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

[Steven A. Falco]

Wolfgang Denk wrote:
> Dear "Steven A. Falco",
> 
> In message <48A35533.1010901 at harris.com> you wrote:
>> 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.
> 
> What does CFA mean?
> 

CFA is "Compact Flash Association".  Since this hook could be used more
generally, a better name is probably CONFIG_TUNE_PIO, so that is what I
used in the respin of the patch shown below.

>> 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).
> 
> Is there a specific reason for using #ifdef's instead of a weak
> function?
> 

No reason.  The respin below uses weak linkage.  I still included ifdefs,
because I'm guessing that if one does not use the tuning feature, then we
wouldn't want the overhead of calculating the pio_mode, only to discard it.
But I can remove the ifdefs completely if you prefer.

I can also present some example code showing how I am using this hook in a
BSP I am working on.  But the BSP is not in good enough shape for
submission.

> Best regards,
> 
> Wolfgang Denk
> 

	Steve


Signed-off-by: Steven A. Falco <sfalco at harris.com>
---
 common/cmd_ide.c |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/ata.h    |    4 +++-
 2 files changed, 55 insertions(+), 1 deletions(-)

diff --git a/common/cmd_ide.c b/common/cmd_ide.c
index b4d9719..0e435a7 100644
--- a/common/cmd_ide.c
+++ b/common/cmd_ide.c
@@ -167,6 +167,10 @@ static void input_data(int dev, ulong *sect_buf, int words);
 static void output_data(int dev, ulong *sect_buf, int words);
 static void ident_cpy (unsigned char *dest, unsigned char *src, unsigned int len);
 
+#ifdef CONFIG_TUNE_PIO
+int inline ide_set_piomode(int pio_mode);
+#endif
+
 #ifndef CFG_ATA_PORT_ADDR
 #define CFG_ATA_PORT_ADDR(port) (port)
 #endif
@@ -838,6 +842,16 @@ __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
+
 #ifdef __PPC__
 # ifdef CONFIG_AMIGAONEG3SE
 static void
@@ -1054,6 +1068,10 @@ 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
@@ -1169,6 +1187,40 @@ 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((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
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;
 
 
-- 
1.5.5.1