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| author | John Klug <john.klug@multitech.com> | 2021-11-29 12:53:26 -0600 |
|---|---|---|
| committer | John Klug <john.klug@multitech.com> | 2021-12-29 08:35:07 -0600 |
| commit | 6321c8be2781b9bfc590262bbb2a6292490f491e (patch) | |
| tree | 5524ac19cdaa0961619e5dbb6eeee03435b88dc7 | |
| parent | 36f6359fda407bba462b5c0d0f9beff807f91c4e (diff) | |
| download | meta-multitech-atmel-6321c8be2781b9bfc590262bbb2a6292490f491e.tar.gz meta-multitech-atmel-6321c8be2781b9bfc590262bbb2a6292490f491e.tar.bz2 meta-multitech-atmel-6321c8be2781b9bfc590262bbb2a6292490f491e.zip | |
Disable CRTSCTS when setting RS485 half duplex to match Vizzini driver
| -rw-r--r-- | recipes-kernel/linux/linux-at91-4.9.87/mtcdt/linux-4.9-rs485-atmel-crtscts.patch | 20 | ||||
| -rw-r--r-- | recipes-kernel/linux/linux-at91_4.9.87.bb | 1 |
2 files changed, 21 insertions, 0 deletions
diff --git a/recipes-kernel/linux/linux-at91-4.9.87/mtcdt/linux-4.9-rs485-atmel-crtscts.patch b/recipes-kernel/linux/linux-at91-4.9.87/mtcdt/linux-4.9-rs485-atmel-crtscts.patch new file mode 100644 index 0000000..1cf147e --- /dev/null +++ b/recipes-kernel/linux/linux-at91-4.9.87/mtcdt/linux-4.9-rs485-atmel-crtscts.patch @@ -0,0 +1,20 @@ +This patch allows RS485 Half Duplex (ATMEL_US_USMODE_RS485 is half duplex) to +work even if handshaking is turned on. This mimics the behavior of the EXAR +USB/Serial driver known as Vizzini. It is impossible to use handshaking when +using ATMEL_US_USMODE_RS485. This provides compatibility between MTCDT-0.1 and +MTCDT-0.2. +======================================================================================= +diff -Naru orig/drivers/tty/serial/atmel_serial.c new/drivers/tty/serial/atmel_serial.c +--- orig/drivers/tty/serial/atmel_serial.c 2021-11-29 12:29:38.472076748 -0600 ++++ new/drivers/tty/serial/atmel_serial.c 2021-11-29 12:26:05.668072459 -0600 +@@ -2171,7 +2171,10 @@ + atmel_uart_writel(port, ATMEL_US_TTGR, + port->rs485.delay_rts_after_send); + mode |= ATMEL_US_USMODE_RS485; ++ /* CRTSCTS is impossible in RS485 mode, and breaks the driver ++ * so we cannot do a send. */ ++ termios->c_cflag &= ~CRTSCTS; + } else if (termios->c_cflag & CRTSCTS) { + /* RS232 with hardware handshake (RTS/CTS) */ + if (atmel_use_fifo(port) && + !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { diff --git a/recipes-kernel/linux/linux-at91_4.9.87.bb b/recipes-kernel/linux/linux-at91_4.9.87.bb index b6df5b8..fc50f0d 100644 --- a/recipes-kernel/linux/linux-at91_4.9.87.bb +++ b/recipes-kernel/linux/linux-at91_4.9.87.bb @@ -64,6 +64,7 @@ SRC_URI_append_mtcdt = "\ file://mt-at91.h \ file://linux-4.9-mtcdt-device-tree.patch \ file://linux-4.9-mtcdt-atmel-multidrop.patch \ + file://linux-4.9-rs485-atmel-crtscts.patch \ " SRC_URI_append_mtrv1 = "\ ${COMMON_PATCHES} \ |