Merge tag 'usb-serial-4.20-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-next

Johan writes:

USB-serial updates for v4.20-rc1

Here are the USB-serial updates for 4.20-rc1, including:

 - support for CBUS GPIO on FTDI devices (FTX and FT232R)
 - fix of a long-standing transfer-length bug

Included are also various clean ups.

All have been in linux-next with no reported issues.

Signed-off-by: Johan Hovold <johan@kernel.org>

* tag 'usb-serial-4.20-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
  USB: serial: cypress_m8: remove set but not used variable 'iflag'
  USB: serial: cypress_m8: fix interrupt-out transfer length
  USB: serial: ftdi_sio: add support for FT232R CBUS gpios
  USB: serial: ftdi_sio: fix gpio name collisions
  USB: serial: ftdi_sio: implement GPIO support for FT-X devices
  USB: serial: cypress_m8: fix spelling mistake "retreiving" -> "retrieving"

3 files changed, 420 insertions, 6 deletions

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index e0035c023120..ed51bc48eea6 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -378,7 +378,7 @@ static int cypress_serial_control(struct tty_struct *tty,
 			retval = -ENOTTY;
 			goto out;
 		}
-		dev_dbg(dev, "%s - retreiving serial line settings\n", __func__);
+		dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
 		do {
 			retval = usb_control_msg(port->serial->dev,
 					usb_rcvctrlpipe(port->serial->dev, 0),
@@ -769,7 +769,7 @@ send:
 
 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
-		port->interrupt_out_buffer, port->interrupt_out_size,
+		port->interrupt_out_buffer, actual_size,
 		cypress_write_int_callback, port, priv->write_urb_interval);
 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
 	if (result) {
@@ -863,7 +863,7 @@ static void cypress_set_termios(struct tty_struct *tty,
 	struct cypress_private *priv = usb_get_serial_port_data(port);
 	struct device *dev = &port->dev;
 	int data_bits, stop_bits, parity_type, parity_enable;
-	unsigned cflag, iflag;
+	unsigned int cflag;
 	unsigned long flags;
 	__u8 oldlines;
 	int linechange = 0;
@@ -899,7 +899,6 @@ static void cypress_set_termios(struct tty_struct *tty,
 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
 
 	cflag = tty->termios.c_cflag;
-	iflag = tty->termios.c_iflag;
 
 	/* check if there are new settings */
 	if (old_termios) {
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index b5cef322826f..f1eb20acb3bb 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -39,6 +39,7 @@
 #include <linux/uaccess.h>
 #include <linux/usb.h>
 #include <linux/serial.h>
+#include <linux/gpio/driver.h>
 #include <linux/usb/serial.h>
 #include "ftdi_sio.h"
 #include "ftdi_sio_ids.h"
@@ -72,6 +73,15 @@ struct ftdi_private {
 	unsigned int latency;		/* latency setting in use */
 	unsigned short max_packet_size;
 	struct mutex cfg_lock; /* Avoid mess by parallel calls of config ioctl() and change_speed() */
+#ifdef CONFIG_GPIOLIB
+	struct gpio_chip gc;
+	struct mutex gpio_lock;	/* protects GPIO state */
+	bool gpio_registered;	/* is the gpiochip in kernel registered */
+	bool gpio_used;		/* true if the user requested a gpio */
+	u8 gpio_altfunc;	/* which pins are in gpio mode */
+	u8 gpio_output;		/* pin directions cache */
+	u8 gpio_value;		/* pin value for outputs */
+#endif
 };
 
 /* struct ftdi_sio_quirk is used by devices requiring special attention. */
@@ -1766,6 +1776,375 @@ static void remove_sysfs_attrs(struct usb_serial_port *port)
 
 }
 
+#ifdef CONFIG_GPIOLIB
+
+static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	int result;
+	u16 val;
+
+	val = (mode << 8) | (priv->gpio_output << 4) | priv->gpio_value;
+	result = usb_control_msg(serial->dev,
+				 usb_sndctrlpipe(serial->dev, 0),
+				 FTDI_SIO_SET_BITMODE_REQUEST,
+				 FTDI_SIO_SET_BITMODE_REQUEST_TYPE, val,
+				 priv->interface, NULL, 0, WDR_TIMEOUT);
+	if (result < 0) {
+		dev_err(&serial->interface->dev,
+			"bitmode request failed for value 0x%04x: %d\n",
+			val, result);
+	}
+
+	return result;
+}
+
+static int ftdi_set_cbus_pins(struct usb_serial_port *port)
+{
+	return ftdi_set_bitmode(port, FTDI_SIO_BITMODE_CBUS);
+}
+
+static int ftdi_exit_cbus_mode(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	priv->gpio_output = 0;
+	priv->gpio_value = 0;
+	return ftdi_set_bitmode(port, FTDI_SIO_BITMODE_RESET);
+}
+
+static int ftdi_gpio_request(struct gpio_chip *gc, unsigned int offset)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	int result;
+
+	if (priv->gpio_altfunc & BIT(offset))
+		return -ENODEV;
+
+	mutex_lock(&priv->gpio_lock);
+	if (!priv->gpio_used) {
+		/* Set default pin states, as we cannot get them from device */
+		priv->gpio_output = 0x00;
+		priv->gpio_value = 0x00;
+		result = ftdi_set_cbus_pins(port);
+		if (result) {
+			mutex_unlock(&priv->gpio_lock);
+			return result;
+		}
+
+		priv->gpio_used = true;
+	}
+	mutex_unlock(&priv->gpio_lock);
+
+	return 0;
+}
+
+static int ftdi_read_cbus_pins(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	unsigned char *buf;
+	int result;
+
+	buf = kmalloc(1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	result = usb_control_msg(serial->dev,
+				 usb_rcvctrlpipe(serial->dev, 0),
+				 FTDI_SIO_READ_PINS_REQUEST,
+				 FTDI_SIO_READ_PINS_REQUEST_TYPE, 0,
+				 priv->interface, buf, 1, WDR_TIMEOUT);
+	if (result < 1) {
+		if (result >= 0)
+			result = -EIO;
+	} else {
+		result = buf[0];
+	}
+
+	kfree(buf);
+
+	return result;
+}
+
+static int ftdi_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	int result;
+
+	result = ftdi_read_cbus_pins(port);
+	if (result < 0)
+		return result;
+
+	return !!(result & BIT(gpio));
+}
+
+static void ftdi_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	mutex_lock(&priv->gpio_lock);
+
+	if (value)
+		priv->gpio_value |= BIT(gpio);
+	else
+		priv->gpio_value &= ~BIT(gpio);
+
+	ftdi_set_cbus_pins(port);
+
+	mutex_unlock(&priv->gpio_lock);
+}
+
+static int ftdi_gpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
+					unsigned long *bits)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	int result;
+
+	result = ftdi_read_cbus_pins(port);
+	if (result < 0)
+		return result;
+
+	*bits = result & *mask;
+
+	return 0;
+}
+
+static void ftdi_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
+					unsigned long *bits)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	mutex_lock(&priv->gpio_lock);
+
+	priv->gpio_value &= ~(*mask);
+	priv->gpio_value |= *bits & *mask;
+	ftdi_set_cbus_pins(port);
+
+	mutex_unlock(&priv->gpio_lock);
+}
+
+static int ftdi_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	return !(priv->gpio_output & BIT(gpio));
+}
+
+static int ftdi_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	int result;
+
+	mutex_lock(&priv->gpio_lock);
+
+	priv->gpio_output &= ~BIT(gpio);
+	result = ftdi_set_cbus_pins(port);
+
+	mutex_unlock(&priv->gpio_lock);
+
+	return result;
+}
+
+static int ftdi_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
+					int value)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	int result;
+
+	mutex_lock(&priv->gpio_lock);
+
+	priv->gpio_output |= BIT(gpio);
+	if (value)
+		priv->gpio_value |= BIT(gpio);
+	else
+		priv->gpio_value &= ~BIT(gpio);
+
+	result = ftdi_set_cbus_pins(port);
+
+	mutex_unlock(&priv->gpio_lock);
+
+	return result;
+}
+
+static int ftdi_read_eeprom(struct usb_serial *serial, void *dst, u16 addr,
+				u16 nbytes)
+{
+	int read = 0;
+
+	if (addr % 2 != 0)
+		return -EINVAL;
+	if (nbytes % 2 != 0)
+		return -EINVAL;
+
+	/* Read EEPROM two bytes at a time */
+	while (read < nbytes) {
+		int rv;
+
+		rv = usb_control_msg(serial->dev,
+				     usb_rcvctrlpipe(serial->dev, 0),
+				     FTDI_SIO_READ_EEPROM_REQUEST,
+				     FTDI_SIO_READ_EEPROM_REQUEST_TYPE,
+				     0, (addr + read) / 2, dst + read, 2,
+				     WDR_TIMEOUT);
+		if (rv < 2) {
+			if (rv >= 0)
+				return -EIO;
+			else
+				return rv;
+		}
+
+		read += rv;
+	}
+
+	return 0;
+}
+
+static int ftdi_gpio_init_ft232r(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	u16 cbus_config;
+	u8 *buf;
+	int ret;
+	int i;
+
+	buf = kmalloc(2, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = ftdi_read_eeprom(port->serial, buf, 0x14, 2);
+	if (ret < 0)
+		goto out_free;
+
+	cbus_config = le16_to_cpup((__le16 *)buf);
+	dev_dbg(&port->dev, "cbus_config = 0x%04x\n", cbus_config);
+
+	priv->gc.ngpio = 4;
+
+	priv->gpio_altfunc = 0xff;
+	for (i = 0; i < priv->gc.ngpio; ++i) {
+		if ((cbus_config & 0xf) == FTDI_FT232R_CBUS_MUX_GPIO)
+			priv->gpio_altfunc &= ~BIT(i);
+		cbus_config >>= 4;
+	}
+out_free:
+	kfree(buf);
+
+	return ret;
+}
+
+static int ftdi_gpio_init_ftx(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	const u16 cbus_cfg_addr = 0x1a;
+	const u16 cbus_cfg_size = 4;
+	u8 *cbus_cfg_buf;
+	int result;
+	u8 i;
+
+	cbus_cfg_buf = kmalloc(cbus_cfg_size, GFP_KERNEL);
+	if (!cbus_cfg_buf)
+		return -ENOMEM;
+
+	result = ftdi_read_eeprom(serial, cbus_cfg_buf,
+				  cbus_cfg_addr, cbus_cfg_size);
+	if (result < 0)
+		goto out_free;
+
+	/* FIXME: FT234XD alone has 1 GPIO, but how to recognize this IC? */
+	priv->gc.ngpio = 4;
+
+	/* Determine which pins are configured for CBUS bitbanging */
+	priv->gpio_altfunc = 0xff;
+	for (i = 0; i < priv->gc.ngpio; ++i) {
+		if (cbus_cfg_buf[i] == FTDI_FTX_CBUS_MUX_GPIO)
+			priv->gpio_altfunc &= ~BIT(i);
+	}
+
+out_free:
+	kfree(cbus_cfg_buf);
+
+	return result;
+}
+
+static int ftdi_gpio_init(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	int result;
+
+	switch (priv->chip_type) {
+	case FT232RL:
+		result = ftdi_gpio_init_ft232r(port);
+		break;
+	case FTX:
+		result = ftdi_gpio_init_ftx(port);
+		break;
+	default:
+		return 0;
+	}
+
+	if (result < 0)
+		return result;
+
+	mutex_init(&priv->gpio_lock);
+
+	priv->gc.label = "ftdi-cbus";
+	priv->gc.request = ftdi_gpio_request;
+	priv->gc.get_direction = ftdi_gpio_direction_get;
+	priv->gc.direction_input = ftdi_gpio_direction_input;
+	priv->gc.direction_output = ftdi_gpio_direction_output;
+	priv->gc.get = ftdi_gpio_get;
+	priv->gc.set = ftdi_gpio_set;
+	priv->gc.get_multiple = ftdi_gpio_get_multiple;
+	priv->gc.set_multiple = ftdi_gpio_set_multiple;
+	priv->gc.owner = THIS_MODULE;
+	priv->gc.parent = &serial->interface->dev;
+	priv->gc.base = -1;
+	priv->gc.can_sleep = true;
+
+	result = gpiochip_add_data(&priv->gc, port);
+	if (!result)
+		priv->gpio_registered = true;
+
+	return result;
+}
+
+static void ftdi_gpio_remove(struct usb_serial_port *port)
+{
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+	if (priv->gpio_registered) {
+		gpiochip_remove(&priv->gc);
+		priv->gpio_registered = false;
+	}
+
+	if (priv->gpio_used) {
+		/* Exiting CBUS-mode does not reset pin states. */
+		ftdi_exit_cbus_mode(port);
+		priv->gpio_used = false;
+	}
+}
+
+#else
+
+static int ftdi_gpio_init(struct usb_serial_port *port)
+{
+	return 0;
+}
+
+static void ftdi_gpio_remove(struct usb_serial_port *port) { }
+
+#endif	/* CONFIG_GPIOLIB */
+
 /*
  * ***************************************************************************
  * FTDI driver specific functions
@@ -1794,7 +2173,7 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
 {
 	struct ftdi_private *priv;
 	const struct ftdi_sio_quirk *quirk = usb_get_serial_data(port->serial);
-
+	int result;
 
 	priv = kzalloc(sizeof(struct ftdi_private), GFP_KERNEL);
 	if (!priv)
@@ -1813,6 +2192,14 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
 		priv->latency = 16;
 	write_latency_timer(port);
 	create_sysfs_attrs(port);
+
+	result = ftdi_gpio_init(port);
+	if (result < 0) {
+		dev_err(&port->serial->interface->dev,
+			"GPIO initialisation failed: %d\n",
+			result);
+	}
+
 	return 0;
 }
 
@@ -1930,6 +2317,8 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)
 {
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
 
+	ftdi_gpio_remove(port);
+
 	remove_sysfs_attrs(port);
 
 	kfree(priv);
diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h
index dcd0b6e05baf..a79a1325b4d9 100644
--- a/drivers/usb/serial/ftdi_sio.h
+++ b/drivers/usb/serial/ftdi_sio.h
@@ -35,7 +35,10 @@
 #define FTDI_SIO_SET_EVENT_CHAR		6 /* Set the event character */
 #define FTDI_SIO_SET_ERROR_CHAR		7 /* Set the error character */
 #define FTDI_SIO_SET_LATENCY_TIMER	9 /* Set the latency timer */
-#define FTDI_SIO_GET_LATENCY_TIMER	10 /* Get the latency timer */
+#define FTDI_SIO_GET_LATENCY_TIMER	0x0a /* Get the latency timer */
+#define FTDI_SIO_SET_BITMODE		0x0b /* Set bitbang mode */
+#define FTDI_SIO_READ_PINS		0x0c /* Read immediate value of pins */
+#define FTDI_SIO_READ_EEPROM		0x90 /* Read EEPROM */
 
 /* Interface indices for FT2232, FT2232H and FT4232H devices */
 #define INTERFACE_A		1
@@ -433,6 +436,29 @@ enum ftdi_sio_baudrate {
  *         1 = active
  */
 
+/* FTDI_SIO_SET_BITMODE */
+#define FTDI_SIO_SET_BITMODE_REQUEST_TYPE 0x40
+#define FTDI_SIO_SET_BITMODE_REQUEST FTDI_SIO_SET_BITMODE
+
+/* Possible bitmodes for FTDI_SIO_SET_BITMODE_REQUEST */
+#define FTDI_SIO_BITMODE_RESET		0x00
+#define FTDI_SIO_BITMODE_CBUS		0x20
+
+/* FTDI_SIO_READ_PINS */
+#define FTDI_SIO_READ_PINS_REQUEST_TYPE 0xc0
+#define FTDI_SIO_READ_PINS_REQUEST FTDI_SIO_READ_PINS
+
+/*
+ * FTDI_SIO_READ_EEPROM
+ *
+ * EEPROM format found in FTDI AN_201, "FT-X MTP memory Configuration",
+ * http://www.ftdichip.com/Support/Documents/AppNotes/AN_201_FT-X%20MTP%20Memory%20Configuration.pdf
+ */
+#define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0
+#define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM
+
+#define FTDI_FTX_CBUS_MUX_GPIO		0x8
+#define FTDI_FT232R_CBUS_MUX_GPIO	0xa
 
 
 /* Descriptors returned by the device