22258fa40e
This patch extends the Ebony and Walnut platform code to instantiate the existing ds1742 RTC class driver for the DS1743 RTC/NVRAM chip found on both those boards. The patch uses a helper function to scan the device tree and instantiate the appropriate platform_device based on it, so it should be easy to extend for other boards which have mmio mapped RTC chips. Along with this, the device tree binding for the ds1743 chips is tweaked, based on the existing DS1385 OF binding found at: http://playground.sun.com/1275/proposals/Closed/Remanded/Accepted/346-it.txt Although that document covers the NVRAM portion of the chip, whereas here we're interested in the RTC portion, so it's not entirely clear if that's a good model. This implements only RTC class driver support - that is /dev/rtc0, not /dev/rtc, and the low-level get/set time callbacks remain unimplemented. That means in order to get at the clock you will either need a modified version of hwclock which will look at /dev/rtc0, or you'll need to configure udev to symlink rtc0 to rtc. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
/*
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* Instantiate mmio-mapped RTC chips based on device tree information
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*
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* Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/of.h>
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#include <linux/init.h>
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#include <linux/of_platform.h>
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static __initdata struct {
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const char *compatible;
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char *plat_name;
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} of_rtc_table[] = {
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{ "ds1743-nvram", "rtc-ds1742" },
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};
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void __init of_instantiate_rtc(void)
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{
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struct device_node *node;
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int err;
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int i;
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for (i = 0; i < ARRAY_SIZE(of_rtc_table); i++) {
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char *plat_name = of_rtc_table[i].plat_name;
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for_each_compatible_node(node, NULL,
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of_rtc_table[i].compatible) {
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struct resource *res;
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res = kmalloc(sizeof(*res), GFP_KERNEL);
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if (!res) {
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printk(KERN_ERR "OF RTC: Out of memory "
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"allocating resource structure for %s\n",
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node->full_name);
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continue;
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}
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err = of_address_to_resource(node, 0, res);
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if (err) {
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printk(KERN_ERR "OF RTC: Error "
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"translating resources for %s\n",
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node->full_name);
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continue;
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}
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printk(KERN_INFO "OF_RTC: %s is a %s @ 0x%llx-0x%llx\n",
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node->full_name, plat_name,
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(unsigned long long)res->start,
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(unsigned long long)res->end);
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platform_device_register_simple(plat_name, -1, res, 1);
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}
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}
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}
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