usb: serial: f81534: add high baud rate support

The F81532/534 had 4 clocksource 1.846/18.46/14.77/24MHz and baud rates can be up to 1.5Mbits with 24MHz.

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.

Signed-off-by Ji-Ze Hong (Peter Hong) <[email protected]>

---
 drivers/usb/serial/f81534.c | 84 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 68 insertions(+), 16 deletions(-)

drivers/usb/serial/f81534.c +1 -0

index cb8214860192..76c676ef5f0d 100644
@@ -45,6 +45,7 @@
 #define F81534_MODEM_CONTROL_REG	(0x04 + F81534_UART_BASE_ADDRESS)
 #define F81534_LINE_STATUS_REG		(0x05 + F81534_UART_BASE_ADDRESS)
 #define F81534_MODEM_STATUS_REG		(0x06 + F81534_UART_BASE_ADDRESS)
+#define F81534_CLOCK_REG		(0x08 + F81534_UART_BASE_ADDRESS)
 #define F81534_CONFIG1_REG		(0x09 + F81534_UART_BASE_ADDRESS)
 
 #define F81534_DEF_CONF_ADDRESS_START	0x3000

drivers/usb/serial/f81534.c +5 -1

 #define F81534_SET_GET_REGISTER		0xA0
 
 #define F81534_NUM_PORT			4

@@ -100,7 +101,6 @@
 #define F81534_CMD_READ			0x03
 
 #define F81534_DEFAULT_BAUD_RATE	9600
-#define F81534_MAX_BAUDRATE		115200
 
 #define F81534_PORT_CONF_DISABLE_PORT	BIT(3)
 #define F81534_PORT_CONF_NOT_EXIST_PORT	BIT(7)

@@ -110,6 +110,22 @@
 #define F81534_1X_RXTRIGGER		0xc3
 #define F81534_8X_RXTRIGGER		0xcf
 
+/*
+ * F81532/534 Clock registers (offset +08h)
+ *
+ * Bit0:	UART Enable (always on)
+ * Bit2-1:	Clock source selector

drivers/usb/serial/f81534.c +19 -2

+
 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) },

@@ -133,6 +149,7 @@ struct f81534_port_private {
 	struct usb_serial_port *port;
 	unsigned long tx_empty;
 	spinlock_t msr_lock;
+	u32 baud_base;
 	u8 shadow_mcr;
 	u8 shadow_lcr;
 	u8 shadow_msr;

@@ -464,13 +481,51 @@ static u32 f81534_calc_baud_divisor(u32 baudrate, u32 clockrate)
 	return DIV_ROUND_CLOSEST(clockrate, baudrate);
 }
 
-static int f81534_set_port_config(struct usb_serial_port *port, u32 baudrate,
-					u8 lcr)
+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);
 	u32 divisor;
 	int status;
+	int idx;
 	u8 value;
+	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};
+
+	do {
+		for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {
+			if (baudrate <= baudrate_table[idx] &&
+					baudrate_table[idx] % baudrate == 0)
+				break;
+		}
+
+		/* Found acceptable baud rate */

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) <[email protected]>

---
 drivers/usb/serial/f81534.c | 54 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 52 insertions(+), 2 deletions(-)

drivers/usb/serial/f81534.c +22 -2

index 76c676ef5f0d..b2d10309c335 100644
@@ -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;

drivers/usb/serial/f81534.c +5 -0

+	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];

The F81532/534 had 3 output pin (M0/SD, M1, M2) with open-drain mode to control transceiver. We'll read it from internal Flash with address 0x2f05~0x2f08 for 4 ports. The value is range from 0 to 7. The M0/SD is MSB of this value. For a examples, If read value is 6, we'll write M0/SD, M1, M2 as 1, 1, 0.

Register mapping for output value:

	Port 0:
		M2: 0x2ae8 bit7, M1: 0x2a90 bit5, M0/SD: 0x2a90 bit4
	Port 1:
		M2: 0x2ae8 bit6, M1: 0x2ae8 bit0, M0/SD: 0x2ae8 bit3
	Port 2:
		M2: 0x2a90 bit0, M1: 0x2ae8 bit2, M0/SD: 0x2a80 bit6
	Port 3:
		M2: 0x2a90 bit3, M1: 0x2a90 bit2, M0/SD: 0x2a90 bit1

Signed-off-by Ji-Ze Hong (Peter Hong) <[email protected]>

---
 drivers/usb/serial/f81534.c | 67 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

drivers/usb/serial/f81534.c +1 -0

index b2d10309c335..30b966d71ae8 100644
@@ -56,6 +56,7 @@
 #define F81534_CUSTOM_NO_CUSTOM_DATA	0xff
 #define F81534_CUSTOM_VALID_TOKEN	0xf0
 #define F81534_CONF_OFFSET		1
+#define F81534_CONF_GPIO_OFFSET		4
 
 #define F81534_MAX_DATA_BLOCK		64
 #define F81534_MAX_BUS_RETRY		20

drivers/usb/serial/f81534.c +34 -0

+};
+
 static int f81534_logic_to_phy_port(struct usb_serial *serial,
 					struct usb_serial_port *port)
 {

@@ -271,6 +289,22 @@ static int f81534_get_register(struct usb_serial *serial, u16 reg, u8 *data)
 	return status;
 }
 
+static int f81534_set_mask_register(struct usb_serial *serial, u16 reg,
+					u8 mask, u8 data)
+{
+	int status;
+	u8 tmp;
+
+	status = f81534_get_register(serial, reg, &tmp);
+	if (status)
+		return status;
+
+	tmp &= ~mask;
+	tmp |= (mask & data);
+
+	return f81534_set_register(serial, reg, tmp);
+}
+
 static int f81534_set_port_register(struct usb_serial_port *port, u16 reg,
 					u8 data)
 {

@@ -1299,6 +1333,37 @@ static void f81534_lsr_worker(struct work_struct *work)
 		dev_warn(&port->dev, "read LSR failed: %d\n", status);
 }
 
+static int f81534_set_port_output_pin(struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv;
+	struct f81534_port_private *port_priv;
+	struct usb_serial *serial;
+	const struct f81534_port_out_pin *pins;
+	int status;
+	int i;
+	u8 value;
+	u8 idx;
+
+	serial = port->serial;
+	serial_priv = usb_get_serial_data(serial);
+	port_priv = usb_get_serial_port_data(port);
+
+	idx = F81534_CONF_GPIO_OFFSET + port_priv->phy_num;

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 Ji-Ze Hong (Peter Hong) <[email protected]>

---
 drivers/usb/serial/f81534.c | 74 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

drivers/usb/serial/f81534.c +0 -0

index 30b966d71ae8..18bd2a478199 100644

drivers/usb/serial/f81534.c +53 -0

+	if (status)
+		return status;
+
+	if ((msr & msr_mask) != msr_mask)
+		return 0;
+
+	status = f81534_set_register(serial,
+				F81534_FIFO_CONTROL_REG + phy * 0x10,
+				UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+				UART_FCR_CLEAR_XMIT);
+	if (status)
+		return status;
+
+	status = f81534_get_register(serial,
+				F81534_MODEM_CONTROL_REG + phy * 0x10,
+				&old_mcr);
+	if (status)
+		return status;
+
+	status = f81534_set_register(serial,
+				F81534_MODEM_CONTROL_REG + phy * 0x10,
+				UART_MCR_LOOP);
+	if (status)
+		return status;
+
+	status = f81534_set_register(serial,
+				F81534_MODEM_CONTROL_REG + phy * 0x10, 0x0);
+	if (status)
+		return status;
+
+	msleep(60);
+
+	status = f81534_get_register(serial,
+				F81534_LINE_STATUS_REG + phy * 0x10, &lsr);
+	if (status)
+		return status;
+
+	status = f81534_set_register(serial,
+				F81534_MODEM_CONTROL_REG + phy * 0x10,
+				old_mcr);
+	if (status)
+		return status;
+
+	if ((lsr & UART_LSR_BI) == UART_LSR_BI)
+		return -ENODEV;
+
+	return 0;
+}
+
+/*
  * We had 2 generation of F81532/534 IC. All has an internal storage.
  *
  * 1st is pure USB-to-TTL RS232 IC and designed for 4 ports only, no any

@@ -832,6 +900,9 @@ 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))
+			continue;
+
 		if (setting[i] & F81534_PORT_UNAVAILABLE)
 			continue;
 

Quoted 22 lines

drivers/usb/serial/f81534.c +22 -0

+static int f81534_set_port_output_pin(struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv;
+	struct f81534_port_private *port_priv;
+	struct usb_serial *serial;
+	const struct f81534_port_out_pin *pins;
+	int status;
+	int i;
+	u8 value;
+	u8 idx;
+
+	serial = port->serial;
+	serial_priv = usb_get_serial_data(serial);
+	port_priv = usb_get_serial_port_data(port);
+
+	idx = F81534_CONF_GPIO_OFFSET + port_priv->phy_num;
+	value = serial_priv->conf_data[idx];
+	pins = &f81534_port_out_pins[port_priv->phy_num];
+
+	for (i = 0; i < ARRAY_SIZE(pins->pin); ++i) {
+		status = f81534_set_mask_register(serial,
+				pins->pin[i].reg_addr, pins->pin[i].reg_mask,

drivers/usb/serial/f81534.c static void f81534_lsr_worker(struct work_struct *work) · line 1361

Quoted 4 lines

drivers/usb/serial/f81534.c +4 -0

+				value & BIT(i) ? pins->pin[i].reg_mask : 0);
+		if (status)
+			return status;
+	}

You're using 24 (get or set) accesses to update these three registers here. Why not read them out (if necessary), determine their new values and then write them back when done instead?

Hi Johan,

Johan Hovold 於 2017/12/19 上午 12:06 寫道:

Quoted 23 lines · Ji-Ze Hong (Peter Hong)

Quoted 22 lines

drivers/usb/serial/f81534.c +22 -0

+static int f81534_set_port_output_pin(struct usb_serial_port *port)
+{
+	struct f81534_serial_private *serial_priv;
+	struct f81534_port_private *port_priv;
+	struct usb_serial *serial;
+	const struct f81534_port_out_pin *pins;
+	int status;
+	int i;
+	u8 value;
+	u8 idx;
+
+	serial = port->serial;
+	serial_priv = usb_get_serial_data(serial);
+	port_priv = usb_get_serial_port_data(port);
+
+	idx = F81534_CONF_GPIO_OFFSET + port_priv->phy_num;
+	value = serial_priv->conf_data[idx];
+	pins = &f81534_port_out_pins[port_priv->phy_num];
+
+	for (i = 0; i < ARRAY_SIZE(pins->pin); ++i) {
+		status = f81534_set_mask_register(serial,
+				pins->pin[i].reg_addr, pins->pin[i].reg_mask,

Quoted 9 lines

drivers/usb/serial/f81534.c static void f81534_lsr_worker(struct work_struct *work) · line 1361

Quoted 4 lines

drivers/usb/serial/f81534.c +4 -0

+				value & BIT(i) ? pins->pin[i].reg_mask : 0);
+		if (status)
+			return status;
+	}

You're using 24 (get or set) accesses to update these three registers here. Why not read them out (if necessary), determine their new values and then write them back when done instead?

In this code, I'm only read/write 3 registers of 0x2ae8, 0x2a90, 0x2a80, but some register will read/write more than once. Should I change the code from port_probe() to attach() and re-write it as:
1: read the 3 register
2: change them will 12 pin desire value
3: write it back
Is it ok?

Quoted 7 lines

In this code, I'm only read/write 3 registers of 0x2ae8, 0x2a90, 0x2a80, but some register will read/write more than once. Should I change the code from port_probe() to attach() and re-write it as:
1: read the 3 register
2: change them will 12 pin desire value
3: write it back
Is it ok?

Do you expect these pins to ever be changed after probe? If not, then perhaps it can be moved to attach(), but otherwise I guess they should be set at port_probe(). By using shadow registers, you should be able to reduce the number of device accesses, but perhaps it's not worth the complexity.

Do you have a rough idea about how long these register updates take? I was just worried that these changes will add up to really long probe times.

Hi Johan,

Quoted 14 lines

Quoted 7 lines

In this code, I'm only read/write 3 registers of 0x2ae8, 0x2a90, 0x2a80, but some register will read/write more than once. Should I change the code from port_probe() to attach() and re-write it as:
1: read the 3 register
2: change them will 12 pin desire value
3: write it back
Is it ok?

Do you expect these pins to ever be changed after probe? If not, then perhaps it can be moved to attach(), but otherwise I guess they should be set at port_probe(). By using shadow registers, you should be able to reduce the number of device accesses, but perhaps it's not worth the complexity.

Quoted 4 lines

Do you have a rough idea about how long these register updates take? I was just worried that these changes will add up to really long probe times.

I had measured the time of the loop in f81534_set_port_output_pin() via getnstimeofday() with 685.410 ~ 3681.682us per port, but normally with 600~800us per port. So I prefer remain the current method of f81534_set_port_output_pin(). Is it ok?