arch/powerpc/platforms/8xx/m8xx_setup.c - arm/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  Copyright (C) 1995  Linus Torvalds
  *  Adapted from 'alpha' version by Gary Thomas
  *  Modified by Cort Dougan (cort@cs.nmt.edu)
  *  Modified for MBX using prep/chrp/pmac functions by Dan (dmalek@jlc.net)
  *  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 <asm/io.h>
 #include <asm/8xx_immap.h>
 #include <asm/prom.h>
 #include <asm/fs_pd.h>
 #include <mm/mmu_decl.h>

 #include "pic.h"

 #include "mpc8xx.h"

 extern int cpm_pic_init(void);
 extern int cpm_get_irq(void);

 /* 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 struct irqaction tbint_irqaction = {
 	.handler = timebase_interrupt,
 	.flags = IRQF_NO_THREAD,
 	.name = "tbint",
 };

 /* per-board overridable init_internal_rtc() function. */
 void __init __attribute__ ((weak))
 init_internal_rtc(void)
 {
 	sit8xx_t __iomem *sys_tmr = immr_map(im_sit);

 	/* Disable the RTC one second and alarm interrupts. */
 	clrbits16(&sys_tmr->sit_rtcsc, (RTCSC_SIE | RTCSC_ALE));

 	/* Enable the RTC */
 	setbits16(&sys_tmr->sit_rtcsc, (RTCSC_RTF | RTCSC_RTE));
 	immr_unmap(sys_tmr);
 }

 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_find_node_by_type(NULL, "cpu");

 	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;
 	cark8xx_t __iomem *clk_r1;
 	car8xx_t __iomem *clk_r2;
 	sitk8xx_t __iomem *sys_tmr1;
 	sit8xx_t __iomem *sys_tmr2;
 	int irq, virq;

 	clk_r1 = immr_map(im_clkrstk);

 	/* Unlock the SCCR. */
 	out_be32(&clk_r1->cark_sccrk, ~KAPWR_KEY);
 	out_be32(&clk_r1->cark_sccrk, KAPWR_KEY);
 	immr_unmap(clk_r1);

 	/* Force all 8xx processors to use divide by 16 processor clock. */
 	clk_r2 = immr_map(im_clkrst);
 	setbits32(&clk_r2->car_sccr, 0x02000000);
 	immr_unmap(clk_r2);

 	/* 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.
 	 */
 	sys_tmr1 = immr_map(im_sitk);
 	out_be32(&sys_tmr1->sitk_tbscrk, ~KAPWR_KEY);
 	out_be32(&sys_tmr1->sitk_rtcsck, ~KAPWR_KEY);
 	out_be32(&sys_tmr1->sitk_tbk, ~KAPWR_KEY);
 	out_be32(&sys_tmr1->sitk_tbscrk, KAPWR_KEY);
 	out_be32(&sys_tmr1->sitk_rtcsck, KAPWR_KEY);
 	out_be32(&sys_tmr1->sitk_tbk, KAPWR_KEY);
 	immr_unmap(sys_tmr1);

 	init_internal_rtc();

 	/* 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_find_node_by_type(NULL, "cpu");
 	virq= irq_of_parse_and_map(cpu, 0);
 	irq = virq_to_hw(virq);

 	sys_tmr2 = immr_map(im_sit);
 	out_be16(&sys_tmr2->sit_tbscr, ((1 << (7 - (irq/2))) << 8) |
 					(TBSCR_TBF | TBSCR_TBE));
 	immr_unmap(sys_tmr2);

 	if (setup_irq(virq, &tbint_irqaction))
 		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)
 {
 	sitk8xx_t __iomem *sys_tmr1;
 	sit8xx_t __iomem *sys_tmr2;
 	int time;

 	sys_tmr1 = immr_map(im_sitk);
 	sys_tmr2 = immr_map(im_sit);
 	time = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
 	              tm->tm_hour, tm->tm_min, tm->tm_sec);

 	out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
 	out_be32(&sys_tmr2->sit_rtc, time);
 	out_be32(&sys_tmr1->sitk_rtck, ~KAPWR_KEY);

 	immr_unmap(sys_tmr2);
 	immr_unmap(sys_tmr1);
 	return 0;
 }

 void mpc8xx_get_rtc_time(struct rtc_time *tm)
 {
 	unsigned long data;
 	sit8xx_t __iomem *sys_tmr = immr_map(im_sit);

 	/* Get time from the RTC. */
 	data = in_be32(&sys_tmr->sit_rtc);
 	to_tm(data, tm);
 	tm->tm_year -= 1900;
 	tm->tm_mon -= 1;
 	immr_unmap(sys_tmr);
 	return;
 }

 void __noreturn mpc8xx_restart(char *cmd)
 {
 	car8xx_t __iomem *clk_r = immr_map(im_clkrst);


 	local_irq_disable();

 	setbits32(&clk_r->car_plprcr, 0x00000080);
 	/* Clear the ME bit in MSR to cause checkstop on machine check
 	*/
 	mtmsr(mfmsr() & ~0x1000);

 	in_8(&clk_r->res[0]);
 	panic("Restart failed\n");
 }

 static void cpm_cascade(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	int cascade_irq = cpm_get_irq();

 	if (cascade_irq >= 0)
 		generic_handle_irq(cascade_irq);

 	chip->irq_eoi(&desc->irq_data);
 }

 /* Initialize the internal interrupt controllers.  The number of
  * interrupts supported can vary with the processor type, and the
  * 82xx family can have up to 64.
  * External interrupts can be either edge or level triggered, and
  * need to be initialized by the appropriate driver.
  */
 void __init mpc8xx_pics_init(void)
 {
 	int irq;

 	if (mpc8xx_pic_init()) {
 		printk(KERN_ERR "Failed interrupt 8xx controller  initialization\n");
 		return;
 	}

 	irq = cpm_pic_init();
 	if (irq)
 		irq_set_chained_handler(irq, cpm_cascade);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 1995 Linus Torvalds
	* Adapted from 'alpha' version by Gary Thomas
	* Modified by Cort Dougan (cort@cs.nmt.edu)
	* Modified for MBX using prep/chrp/pmac functions by Dan (dmalek@jlc.net)
	* 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 <asm/io.h>
	#include <asm/8xx_immap.h>
	#include <asm/prom.h>
	#include <asm/fs_pd.h>
	#include <mm/mmu_decl.h>

	#include "pic.h"

	#include "mpc8xx.h"

	extern int cpm_pic_init(void);
	extern int cpm_get_irq(void);

	/* 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 struct irqaction tbint_irqaction = {
	.handler = timebase_interrupt,
	.flags = IRQF_NO_THREAD,
	.name = "tbint",
	};

	/* per-board overridable init_internal_rtc() function. */
	void __init __attribute__ ((weak))
	init_internal_rtc(void)
	{
	sit8xx_t __iomem *sys_tmr = immr_map(im_sit);

	/* Disable the RTC one second and alarm interrupts. */
	clrbits16(&sys_tmr->sit_rtcsc, (RTCSC_SIE \| RTCSC_ALE));

	/* Enable the RTC */
	setbits16(&sys_tmr->sit_rtcsc, (RTCSC_RTF \| RTCSC_RTE));
	immr_unmap(sys_tmr);
	}

	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_find_node_by_type(NULL, "cpu");

	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;
	cark8xx_t __iomem *clk_r1;
	car8xx_t __iomem *clk_r2;
	sitk8xx_t __iomem *sys_tmr1;
	sit8xx_t __iomem *sys_tmr2;
	int irq, virq;

	clk_r1 = immr_map(im_clkrstk);

	/* Unlock the SCCR. */
	out_be32(&clk_r1->cark_sccrk, ~KAPWR_KEY);
	out_be32(&clk_r1->cark_sccrk, KAPWR_KEY);
	immr_unmap(clk_r1);

	/* Force all 8xx processors to use divide by 16 processor clock. */
	clk_r2 = immr_map(im_clkrst);
	setbits32(&clk_r2->car_sccr, 0x02000000);
	immr_unmap(clk_r2);

	/* 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.
	*/
	sys_tmr1 = immr_map(im_sitk);
	out_be32(&sys_tmr1->sitk_tbscrk, ~KAPWR_KEY);
	out_be32(&sys_tmr1->sitk_rtcsck, ~KAPWR_KEY);
	out_be32(&sys_tmr1->sitk_tbk, ~KAPWR_KEY);
	out_be32(&sys_tmr1->sitk_tbscrk, KAPWR_KEY);
	out_be32(&sys_tmr1->sitk_rtcsck, KAPWR_KEY);
	out_be32(&sys_tmr1->sitk_tbk, KAPWR_KEY);
	immr_unmap(sys_tmr1);

	init_internal_rtc();

	/* 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_find_node_by_type(NULL, "cpu");
	virq= irq_of_parse_and_map(cpu, 0);
	irq = virq_to_hw(virq);

	sys_tmr2 = immr_map(im_sit);
	out_be16(&sys_tmr2->sit_tbscr, ((1 << (7 - (irq/2))) << 8) \|
	(TBSCR_TBF \| TBSCR_TBE));
	immr_unmap(sys_tmr2);

	if (setup_irq(virq, &tbint_irqaction))
	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)
	{
	sitk8xx_t __iomem *sys_tmr1;
	sit8xx_t __iomem *sys_tmr2;
	int time;

	sys_tmr1 = immr_map(im_sitk);
	sys_tmr2 = immr_map(im_sit);
	time = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
	tm->tm_hour, tm->tm_min, tm->tm_sec);

	out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
	out_be32(&sys_tmr2->sit_rtc, time);
	out_be32(&sys_tmr1->sitk_rtck, ~KAPWR_KEY);

	immr_unmap(sys_tmr2);
	immr_unmap(sys_tmr1);
	return 0;
	}

	void mpc8xx_get_rtc_time(struct rtc_time *tm)
	{
	unsigned long data;
	sit8xx_t __iomem *sys_tmr = immr_map(im_sit);

	/* Get time from the RTC. */
	data = in_be32(&sys_tmr->sit_rtc);
	to_tm(data, tm);
	tm->tm_year -= 1900;
	tm->tm_mon -= 1;
	immr_unmap(sys_tmr);
	return;
	}

	void __noreturn mpc8xx_restart(char *cmd)
	{
	car8xx_t __iomem *clk_r = immr_map(im_clkrst);


	local_irq_disable();

	setbits32(&clk_r->car_plprcr, 0x00000080);
	/* Clear the ME bit in MSR to cause checkstop on machine check
	*/
	mtmsr(mfmsr() & ~0x1000);

	in_8(&clk_r->res[0]);
	panic("Restart failed\n");
	}

	static void cpm_cascade(struct irq_desc *desc)
	{
	struct irq_chip *chip = irq_desc_get_chip(desc);
	int cascade_irq = cpm_get_irq();

	if (cascade_irq >= 0)
	generic_handle_irq(cascade_irq);

	chip->irq_eoi(&desc->irq_data);
	}

	/* Initialize the internal interrupt controllers. The number of
	* interrupts supported can vary with the processor type, and the
	* 82xx family can have up to 64.
	* External interrupts can be either edge or level triggered, and
	* need to be initialized by the appropriate driver.
	*/
	void __init mpc8xx_pics_init(void)
	{
	int irq;

	if (mpc8xx_pic_init()) {
	printk(KERN_ERR "Failed interrupt 8xx controller initialization\n");
	return;
	}

	irq = cpm_pic_init();
	if (irq)
	irq_set_chained_handler(irq, cpm_cascade);
	}