From: Manivannan Sadhasivam <[email protected]> Add gpiochip support for Maxlinear/Exar USB to serial converter for controlling the available gpios.
Cc: Linus Walleij <[email protected]> Cc: [email protected] Signed-off-by: Manivannan Sadhasivam <[email protected]> --- drivers/usb/serial/xr_serial.c | 186 ++++++++++++++++++++++++++++++++- drivers/usb/serial/xr_serial.h | 7 ++ 2 files changed, 192 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c index ea4a0b167d3f..d86fd40839f8 100644 --- a/drivers/usb/serial/xr_serial.c +++ b/drivers/usb/serial/xr_serial.c @@ -476,6 +476,189 @@ static void xr_break_ctl(struct tty_struct *tty, int break_state) state); } +#ifdef CONFIG_GPIOLIB + +static int xr_gpio_request(struct gpio_chip *gc, unsigned int offset) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + /* Check if the requested GPIO is occupied */ + if (port_priv->gpio_altfunc & BIT(offset)) + return -ENODEV; + + return 0; +} + +static int xr_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u16 gpio_status; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_status, &gpio_status); + if (ret) + return ret; + + return !!(gpio_status & BIT(gpio)); +} + +static void xr_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + if (val) + xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_set, BIT(gpio)); + else + xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_clr, BIT(gpio)); +} + +static int xr_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u16 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + /* Logic 0 = input and Logic 1 = output */ + return !(gpio_dir & BIT(gpio)); +} + +static int xr_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u16 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + gpio_dir &= ~BIT(gpio); + + return xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, gpio_dir); +} + +static int xr_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio, + int val) +{ + struct usb_serial_port *port = gpiochip_get_data(gc); + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u16 gpio_dir; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, &gpio_dir); + if (ret) + return ret; + + gpio_dir |= BIT(gpio); + + ret = xr_set_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_dir, gpio_dir); + if (ret) + return ret; + + xr_gpio_set(gc, gpio, val); + + return 0; +} + +static int xr21v141x_gpio_init(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret; + u16 gpio_mode; + + port_priv->gc.ngpio = 6; + + ret = xr_get_reg(port, XR21V141X_UART_REG_BLOCK, + port_priv->regs->gpio_mode, &gpio_mode); + if (ret) + return ret; + + /* Mark all pins which are not in GPIO mode */ + if (gpio_mode & UART_MODE_RTS_CTS) + port_priv->gpio_altfunc |= (BIT(4) | BIT(5)); + else if (gpio_mode & UART_MODE_DTR_DSR) + port_priv->gpio_altfunc |= (BIT(2) | BIT(3)); + else if (gpio_mode & UART_MODE_RS485) + port_priv->gpio_altfunc |= BIT(5); + else if (gpio_mode & UART_MODE_RS485_ADDR) + port_priv->gpio_altfunc |= BIT(5); + else + port_priv->gpio_altfunc = 0; /* All GPIOs are available */ + + return ret; +} + +static int xr_gpio_init(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + int ret = 0; + + if (port_priv->idProduct == XR21V141X_ID) + ret = xr21v141x_gpio_init(port); + + if (ret < 0) + return ret; + + port_priv->gc.label = "xr_gpios"; + port_priv->gc.request = xr_gpio_request; + port_priv->gc.get_direction = xr_gpio_direction_get; + port_priv->gc.direction_input = xr_gpio_direction_input; + port_priv->gc.direction_output = xr_gpio_direction_output; + port_priv->gc.get = xr_gpio_get; + port_priv->gc.set = xr_gpio_set; + port_priv->gc.owner = THIS_MODULE; + port_priv->gc.parent = &port->dev; + port_priv->gc.base = -1; + port_priv->gc.can_sleep = true; + + ret = gpiochip_add_data(&port_priv->gc, port); + if (!ret) + port_priv->gpio_registered = true; + + return ret; +} + +static void xr_gpio_remove(struct usb_serial_port *port) +{ + struct xr_port_private *port_priv = usb_get_serial_port_data(port); + + if (port_priv->gpio_registered) { + gpiochip_remove(&port_priv->gc); + port_priv->gpio_registered = false; + } +} + +#else + +static int xr_gpio_init(struct usb_serial_port *port) +{ + return 0; +} + +static void xr_gpio_remove(struct usb_serial_port *port) +{ + /* Nothing to do */ +} + +#endif + static int xr_port_probe(struct usb_serial_port *port) { struct usb_serial *serial = port->serial; @@ -495,13 +678,14 @@ static int xr_port_probe(struct usb_serial_port *port) usb_set_serial_port_data(port, port_priv); - return 0; + return xr_gpio_init(port); } static int xr_port_remove(struct usb_serial_port *port) { struct xr_port_private *port_priv = usb_get_serial_port_data(port); + xr_gpio_remove(port); kfree(port_priv); return 0; diff --git a/drivers/usb/serial/xr_serial.h b/drivers/usb/serial/xr_serial.h index d2977ef847a0..079098cf553a 100644 --- a/drivers/usb/serial/xr_serial.h +++ b/drivers/usb/serial/xr_serial.h @@ -3,6 +3,8 @@ #ifndef __LINUX_USB_SERIAL_XR_SERIAL_H #define __LINUX_USB_SERIAL_XR_SERIAL_H +#include <linux/gpio/driver.h> + struct xr_uart_regs { u8 enable; u8 format; @@ -21,6 +23,11 @@ struct xr_uart_regs { }; struct xr_port_private { +#ifdef CONFIG_GPIOLIB + struct gpio_chip gc; + bool gpio_registered; + u8 gpio_altfunc; +#endif const struct xr_uart_regs *regs; u16 idProduct; u8 reg_width; -- 2.17.1
