// 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 #include #include #include #include #include #include #include #include #include #include #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) { generic_handle_irq(cpm_get_irq()); } /* 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); }