[PATCH v5 6/9] tty: serial: atmel: Separate mode clearing between UART and USART

From: Sergiu Moga
Date: Thu Sep 22 2022 - 07:43:55 EST


When clearing the mode of the serial IP inside the atmel_set_termios()
method, make sure that the difference between the bitfields placement
of the UART IP's and USART IP's is taken into account, as some of
them overlap with each other. For example, ATMEL_UA_BRSRCCK overlaps
with ATMEL_US_NBSTOP and ATMEL_US_USCLKS overlaps with ATMEL_UA_FILTER.

Furthermore, add definitions for the Baud Rate Source Clock and the
Filter bitfields of the Mode Register of UART IP's, since they were
missing.

Signed-off-by: Sergiu Moga <sergiu.moga@xxxxxxxxxxxxx>
---


v1 -> v5:
- This patch was not here before but it also includes the previous patch:
`[PATCH v4 7/9] tty: serial: atmel: Define BRSRCCK bitmask of UART IP's Mode Register`
squashed into it and define BRSRCCK as a bitfield instead of a bitmask,
since it is only 1 bit.



drivers/tty/serial/atmel_serial.c | 7 +++++--
drivers/tty/serial/atmel_serial.h | 2 ++
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index ab4a9dfae07d..e3e14cb7668b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2134,8 +2134,11 @@ static void atmel_set_termios(struct uart_port *port,
mode = old_mode = atmel_uart_readl(port, ATMEL_US_MR);

/* reset the mode, clock divisor, parity, stop bits and data size */
- mode &= ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP |
- ATMEL_US_PAR | ATMEL_US_USMODE);
+ if (atmel_port->is_usart)
+ mode &= ~(ATMEL_US_NBSTOP | ATMEL_US_PAR | ATMEL_US_CHRL |
+ ATMEL_US_USCLKS | ATMEL_US_USMODE);
+ else
+ mode &= ~(ATMEL_UA_BRSRCCK | ATMEL_US_PAR | ATMEL_UA_FILTER);

baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);

diff --git a/drivers/tty/serial/atmel_serial.h b/drivers/tty/serial/atmel_serial.h
index 0d8a0f9cc5c3..2a525b58e11a 100644
--- a/drivers/tty/serial/atmel_serial.h
+++ b/drivers/tty/serial/atmel_serial.h
@@ -50,6 +50,7 @@
#define ATMEL_US_USCLKS_MCK (0 << 4)
#define ATMEL_US_USCLKS_MCK_DIV8 (1 << 4)
#define ATMEL_US_USCLKS_SCK (3 << 4)
+#define ATMEL_UA_FILTER BIT(4)
#define ATMEL_US_CHRL GENMASK(7, 6) /* Character Length */
#define ATMEL_US_CHRL_5 (0 << 6)
#define ATMEL_US_CHRL_6 (1 << 6)
@@ -67,6 +68,7 @@
#define ATMEL_US_NBSTOP_1 (0 << 12)
#define ATMEL_US_NBSTOP_1_5 (1 << 12)
#define ATMEL_US_NBSTOP_2 (2 << 12)
+#define ATMEL_UA_BRSRCCK BIT(12) /* Clock Selection for UART */
#define ATMEL_US_CHMODE GENMASK(15, 14) /* Channel Mode */
#define ATMEL_US_CHMODE_NORMAL (0 << 14)
#define ATMEL_US_CHMODE_ECHO (1 << 14)
--
2.34.1