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Commit 268ddb5e authored by Ji-Ze Hong (Peter Hong)'s avatar Ji-Ze Hong (Peter Hong) Committed by Johan Hovold
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USB: serial: f81232: add high baud rate support 



The F81232 had 4 clocksource 1.846/18.46/14.77/24MHz and baud rates
can be up to 1.5Mbits with 24MHz.

F81232 Clock registers (106h)

Bit1-0:     Clock source selector
                    00: 1.846MHz.
                    01: 18.46MHz.
                    10: 24MHz.
                    11: 14.77MHz.

Signed-off-by: default avatarJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 1c6b7ab2

drivers/usb/serial/f81232.c

+94 −11
Original line number Diff line number Diff line
@@ -28,7 +28,8 @@ static const struct usb_device_id id_table[] = { 
MODULE_DEVICE_TABLE(usb, id_table);



/* Maximum baudrate for F81232 */

#define F81232_MAX_BAUDRATE		115200

#define F81232_MAX_BAUDRATE		1500000

#define F81232_DEF_BAUDRATE		9600



/* USB Control EP parameter */

#define F81232_REGISTER_REQUEST		0xa0
@@ -44,18 +45,42 @@ MODULE_DEVICE_TABLE(usb, id_table); 
#define LINE_STATUS_REGISTER		(0x05 + SERIAL_BASE_ADDRESS)

#define MODEM_STATUS_REGISTER		(0x06 + SERIAL_BASE_ADDRESS)



/*

 * F81232 Clock registers (106h)

 *

 * Bit1-0:	Clock source selector

 *			00: 1.846MHz.

 *			01: 18.46MHz.

 *			10: 24MHz.

 *			11: 14.77MHz.

 */

#define F81232_CLK_REGISTER		0x106

#define F81232_CLK_1_846_MHZ		0

#define F81232_CLK_18_46_MHZ		BIT(0)

#define F81232_CLK_24_MHZ		BIT(1)

#define F81232_CLK_14_77_MHZ		(BIT(1) | BIT(0))

#define F81232_CLK_MASK			GENMASK(1, 0)



struct f81232_private {

	struct mutex lock;

	u8 modem_control;

	u8 modem_status;

	speed_t baud_base;

	struct work_struct lsr_work;

	struct work_struct interrupt_work;

	struct usb_serial_port *port;

};



static int calc_baud_divisor(speed_t baudrate)

static u32 const baudrate_table[] = { 115200, 921600, 1152000, 1500000 };

static u8 const clock_table[] = { F81232_CLK_1_846_MHZ, F81232_CLK_14_77_MHZ,

				F81232_CLK_18_46_MHZ, F81232_CLK_24_MHZ };



static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)

{

	return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);

	if (!baudrate)

		return 0;



	return DIV_ROUND_CLOSEST(clockrate, baudrate);

}



static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
@@ -129,6 +154,21 @@ static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val) 
	return status;

}



static int f81232_set_mask_register(struct usb_serial_port *port, u16 reg,

					u8 mask, u8 val)

{

	int status;

	u8 tmp;



	status = f81232_get_register(port, reg, &tmp);

	if (status)

		return status;



	tmp = (tmp & ~mask) | (val & mask);



	return f81232_set_register(port, reg, tmp);

}



static void f81232_read_msr(struct usb_serial_port *port)

{

	int status;
@@ -346,13 +386,53 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state) 
	 */

}



static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)

static int f81232_find_clk(speed_t baudrate)

{

	int idx;



	for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {

		if (baudrate <= baudrate_table[idx] &&

				baudrate_table[idx] % baudrate == 0)

			return idx;

	}



	return -EINVAL;

}



static void f81232_set_baudrate(struct tty_struct *tty,

				struct usb_serial_port *port, speed_t baudrate,

				speed_t old_baudrate)

{

	struct f81232_private *priv = usb_get_serial_port_data(port);

	u8 lcr;

	int divisor;

	int status = 0;

	int i;

	int idx;

	speed_t baud_list[] = { baudrate, old_baudrate, F81232_DEF_BAUDRATE };



	for (i = 0; i < ARRAY_SIZE(baud_list); ++i) {

		idx = f81232_find_clk(baud_list[i]);

		if (idx >= 0) {

			baudrate = baud_list[i];

			tty_encode_baud_rate(tty, baudrate, baudrate);

			break;

		}

	}



	if (idx < 0)

		return;



	divisor = calc_baud_divisor(baudrate);

	priv->baud_base = baudrate_table[idx];

	divisor = calc_baud_divisor(baudrate, priv->baud_base);



	status = f81232_set_mask_register(port, F81232_CLK_REGISTER,

			F81232_CLK_MASK, clock_table[idx]);

	if (status) {

		dev_err(&port->dev, "%s failed to set CLK_REG: %d\n",

			__func__, status);

		return;

	}



	status = f81232_get_register(port, LINE_CONTROL_REGISTER,

			 &lcr); /* get LCR */
@@ -442,6 +522,7 @@ static void f81232_set_termios(struct tty_struct *tty, 
	u8 new_lcr = 0;

	int status = 0;

	speed_t baudrate;

	speed_t old_baud;



	/* Don't change anything if nothing has changed */

	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
@@ -454,11 +535,12 @@ static void f81232_set_termios(struct tty_struct *tty, 


	baudrate = tty_get_baud_rate(tty);

	if (baudrate > 0) {

		if (baudrate > F81232_MAX_BAUDRATE) {

			baudrate = F81232_MAX_BAUDRATE;

			tty_encode_baud_rate(tty, baudrate, baudrate);

		}

		f81232_set_baudrate(port, baudrate);

		if (old_termios)

			old_baud = tty_termios_baud_rate(old_termios);

		else

			old_baud = F81232_DEF_BAUDRATE;



		f81232_set_baudrate(tty, port, baudrate, old_baud);

	}



	if (C_PARENB(tty)) {
@@ -595,11 +677,12 @@ static int f81232_get_serial_info(struct tty_struct *tty, 
		struct serial_struct *ss)

{

	struct usb_serial_port *port = tty->driver_data;

	struct f81232_private *priv = usb_get_serial_port_data(port);



	ss->type = PORT_16550A;

	ss->line = port->minor;

	ss->port = port->port_number;

	ss->baud_base = F81232_MAX_BAUDRATE;

	ss->baud_base = priv->baud_base;

	return 0;

}