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Commit bb543ca2 authored by Ji-Ze Hong (Peter Hong)'s avatar Ji-Ze Hong (Peter Hong) Committed by Johan Hovold
Browse files

USB: serial: f81534: add H/W disable port support 



The F81532/534 can be disable port by manufacturer with
following H/W design.
    1: Connect DCD/DSR/CTS/RI pin to ground.
    2: Connect RX pin to ground.

In driver, we'll implements some detect method likes following:
    1: Read MSR.
    2: Turn MCR LOOP bit on, off and read LSR after delay with 60ms.
       It'll contain BREAK status in LSR.

Signed-off-by: default avatarJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent f047d357

drivers/usb/serial/f81534.c

+81 −0
Original line number Diff line number Diff line
@@ -307,6 +307,20 @@ static int f81534_set_mask_register(struct usb_serial *serial, u16 reg, 
	return f81534_set_register(serial, reg, tmp);

}



static int f81534_set_phy_port_register(struct usb_serial *serial, int phy,

					u16 reg, u8 data)

{

	return f81534_set_register(serial, reg + F81534_UART_OFFSET * phy,

					data);

}



static int f81534_get_phy_port_register(struct usb_serial *serial, int phy,

					u16 reg, u8 *data)

{

	return f81534_get_register(serial, reg + F81534_UART_OFFSET * phy,

					data);

}



static int f81534_set_port_register(struct usb_serial_port *port, u16 reg,

					u8 data)

{
@@ -732,6 +746,70 @@ static int f81534_find_config_idx(struct usb_serial *serial, u8 *index) 
	return 0;

}



/*

 * The F81532/534 will not report serial port to USB serial subsystem when

 * H/W DCD/DSR/CTS/RI/RX pin connected to ground.

 *

 * To detect RX pin status, we'll enable MCR interal loopback, disable it and

 * delayed for 60ms. It connected to ground If LSR register report UART_LSR_BI.

 */

static bool f81534_check_port_hw_disabled(struct usb_serial *serial, int phy)

{

	int status;

	u8 old_mcr;

	u8 msr;

	u8 lsr;

	u8 msr_mask;



	msr_mask = UART_MSR_DCD | UART_MSR_RI | UART_MSR_DSR | UART_MSR_CTS;



	status = f81534_get_phy_port_register(serial, phy,

				F81534_MODEM_STATUS_REG, &msr);

	if (status)

		return false;



	if ((msr & msr_mask) != msr_mask)

		return false;



	status = f81534_set_phy_port_register(serial, phy,

				F81534_FIFO_CONTROL_REG, UART_FCR_ENABLE_FIFO |

				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);

	if (status)

		return false;



	status = f81534_get_phy_port_register(serial, phy,

				F81534_MODEM_CONTROL_REG, &old_mcr);

	if (status)

		return false;



	status = f81534_set_phy_port_register(serial, phy,

				F81534_MODEM_CONTROL_REG, UART_MCR_LOOP);

	if (status)

		return false;



	status = f81534_set_phy_port_register(serial, phy,

				F81534_MODEM_CONTROL_REG, 0x0);

	if (status)

		return false;



	msleep(60);



	status = f81534_get_phy_port_register(serial, phy,

				F81534_LINE_STATUS_REG, &lsr);

	if (status)

		return false;



	status = f81534_set_phy_port_register(serial, phy,

				F81534_MODEM_CONTROL_REG, old_mcr);

	if (status)

		return false;



	if ((lsr & UART_LSR_BI) == UART_LSR_BI)

		return true;



	return false;

}



/*

 * We had 2 generation of F81532/534 IC. All has an internal storage.

 *
@@ -823,6 +901,9 @@ static int f81534_calc_num_ports(struct usb_serial *serial, 


	/* New style, find all possible ports */

	for (i = 0; i < F81534_NUM_PORT; ++i) {

		if (f81534_check_port_hw_disabled(serial, i))

			serial_priv->conf_data[i] |= F81534_PORT_UNAVAILABLE;



		if (serial_priv->conf_data[i] & F81534_PORT_UNAVAILABLE)

			continue;