arm: sunxi: add support for DIP detection to CHIP board
Add the extension_board_scan specific function to scan the information
of the EEPROM on one-wire and fill the extension struct.
Add the Kconfig symbol to enable the needs to detect DIPs.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/board/sunxi/chip.c b/board/sunxi/chip.c
new file mode 100644
index 0000000..cde04be
--- /dev/null
+++ b/board/sunxi/chip.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * Köry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ * Based on initial code from Maxime Ripard
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <dm.h>
+#include <w1.h>
+#include <w1-eeprom.h>
+#include <dm/device-internal.h>
+
+#include <asm/arch/gpio.h>
+
+#include <extension_board.h>
+
+#define for_each_w1_device(b, d) \
+ for (device_find_first_child(b, d); *d; device_find_next_child(d))
+
+#define dip_convert(field) \
+ ( \
+ (sizeof(field) == 1) ? field : \
+ (sizeof(field) == 2) ? be16_to_cpu(field) : \
+ (sizeof(field) == 4) ? be32_to_cpu(field) : \
+ -1 \
+ )
+
+#define DIP_MAGIC 0x50494843 /* CHIP */
+
+struct dip_w1_header {
+ u32 magic; /* CHIP */
+ u8 version; /* spec version */
+ u32 vendor_id;
+ u16 product_id;
+ u8 product_version;
+ char vendor_name[32];
+ char product_name[32];
+ u8 rsvd[36]; /* rsvd for future spec versions */
+ u8 data[16]; /* user data, per-dip specific */
+} __packed;
+
+int extension_board_scan(struct list_head *extension_list)
+{
+ struct extension *dip;
+ struct dip_w1_header w1_header;
+ struct udevice *bus, *dev;
+ u32 vid;
+ u16 pid;
+ int ret;
+
+ int num_dip = 0;
+
+ sunxi_gpio_set_pull(SUNXI_GPD(2), SUNXI_GPIO_PULL_UP);
+
+ ret = w1_get_bus(0, &bus);
+ if (ret) {
+ printf("one wire interface not found\n");
+ return 0;
+ }
+
+ for_each_w1_device(bus, &dev) {
+ if (w1_get_device_family(dev) != W1_FAMILY_DS2431)
+ continue;
+
+ ret = device_probe(dev);
+ if (ret) {
+ printf("Couldn't probe device %s: error %d",
+ dev->name, ret);
+ continue;
+ }
+
+ w1_eeprom_read_buf(dev, 0, (u8 *)&w1_header, sizeof(w1_header));
+
+ if (w1_header.magic != DIP_MAGIC)
+ continue;
+
+ vid = dip_convert(w1_header.vendor_id);
+ pid = dip_convert(w1_header.product_id);
+
+ printf("DIP: %s (0x%x) from %s (0x%x)\n",
+ w1_header.product_name, pid,
+ w1_header.vendor_name, vid);
+
+ dip = calloc(1, sizeof(struct extension));
+ if (!dip) {
+ printf("Error in memory allocation\n");
+ return num_dip;
+ }
+
+ snprintf(dip->overlay, sizeof(dip->overlay), "dip-%x-%x.dtbo",
+ vid, pid);
+ strncpy(dip->name, w1_header.product_name, 32);
+ strncpy(dip->owner, w1_header.vendor_name, 32);
+ list_add_tail(&dip->list, extension_list);
+ num_dip++;
+ }
+ return num_dip;
+}