[PATCH v2 11/15] Add code to send upgrade firmware command to OSTC3

[Anton Lundin]

This function triggers a reboot into the bootloader which flashes the
new firmware to Prom.

This code is inspired by JeanDo ostc-companion.

Reviewed-by: Jef Driesen <jef at libdivecomputer.org>
Signed-off-by: Anton Lundin <glance at acc.umu.se>
---
 src/hw_ostc3.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/hw_ostc3.c b/src/hw_ostc3.c
index 35df0c7..06e3827 100644
--- a/src/hw_ostc3.c
+++ b/src/hw_ostc3.c
@@ -57,6 +57,7 @@
 #define S_ERASE    0x42
 #define S_READY    0x4C
 #define READY      0x4D
+#define S_UPGRADE  0x50
 #define HEADER     0x61
 #define CLOCK      0x62
 #define CUSTOMTEXT 0x63
@@ -73,6 +74,7 @@ typedef enum hw_ostc3_state_t {
 	OPEN,
 	DOWNLOAD,
 	SERVICE,
+	REBOOTING,
 } hw_ostc3_state_t;
 
 typedef struct hw_ostc3_device_t {
@@ -329,7 +331,7 @@ hw_ostc3_device_close (dc_device_t *abstract)
 	dc_status_t rc = DC_STATUS_SUCCESS;
 
 	// Send the exit command
-	if (device->state != OPEN) {
+	if (device->state != REBOOTING && device->state != OPEN) {
 		rc = hw_ostc3_transfer (device, NULL, EXIT, NULL, 0, NULL, 0);
 		if (rc != DC_STATUS_SUCCESS) {
 			ERROR (abstract->context, "Failed to send the command.");
@@ -917,3 +919,31 @@ hw_ostc3_firmware_block_write (hw_ostc3_device_t *device, unsigned int addr, uns
 
 	return hw_ostc3_transfer (device, NULL, S_BLOCK_WRITE, buffer, sizeof(buffer), NULL, 0);
 }
+
+static dc_status_t
+hw_ostc3_firmware_upgrade (dc_device_t *abstract, unsigned int checksum)
+{
+	dc_status_t rc = DC_STATUS_SUCCESS;
+	hw_ostc3_device_t *device = (hw_ostc3_device_t *) abstract;
+	dc_context_t *context = (abstract ? abstract->context : NULL);
+	unsigned char buffer[5];
+	array_uint32_le_set(buffer, checksum);
+
+	// Compute a one byte checksum, so the device can validate the firmware image.
+	buffer[4] = 0x55;
+	for(int i = 0; i < 4; i++) {
+		buffer[4] ^= buffer[i];
+		buffer[4]  = (buffer[4]<<1 | buffer[4]>>7);
+	}
+
+	rc = hw_ostc3_transfer(device, NULL, S_UPGRADE, buffer, sizeof(buffer), NULL, 0);
+	if (rc != DC_STATUS_SUCCESS) {
+		ERROR (context, "Failed to send flash firmware command");
+		return rc;
+	}
+
+	// Now the device resets, and if everything is well, it reprograms.
+	device->state = REBOOTING;
+
+	return DC_STATUS_SUCCESS;
+}
-- 
2.1.0