Re: [PATCH v3] Create add_rtc() function to enable the RTC CMOS driver
From: David Gibson <hidden>
Date: 2007-06-22 03:31:58
On Wed, Jun 20, 2007 at 09:59:32AM -0700, Wade Farnsworth wrote:
In order to use the RTC CMOS driver, each architecture must register a platform device for the RTC. This creates a function to register the platform device based on the RTC device node and verifies that the RTC port against the hard-coded value in asm/mc146818rtc.h. Signed-off-by: Wade Farnsworth <redacted>
Hrm. It seems rather specific. Can we do this more generally, by creating an of_platform device which binds to rtc nodes, then registers an appropriate platform device for each so that the generic rtc drivers pick them up. Obviously we'd need some sort of table mapping the device node compatible properties to the appropriate platform device names.
quoted hunk ↗ jump to hunk
Index: linux-2.6-powerpc-8641/arch/powerpc/sysdev/Makefile ===================================================================--- linux-2.6-powerpc-8641.orig/arch/powerpc/sysdev/Makefile +++ linux-2.6-powerpc-8641/arch/powerpc/sysdev/Makefile@@ -18,6 +18,7 @@ obj-$(CONFIG_TSI108_BRIDGE) += tsi108_pc obj-$(CONFIG_QUICC_ENGINE) += qe_lib/ mv64x60-$(CONFIG_PCI) += mv64x60_pci.o obj-$(CONFIG_MV64X60) += $(mv64x60-y) mv64x60_pic.o mv64x60_dev.o +obj-$(CONFIG_RTC_DRV_CMOS) += rtc_cmos_setup.o # contains only the suspend handler for time obj-$(CONFIG_PM) += timer.oIndex: linux-2.6-powerpc-8641/arch/powerpc/sysdev/rtc_cmos_setup.c ===================================================================--- /dev/null +++ linux-2.6-powerpc-8641/arch/powerpc/sysdev/rtc_cmos_setup.c@@ -0,0 +1,51 @@ +/* + * Setup code for PC-style Real-Time Clock. + * + * Author: Wade Farnsworth <wfarnsworth@mvista.com> + * + * 2007 (c) MontaVista Software, Inc. This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whetherexpress + * or implied. + */ + +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/mc146818rtc.h> + +#include <asm/prom.h> + +static int __init add_rtc(void) +{ + struct device_node *np; + struct platform_device *pd; + struct resource res; + + np = of_find_compatible_node(NULL, NULL, "pnpPNP,b00"); + if (!np) + return -ENODEV; + + if (of_address_to_resource(np, 0, &res)) { + of_node_put(np); + return -ENODEV; + } + + /* + * RTC_PORT(x) is hardcoded in asm/mc146818rtc.h. Verify that the + * address provided by the device node matches. + */ + if (res.start != RTC_PORT(0)) { + of_node_put(np); + return -ENODEV; + }
This looks totally bogus. If we have a device tree we should be using the address information from there, not using hardcoded magic. Sounds like asm/mc146818rtc.h needs some serious fixing.
+
+ pd = platform_device_register_simple("rtc_cmos", -1,
+ &res, 1);
+ of_node_put(np);
+ if (IS_ERR(pd))
+ return PTR_ERR(pd);
+
+ return 0;
+}
+fs_initcall(add_rtc);
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https://ozlabs.org/mailman/listinfo/linuxppc-dev-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson