ARM: OMAP5/DRA7: Split iodelay functionality into sub steps

Since many platforms may need different pad configuration required
depending on variation of the platform with minor deltas, it is
easier to maintain a sub step based approach to allow for pin mux
and iodelay configuration which may depend on the platform variations
and need to be done in IO isolation.

While we retain the older __recalibrate_iodelay function which provides
a ready sequencing, __recalibrate_iodelay_start and
__recalibrate_iodelay_end may be alternatively used now and the callers
will be responsible for the correct sequencing of operations.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c

@@ -166,16 +166,14 @@ static int do_set_iodelay(u32 base, struct iodelay_cfg_entry const *array,
 	return 0;
 }
 
-void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads,
+int __recalibrate_iodelay_start(void)
-			   struct iodelay_cfg_entry const *iodelay,
-			   int niodelays)
 {
 	int ret = 0;
 
 	/* IO recalibration should be done only from SRAM */
 	if (OMAP_INIT_CONTEXT_SPL != omap_hw_init_context()) {
 		puts("IODELAY recalibration called from invalid context - use only from SPL in SRAM\n");
-		return;
+		return -1;
 	}
 
 	/* unlock IODELAY CONFIG registers */
@@ -191,23 +189,27 @@ void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads,
 		goto err;
 
 	ret = update_delay_mechanism((*ctrl)->iodelay_config_base);
-	if (ret)
-		goto err;
 
-	/* Configure Mux settings */
+err:
-	do_set_mux32((*ctrl)->control_padconf_core_base, pad, npads);
+	return ret;
+}
 
-	/* Configure Manual IO timing modes */
+void __recalibrate_iodelay_end(int ret)
-	ret = do_set_iodelay((*ctrl)->iodelay_config_base, iodelay, niodelays);
+{
-	if (ret)
-		goto err;
 
-	ret = isolate_io(DEISOLATE_IO);
+	/* IO recalibration should be done only from SRAM */
+	if (OMAP_INIT_CONTEXT_SPL != omap_hw_init_context()) {
+		puts("IODELAY recalibration called from invalid context - use only from SPL in SRAM\n");
+		return;
+	}
+
+	if (!ret)
+		ret = isolate_io(DEISOLATE_IO);
 
-err:
 	/* lock IODELAY CONFIG registers */
 	writel(CFG_IODELAY_LOCK_KEY, (*ctrl)->iodelay_config_base +
 	       CFG_REG_8_OFFSET);
+
 	/*
 	 * UART cannot be used during IO recalibration sequence as IOs are in
 	 * isolation. So error handling and debug prints are done after
@@ -232,7 +234,41 @@ err:
 	case ERR_FPDE:
 		puts("IODELAY: FPDE calculation failed\n");
 		break;
+	case -1:
+		puts("IODELAY: Wrong Context call?\n");
+		break;
 	default:
 		debug("IODELAY: IO delay recalibration successfully completed\n");
 	}
+
+	return;
+}
+
+void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads,
+			   struct iodelay_cfg_entry const *iodelay,
+			   int niodelays)
+{
+	int ret = 0;
+
+	/* IO recalibration should be done only from SRAM */
+	if (OMAP_INIT_CONTEXT_SPL != omap_hw_init_context()) {
+		puts("IODELAY recalibration called from invalid context - use only from SPL in SRAM\n");
+		return;
+	}
+
+	ret = __recalibrate_iodelay_start();
+	if (ret)
+		goto err;
+
+	/* Configure Mux settings */
+	do_set_mux32((*ctrl)->control_padconf_core_base, pad, npads);
+
+	/* Configure Manual IO timing modes */
+	ret = do_set_iodelay((*ctrl)->iodelay_config_base, iodelay, niodelays);
+	if (ret)
+		goto err;
+
+err:
+	__recalibrate_iodelay_end(ret);
+
 }

arch/arm/include/asm/arch-omap5/dra7xx_iodelay.h

@@ -83,5 +83,7 @@
 void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads,
 			   struct iodelay_cfg_entry const *iodelay,
 			   int niodelays);
+int __recalibrate_iodelay_start(void);
+void __recalibrate_iodelay_end(int ret);
 
 #endif