Adds the support of RX FIFO threshold in order to improve the RX FIFO
management.
This is done by enabling fifo threshold interrupt, instead of relying
on rx empty/fifo not full irq. That basically generates one irq/char
currently. With this patch:
- RXCFG is set to half fifo size (e.g. 16/2 = 8 data for a 16 data depth
FIFO)
- irq rate may be reduced by up to 1/RXCFG, e.g. 1 over 8 with current
RXCFG setting.
- Receiver timeout is used to gather chars when FIFO threshold isn't
reached.
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds the support of TX FIFO threshold in order to improve the TX FIFO
management:
- TX FIFO threshold irq enabling (instead of relying on tx empty / fifo
not full irq that generates one irq/char)
- TXCFG is set to half fifo size (e.g. 16/2 = 8 data for a 16 data depth
FIFO)
- irq rate may be reduced by up to 1/TXCFG, e.g. 1 over 8 with current
TXCFG setting.
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support of RX timeout interrupts to limit the number of interrupts.
RX timeout is a number of bits (baud clock cycles) without
transmission seen in the receiver. One character is used as an arbitrary
RX timeout value.
If parity is enabled, the number of bits has to include parity bit.
Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Fixes a rx data error when data length < 8 bits and parity is enabled.
RDR register MSB is used for parity bit reception.
- Adds a mask to ignore MSB when data is get from RDR.
Fixes: 3489187204 ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Fixes parity and framing error bit by clearing parity and framing error
flag. The current implementation doesn't clear the error bits when an
error is detected.
- Fixes the incorrect name of framing error clearing flag in header file.
- Fixes misalignement between data frame and errors status. The status
read for "n" frame was the status of "n+1" frame".
- Fixes break detection was not triggered by the expected register.
Fixes: 48a6092fb4 ("serial: stm32-usart: Add STM32 USART Driver")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
STM32 supports either:
- 8 and 9 bits word length (including parity bit) for stm32f4 compatible
devices
- 7, 8 and 9 bits word length (including parity bit) for stm32f7 and
stm32h7 compatible devices.
As a consequence STM32 supports the following termios configurations:
- CS7 with parity bit, and CS8 (with or without parity bit) for stm32f4
compatible devices.
- CS6 with parity bit, CS7 and CS8 (with or without parity bit) for
stm32f7 and stm32h7 compatible devices.
This patch is fixing word length by configuring correctly the SoC with
supported configurations.
Fixes: ada8618ff3 ("serial: stm32: adding support for stm32f7")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds fifo mode support for rx and tx.
A fifo configuration is set in each port structure.
Add has_fifo flag to usart configuration to use fifo only when possible.
Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for wake-up from low power modes. This extends stm32f7.
Introduce new compatible for stm32h7 to manage wake-up capability.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Increase max number of ports for stm32h7
which supports up to 8 uart and usart instances.
Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Correct management of multi-ports. Each port has
its own last residue value and its own alias.
Signed-off-by: Gerald Baeza <gerald.baeza@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/stm32-usart.c: In function ‘stm32_receive_chars’:
drivers/tty/serial/stm32-usart.c:130: warning: comparison is always true due to limited range of data type
drivers/tty/serial/stm32-usart.c: In function ‘stm32_tx_dma_complete’:
drivers/tty/serial/stm32-usart.c:177: warning: comparison is always false due to limited range of data type
stm32_usart_offsets.icr is u8, while UNDEF_REG = ~0 is int, and thus
0xffffffff.
As all registers in stm32_usart_offsets are u8, change the definition of
UNDEF_REG to 0xff to fix this.
Fixes: ada8618ff3 ("serial: stm32: adding support for stm32f7")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
