dfu: allow to manage DFU on several devices

Add support of DFU for several interface/device
with one command.

The format for "dfu_alt_info" in this case is :
- <interface> <dev>'='alternate list (';' separated)
- each interface is separated by '&'

The previous behavior is always supported.

One example for NOR (bootloaders) + NAND (rootfs in UBI):

U-Boot> env set dfu_alt_info \
"sf 0:0:10000000:0=spl part 0 1;u-boot part 0 2; \
u-boot-env part 0 3&nand 0=UBI partubi 0,3"

U-Boot> dfu 0 list

DFU alt settings list:
dev: SF alt: 0 name: spl layout: RAW_ADDR
dev: SF alt: 1 name: ssbl layout: RAW_ADDR
dev: SF alt: 2 name: u-boot-env layout: RAW_ADDR
dev: NAND alt: 3 name: UBI layout: RAW_ADDR

U-Boot> dfu 0

$> dfu-util -l

Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
 intf=0, alt=3, name="UBI", serial="002700333338511934383330"
Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
 intf=0, alt=2, name="u-boot-env", serial="002700333338511934383330"
Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
 intf=0, alt=1, name="u-boot", serial="002700333338511934383330"
Found DFU: [0483:5720] ver=9999, devnum=96, cfg=1,\
 intf=0, alt=0, name="spl", serial="002700333338511934383330"

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index 900a844..8bd5216 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -53,6 +53,54 @@
 	return ++i;
 }
 
+/*
+ * treat dfu_alt_info with several interface information
+ * to allow DFU on several device with one command,
+ * the string format is
+ * interface devstring'='alternate list (';' separated)
+ * and each interface separated by '&'
+ */
+int dfu_config_interfaces(char *env)
+{
+	struct dfu_entity *dfu;
+	char *s, *i, *d, *a, *part;
+	int ret = -EINVAL;
+	int n = 1;
+
+	s = env;
+	for (; *s; s++) {
+		if (*s == ';')
+			n++;
+		if (*s == '&')
+			n++;
+	}
+	ret = dfu_alt_init(n, &dfu);
+	if (ret)
+		return ret;
+
+	s = env;
+	while (s) {
+		ret = -EINVAL;
+		i = strsep(&s, " ");
+		if (!i)
+			break;
+		d = strsep(&s, "=");
+		if (!d)
+			break;
+		a = strsep(&s, "&");
+		if (!a)
+			a = s;
+		do {
+			part = strsep(&a, ";");
+			ret = dfu_alt_add(dfu, i, d, part);
+			if (ret)
+				return ret;
+		} while (a);
+	}
+
+	return ret;
+}
+
 int dfu_init_env_entities(char *interface, char *devstr)
 {
 	const char *str_env;
@@ -69,7 +117,11 @@
 	}
 
 	env_bkp = strdup(str_env);
-	ret = dfu_config_entities(env_bkp, interface, devstr);
+	if (!interface && !devstr)
+		ret = dfu_config_interfaces(env_bkp);
+	else
+		ret = dfu_config_entities(env_bkp, interface, devstr);
+
 	if (ret) {
 		pr_err("DFU entities configuration failed!\n");
 		pr_err("(partition table does not match dfu_alt_info?)\n");
@@ -83,6 +135,7 @@
 
 static unsigned char *dfu_buf;
 static unsigned long dfu_buf_size;
+static enum dfu_device_type dfu_buf_device_type;
 
 unsigned char *dfu_free_buf(void)
 {
@@ -100,6 +153,10 @@
 {
 	char *s;
 
+	/* manage several entity with several contraint */
+	if (dfu_buf && dfu->dev_type != dfu_buf_device_type)
+		dfu_free_buf();
+
 	if (dfu_buf != NULL)
 		return dfu_buf;
 
@@ -118,6 +175,7 @@
 		printf("%s: Could not memalign 0x%lx bytes\n",
 		       __func__, dfu_buf_size);
 
+	dfu_buf_device_type = dfu->dev_type;
 	return dfu_buf;
 }