From: Darren Hart <[email protected]> For cases where boards with non-default clocks are not yet added to the kernel or when the clock varies across hardware revisions, it is useful to be able to specify the UART clock on the kernel command line.
Add the user_uartclk parameter and prefer it, if set, to the default and board specific UART clock settings. Specify user_uartclock on the command-line with "pch_uart.user_uartclk=48000000". Signed-off-by: Darren Hart <[email protected]> CC: Tomoya MORINAGA <[email protected]> CC: Feng Tang <[email protected]> CC: Greg Kroah-Hartman <[email protected]> CC: Alan Cox <[email protected]> CC: [email protected] --- drivers/tty/serial/pch_uart.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index 1706169..2233e31 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -290,6 +290,7 @@ static struct pch_uart_driver_data drv_dat[] = { static struct eg20t_port *pch_uart_ports[PCH_UART_NR]; #endif static unsigned int default_baud = 9600; +static unsigned int user_uartclk = 0; static const int trigger_level_256[4] = { 1, 64, 128, 224 }; static const int trigger_level_64[4] = { 1, 16, 32, 56 }; static const int trigger_level_16[4] = { 1, 4, 8, 14 }; @@ -300,6 +301,9 @@ static int pch_uart_get_uartclk(void) { const char *cmp; + if (user_uartclk) + return user_uartclk; + cmp = dmi_get_system_info(DMI_BOARD_NAME); if (cmp && strstr(cmp, "CM-iTC")) return CMITC_UARTCLK; @@ -1799,3 +1803,4 @@ module_exit(pch_uart_module_exit); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Intel EG20T PCH UART PCI Driver"); module_param(default_baud, uint, S_IRUGO); +module_param(user_uartclk, uint, S_IRUGO); -- 1.7.6.5 _______________________________________________ yocto mailing list [email protected] https://lists.yoctoproject.org/listinfo/yocto
