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authorErwan Le Ray <erwan.leray@st.com>2019-06-18 12:02:26 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-21 11:17:36 +0200
commit84872dc448fe0ae11fe8412f4966e9c431a45b8f (patch)
tree38c487121a9a239cfdee11211fd0cfe600a0dc29 /drivers/tty
parentd0a6a7bcc3fa0e97efce1d9a5c4cca6f3474c6bb (diff)
downloadlinux-84872dc448fe0ae11fe8412f4966e9c431a45b8f.tar.bz2
serial: stm32: add RX and TX FIFO flush
Adds a flush of RX and TX FIFOs, and fixes some errors: - adds RX FIFO flush in startup fonction - removes the useless transmitter enabling in startup fonction (e.g. receiver only, see Documentation/serial/driver) - configures FIFO threshold before enabling it, rather than after - flushes both TX and RX in set_termios function Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/stm32-usart.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index fd9fb33ce4fe..24a2261f879a 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -599,11 +599,11 @@ static int stm32_startup(struct uart_port *port)
if (ret)
return ret;
- val = stm32_port->cr1_irq | USART_CR1_TE | USART_CR1_RE;
- if (stm32_port->fifoen)
- val |= USART_CR1_FIFOEN;
- stm32_set_bits(port, ofs->cr1, val);
+ /* RX FIFO Flush */
+ if (ofs->rqr != UNDEF_REG)
+ stm32_set_bits(port, ofs->rqr, USART_RQR_RXFRQ);
+ /* Tx and RX FIFO configuration */
if (stm32_port->fifoen) {
val = readl_relaxed(port->membase + ofs->cr3);
val &= ~(USART_CR3_TXFTCFG_MASK | USART_CR3_RXFTCFG_MASK);
@@ -612,6 +612,12 @@ static int stm32_startup(struct uart_port *port)
writel_relaxed(val, port->membase + ofs->cr3);
}
+ /* RX FIFO enabling */
+ val = stm32_port->cr1_irq | USART_CR1_RE;
+ if (stm32_port->fifoen)
+ val |= USART_CR1_FIFOEN;
+ stm32_set_bits(port, ofs->cr1, val);
+
return 0;
}
@@ -694,8 +700,12 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
/* Stop serial port and reset value */
writel_relaxed(0, port->membase + ofs->cr1);
- cr1 = USART_CR1_TE | USART_CR1_RE;
+ /* flush RX & TX FIFO */
+ if (ofs->rqr != UNDEF_REG)
+ stm32_set_bits(port, ofs->rqr,
+ USART_RQR_TXFRQ | USART_RQR_RXFRQ);
+ cr1 = USART_CR1_TE | USART_CR1_RE;
if (stm32_port->fifoen)
cr1 |= USART_CR1_FIFOEN;
cr2 = 0;