[PATCH 05/16] drivers/fsi: Add fake master driver

On Tue, Dec 06, 2016 at 06:14:26PM -0600, Chris Bostic wrote:

From: Jeremy Kerr <jk@ozlabs.org>

For debugging, add a fake master driver, that only supports reads,
returning a fixed set of data.

+config FSI_MASTER_FAKE
+	tristate "Fake FSI master"
+	depends on FSI
+	---help---
+	This option enables a fake FSI master driver for debugging.
+endif

+static const struct of_device_id fsi_master_fake_match[] = {
+	{ .compatible = "ibm,fsi-master-fake" },
+	{ },
+};

NAK.

DT should be treated as an ABI, and should describe the HW explicitly.
This makes no sense. This is also missing a binding document.

Have your module take a module parameter allowing you to bind it to
arbitrary devices, or do something like what PCI does where you can
bind/unbind arbitrary drivers to devices using sysfs.

+
+static struct platform_driver fsi_master_fake_driver = {
+	.driver = {
+		.name		= "fsi-master-fake",
+		.of_match_table	= fsi_master_fake_match,
+	},
+	.probe	= fsi_master_fake_probe,
+};
+
+static int __init fsi_master_fake_init(void)
+{
+	struct device_node *np;
+
+	platform_driver_register(&fsi_master_fake_driver);
+
+	for_each_compatible_node(np, NULL, "ibm,fsi-master-fake")
+		of_platform_device_create(np, NULL, NULL);

As a general note, please use for_each_matching_node in situations like
this. That way you can reuse your existing of_device_id table, and not
reproduce the string.

That said, this is not necessary. The platform driver has an
of_match_table, so presumes the parent bus registers children, and hence
they should already have platform devices.

Thanks,
Mark.