[U-Boot] [RFC] setting pio modes for IDE devices

[Steven A. Falco <sfalco@harris.com>]

The following patch adds the ability to call-out from the ide_ident
routine to a board-specific routine to set the PIO mode of an attached
device.

This feature is controlled by the preprocessor variable CONFIG_TUNE_CFA.

cmd_ide.c is modified to use the "drive identify information" read from the
device to compute a pio mode in the range 0 to 6.  This is then passed
to a board-specific routine, ide_set_piomode, to set the mode in
hardware.

Two other files are touched: file ata.h, to include word 163, which is the
"advanced CF parameters", and file ide.h, to add a prototype for the
board-specific routine (again controlled by the CONFIG_TUNE_CFA
variable).

Please let me know if this or some variation on the idea would be
acceptible.

	Steve


diff --git a/common/cmd_ide.c b/common/cmd_ide.c
index b4d9719..00b85db 100644
--- a/common/cmd_ide.c
+++ b/common/cmd_ide.c
@@ -1054,6 +1054,10 @@ static void ide_ident (block_dev_desc_t *dev_desc)
 	int do_retry = 0;
 #endif
 
+#ifdef CONFIG_TUNE_CFA
+	int pio_mode;
+#endif
+
 #if 0
 	int mode, cycle_time;
 #endif
@@ -1169,6 +1173,40 @@ static void ide_ident (block_dev_desc_t *dev_desc)
 	else
 		dev_desc->removable = 0;
 
+#ifdef CONFIG_TUNE_CFA
+	/* 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((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_CFA */
+
 #if 0
 	/*
 	 * Drive PIO mode autoselection
diff --git a/include/ata.h b/include/ata.h
index aa6e90d..3269636 100644
--- a/include/ata.h
+++ b/include/ata.h
@@ -294,7 +294,9 @@ 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;
 
 
diff --git a/include/ide.h b/include/ide.h
index 222f4f8..ae4624b 100644
--- a/include/ide.h
+++ b/include/ide.h
@@ -54,4 +54,9 @@ void ide_init(void);
 ulong ide_read(int device, lbaint_t blknr, ulong blkcnt, void *buffer);
 ulong ide_write(int device, lbaint_t blknr, ulong blkcnt, void *buffer);
 
+#ifdef CONFIG_TUNE_CFA
+/* Returns 0 on success, else returns 1.  pio_mode can be 0 through 6. */
+extern int ide_set_piomode(int pio_mode);
+#endif
+
 #endif /* _IDE_H */