post/i2c: Add ability to ignore I2C devices

Add the ability to not report an I2C POST error for a set of given I2C addresses on bootup. This is useful for cases when a device may or may not be present, and neither case is considered an error. For example: - Some form factors such as XMC and Compact PCI Express have an I2C EEPROM whose address changes based on geographical address. Eg installed in one slot its EEPROM address is, 0x50, in another its 0x51, etc. This allows multiple devices to have their EEPROMs present on the same I2C bus. Thus the I2C devices present for an XMC or CPCIe card depend on if and where other cards are installed in the same system. - Some cards have optional I2C devices. Eg one hardware build configuration has different I2C devices than another and software can't determine if the optional device should be present or not. - Some cards have optional daughtercards with I2C devices on them. - I2C EEPROMs address range depends on their size. Its possible to support differently size EEPROMs by only probing the EEPROM's base address and ignoring the other addresses that are impacted by its size. A new CONFIG_SYS_POST_I2C_IGNORES define has been added which specifies a list of I2C addresses for the I2C POST to ignore. Signed-off-by: Peter Tyser <ptyser@xes-inc.com> Acked-by: Heiko Schocher <hs@denx.de> Acked-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

post/i2c: Add ability to ignore I2C devices
Add the ability to not report an I2C POST error for a set of given I2C addresses on bootup. This is useful for cases when a device may or may not be present, and neither case is considered an error. For example: - Some form factors such as XMC and Compact PCI Express have an I2C EEPROM whose address changes based on geographical address. Eg installed in one slot its EEPROM address is, 0x50, in another its 0x51, etc. This allows multiple devices to have their EEPROMs present on the same I2C bus. Thus the I2C devices present for an XMC or CPCIe card depend on if and where other cards are installed in the same system. - Some cards have optional I2C devices. Eg one hardware build configuration has different I2C devices than another and software can't determine if the optional device should be present or not. - Some cards have optional daughtercards with I2C devices on them. - I2C EEPROMs address range depends on their size. Its possible to support differently size EEPROMs by only probing the EEPROM's base address and ignoring the other addresses that are impacted by its size. A new CONFIG_SYS_POST_I2C_IGNORES define has been added which specifies a list of I2C addresses for the I2C POST to ignore. Signed-off-by: Peter Tyser <ptyser@xes-inc.com> Acked-by: Heiko Schocher <hs@denx.de> Acked-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Peter Tyser · Kumar Gala
1 parent 60aaaa0782
Showing 2 changed files with 32 additions and 2 deletions Side-by-side Diff
doc/README.POST
post/drivers/i2c.c
@@ -665,6 +665,14 @@
 devices are detected.  If CONFIG_SYS_POST_I2C_ADDRS is not defined
 the test will pass if any I2C device is found.
  
+The CONFIG_SYS_POST_I2C_IGNORES define can be used to list I2C
+devices which may or may not be present when using
+CONFIG_SYS_POST_I2C_ADDRS.  The I2C POST test will pass regardless
+if the devices in CONFIG_SYS_POST_I2C_IGNORES are found or not.
+This is useful in cases when I2C devices are optional (eg on a
+daughtercard that may or may not be present) or not critical
+to board operation.
+
 2.2.2.2. Watchdog timer test
  
 To test the watchdog timer the scheme mentioned above (refer to
@@ -27,8 +27,12 @@
  * For verifying the I2C bus, a full I2C bus scanning is performed.
  *
  * #ifdef CONFIG_SYS_POST_I2C_ADDRS
- *   The test is considered as passed if all the devices and
- *   only the devices in the list are found.
+ *   The test is considered as passed if all the devices and only the devices
+ *   in the list are found.
+ *   #ifdef CONFIG_SYS_POST_I2C_IGNORES
+ *     Ignore devices listed in CONFIG_SYS_POST_I2C_IGNORES.  These devices
+ *     are optional or not vital to board functionality.
+ *   #endif
  * #else [ ! CONFIG_SYS_POST_I2C_ADDRS ]
  *   The test is considered as passed if any I2C device is found.
  * #endif
  
@@ -40,12 +44,28 @@
  
 #if CONFIG_POST & CONFIG_SYS_POST_I2C
  
+static int i2c_ignore_device(unsigned int chip)
+{
+#ifdef CONFIG_SYS_POST_I2C_IGNORES
+	const unsigned char i2c_ignore_list[] = CONFIG_SYS_POST_I2C_IGNORES;
+	int i;
+
+	for (i = 0; i < sizeof(i2c_ignore_list); i++)
+		if (i2c_ignore_list[i] == chip)
+			return 1;
+#endif
+
+	return 0;
+}
+
 int i2c_post_test (int flags)
 {
 	unsigned int i;
 #ifndef CONFIG_SYS_POST_I2C_ADDRS
 	/* Start at address 1, address 0 is the general call address */
 	for (i = 1; i < 128; i++)
+		if (i2c_ignore_device(i))
+			continue;
 		if (i2c_probe (i) == 0)
 			return 0;
  
@@ -58,6 +78,8 @@
  
 	/* Start at address 1, address 0 is the general call address */
 	for (i = 1; i < 128; i++) {
+		if (i2c_ignore_device(i))
+			continue;
 		if (i2c_probe(i) != 0)
 			continue;
...	...	@@ -665,6 +665,14 @@
665	665	devices are detected. If CONFIG_SYS_POST_I2C_ADDRS is not defined
666	666	the test will pass if any I2C device is found.
667	667
	668	+The CONFIG_SYS_POST_I2C_IGNORES define can be used to list I2C
	669	+devices which may or may not be present when using
	670	+CONFIG_SYS_POST_I2C_ADDRS. The I2C POST test will pass regardless
	671	+if the devices in CONFIG_SYS_POST_I2C_IGNORES are found or not.
	672	+This is useful in cases when I2C devices are optional (eg on a
	673	+daughtercard that may or may not be present) or not critical
	674	+to board operation.
	675	+
668	676	2.2.2.2. Watchdog timer test
669	677
670	678	To test the watchdog timer the scheme mentioned above (refer to
...	...	@@ -27,8 +27,12 @@
27	27	* For verifying the I2C bus, a full I2C bus scanning is performed.
28	28	*
29	29	* #ifdef CONFIG_SYS_POST_I2C_ADDRS
30		- * The test is considered as passed if all the devices and
31		- * only the devices in the list are found.
	30	+ * The test is considered as passed if all the devices and only the devices
	31	+ * in the list are found.
	32	+ * #ifdef CONFIG_SYS_POST_I2C_IGNORES
	33	+ * Ignore devices listed in CONFIG_SYS_POST_I2C_IGNORES. These devices
	34	+ * are optional or not vital to board functionality.
	35	+ * #endif
32	36	* #else [ ! CONFIG_SYS_POST_I2C_ADDRS ]
33	37	* The test is considered as passed if any I2C device is found.
34	38	* #endif
35	39
...	...	@@ -40,12 +44,28 @@
40	44
41	45	#if CONFIG_POST & CONFIG_SYS_POST_I2C
42	46
	47	+static int i2c_ignore_device(unsigned int chip)
	48	+{
	49	+#ifdef CONFIG_SYS_POST_I2C_IGNORES
	50	+ const unsigned char i2c_ignore_list[] = CONFIG_SYS_POST_I2C_IGNORES;
	51	+ int i;
	52	+
	53	+ for (i = 0; i < sizeof(i2c_ignore_list); i++)
	54	+ if (i2c_ignore_list[i] == chip)
	55	+ return 1;
	56	+#endif
	57	+
	58	+ return 0;
	59	+}
	60	+
43	61	int i2c_post_test (int flags)
44	62	{
45	63	unsigned int i;
46	64	#ifndef CONFIG_SYS_POST_I2C_ADDRS
47	65	/* Start at address 1, address 0 is the general call address */
48	66	for (i = 1; i < 128; i++)
	67	+ if (i2c_ignore_device(i))
	68	+ continue;
49	69	if (i2c_probe (i) == 0)
50	70	return 0;
51	71
...	...	@@ -58,6 +78,8 @@
58	78
59	79	/* Start at address 1, address 0 is the general call address */
60	80	for (i = 1; i < 128; i++) {
	81	+ if (i2c_ignore_device(i))
	82	+ continue;
61	83	if (i2c_probe(i) != 0)
62	84	continue;
63	85