From c112653b89e0cea4aa2ea26fcfbbb30a2193339e Mon Sep 17 00:00:00 2001 From: Lech Perczak Date: Mon, 21 Feb 2022 11:56:13 +0100 Subject: sc16is7xx: Preserve EFR bits on update MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Preserve unaffected bits state when accessing EFR register. This prevents hardware flow control bits from being cleared on enhanced functions access. Signed-off-by: Lech Perczak Signed-off-by: Tomasz Moń Link: https://lore.kernel.org/r/20220221105618.3503470-2-tomasz.mon@camlingroup.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sc16is7xx.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'drivers/tty/serial/sc16is7xx.c') diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 64e7e6c8145f..3a808b2cae4f 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -289,6 +289,14 @@ * XON1, XON2, XOFF1 and * XOFF2 */ +#define SC16IS7XX_EFR_FLOWCTRL_BITS (SC16IS7XX_EFR_AUTORTS_BIT | \ + SC16IS7XX_EFR_AUTOCTS_BIT | \ + SC16IS7XX_EFR_XOFF2_DETECT_BIT | \ + SC16IS7XX_EFR_SWFLOW3_BIT | \ + SC16IS7XX_EFR_SWFLOW2_BIT | \ + SC16IS7XX_EFR_SWFLOW1_BIT | \ + SC16IS7XX_EFR_SWFLOW0_BIT) + /* Misc definitions */ #define SC16IS7XX_FIFO_SIZE (64) @@ -523,8 +531,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Enable enhanced features */ regcache_cache_bypass(s->regmap, true); - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, - SC16IS7XX_EFR_ENABLE_BIT); + sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_ENABLE_BIT, + SC16IS7XX_EFR_ENABLE_BIT); + regcache_cache_bypass(s->regmap, false); /* Put LCR back to the normal mode */ @@ -932,7 +942,10 @@ static void sc16is7xx_set_termios(struct uart_port *port, if (termios->c_iflag & IXOFF) flow |= SC16IS7XX_EFR_SWFLOW1_BIT; - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow); + sc16is7xx_port_update(port, + SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_FLOWCTRL_BITS, + flow); regcache_cache_bypass(s->regmap, false); /* Update LCR register */ @@ -1007,8 +1020,9 @@ static int sc16is7xx_startup(struct uart_port *port) regcache_cache_bypass(s->regmap, true); /* Enable write access to enhanced features and internal clock div */ - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, - SC16IS7XX_EFR_ENABLE_BIT); + sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_ENABLE_BIT, + SC16IS7XX_EFR_ENABLE_BIT); /* Enable TCR/TLR */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, -- cgit v1.2.3