From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: [PATCH 3/5] pch_uart: Add user_uartclk parameter Date: Fri, 9 Mar 2012 09:51:50 -0800 Message-ID: References: Return-path: Received: from mga03.intel.com ([143.182.124.21]:59515 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753405Ab2CIRxA (ORCPT ); Fri, 9 Mar 2012 12:53:00 -0500 In-Reply-To: In-Reply-To: References: Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Linux Kernel Mailing List Cc: Darren Hart , Tomoya MORINAGA , Feng Tang , Greg Kroah-Hartman , Alan Cox , linux-serial@vger.kernel.org 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 CC: Tomoya MORINAGA CC: Feng Tang CC: Greg Kroah-Hartman CC: Alan Cox CC: linux-serial@vger.kernel.org --- 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 88a1be0..46f6fbf 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -295,6 +295,7 @@ 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 }; @@ -372,6 +373,9 @@ 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; @@ -1860,3 +1864,4 @@ 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