Messages in this thread Patch in this message | | | Date | Tue, 21 Jun 2011 21:55:59 +0800 | From | Shawn Guo <> | Subject | Re: [PATCH 1/3] serial/imx: add device tree support |
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Hi Grant,
I just gave a try to use aliases node for identify the device index. Please take a look and let me know if it's what you expect.
On Sun, Jun 19, 2011 at 03:30:02PM +0800, Shawn Guo wrote: [...] > > > > > > +#ifdef CONFIG_OF > > > +static int serial_imx_probe_dt(struct imx_port *sport, > > > + struct platform_device *pdev) > > > +{ > > > + struct device_node *node = pdev->dev.of_node; > > > + const __be32 *line; > > > + > > > + if (!node) > > > + return -ENODEV; > > > + > > > + line = of_get_property(node, "id", NULL); > > > + if (!line) > > > + return -ENODEV; > > > + > > > + sport->port.line = be32_to_cpup(line) - 1; > > > > Hmmm, I really would like to be rid of this. Instead, if uarts must > > be enumerated, the driver should look for a /aliases/uart* property > > that matches the of_node. Doing it that way is already established in > > the OpenFirmware documentation, and it ensures there are no overlaps > > in the global namespace. > > > > I just gave one more try to avoid using 'aliases', and you gave a > 'no' again. Now, I know how hard you are on this. Okay, I start > thinking about your suggestion seriously :) > > > We do need some infrastructure to make that easier though. Would you > > have time to help put that together? > > > Ok, I will give it a try. >
diff --git a/arch/arm/boot/dts/imx51-babbage.dts b/arch/arm/boot/dts/imx51-babbage.dts index da0381a..f4a5c3c 100644 --- a/arch/arm/boot/dts/imx51-babbage.dts +++ b/arch/arm/boot/dts/imx51-babbage.dts @@ -18,6 +18,12 @@ compatible = "fsl,imx51-babbage", "fsl,imx51"; interrupt-parent = <&tzic>; + aliases { + serial0 = &uart0; + serial1 = &uart1; + serial2 = &uart2; + }; + chosen { bootargs = "console=ttymxc0,115200 root=/dev/mmcblk0p3 rootwait"; }; @@ -47,29 +53,29 @@ reg = <0x70000000 0x40000>; ranges; - uart@7000c000 { + uart2: uart@7000c000 { compatible = "fsl,imx51-uart", "fsl,imx21-uart"; reg = <0x7000c000 0x4000>; interrupts = <33>; id = <3>; - fsl,has-rts-cts; + fsl,uart-has-rtscts; }; }; - uart@73fbc000 { + uart0: uart@73fbc000 { compatible = "fsl,imx51-uart", "fsl,imx21-uart"; reg = <0x73fbc000 0x4000>; interrupts = <31>; id = <1>; - fsl,has-rts-cts; + fsl,uart-has-rtscts; }; - uart@73fc0000 { + uart1: uart@73fc0000 { compatible = "fsl,imx51-uart", "fsl,imx21-uart"; reg = <0x73fc0000 0x4000>; interrupts = <32>; id = <2>; - fsl,has-rts-cts; + fsl,uart-has-rtscts; }; }; diff --git a/drivers/of/base.c b/drivers/of/base.c index 632ebae..13df5d2 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -737,6 +737,37 @@ err0: EXPORT_SYMBOL(of_parse_phandles_with_args); /** + * of_get_device_index - Get device index by looking up "aliases" node + * @np: Pointer to device node that asks for device index + * @name: The device alias without index number + * + * Returns the device index if find it, else returns -ENODEV. + */ +int of_get_device_index(struct device_node *np, const char *alias) +{ + struct device_node *aliases = of_find_node_by_name(NULL, "aliases"); + struct property *prop; + char name[32]; + int index = 0; + + if (!aliases) + return -ENODEV; + + while (1) { + snprintf(name, sizeof(name), "%s%d", alias, index); + prop = of_find_property(aliases, name, NULL); + if (!prop) + return -ENODEV; + if (np == of_find_node_by_path(prop->value)) + break; + index++; + } + + return index; +} +EXPORT_SYMBOL(of_get_device_index); + +/** * prom_add_property - Add a property to a node */ int prom_add_property(struct device_node *np, struct property *prop) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index da436e0..852668f 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1271,18 +1271,18 @@ static int serial_imx_probe_dt(struct imx_port *sport, struct device_node *node = pdev->dev.of_node; const struct of_device_id *of_id = of_match_device(imx_uart_dt_ids, &pdev->dev); - const __be32 *line; + int line; if (!node) return -ENODEV; - line = of_get_property(node, "id", NULL); - if (!line) + line = of_get_device_index(node, "serial"); + if (IS_ERR_VALUE(line)) return -ENODEV; - sport->port.line = be32_to_cpup(line) - 1; + sport->port.line = line; - if (of_get_property(node, "fsl,has-rts-cts", NULL)) + if (of_get_property(node, "fsl,uart-has-rtscts", NULL)) sport->have_rtscts = 1; if (of_get_property(node, "fsl,irda-mode", NULL)) diff --git a/include/linux/of.h b/include/linux/of.h index bfc0ed1..3153752 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -213,6 +213,8 @@ extern int of_parse_phandles_with_args(struct device_node *np, const char *list_name, const char *cells_name, int index, struct device_node **out_node, const void **out_args); +extern int of_get_device_index(struct device_node *np, const char *alias); + extern int of_machine_is_compatible(const char *compat); extern int prom_add_property(struct device_node* np, struct property* prop); -- Regards, Shawn
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