stm32mp1: support dynamic MTDPARTS

This patch configure the default value for mtdids and mtparts
dynamically according the presence of nor and nand in
the board device tree

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index 76917b022e..360b0df9f6 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -504,3 +504,88 @@ void board_quiesce_devices(void)
 {
 	setup_led(LEDST_OFF);
 }
+
+#ifdef CONFIG_SYS_MTDPARTS_RUNTIME
+
+#define MTDPARTS_LEN		256
+#define MTDIDS_LEN		128
+
+/**
+ * The mtdparts_nand0 and mtdparts_nor0 variable tends to be long.
+ * If we need to access it before the env is relocated, then we need
+ * to use our own stack buffer. gd->env_buf will be too small.
+ *
+ * @param buf temporary buffer pointer MTDPARTS_LEN long
+ * @return mtdparts variable string, NULL if not found
+ */
+static const char *env_get_mtdparts(const char *str, char *buf)
+{
+	if (gd->flags & GD_FLG_ENV_READY)
+		return env_get(str);
+	if (env_get_f(str, buf, MTDPARTS_LEN) != -1)
+		return buf;
+
+	return NULL;
+}
+
+/**
+ * update the variables "mtdids" and "mtdparts" with content of mtdparts_<dev>
+ */
+static void board_get_mtdparts(const char *dev,
+			       char *mtdids,
+			       char *mtdparts)
+{
+	char env_name[32] = "mtdparts_";
+	char tmp_mtdparts[MTDPARTS_LEN];
+	const char *tmp;
+
+	/* name of env variable to read = mtdparts_<dev> */
+	strcat(env_name, dev);
+	tmp = env_get_mtdparts(env_name, tmp_mtdparts);
+	if (tmp) {
+		/* mtdids: "<dev>=<dev>, ...." */
+		if (mtdids[0] != '\0')
+			strcat(mtdids, ",");
+		strcat(mtdids, dev);
+		strcat(mtdids, "=");
+		strcat(mtdids, dev);
+
+		/* mtdparts: "mtdparts=<dev>:<mtdparts_<dev>>;..." */
+		if (mtdparts[0] != '\0')
+			strncat(mtdparts, ";", MTDPARTS_LEN);
+		else
+			strcat(mtdparts, "mtdparts=");
+		strncat(mtdparts, dev, MTDPARTS_LEN);
+		strncat(mtdparts, ":", MTDPARTS_LEN);
+		strncat(mtdparts, tmp, MTDPARTS_LEN);
+	}
+}
+
+void board_mtdparts_default(const char **mtdids, const char **mtdparts)
+{
+	struct udevice *dev;
+	static char parts[2 * MTDPARTS_LEN + 1];
+	static char ids[MTDIDS_LEN + 1];
+	static bool mtd_initialized;
+
+	if (mtd_initialized) {
+		*mtdids = ids;
+		*mtdparts = parts;
+		return;
+	}
+
+	memset(parts, 0, sizeof(parts));
+	memset(ids, 0, sizeof(ids));
+
+	if (!uclass_get_device(UCLASS_MTD, 0, &dev))
+		board_get_mtdparts("nand0", ids, parts);
+
+	if (!uclass_get_device(UCLASS_SPI_FLASH, 0, &dev))
+		board_get_mtdparts("nor0", ids, parts);
+
+	mtd_initialized = true;
+	*mtdids = ids;
+	*mtdparts = parts;
+	debug("%s:mtdids=%s & mtdparts=%s\n", __func__, ids, parts);
+}
+#endif