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/*
*
* Utility functions for the Freescale MPC52xx.
*
* Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
*
* 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, whether express or implied.
*
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/of_platform.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/mpc52xx.h>
/* MPC5200 device tree match tables */
static struct of_device_id mpc52xx_xlb_ids[] __initdata = {
{ .compatible = "fsl,mpc5200-xlb", },
{ .compatible = "mpc5200-xlb", },
{}
};
static struct of_device_id mpc52xx_bus_ids[] __initdata = {
{ .compatible = "fsl,mpc5200-immr", },
{ .compatible = "fsl,mpc5200b-immr", },
{ .compatible = "fsl,lpb", },
/* depreciated matches; shouldn't be used in new device trees */
{ .type = "builtin", .compatible = "mpc5200", }, /* efika */
{ .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
{}
};
/*
* This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
* Permanent mapping is required because mpc52xx_restart() can be called
* from interrupt context while node mapping (which calls ioremap())
* cannot be used at such point.
*/
static spinlock_t mpc52xx_lock = SPIN_LOCK_UNLOCKED;
static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
/**
* mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
* @node: device node
*
* Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
*/
unsigned int
mpc52xx_find_ipb_freq(struct device_node *node)
{
struct device_node *np;
const unsigned int *p_ipb_freq = NULL;
of_node_get(node);
while (node) {
p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
if (p_ipb_freq)
break;
np = of_get_parent(node);
of_node_put(node);
node = np;
}
if (node)
of_node_put(node);
return p_ipb_freq ? *p_ipb_freq : 0;
}
EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
/*
* Configure the XLB arbiter settings to match what Linux expects.
*/
void __init
mpc5200_setup_xlb_arbiter(void)
{
struct device_node *np;
struct mpc52xx_xlb __iomem *xlb;
np = of_find_matching_node(NULL, mpc52xx_xlb_ids);
xlb = of_iomap(np, 0);
of_node_put(np);
if (!xlb) {
printk(KERN_ERR __FILE__ ": "
"Error mapping XLB in mpc52xx_setup_cpu(). "
"Expect some abnormal behavior\n");
return;
}
/* Configure the XLB Arbiter priorities */
out_be32(&xlb->master_pri_enable, 0xff);
out_be32(&xlb->master_priority, 0x11111111);
/* Disable XLB pipelining
* (cfr errate 292. We could do this only just before ATA PIO
* transaction and re-enable it afterwards ...)
*/
out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
iounmap(xlb);
}
/**
* mpc52xx_declare_of_platform_devices: register internal devices and children
* of the localplus bus to the of_platform
* bus.
*/
void __init
mpc52xx_declare_of_platform_devices(void)
{
/* Find every child of the SOC node and add it to of_platform */
if (of_platform_bus_probe(NULL, mpc52xx_bus_ids, NULL))
printk(KERN_ERR __FILE__ ": "
"Error while probing of_platform bus\n");
}
/*
* match tables used by mpc52xx_map_common_devices()
*/
static struct of_device_id mpc52xx_gpt_ids[] __initdata = {
{ .compatible = "fsl,mpc5200-gpt", },
{ .compatible = "mpc5200-gpt", }, /* old */
{}
};
static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
{ .compatible = "fsl,mpc5200-cdm", },
{ .compatible = "mpc5200-cdm", }, /* old */
{}
};
/**
* mpc52xx_map_common_devices: iomap devices required by common code
*/
void __init
mpc52xx_map_common_devices(void)
{
struct device_node *np;
/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
* possibly from a interrupt context. wdt is only implement
* on a gpt0, so check has-wdt property before mapping.
*/
for_each_matching_node(np, mpc52xx_gpt_ids) {
if (of_get_property(np, "fsl,has-wdt", NULL) ||
of_get_property(np, "has-wdt", NULL)) {
mpc52xx_wdt = of_iomap(np, 0);
of_node_put(np);
break;
}
}
/* Clock Distribution Module, used by PSC clock setting function */
np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
mpc52xx_cdm = of_iomap(np, 0);
of_node_put(np);
}
/**
* mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports
*
* @psc_id: id of psc port; must be 1,2,3 or 6
* @clkdiv: clock divider value to put into CDM PSC register.
*/
int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
{
unsigned long flags;
u16 __iomem *reg;
u32 val;
u32 mask;
u32 mclken_div;
if (!mpc52xx_cdm)
return -ENODEV;
mclken_div = 0x8000 | (clkdiv & 0x1FF);
switch (psc_id) {
case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break;
case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break;
case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break;
default:
return -ENODEV;
}
/* Set the rate and enable the clock */
spin_lock_irqsave(&mpc52xx_lock, flags);
out_be16(reg, mclken_div);
val = in_be32(&mpc52xx_cdm->clk_enables);
out_be32(&mpc52xx_cdm->clk_enables, val | mask);
spin_unlock_irqrestore(&mpc52xx_lock, flags);
return 0;
}
/**
* mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
*/
void
mpc52xx_restart(char *cmd)
{
local_irq_disable();
/* Turn on the watchdog and wait for it to expire.
* It effectively does a reset. */
if (mpc52xx_wdt) {
out_be32(&mpc52xx_wdt->mode, 0x00000000);
out_be32(&mpc52xx_wdt->count, 0x000000ff);
out_be32(&mpc52xx_wdt->mode, 0x00009004);
} else
printk("mpc52xx_restart: Can't access wdt. "
"Restart impossible, system halted.\n");
while (1);
}
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