From 478d1051a0293b8a8857267bb0f768ebcb05cfde Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 29 May 2015 21:20:33 +0200 Subject: [PATCH] sc16is7xx: use kworker for RS-485 configuration RS-485 configuration is also done under the spinlock so no blocking I/O allowed. Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sc16is7xx.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 86a679a5870b..9e6576004a42 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -303,6 +303,7 @@ struct sc16is7xx_devtype { #define SC16IS7XX_RECONF_MD (1 << 0) #define SC16IS7XX_RECONF_IER (1 << 1) +#define SC16IS7XX_RECONF_RS485 (1 << 2) struct sc16is7xx_one_config { unsigned int flags; @@ -668,6 +669,26 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws) sc16is7xx_handle_tx(port); } +static void sc16is7xx_reconf_rs485(struct uart_port *port) +{ + const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT | + SC16IS7XX_EFCR_RTS_INVERT_BIT; + u32 efcr = 0; + struct serial_rs485 *rs485 = &port->rs485; + unsigned long irqflags; + + spin_lock_irqsave(&port->lock, irqflags); + if (rs485->flags & SER_RS485_ENABLED) { + efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT; + + if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT; + } + spin_unlock_irqrestore(&port->lock, irqflags); + + sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr); +} + static void sc16is7xx_reg_proc(struct kthread_work *ws) { struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work); @@ -688,6 +709,9 @@ static void sc16is7xx_reg_proc(struct kthread_work *ws) if (config.flags & SC16IS7XX_RECONF_IER) sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG, config.ier_clear, 0); + + if (config.flags & SC16IS7XX_RECONF_RS485) + sc16is7xx_reconf_rs485(&one->port); } static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit) @@ -845,9 +869,8 @@ static void sc16is7xx_set_termios(struct uart_port *port, static int sc16is7xx_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) { - const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT | - SC16IS7XX_EFCR_RTS_INVERT_BIT; - u32 efcr = 0; + struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); if (rs485->flags & SER_RS485_ENABLED) { bool rts_during_rx, rts_during_tx; @@ -855,13 +878,7 @@ static int sc16is7xx_config_rs485(struct uart_port *port, rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND; rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND; - efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT; - - if (!rts_during_rx && rts_during_tx) - /* default */; - else if (rts_during_rx && !rts_during_tx) - efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT; - else + if (rts_during_rx == rts_during_tx) dev_err(port->dev, "unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n", rts_during_tx, rts_during_rx); @@ -875,9 +892,9 @@ static int sc16is7xx_config_rs485(struct uart_port *port, return -EINVAL; } - sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr); - port->rs485 = *rs485; + one->config.flags |= SC16IS7XX_RECONF_RS485; + queue_kthread_work(&s->kworker, &one->reg_work); return 0; } -- 2.11.0