// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1995 Linus Torvalds
* Adapted from 'alpha' version by Gary Thomas
* Modified by Cort Dougan ([email protected])
* Modified for MBX using prep/chrp/pmac functions by Dan ([email protected])
* Further modified for generic 8xx by Dan.
*/
/*
* bootup setup stuff..
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/fsl_devices.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <asm/io.h>
#include <asm/8xx_immap.h>
#include <mm/mmu_decl.h>
#include "pic.h"
#include "mpc8xx.h"
/* A place holder for time base interrupts, if they are ever enabled. */
static irqreturn_t timebase_interrupt(int irq, void *dev)
{
printk ("timebase_interrupt()\n");
return IRQ_HANDLED;
}
static int __init get_freq(char *name, unsigned long *val)
{
struct device_node *cpu;
const unsigned int *fp;
int found = 0;
/* The cpu node should have timebase and clock frequency properties */
cpu = of_get_cpu_node(0, NULL);
if (cpu) {
fp = of_get_property(cpu, name, NULL);
if (fp) {
found = 1;
*val = *fp;
}
of_node_put(cpu);
}
return found;
}
/* The decrementer counts at the system (internal) clock frequency divided by
* sixteen, or external oscillator divided by four. We force the processor
* to use system clock divided by sixteen.
*/
void __init mpc8xx_calibrate_decr(void)
{
struct device_node *cpu;
int irq, virq;
/* Unlock the SCCR. */
out_be32(&mpc8xx_immr->im_clkrstk.cark_sccrk, ~KAPWR_KEY);
out_be32(&mpc8xx_immr->im_clkrstk.cark_sccrk, KAPWR_KEY);
/* Force all 8xx processors to use divide by 16 processor clock. */
setbits32(&mpc8xx_immr->im_clkrst.car_sccr, 0x02000000);
/* Processor frequency is MHz.
*/
ppc_proc_freq = 50000000;
if (!get_freq("clock-frequency", &ppc_proc_freq))
printk(KERN_ERR "WARNING: Estimating processor frequency "
"(not found)\n");
ppc_tb_freq = ppc_proc_freq / 16;
printk("Decrementer Frequency = 0x%lx\n", ppc_tb_freq);
/* Perform some more timer/timebase initialization. This used
* to be done elsewhere, but other changes caused it to get
* called more than once....that is a bad thing.
*
* First, unlock all of the registers we are going to modify.
* To protect them from corruption during power down, registers
* that are maintained by keep alive power are "locked". To
* modify these registers we have to write the key value to
* the key location associated with the register.
* Some boards power up with these unlocked, while others
* are locked. Writing anything (including the unlock code?)
* to the unlocked registers will lock them again. So, here
* we guarantee the registers are locked, then we unlock them
* for our use.
*/
out_be32(&mpc8xx_immr->im_sitk.sitk_tbscrk, ~KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sitk.sitk_rtcsck, ~KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sitk.sitk_tbk, ~KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sitk.sitk_tbscrk, KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sitk.sitk_rtcsck, KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sitk.sitk_tbk, KAPWR_KEY);
/* Disable the RTC one second and alarm interrupts. */
clrbits16(&mpc8xx_immr->im_sit.sit_rtcsc, (RTCSC_SIE | RTCSC_ALE));
/* Enable the RTC */
setbits16(&mpc8xx_immr->im_sit.sit_rtcsc, (RTCSC_RTF | RTCSC_RTE));
/* Enabling the decrementer also enables the timebase interrupts
* (or from the other point of view, to get decrementer interrupts
* we have to enable the timebase). The decrementer interrupt
* is wired into the vector table, nothing to do here for that.
*/
cpu = of_get_cpu_node(0, NULL);
virq= irq_of_parse_and_map(cpu, 0);
of_node_put(cpu);
irq = virq_to_hw(virq);
out_be16(&mpc8xx_immr->im_sit.sit_tbscr,
((1 << (7 - (irq / 2))) << 8) | (TBSCR_TBF | TBSCR_TBE));
if (request_irq(virq, timebase_interrupt, IRQF_NO_THREAD, "tbint",
NULL))
panic("Could not allocate timer IRQ!");
}
/* The RTC on the MPC8xx is an internal register.
* We want to protect this during power down, so we need to unlock,
* modify, and re-lock.
*/
int mpc8xx_set_rtc_time(struct rtc_time *tm)
{
time64_t time;
time = rtc_tm_to_time64(tm);
out_be32(&mpc8xx_immr->im_sitk.sitk_rtck, KAPWR_KEY);
out_be32(&mpc8xx_immr->im_sit.sit_rtc, (u32)time);
out_be32(&mpc8xx_immr->im_sitk.sitk_rtck, ~KAPWR_KEY);
return 0;
}
void mpc8xx_get_rtc_time(struct rtc_time *tm)
{
unsigned long data;
/* Get time from the RTC. */
data = in_be32(&mpc8xx_immr->im_sit.sit_rtc);
rtc_time64_to_tm(data, tm);
return;
}
void __noreturn mpc8xx_restart(char *cmd)
{
local_irq_disable();
setbits32(&mpc8xx_immr->im_clkrst.car_plprcr, 0x00000080);
/* Clear the ME bit in MSR to cause checkstop on machine check
*/
mtmsr(mfmsr() & ~0x1000);
in_8(&mpc8xx_immr->im_clkrst.res[0]);
panic("Restart failed\n");
}
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