So far, we had no explicit mapping table between bootsource_instance
and device id numbering in barebox and mostly depended on DT aliases
reflecting the numbering of the bootrom. Add a new bootsource_set()
that optionally consults a mapping table in the DT to arrive at the
correct numbers.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/barebox/aliases.rst | 36 +++++++
common/bootsource.c | 101 +++++++++++++-----
include/bootsource.h | 40 ++++++-
3 files changed, 149 insertions(+), 28 deletions(-)
create mode 100644 Documentation/devicetree/bindings/barebox/aliases.rst
diff --git a/Documentation/devicetree/bindings/barebox/aliases.rst b/Documentation/devicetree/bindings/barebox/aliases.rst
new file mode 100644
index 000000000000..527cc85ef696
--- /dev/null
+++ b/Documentation/devicetree/bindings/barebox/aliases.rst
@@ -0,0 +1,36 @@
+barebox DT aliases
+==================
+
+barebox can use the properties in the ``/aliases`` node to arrive
+at deterministic names for devices, e.g.::
+
+.. code-block:: none
+ / {
+ aliases {
+ mmc0 = &sdhci;
+ wdog0 = &iwdg;
+ };
+ };
+
+will assign the MMC device created from probing the node at ``&sdhci``
+the name ``/dev/mmc0``. Similarly, the watchdog device created from
+probing the node at ``&iwdg`` will be named ``wdog0``.
+
+By default, barebox will assume the aliases in the DT to align with
+the bootsource communicated by the firmware. If this is not the case,
+a device tree override is possible via an
+``/aliases/barebox,bootsource-${bootsource}${bootsource_instance}``
+property:
+
+.. code-block:: none
+
+ &{/aliases} {
+ mmc0 = &sdmmc0;
+ mmc1 = &sdhci;
+ barebox,bootsource-mmc0 = &sdhci;
+ barebox,bootsource-mmc1 = &sdmmc0;
+ };
+
+This will ensure that when booting from MMC, ``/dev/mmc${bootsource_instance}``
+will point at the correct boot device, despite bootrom and board DT alias
+order being different.
diff --git a/common/bootsource.c b/common/bootsource.c
index c37da38f7f99..d74c5e5cbe9f 100644
--- a/common/bootsource.c
+++ b/common/bootsource.c
@@ -33,6 +33,34 @@ static enum bootsource bootsource = BOOTSOURCE_UNKNOWN;
static int bootsource_instance = BOOTSOURCE_INSTANCE_UNKNOWN;
const char *bootsource_alias_name = NULL;
+const char *bootsource_get_alias_stem(enum bootsource bs)
+{
+ switch (bs) {
+ /*
+ * For I2C and SPI EEPROMs we set the stem to be 'i2c'
+ * and 'spi' correspondingly. The resulting alias will
+ * be pointing at the controller said EEPROM is
+ * attached to.
+ *
+ * NOTE: This code assumes single bootable EEPROM per
+ * controller
+ */
+ case BOOTSOURCE_I2C_EEPROM:
+ return bootsource_str[BOOTSOURCE_I2C];
+ case BOOTSOURCE_SPI_EEPROM:
+ case BOOTSOURCE_SPI_NOR:
+ return bootsource_str[BOOTSOURCE_SPI];
+ case BOOTSOURCE_SERIAL: /* FALLTHROUGH */
+ case BOOTSOURCE_I2C: /* FALLTHROUGH */
+ case BOOTSOURCE_MMC: /* FALLTHROUGH */
+ case BOOTSOURCE_SPI: /* FALLTHROUGH */
+ case BOOTSOURCE_CAN:
+ return bootsource_str[bootsource];
+ default:
+ return NULL;
+ }
+}
+
/**
* bootsource_get_alias_name() - Get the name of the bootsource alias
*
@@ -58,33 +86,9 @@ char *bootsource_get_alias_name(void)
if (bootsource_alias_name)
return strdup(bootsource_alias_name);
- switch (bootsource) {
- /*
- * For I2C and SPI EEPROMs we set the stem to be 'i2c'
- * and 'spi' correspondingly. The resulting alias will
- * be pointing at the controller said EEPROM is
- * attached to.
- *
- * NOTE: This code assumes single bootable EEPROM per
- * controller
- */
- case BOOTSOURCE_I2C_EEPROM:
- stem = bootsource_str[BOOTSOURCE_I2C];
- break;
- case BOOTSOURCE_SPI_EEPROM:
- case BOOTSOURCE_SPI_NOR:
- stem = bootsource_str[BOOTSOURCE_SPI];
- break;
- case BOOTSOURCE_SERIAL: /* FALLTHROUGH */
- case BOOTSOURCE_I2C: /* FALLTHROUGH */
- case BOOTSOURCE_MMC: /* FALLTHROUGH */
- case BOOTSOURCE_SPI: /* FALLTHROUGH */
- case BOOTSOURCE_CAN:
- stem = bootsource_str[bootsource];
- break;
- default:
+ stem = bootsource_get_alias_stem(bootsource);
+ if (!stem)
return NULL;
- }
/*
* We expect SoC specific bootsource detection code to properly
@@ -123,6 +127,51 @@ void bootsource_set_raw_instance(int instance)
pr_setenv("bootsource_instance", "%d", instance);
}
+int bootsource_of_alias_xlate(enum bootsource bs, int instance)
+{
+ char alias[sizeof("barebox,bootsource-harddisk4294967295")];
+ const char *bootsource_stem;
+ struct device_node *np;
+ int alias_id;
+
+ if (!IS_ENABLED(CONFIG_OFDEVICE))
+ return BOOTSOURCE_INSTANCE_UNKNOWN;
+
+ if (bs == BOOTSOURCE_UNKNOWN ||
+ instance == BOOTSOURCE_INSTANCE_UNKNOWN)
+ return BOOTSOURCE_INSTANCE_UNKNOWN;
+
+ bootsource_stem = bootsource_get_alias_stem(bs);
+ if (!bootsource_stem)
+ return BOOTSOURCE_INSTANCE_UNKNOWN;
+
+ scnprintf(alias, sizeof(alias), "barebox,bootsource-%s%u",
+ bootsource_stem, instance);
+
+ np = of_find_node_by_alias(NULL, alias);
+ if (!np)
+ return BOOTSOURCE_INSTANCE_UNKNOWN;
+
+ alias_id = of_alias_get_id(np, bootsource_stem);
+ if (alias_id < 0)
+ return BOOTSOURCE_INSTANCE_UNKNOWN;
+
+ return alias_id;
+}
+
+int bootsource_set(enum bootsource bs, int instance)
+{
+ int alias_id;
+
+ alias_id = bootsource_of_alias_xlate(bs, instance);
+ if (alias_id == BOOTSOURCE_INSTANCE_UNKNOWN)
+ alias_id = instance;
+
+ bootsource_set_raw(bs, alias_id);
+
+ return alias_id;
+}
+
enum bootsource bootsource_get(void)
{
return bootsource;
diff --git a/include/bootsource.h b/include/bootsource.h
index 390d6f5d2b3a..9ca4fcc525b5 100644
--- a/include/bootsource.h
+++ b/include/bootsource.h
@@ -26,9 +26,45 @@ enum bootsource {
enum bootsource bootsource_get(void);
int bootsource_get_instance(void);
-void bootsource_set_raw(enum bootsource src, int instance);
-void bootsource_set_raw_instance(int instance);
void bootsource_set_alias_name(const char *name);
char *bootsource_get_alias_name(void);
+const char *bootsource_get_alias_stem(enum bootsource bs);
+int bootsource_of_alias_xlate(enum bootsource bs, int instance);
+
+/**
+ * bootsource_set - set bootsource with optional DT mapping table
+ * @bs: bootrom reported bootsource
+ * @instance: bootrom reported instance
+ *
+ * Returns computed bootsource instace
+ *
+ * Normal bootsource_set_raw_instance() expects numbering used by
+ * bootrom for instance to align with DT aliases, e.g.
+ * $bootsource = "mmc" && $bootsource_instance = 1 -> /aliases/mmc1
+ * bootsource_set() will instead consult
+ * /aliases/barebox,bootsource-mmc1 which may point at a different
+ * device than mmc1. In absence of appropriate barebox,bootsource-*
+ * alias, instance is set without translation.
+ */
+int bootsource_set(enum bootsource bs, int instance);
+
+/**
+ * bootsource_set_raw - set bootsource as-is
+ * @bs: bootsource to report
+ * @instance: bootsource instance to report
+ *
+ * This sets bootsource and bootsource_instance directly.
+ * Preferably, use bootsource_set in new code.
+ */
+void bootsource_set_raw(enum bootsource src, int instance);
+
+/**
+ * bootsource_set_raw_instance - set bootsource_instance as-is
+ * @bs: bootrom reported bootsource
+ * @instance: bootrom reported instance
+ *
+ * This directly sets bootsource_instance without changing bootsource.
+ */
+void bootsource_set_raw_instance(int instance);
#endif /* __BOOTSOURCE_H__ */
--
2.30.2
