diff mbox

[U-Boot,4/8] x86: Initialize i8254 timer counter 1

Message ID 1445564355-19911-5-git-send-email-bmeng.cn@gmail.com
State Superseded
Headers show

Commit Message

Bin Meng Oct. 23, 2015, 1:39 a.m. UTC 
Initialize counter 1, used to refresh request signal. This is
required for legacy purpose as some codes like vgabios utilizes
counter 1 to provide delay functionality.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---

 arch/x86/lib/pcat_timer.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Simon Glass Oct. 23, 2015, 1:47 a.m. UTC | #1 
On 22 October 2015 at 19:39, Bin Meng <bmeng.cn@gmail.com> wrote:
> Initialize counter 1, used to refresh request signal. This is
> required for legacy purpose as some codes like vgabios utilizes
> counter 1 to provide delay functionality.
>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>
>  arch/x86/lib/pcat_timer.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Acked-by: Simon Glass <sjg@chromium.org>
diff mbox

Patch

diff --git a/arch/x86/lib/pcat_timer.c b/arch/x86/lib/pcat_timer.c
index ce15818..347cdda 100644
--- a/arch/x86/lib/pcat_timer.c
+++ b/arch/x86/lib/pcat_timer.c
@@ -9,11 +9,21 @@ 
 #include <asm/io.h>
 #include <asm/i8254.h>
 
+#define TIMER1_VALUE	18	/* 15.6us */
 #define TIMER2_VALUE	0x0a8e	/* 440Hz */
 
 int pcat_timer_init(void)
 {
 	/*
+	 * Initialize counter 1, used to refresh request signal.
+	 * This is required for legacy purpose as some codes like
+	 * vgabios utilizes counter 1 to provide delay functionality.
+	 */
+	outb(PIT_CMD_CTR1 | PIT_CMD_LOW | PIT_CMD_MODE2,
+	     PIT_BASE + PIT_COMMAND);
+	outb(TIMER1_VALUE, PIT_BASE + PIT_T1);
+
+	/*
 	 * Initialize counter 2, used to drive the speaker.
 	 * To start a beep, set both bit0 and bit1 of port 0x61.
 	 * To stop it, clear both bit0 and bit1 of port 0x61.