diff options
Diffstat (limited to 'drivers/usb/serial/ftdi_sio.c')
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 360 |
1 files changed, 359 insertions, 1 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index b5cef322826f..6b727ada20cf 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 +1776,344 @@ static void remove_sysfs_attrs(struct usb_serial_port *port) } +#ifdef CONFIG_GPIOLIB + +static const char * const ftdi_ftx_gpio_names[] = { + "CBUS0", "CBUS1", "CBUS2", "CBUS3" +}; + +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 ftx_gpioconf_init(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; + priv->gc.names = ftdi_ftx_gpio_names; + + /* 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 FTX: + result = ftx_gpioconf_init(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 +2142,7 @@ 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 +2161,14 @@ 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 +2286,8 @@ 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); |