mirror of https://gitee.com/openkylin/linux.git
156 lines
3.7 KiB
C
156 lines
3.7 KiB
C
/*
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*
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* Utility functions for the Freescale MPC52xx.
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*
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* Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*
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*/
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/of_platform.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/mpc52xx.h>
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/*
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* This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
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* Permanent mapping is required because mpc52xx_restart() can be called
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* from interrupt context while node mapping (which calls ioremap())
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* cannot be used at such point.
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*/
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static volatile struct mpc52xx_gpt *mpc52xx_wdt = NULL;
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/**
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* mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
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* @node: device node
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*
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* Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
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*/
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unsigned int
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mpc52xx_find_ipb_freq(struct device_node *node)
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{
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struct device_node *np;
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const unsigned int *p_ipb_freq = NULL;
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of_node_get(node);
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while (node) {
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p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
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if (p_ipb_freq)
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break;
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np = of_get_parent(node);
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of_node_put(node);
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node = np;
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}
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if (node)
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of_node_put(node);
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return p_ipb_freq ? *p_ipb_freq : 0;
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}
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EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
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/*
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* Configure the XLB arbiter settings to match what Linux expects.
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*/
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void __init
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mpc5200_setup_xlb_arbiter(void)
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{
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struct device_node *np;
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struct mpc52xx_xlb __iomem *xlb;
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np = of_find_compatible_node(NULL, NULL, "mpc5200-xlb");
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xlb = of_iomap(np, 0);
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of_node_put(np);
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if (!xlb) {
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printk(KERN_ERR __FILE__ ": "
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"Error mapping XLB in mpc52xx_setup_cpu(). "
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"Expect some abnormal behavior\n");
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return;
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}
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/* Configure the XLB Arbiter priorities */
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out_be32(&xlb->master_pri_enable, 0xff);
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out_be32(&xlb->master_priority, 0x11111111);
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/* Disable XLB pipelining
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* (cfr errate 292. We could do this only just before ATA PIO
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* transaction and re-enable it afterwards ...)
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*/
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out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
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iounmap(xlb);
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}
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static struct of_device_id mpc52xx_bus_ids[] __initdata= {
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{ .compatible = "fsl,mpc5200-immr", },
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{ .compatible = "fsl,lpb", },
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/* depreciated matches; shouldn't be used in new device trees */
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{ .type = "builtin", .compatible = "mpc5200", }, /* efika */
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{ .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
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{},
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};
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void __init
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mpc52xx_declare_of_platform_devices(void)
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{
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/* Find every child of the SOC node and add it to of_platform */
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if (of_platform_bus_probe(NULL, mpc52xx_bus_ids, NULL))
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printk(KERN_ERR __FILE__ ": "
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"Error while probing of_platform bus\n");
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}
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void __init
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mpc52xx_map_wdt(void)
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{
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const void *has_wdt;
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struct device_node *np;
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/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
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* possibly from a interrupt context. wdt is only implement
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* on a gpt0, so check has-wdt property before mapping.
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*/
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for_each_compatible_node(np, NULL, "fsl,mpc5200-gpt") {
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has_wdt = of_get_property(np, "fsl,has-wdt", NULL);
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if (has_wdt) {
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mpc52xx_wdt = of_iomap(np, 0);
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of_node_put(np);
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return;
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}
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}
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for_each_compatible_node(np, NULL, "mpc5200-gpt") {
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has_wdt = of_get_property(np, "has-wdt", NULL);
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if (has_wdt) {
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mpc52xx_wdt = of_iomap(np, 0);
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of_node_put(np);
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return;
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}
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}
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}
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void
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mpc52xx_restart(char *cmd)
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{
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local_irq_disable();
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/* Turn on the watchdog and wait for it to expire.
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* It effectively does a reset. */
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if (mpc52xx_wdt) {
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out_be32(&mpc52xx_wdt->mode, 0x00000000);
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out_be32(&mpc52xx_wdt->count, 0x000000ff);
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out_be32(&mpc52xx_wdt->mode, 0x00009004);
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} else
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printk("mpc52xx_restart: Can't access wdt. "
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"Restart impossible, system halted.\n");
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while (1);
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}
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