Re: [PATCH v4,4/4] drivers: uio: new driver for fsl_85xx_cache_sram

On Fri, 2020-04-17 at 10:31 +0800, 王文虎 wrote:

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On Thu, 2020-04-16 at 08:35 -0700, Wang Wenhu wrote:

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+#define UIO_INFO_VER	"devicetree,pseudo"

What does this mean?  Changing a number into a non-obvious string (Why
"pseudo"?  Why does the UIO user care that the config came from the
device
tree?) just to avoid setting off Greg's version number autoresponse
isn't
really helping anything.

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+static const struct of_device_id uio_mpc85xx_l2ctlr_of_match[] = {
+	{	.compatible = "uio,mpc85xx-cache-sram",	},

Form is <vendor>,<device> and "uio" is not a vendor (and never will be).

Should have been something like "fsl,mpc85xx-cache-sram-uio", and if it is
to be defined with module parameters, this would be user defined.
Anyway, <vendor>,<device> should always be used.

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+	{},
+};
+
+static struct platform_driver uio_fsl_85xx_cache_sram = {
+	.probe = uio_fsl_85xx_cache_sram_probe,
+	.remove = uio_fsl_85xx_cache_sram_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table	= uio_mpc85xx_l2ctlr_of_match,
+	},
+};

Greg's comment notwithstanding, I really don't think this belongs in the
device tree (and if I do get overruled on that point, it at least needs
a
binding document).  Let me try to come up with a patch for dynamic
allocation.

Agreed. "UIO" bindings have long been rejected.

Sounds it is. And does the modification below fit well?
---
-static const struct of_device_id uio_mpc85xx_l2ctlr_of_match[] = {
-       {       .compatible = "uio,mpc85xx-cache-sram", },
-       {},
+#ifdef CONFIG_OF
+static struct of_device_id uio_fsl_85xx_cache_sram_of_match[] = {
+       { /* This is filled with module_parm */ },
+       { /* Sentinel */ },
 };
+MODULE_DEVICE_TABLE(of, uio_fsl_85xx_cache_sram_of_match);
+module_param_string(of_id, uio_fsl_85xx_cache_sram_of_match[0].compatible,
+                           sizeof(uio_fsl_85xx_cache_sram_of_match[0].compa
tible), 0);
+MODULE_PARM_DESC(of_id, "platform device id to be handled by cache-sram-
uio");
+#endif

No.  The point is that you wouldn't be configuring this with the device tree
at all.

-Scott