On Mon, Mar 24, 2014 at 6:02 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Monday 24 March 2014 16:17:42 Zhangfei Gao wrote: >> On Thu, Mar 20, 2014 at 10:31 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> >> > >> >> >> + if (!ppebase) { >> >> >> + struct device_node *n; >> >> >> + >> >> >> + n = of_find_compatible_node(NULL, NULL, "hisilicon,hip04-ppebase"); >> >> >> + if (!n) { >> >> >> + ret = -EINVAL; >> >> >> + netdev_err(ndev, "not find hisilicon,ppebase\n"); >> >> >> + goto init_fail; >> >> >> + } >> >> >> + ppebase = of_iomap(n, 0); >> >> >> + } >> >> > >> >> > How about using syscon_regmap_lookup_by_phandle() here? That way, you can have >> >> > a more generic abstraction of the ppe, and stick the port and id in there as >> >> > well, e.g. >> >> > >> >> > ppe-syscon = <&hip04ppe 1 4>; // ppe, port, id >> >> Even if using syscon_regmap_lookup_by_phandle, there still have static >> struct regmap, since three controllers >> share one regmap. > > The regmap is then owned by the syscon driver, while each controller takes > a reference to the regmap that it can store in its own private data > structure. However, as we discussed using a ppe driver sounds nicer than > regmap. > >> > It's probably a little simpler to avoid the sub-nodes and instead do >> > >> >> ppe: ppe@28c0000 { >> >> compatible = "hisilicon,hip04-ppe"; >> >> reg = <0x28c0000 0x10000>; >> >> #address-cells = <1>; >> >> #size-cells = <0>; >> >> }; >> >> fe: ethernet@28b0000 { >> >> compatible = "hisilicon,hip04-mac"; >> >> reg = <0x28b0000 0x10000>; >> >> interrupts = <0 413 4>; >> >> phy-mode = "mii"; >> >> port-handle = <&ppe 31>; >> >> }; >> > >> > In the code, I would create a simple ppe driver that exports >> > a few functions. you need. In the ethernet driver probe() function, >> > you should get a handle to the ppe using >> > >> > /* look up "port-handle" property of the current device, find ppe and port */ >> > struct hip04_ppe *ppe = hip04_ppe_get(dev->of_node); >> > if (IS_ERR(ppe)) >> > return PTR_ERR(ptr); /* this handles -EPROBE_DEFER */ >> > >> > and then in other code you can just do >> > >> > hip04_ppe_set_foo(priv->ppe, foo_config); >> > >> > This is a somewhat more high-level abstraction that syscon, which >> > just gives you a 'struct regmap' structure for doing register-level >> > configuration like you have today. >> > >> >> Do you mean create one additional file like ppe.c with some exported >> function to remove the static ppebase? > > It doesn't have to be a separate file, as long as you register a > separate platform_driver for the ppe. > >> Since the ppe is specifically bounded with ethernet, and does not used >> anywhere else, >> the exported function may not be used anywhere else. >> Is it make it more complicated since there are probe, remove etc. >> >> So I may still prefer using "static void __iomem *ppebase", as it is simpler. > > The trouble is that the driver should not rely on being only there > for a single instance, that's not how we write drivers. > > I'm fine with either a syscon instance (which would be simpler) or a > separate ppe driver as part of the hip04-mac driver (which would be > a nicer abstraction). > Understand now. Will update with syscon, as it is simpler. Thanks for your patience. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html