- Add minimal support for TI16754 4xUART chip into sio(4) driver and remove

  now unnecessary hack from the previous commit;
- Add support for Interrupt Latch Register (ILR) into puc(4). So far only
  ILRs compatible with specifications from Digi International are supported.
  Support for other types of ILRs could be easily added later;
- Correct clock frequency for IC Book Labs Dreadnought x16 Lite board;
- Enable ILR detection/usage for IC Book Labs Dreadnought x16 boards.

Sponsored by:   IC Book Labs
MFC after:      2 weeks

1 files changed, 33 insertions, 1 deletions

diff --git a/sys/dev/sio/sio.c b/sys/dev/sio/sio.c
index f5e7363..dcfd46a 100644
--- a/sys/dev/sio/sio.c
+++ b/sys/dev/sio/sio.c
@@ -120,6 +120,7 @@
 #define COM_C_IIR_TXRDYBUG	(0x80000)
 #define COM_IIR_TXRDYBUG(flags)	((flags) & COM_C_IIR_TXRDYBUG)
 #define COM_NOSCR(flags)	((flags) & 0x100000)
+#define COM_TI16754(flags)	((flags) & 0x200000)
 #define	COM_FIFOSIZE(flags)	(((flags) & 0xff000000) >> 24)
 
 #define	sio_getreg(com, off) \
@@ -605,6 +606,33 @@ sioprobe(dev, xrid, rclk, noprobe)
 /* EXTRA DELAY? */
 
 	/*
+	 * For the TI16754 chips set prescaler to 1 (4 is often the
+	 * default after-reset value), otherwise it's impossible to
+	 * get highest baudrates.
+	 */
+	if (COM_TI16754(flags)) {
+		u_char t1, t2;
+
+		/* Save LCR */
+		t1 = sio_getreg(com, com_lctl);
+		/* Enable EFR */
+		sio_setreg(com, com_lctl, 0xbf);
+		/* Save EFR */
+		t2 = sio_getreg(com, com_iir);
+		/* Unlock MCR[7] */
+		sio_setreg(com, com_iir, t2 | 0x10);
+		/* Disable EFR */
+		sio_setreg(com, com_lctl, 0);
+		/* Set prescaler to 1 */
+		sio_setreg(com, com_mcr, sio_getreg(com, com_mcr) & 0x7f);
+		/* Enable EFR */
+		sio_setreg(com, com_lctl, 0xbf);
+		/* Restore EFR */
+		sio_setreg(com, com_iir, t2);
+		/* Restore LCR */
+		sio_setreg(com, com_lctl, t1);
+	}
+	/*
 	 * Initialize the speed and the word size and wait long enough to
 	 * drain the maximum of 16 bytes of junk in device output queues.
 	 * The speed is undefined after a master reset and must be set
@@ -731,6 +759,7 @@ sioprobe(dev, xrid, rclk, noprobe)
 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
 	failures[2] = (sio_getreg(com, com_mcr) & 0x7f) - mcr_image;
+	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
 	DELAY(10000);		/* Some internal modems need this time */
 	irqmap[1] = isa_irq_pending();
 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
@@ -1007,6 +1036,9 @@ sioattach(dev, xrid, rclk)
 				com->st16650a = 1;
 				com->tx_fifo_size = 32;
 				printf(" ST16650A");
+			} else if (COM_TI16754(flags)) {
+				com->tx_fifo_size = 64;
+				printf(" TI16754");
 			} else {
 				com->tx_fifo_size = COM_FIFOSIZE(flags);
 				printf(" 16550A");
@@ -1019,7 +1051,7 @@ sioattach(dev, xrid, rclk)
 				break;
 			}
 #endif
-		if (!com->st16650a) {
+		if (!com->st16650a && !COM_TI16754(flags)) {
 			if (!com->tx_fifo_size)
 				com->tx_fifo_size = 16;
 			else