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authorLech Perczak <l.perczak@camlintechnologies.com>2022-02-21 11:56:13 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-02-25 10:24:27 +0100
commitc112653b89e0cea4aa2ea26fcfbbb30a2193339e (patch)
treee24b54727a9a59274efb3ce8d1cc16dbe63bccd9 /drivers/tty/serial/sc16is7xx.c
parent932d596378b0253354246f4aa3662add4883a167 (diff)
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sc16is7xx: Preserve EFR bits on update
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 <l.perczak@camlintechnologies.com> Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com> Link: https://lore.kernel.org/r/20220221105618.3503470-2-tomasz.mon@camlingroup.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/sc16is7xx.c')
-rw-r--r--drivers/tty/serial/sc16is7xx.c24
1 files changed, 19 insertions, 5 deletions
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,