diff options
| -rw-r--r-- | drivers/tty/serial/stm32-usart.c | 56 | ||||
| -rw-r--r-- | drivers/tty/serial/stm32-usart.h | 3 |
2 files changed, 50 insertions, 9 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index e8d7a7bb4339..e8321850938a 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -599,6 +599,36 @@ static void stm32_shutdown(struct uart_port *port) free_irq(port->irq, port); } +unsigned int stm32_get_databits(struct ktermios *termios) +{ + unsigned int bits; + + tcflag_t cflag = termios->c_cflag; + + switch (cflag & CSIZE) { + /* + * CSIZE settings are not necessarily supported in hardware. + * CSIZE unsupported configurations are handled here to set word length + * to 8 bits word as default configuration and to print debug message. + */ + case CS5: + bits = 5; + break; + case CS6: + bits = 6; + break; + case CS7: + bits = 7; + break; + /* default including CS8 */ + default: + bits = 8; + break; + } + + return bits; +} + static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { @@ -606,7 +636,7 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct stm32_usart_config *cfg = &stm32_port->info->cfg; struct serial_rs485 *rs485conf = &port->rs485; - unsigned int baud; + unsigned int baud, bits; u32 usartdiv, mantissa, fraction, oversampling; tcflag_t cflag = termios->c_cflag; u32 cr1, cr2, cr3; @@ -632,16 +662,28 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, if (cflag & CSTOPB) cr2 |= USART_CR2_STOP_2B; + bits = stm32_get_databits(termios); + if (cflag & PARENB) { + bits++; cr1 |= USART_CR1_PCE; - if ((cflag & CSIZE) == CS8) { - if (cfg->has_7bits_data) - cr1 |= USART_CR1_M0; - else - cr1 |= USART_CR1_M; - } } + /* + * Word length configuration: + * CS8 + parity, 9 bits word aka [M1:M0] = 0b01 + * CS7 or (CS6 + parity), 7 bits word aka [M1:M0] = 0b10 + * CS8 or (CS7 + parity), 8 bits word aka [M1:M0] = 0b00 + * M0 and M1 already cleared by cr1 initialization. + */ + if (bits == 9) + cr1 |= USART_CR1_M0; + else if ((bits == 7) && cfg->has_7bits_data) + cr1 |= USART_CR1_M1; + else if (bits != 8) + dev_dbg(port->dev, "Unsupported data bits config: %u bits\n" + , bits); + if (cflag & PARODD) cr1 |= USART_CR1_PS; diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index 6f294e280ea3..a70aa5006ab9 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -151,8 +151,7 @@ struct stm32_usart_info stm32h7_info = { #define USART_CR1_PS BIT(9) #define USART_CR1_PCE BIT(10) #define USART_CR1_WAKE BIT(11) -#define USART_CR1_M BIT(12) -#define USART_CR1_M0 BIT(12) /* F7 */ +#define USART_CR1_M0 BIT(12) /* F7 (CR1_M for F4) */ #define USART_CR1_MME BIT(13) /* F7 */ #define USART_CR1_CMIE BIT(14) /* F7 */ #define USART_CR1_OVER8 BIT(15) |