Thu, 3 Apr 2014 00:49:14 -0400 от jon@xxxxxxxxxx: > From: Jon Ringle <jringle@xxxxxxxxxxxxx> > > The SC16IS7xx is a slave I2C-bus/SPI interface to a single-channel > high performance UART. The SC16IS7xx’s internal register set is > backward-compatible with the widely used and widely popular 16C450. > > The SC16IS7xx also provides additional advanced features such as > auto hardware and software flow control, automatic RS-485 support, and > software reset. > > Signed-off-by: Jon Ringle <jringle@xxxxxxxxxxxxx> > --- ... > + tristate "SC16IS7xx serial support" > + select SERIAL_CORE > + select REGMAP_I2C if I2C > + default n "n" is already default choice. There is no need to specify this. ... > +#include <linux/serial.h> > +#include <linux/spi/spi.h> What a reason to include SPI header? ... > + * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is > + * no built-in hardware check to make sure this condition is met. Also, the TCR > + * must be programmed with this condition before auto RTS or software flow > + * control is enabled to avoid spurious operation of the device. > + */ > +#define SC16IS7XX_TCR_RX_HALT(words) (((words / 4) & 0x0f) << 0) > +#define SC16IS7XX_TCR_RX_RESUME(words) (((words / 4) & 0x0f) << 4) "words" on the right side should be framed by brackets. ... > + * When TLR is used for RX trigger level control, FCR[7:6] should be left at the > + * default state, that is, ‘00’. > + */ > +#define SC16IS7XX_TLR_TX_TRIGGER(words) (((words / 4) & 0x0f) << 0) > +#define SC16IS7XX_TLR_RX_TRIGGER(words) (((words / 4) & 0x0f) << 4) Ditto. ... > +static void sc16is7xx_config_rs485(struct uart_port *port, > + struct serial_rs485 *rs485) > +{ > + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); > + > + one->rs485 = *rs485; > + > + if (one->rs485.flags & SER_RS485_ENABLED) { > + sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, > + SC16IS7XX_EFCR_AUTO_RS485_BIT, > + SC16IS7XX_EFCR_AUTO_RS485_BIT); > + } else { > + sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, > + SC16IS7XX_EFCR_AUTO_RS485_BIT, > + 0); > + } > +} This function will get "unused" warning if TIOCSRS485 and TIOCGRS485 is not defined. ... > +static int sc16is7xx_startup(struct uart_port *port) > +{ ... > + sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, > + SC16IS7XX_EFCR_AUTO_RS485_BIT, > + SC16IS7XX_EFCR_AUTO_RS485_BIT); You should do not set optional RS485 mode unconditionally. Since IOCTL for RS485 is used, this should be enough. --- ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f