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>

diff --git a/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c b/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c
index 9fa6e6991f0ef7d168ed53f3903e9a16e8448568..744950f01bd96eb9827594dd7ef355cfc820b7d7 100644 (file)
--- a/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c
+++ b/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,
-                          struct iodelay_cfg_entry const *iodelay,
-                          int niodelays)
+int __recalibrate_iodelay_start(void)
 {
        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 */
-       do_set_mux32((*ctrl)->control_padconf_core_base, pad, npads);
+err:
+       return ret;
+}
 
-       /* Configure Manual IO timing modes */
-       ret = do_set_iodelay((*ctrl)->iodelay_config_base, iodelay, niodelays);
-       if (ret)
-               goto err;
+void __recalibrate_iodelay_end(int ret)
+{
 
-       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);
+
 }

diff --git a/arch/arm/include/asm/arch-omap5/dra7xx_iodelay.h b/arch/arm/include/asm/arch-omap5/dra7xx_iodelay.h
index 4cd0a3cc80d04467d22c2260d2d18b7a9f4368fa..0de8a800c1a2f623adfe1933abd6920734f8f191 100644 (file)
--- a/arch/arm/include/asm/arch-omap5/dra7xx_iodelay.h
+++ b/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