Add a hook to allow board-specific PIO mode setting.

This patch adds a hook whereby a board-specific routine can be called to
configure hardware for a PIO mode.  The prototype for the board-specific
routine is:

	int inline ide_set_piomode(int pio_mode)

ide_set_piomode should be prepared to configure hardware for a pio_mode
between 0 and 6, inclusive.  It should return 0 on success or 1 on failure.

Signed-off-by: Steven A. Falco <sfalco@harris.com>

common/cmd_ide.c

@@ -543,6 +543,16 @@ __ide_inb(int dev, int port)
 unsigned char inline ide_inb(int dev, int port)
 			__attribute__((weak, alias("__ide_inb")));
 
+#ifdef CONFIG_TUNE_PIO
+int inline
+__ide_set_piomode(int pio_mode)
+{
+	return 0;
+}
+int inline ide_set_piomode(int pio_mode)
+			__attribute__((weak, alias("__ide_set_piomode")));
+#endif
+
 void ide_init (void)
 {
 
@@ -1053,6 +1063,10 @@ static void ide_ident (block_dev_desc_t *dev_desc)
 	int do_retry = 0;
 #endif
 
+#ifdef CONFIG_TUNE_PIO
+	int pio_mode;
+#endif
+
 #if 0
 	int mode, cycle_time;
 #endif
@@ -1168,6 +1182,38 @@ static void ide_ident (block_dev_desc_t *dev_desc)
 	else
 		dev_desc->removable = 0;
 
+#ifdef CONFIG_TUNE_PIO
+	/* Mode 0 - 2 only, are directly determined by word 51. */
+	pio_mode = iop->tPIO;
+	if (pio_mode > 2) {
+		printf("WARNING: Invalid PIO (word 51 = %d).\n", pio_mode);
+		pio_mode = 0; /* Force it to dead slow, and hope for the best... */
+	}
+
+	/* Any CompactFlash Storage Card that supports PIO mode 3 or above
+	 * shall set bit 1 of word 53 to one and support the fields contained
+	 * in words 64 through 70.
+	 */
+	if (iop->field_valid & 0x02) {
+		/* Mode 3 and above are possible.  Check in order from slow
+		 * to fast, so we wind up with the highest mode allowed.
+		 */
+		if (iop->eide_pio_modes & 0x01)
+			pio_mode = 3;
+		if (iop->eide_pio_modes & 0x02)
+			pio_mode = 4;
+		if (ata_id_is_cfa((u16 *)iop)) {
+			if ((iop->cf_advanced_caps & 0x07) == 0x01)
+				pio_mode = 5;
+			if ((iop->cf_advanced_caps & 0x07) == 0x02)
+				pio_mode = 6;
+		}
+	}
+
+	/* System-specific, depends on bus speeds, etc. */
+	ide_set_piomode(pio_mode);
+#endif /* CONFIG_TUNE_PIO */
+
 #if 0
 	/*
 	 * Drive PIO mode autoselection

include/ata.h

@@ -236,7 +236,9 @@ typedef struct hd_driveid {
 	unsigned short	words130_155[26];/* reserved vendor words 130-155 */
 	unsigned short	word156;
 	unsigned short	words157_159[3];/* reserved vendor words 157-159 */
-	unsigned short	words160_255[95];/* reserved words 160-255 */
+	unsigned short	words160_162[3];/* reserved words 160-162 */
+	unsigned short	cf_advanced_caps;
+	unsigned short	words164_255[92];/* reserved words 164-255 */
 } hd_driveid_t;