[PATCH 08/11] Add code to write rom of the OSTC3

[Anton Lundin]

On 16 December, 2014 - Jef Driesen wrote:

> On 2014-11-21 21:28, Anton Lundin wrote:
> >+static dc_status_t
> >+hw_ostc3_device_write_block (dc_device_t *abstract, unsigned int
> >addr, unsigned char block[], unsigned int block_size)
> >+{
> >+	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);
> >+#if 0
> >+	// FIXME: This variant doens't work
> >+	// Things doesn't get written to memory. Timing issues?
> >+	// Version below works, serial_sleep (2) is probably the thing.
> >+	unsigned char buffer[4 + block_size];
> >+	buffer[0] = WRITE_BLOCK;
> >+	uint24_be_array(addr, buffer + 1);
> >+	memcpy(buffer + 4, block, block_size);
> >+
> >+	rc = hw_ostc3_transfer(device, NULL, WRITE_BLOCK, buffer,
> >sizeof(buffer), NULL, 0);
> >+	serial_sleep (device->port, 1100);
> >+	return rc;
> >+#else
...
> 
> With the exception of those sleep calls, that's identical to the
> hw_ostc3_transfer() function. Notice how your code is missing the read of
> the echo. I'm pretty sure that got lost due to the flushing. So this
> probably works correctly only by accident.
> 
> The reason why hw_ostc3_transfer doesn't work for you, might be because you
> include the WRITE_BLOCK byte in the input buffer. That causes it to send
> twice. The ostc probably doesn't like that. Can you have a look at this? I
> have the feeling that we can use hw_ostc3_transfer here after all. Worst
> case we may need to add those sleep calls there, wrapped in a "if (cmd ==
> WRITE_BLOCK)".
> 
> >+	n = serial_read (device->port, &response, sizeof (response));
> >+	if (n != sizeof (response) || response != S_READY)
> >+		return EXITCODE (n);
> 
> You should split those checks in two parts. Right now you'll return
> DC_STATUS_TIMEOUT when response!=S_READY, and that's misleading. If we can
> re-use hw_ostc3_transfer, then this is no longer an issue.
> 

After i started to rewrite the code for like the .. 7th time i spotted
the bug in the hw_ostc3_transfer-based variant, and indeed it was the
extra WRITE_BLOCK i never spotted.

Now the hw_ostc3_device_write_block-helper looks like this:

static dc_status_t
hw_ostc3_device_write_block (hw_ostc3_device_t *device, unsigned int addr, unsigned char block[], unsigned int block_size)
{
	unsigned char buffer[3 + block_size];
	array_uint24_be_set(buffer, addr);
	memcpy(buffer + 3, block, block_size);

	return hw_ostc3_transfer(device, NULL, WRITE_BLOCK, buffer, sizeof(buffer), NULL, 0);
}


Just like hw_ostc3_device_read_block, and works just fine.


//Anton

-- 
Anton Lundin	+46702-161604