:
> 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 <[email protected]>
> ---
> 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);

This looks misaligned. 'dev' should be aligned with opening
parenthesis.

> +
> + 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);

Please add defines with the bit names.

> +
> + 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));
> + }

Please make sure you correct the rs485 configuration with what you can
actually support. Look at 8250_lpc18xx.c as an example. In your case
when the function returns it should have SER_RS485_ENABLED and one of
SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND set and nothing else
(or be completely zeroed if SER_RS485_ENABLED was not set).

2015-07-28 01:44:28

by Ji-Ze Hong (Peter Hong)

[permalink] [raw]
Subject: Re: [PATCH 1/1] serial: 8250_pci: add RS485 for F81504/508/512

Hi Jakub Kiciński,

Jakub Kiciński 於 2015/7/25 下午 05:35 寫道:
> Please make sure you correct the rs485 configuration with what you can
> actually support. Look at 8250_lpc18xx.c as an example. In your case
> when the function returns it should have SER_RS485_ENABLED and one of
> SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND set and nothing else
> (or be completely zeroed if SER_RS485_ENABLED was not set).
>

Thanks for your advice, I'll fix it and re-send patch

--
With Best Regards,
Peter Hung