From ba93cc7da8965bd513a7393db0f030e51bff4b60 Mon Sep 17 00:00:00 2001 From: Karoly Pados Date: Tue, 25 Sep 2018 15:59:11 +0200 Subject: USB: serial: ftdi_sio: implement GPIO support for FT-X devices This patch allows using the CBUS pins of FT-X devices as GPIO in CBUS bitbanging mode. There is no conflict between the GPIO and VCP functionality in this mode. Tested on FT230X and FT231X. As there is no way to request the current CBUS register configuration from the device, all CBUS pins are set to a known state when the first GPIO is requested. This allows using libftdi to set the GPIO pins before loading this module for UART functionality, a behavior that existing applications might be relying upon (though no specific case is known to the authors of this patch). Signed-off-by: Karoly Pados [ johan: minor style changes ] Signed-off-by: Johan Hovold --- drivers/usb/serial/ftdi_sio.c | 360 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 359 insertions(+), 1 deletion(-) (limited to 'drivers/usb/serial/ftdi_sio.c') 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 #include #include +#include #include #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); -- cgit v1.2.3 From e0658e3074231d68f6546be1c5916ba2f4dc1295 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 30 Sep 2018 14:27:02 +0200 Subject: USB: serial: ftdi_sio: fix gpio name collisions Drop the gpio line names, which cause gpiolib to complain loudly whenever a second ftdi gpiochip is registered: gpio gpiochip5: Detected name collision for GPIO name 'CBUS0' gpio gpiochip5: Detected name collision for GPIO name 'CBUS1' gpio gpiochip5: Detected name collision for GPIO name 'CBUS2' gpio gpiochip5: Detected name collision for GPIO name 'CBUS3' and also prevents the legacy sysfs interface from being used (as the line names are used as device names whenever they are set): sysfs: cannot create duplicate filename '/class/gpio/CBUS0' Until non-unique names are supported by gpiolib (without warnings and stack dumps), let's leave the gpio lines unnamed. Signed-off-by: Johan Hovold --- drivers/usb/serial/ftdi_sio.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers/usb/serial/ftdi_sio.c') diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 6b727ada20cf..be50b2a200aa 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1778,10 +1778,6 @@ 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); @@ -2032,7 +2028,6 @@ static int ftx_gpioconf_init(struct usb_serial_port *port) /* 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; -- cgit v1.2.3 From ff32d97e39e7053fdc1d316bd2e2eff70b77fdd2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 30 Sep 2018 14:27:03 +0200 Subject: USB: serial: ftdi_sio: add support for FT232R CBUS gpios Enable support for cbus gpios on FT232R. The cbus configuration is stored in one word in the EEPROM at offset 0x0a (byte-offset 0x14) with the mux config for CBUS0, CBUS1, CBUS2 and CBUS3 in bits 0..3, 4..7, 8..11 and 12..15, respectively. Tested using FT232RL by configuring one cbus pin at a time. Signed-off-by: Johan Hovold --- drivers/usb/serial/ftdi_sio.c | 40 ++++++++++++++++++++++++++++++++++++++-- drivers/usb/serial/ftdi_sio.h | 3 ++- 2 files changed, 40 insertions(+), 3 deletions(-) (limited to 'drivers/usb/serial/ftdi_sio.c') diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index be50b2a200aa..f1eb20acb3bb 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2007,7 +2007,40 @@ static int ftdi_read_eeprom(struct usb_serial *serial, void *dst, u16 addr, return 0; } -static int ftx_gpioconf_init(struct usb_serial_port *port) +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; @@ -2049,8 +2082,11 @@ static int ftdi_gpio_init(struct usb_serial_port *port) int result; switch (priv->chip_type) { + case FT232RL: + result = ftdi_gpio_init_ft232r(port); + break; case FTX: - result = ftx_gpioconf_init(port); + result = ftdi_gpio_init_ftx(port); break; default: return 0; diff --git a/drivers/usb/serial/ftdi_sio.h b/drivers/usb/serial/ftdi_sio.h index 6cfe682f8348..a79a1325b4d9 100644 --- a/drivers/usb/serial/ftdi_sio.h +++ b/drivers/usb/serial/ftdi_sio.h @@ -457,7 +457,8 @@ enum ftdi_sio_baudrate { #define FTDI_SIO_READ_EEPROM_REQUEST_TYPE 0xc0 #define FTDI_SIO_READ_EEPROM_REQUEST FTDI_SIO_READ_EEPROM -#define FTDI_FTX_CBUS_MUX_GPIO 8 +#define FTDI_FTX_CBUS_MUX_GPIO 0x8 +#define FTDI_FT232R_CBUS_MUX_GPIO 0xa /* Descriptors returned by the device -- cgit v1.2.3