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Message-ID: <20171218151829.GB3374@localhost>
Date: Mon, 18 Dec 2017 16:18:29 +0100
From: Johan Hovold <johan@...nel.org>
To: "Ji-Ze Hong (Peter Hong)" <hpeter@...il.com>
Cc: johan@...nel.org, gregkh@...uxfoundation.org,
linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
"Ji-Ze Hong (Peter Hong)" <hpeter+linux_kernel@...il.com>
Subject: Re: [PATCH V1 2/4] usb: serial: f81534: add auto RTS direction
support
On Thu, Nov 16, 2017 at 03:46:07PM +0800, Ji-Ze Hong (Peter Hong) wrote:
> The F81532/534 had auto RTS direction support for RS485 mode.
> We'll read it from internal Flash with address 0x2f01~0x2f04 for 4 ports.
> There are 4 conditions below:
> 0: F81534_PORT_CONF_RS232.
> 1: F81534_PORT_CONF_RS485.
> 2: value error, default to F81534_PORT_CONF_RS232.
> 3: F81534_PORT_CONF_RS485_INVERT.
>
> F81532/534 Clock register (offset +08h)
>
> Bit0: UART Enable (always on)
> Bit2-1: Clock source selector
> 00: 1.846MHz.
> 01: 18.46MHz.
> 10: 24MHz.
> 11: 14.77MHz.
> Bit4: Auto direction(RTS) control (RTS pin Low when TX)
> Bit5: Invert direction(RTS) when Bit4 enabled (RTS pin high when TX)
>
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@...il.com>
> ---
> drivers/usb/serial/f81534.c | 54 +++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 52 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c
> index 76c676ef5f0d..b2d10309c335 100644
> --- a/drivers/usb/serial/f81534.c
> +++ b/drivers/usb/serial/f81534.c
> @@ -102,11 +102,16 @@
>
> #define F81534_DEFAULT_BAUD_RATE 9600
>
> +#define F81534_PORT_CONF_RS232 0
> +#define F81534_PORT_CONF_RS485 BIT(0)
> +#define F81534_PORT_CONF_RS485_INVERT (BIT(0) | BIT(1))
> #define F81534_PORT_CONF_DISABLE_PORT BIT(3)
> #define F81534_PORT_CONF_NOT_EXIST_PORT BIT(7)
> #define F81534_PORT_UNAVAILABLE \
> (F81534_PORT_CONF_DISABLE_PORT | F81534_PORT_CONF_NOT_EXIST_PORT)
>
> +#define F81534_UART_MODE_MASK (BIT(0) | BIT(1))
> +
> #define F81534_1X_RXTRIGGER 0xc3
> #define F81534_8X_RXTRIGGER 0xcf
>
> @@ -119,6 +124,8 @@
> * 01: 18.46MHz.
> * 10: 24MHz.
> * 11: 14.77MHz.
> + * Bit4: Auto direction(RTS) control (RTS pin Low when TX)
> + * Bit5: Invert direction(RTS) when Bit4 enabled (RTS pin high when TX)
> */
>
> #define F81534_CLK_1_846_MHZ BIT(0)
> @@ -126,6 +133,9 @@
> #define F81534_CLK_24_MHZ (BIT(0) | BIT(2))
> #define F81534_CLK_14_77_MHZ (BIT(0) | BIT(1) | BIT(2))
>
> +#define F81534_CLK_RS485_MODE BIT(4)
> +#define F81534_CLK_RS485_INVERT BIT(5)
> +
> static const struct usb_device_id f81534_id_table[] = {
> { USB_DEVICE(FINTEK_VENDOR_ID_1, FINTEK_DEVICE_ID) },
> { USB_DEVICE(FINTEK_VENDOR_ID_2, FINTEK_DEVICE_ID) },
> @@ -485,16 +495,20 @@ static int f81534_set_port_config(struct usb_serial_port *port,
> struct tty_struct *tty, u32 baudrate, u32 old_baudrate, u8 lcr)
> {
> struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
> + struct f81534_serial_private *serial_priv;
> u32 divisor;
> int status;
> int idx;
> u8 value;
> + u8 tmp;
> static u32 const baudrate_table[] = {115200, 921600, 1152000,
> 1500000};
> static u8 const clock_table[] = {F81534_CLK_1_846_MHZ,
> F81534_CLK_14_77_MHZ, F81534_CLK_18_46_MHZ,
> F81534_CLK_24_MHZ};
>
> + serial_priv = usb_get_serial_data(port->serial);
> +
> do {
> for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {
> if (baudrate <= baudrate_table[idx] &&
> @@ -520,8 +534,25 @@ static int f81534_set_port_config(struct usb_serial_port *port,
> } while (1);
>
> port_priv->baud_base = baudrate_table[idx];
> - status = f81534_set_port_register(port, F81534_CLOCK_REG,
> - clock_table[idx]);
> + tmp = serial_priv->conf_data[port_priv->phy_num];
> +
> + switch (tmp & F81534_UART_MODE_MASK) {
> + case F81534_PORT_CONF_RS485_INVERT:
> + value = F81534_CLK_RS485_MODE | F81534_CLK_RS485_INVERT;
> + break;
> + case F81534_PORT_CONF_RS485:
> + value = F81534_CLK_RS485_MODE;
> + break;
> +
> + default:
> + /* fall through, default RS232 Mode */
> + case F81534_PORT_CONF_RS232:
> + value = 0;
> + break;
> + }
> +
> + value |= clock_table[idx];
With the shadow clock register I mentioned earlier, this can be
determined once at probe instead of at every termios change.
> + status = f81534_set_port_register(port, F81534_CLOCK_REG, value);
> if (status) {
> dev_err(&port->dev, "CLOCK_REG setting failed\n");
> return status;
> @@ -1270,9 +1301,12 @@ static void f81534_lsr_worker(struct work_struct *work)
>
> static int f81534_port_probe(struct usb_serial_port *port)
> {
> + struct f81534_serial_private *serial_priv;
> struct f81534_port_private *port_priv;
> int ret;
> + u8 value;
>
> + serial_priv = usb_get_serial_data(port->serial);
> port_priv = devm_kzalloc(&port->dev, sizeof(*port_priv), GFP_KERNEL);
> if (!port_priv)
> return -ENOMEM;
> @@ -1304,6 +1338,22 @@ static int f81534_port_probe(struct usb_serial_port *port)
> if (ret)
> return ret;
>
> + value = serial_priv->conf_data[port_priv->phy_num];
> + switch (value & F81534_UART_MODE_MASK) {
> + case F81534_PORT_CONF_RS485_INVERT:
> + dev_info(&port->dev, "RS485 invert mode.\n");
> + break;
> + case F81534_PORT_CONF_RS485:
> + dev_info(&port->dev, "RS485 mode.\n");
> + break;
> +
> + default:
> + /* fall through, default RS232 Mode */
No need for fallthrough comment here.
> + case F81534_PORT_CONF_RS232:
> + dev_info(&port->dev, "RS232 mode.\n");
> + break;
> + }
> +
> return 0;
> }
Johan
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