Patch set updated for coreboot: 4399055 keyboard: Check keyboard controller is ready before initialization

[Andrew Wu]

Andrew Wu ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3958

-gerrit

commit 4399055945c2d3653f3624116b1d2f58704423d3
Author: Andrew Wu 
Date:   Fri Oct 11 13:44:55 2013 +0800

keyboard: Check keyboard controller is ready before initialization

PS/2 keyboard controller (8042) has a system flag bit in status byte
    (bit 2 of 0x64 port). This bit indicates keyboard controller is ready
    or not. System reset clears this bit, and when keyboard controller is
    ready, this bit is set.

Add checking system flag bit in pc_keyboard_init function to make
    sure keyboard controller is ready to accept commands.

It is important for Vortex86EX keyboard controller, which has a long
    startup time.

Change-Id: I2cdb533a5b25575e1717434533a60decf748f6d8
    Signed-off-by: Andrew Wu 
---
 src/drivers/pc80/keyboard.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/drivers/pc80/keyboard.c b/src/drivers/pc80/keyboard.c
index 2888bcf..7388920 100644
--- a/src/drivers/pc80/keyboard.c
+++ b/src/drivers/pc80/keyboard.c
@@ -31,6 +31,7 @@
 #define KBD_STATUS	0x64
 #define   KBD_IBF	(1 << 1) // 1: input buffer full (data ready for ec)
 #define   KBD_OBF	(1 << 0) // 1: output buffer full (data ready for host)
+#define   KBD_SYS_FLAG	(1 << 2) // 1: self-test passed

// Keyboard Controller Commands
 #define KBC_CMD_READ_COMMAND	0x20 // Read command byte
@@ -64,6 +65,18 @@
 /* Wait 400ms for keyboard controller answers */
 #define KBC_TIMEOUT_IN_MS 400

+static int kbc_wait_system_flag(void)
+{
+	u32 timeout;
+	for (timeout = KBC_TIMEOUT_IN_MS;
+	     timeout && ((inb(KBD_STATUS) & KBD_SYS_FLAG) == 0); timeout--)
+		mdelay(1);
+
+	if (!timeout)
+		printk(BIOS_INFO, "Keyboard controller timed out setting system flag\n");
+	return !!timeout;
+}
+
 static int kbc_input_buffer_empty(void)
 {
    u32 timeout;
@@ -113,6 +126,10 @@ static int kbc_self_test(void)
 {
    u8 self_test;

+	/* Wait until keyboard controller ready (system flag = 1) */
+	if (!kbc_wait_system_flag())
+		return 0;
+
    /* Clean up any junk that might have been in the KBC.
     * Both input and output buffers must be empty.
     */