the values given by the device tree.
Any driver for devices capable of working both as RS232 and RS485 should
- implement the rs485_config callback in the uart_port structure. The
- serial_core calls rs485_config to do the device specific part in response
- to TIOCSRS485 and TIOCGRS485 ioctls (see below). The rs485_config callback
- receives a pointer to struct serial_rs485.
+ implement the rs485_config callback and provide rs485_supported in the
+ uart_port structure. The serial core calls rs485_config to do the device
+ specific part in response to TIOCSRS485 ioctl (see below). The rs485_config
+ callback receives a pointer to a sanitizated serial_rs485 structure. The
+ serial_rs485 userspace provides is sanitized before calling rs485_config
+ using rs485_supported that indicates what RS485 features the driver supports
+ for the uart_port. TIOCGRS485 ioctl can be used to read back the
+ serial_rs485 structure matching to the current configuration.
4. Usage from user-level
========================
static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485)
{
+ u32 supported_flags = port->rs485_supported->flags;
+
/* pick sane settings if the user hasn't */
- if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+ if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) &&
+ !(rs485->flags & SER_RS485_RTS_ON_SEND) ==
!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
dev_warn_ratelimited(port->dev,
"%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n",
port->name, port->line);
rs485->flags |= SER_RS485_RTS_ON_SEND;
rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
+ supported_flags |= SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND;
}
- if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) {
+ if (!port->rs485_supported->delay_rts_before_send) {
+ if (rs485->delay_rts_before_send) {
+ dev_warn_ratelimited(port->dev,
+ "%s (%d): RTS delay before sending not supported\n",
+ port->name, port->line);
+ }
+ rs485->delay_rts_before_send = 0;
+ } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) {
rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY;
dev_warn_ratelimited(port->dev,
"%s (%d): RTS delay before sending clamped to %u ms\n",
port->name, port->line, rs485->delay_rts_before_send);
}
- if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) {
+ if (!port->rs485_supported->delay_rts_after_send) {
+ if (rs485->delay_rts_after_send) {
+ dev_warn_ratelimited(port->dev,
+ "%s (%d): RTS delay after sending not supported\n",
+ port->name, port->line);
+ }
+ rs485->delay_rts_after_send = 0;
+ } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) {
rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY;
dev_warn_ratelimited(port->dev,
"%s (%d): RTS delay after sending clamped to %u ms\n",
port->name, port->line, rs485->delay_rts_after_send);
}
+
+ rs485->flags &= supported_flags;
+
/* Return clean padding area to userspace */
memset(rs485->padding, 0, sizeof(rs485->padding));
}
int uart_rs485_config(struct uart_port *port)
{
- return port->rs485_config(port, &port->rs485);
+ struct serial_rs485 *rs485 = &port->rs485;
+
+ uart_sanitize_serial_rs485(port, rs485);
+
+ return port->rs485_config(port, rs485);
}
EXPORT_SYMBOL_GPL(uart_rs485_config);