arch/powerpc/platforms/8xx/m8xx_setup.c

   1 /*
   2  *  Copyright (C) 1995  Linus Torvalds
   3  *  Adapted from 'alpha' version by Gary Thomas
   4  *  Modified by Cort Dougan (cort@cs.nmt.edu)
   5  *  Modified for MBX using prep/chrp/pmac functions by Dan (dmalek@jlc.net)
   6  *  Further modified for generic 8xx by Dan.
   7  */
   8
   9 /*
  10  * bootup setup stuff..
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/init.h>
  16 #include <linux/time.h>
  17 #include <linux/rtc.h>
  18 #include <linux/fsl_devices.h>
  19
  20 #include <asm/io.h>
  21 #include <asm/8xx_immap.h>
  22 #include <asm/prom.h>
  23 #include <asm/fs_pd.h>
  24 #include <mm/mmu_decl.h>
  25
  26 #include <sysdev/mpc8xx_pic.h>
  27
  28 #include "mpc8xx.h"
  29
  30 extern int cpm_pic_init(void);
  31 extern int cpm_get_irq(void);
  32
  33 /* A place holder for time base interrupts, if they are ever enabled. */
  34 static irqreturn_t timebase_interrupt(int irq, void *dev)
  35 {
  36         printk ("timebase_interrupt()\n");
  37
  38         return IRQ_HANDLED;
  39 }
  40
  41 static struct irqaction tbint_irqaction = {
  42         .handler = timebase_interrupt,
  43         .flags = IRQF_NO_THREAD,
  44         .name = "tbint",
  45 };
  46
  47 /* per-board overridable init_internal_rtc() function. */
  48 void __init __attribute__ ((weak))
  49 init_internal_rtc(void)
  50 {
  51         sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
  52
  53         /* Disable the RTC one second and alarm interrupts. */
  54         clrbits16(&sys_tmr->sit_rtcsc, (RTCSC_SIE | RTCSC_ALE));
  55
  56         /* Enable the RTC */
  57         setbits16(&sys_tmr->sit_rtcsc, (RTCSC_RTF | RTCSC_RTE));
  58         immr_unmap(sys_tmr);
  59 }
  60
  61 static int __init get_freq(char *name, unsigned long *val)
  62 {
  63         struct device_node *cpu;
  64         const unsigned int *fp;
  65         int found = 0;
  66
  67         /* The cpu node should have timebase and clock frequency properties */
  68         cpu = of_find_node_by_type(NULL, "cpu");
  69
  70         if (cpu) {
  71                 fp = of_get_property(cpu, name, NULL);
  72                 if (fp) {
  73                         found = 1;
  74                         *val = *fp;
  75                 }
  76
  77                 of_node_put(cpu);
  78         }
  79
  80         return found;
  81 }
  82
  83 /* The decrementer counts at the system (internal) clock frequency divided by
  84  * sixteen, or external oscillator divided by four.  We force the processor
  85  * to use system clock divided by sixteen.
  86  */
  87 void __init mpc8xx_calibrate_decr(void)
  88 {
  89         struct device_node *cpu;
  90         cark8xx_t __iomem *clk_r1;
  91         car8xx_t __iomem *clk_r2;
  92         sitk8xx_t __iomem *sys_tmr1;
  93         sit8xx_t __iomem *sys_tmr2;
  94         int irq, virq;
  95
  96         clk_r1 = immr_map(im_clkrstk);
  97
  98         /* Unlock the SCCR. */
  99         out_be32(&clk_r1->cark_sccrk, ~KAPWR_KEY);
 100         out_be32(&clk_r1->cark_sccrk, KAPWR_KEY);
 101         immr_unmap(clk_r1);
 102
 103         /* Force all 8xx processors to use divide by 16 processor clock. */
 104         clk_r2 = immr_map(im_clkrst);
 105         setbits32(&clk_r2->car_sccr, 0x02000000);
 106         immr_unmap(clk_r2);
 107
 108         /* Processor frequency is MHz.
 109          */
 110         ppc_proc_freq = 50000000;
 111         if (!get_freq("clock-frequency", &ppc_proc_freq))
 112                 printk(KERN_ERR "WARNING: Estimating processor frequency "
 113                                 "(not found)\n");
 114
 115         ppc_tb_freq = ppc_proc_freq / 16;
 116         printk("Decrementer Frequency = 0x%lx\n", ppc_tb_freq);
 117
 118         /* Perform some more timer/timebase initialization.  This used
 119          * to be done elsewhere, but other changes caused it to get
 120          * called more than once....that is a bad thing.
 121          *
 122          * First, unlock all of the registers we are going to modify.
 123          * To protect them from corruption during power down, registers
 124          * that are maintained by keep alive power are "locked".  To
 125          * modify these registers we have to write the key value to
 126          * the key location associated with the register.
 127          * Some boards power up with these unlocked, while others
 128          * are locked.  Writing anything (including the unlock code?)
 129          * to the unlocked registers will lock them again.  So, here
 130          * we guarantee the registers are locked, then we unlock them
 131          * for our use.
 132          */
 133         sys_tmr1 = immr_map(im_sitk);
 134         out_be32(&sys_tmr1->sitk_tbscrk, ~KAPWR_KEY);
 135         out_be32(&sys_tmr1->sitk_rtcsck, ~KAPWR_KEY);
 136         out_be32(&sys_tmr1->sitk_tbk, ~KAPWR_KEY);
 137         out_be32(&sys_tmr1->sitk_tbscrk, KAPWR_KEY);
 138         out_be32(&sys_tmr1->sitk_rtcsck, KAPWR_KEY);
 139         out_be32(&sys_tmr1->sitk_tbk, KAPWR_KEY);
 140         immr_unmap(sys_tmr1);
 141
 142         init_internal_rtc();
 143
 144         /* Enabling the decrementer also enables the timebase interrupts
 145          * (or from the other point of view, to get decrementer interrupts
 146          * we have to enable the timebase).  The decrementer interrupt
 147          * is wired into the vector table, nothing to do here for that.
 148          */
 149         cpu = of_find_node_by_type(NULL, "cpu");
 150         virq= irq_of_parse_and_map(cpu, 0);
 151         irq = virq_to_hw(virq);
 152
 153         sys_tmr2 = immr_map(im_sit);
 154         out_be16(&sys_tmr2->sit_tbscr, ((1 << (7 - (irq/2))) << 8) |
 155                                         (TBSCR_TBF | TBSCR_TBE));
 156         immr_unmap(sys_tmr2);
 157
 158         if (setup_irq(virq, &tbint_irqaction))
 159                 panic("Could not allocate timer IRQ!");
 160 }
 161
 162 /* The RTC on the MPC8xx is an internal register.
 163  * We want to protect this during power down, so we need to unlock,
 164  * modify, and re-lock.
 165  */
 166
 167 int mpc8xx_set_rtc_time(struct rtc_time *tm)
 168 {
 169         sitk8xx_t __iomem *sys_tmr1;
 170         sit8xx_t __iomem *sys_tmr2;
 171         int time;
 172
 173         sys_tmr1 = immr_map(im_sitk);
 174         sys_tmr2 = immr_map(im_sit);
 175         time = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
 176                       tm->tm_hour, tm->tm_min, tm->tm_sec);
 177
 178         out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
 179         out_be32(&sys_tmr2->sit_rtc, time);
 180         out_be32(&sys_tmr1->sitk_rtck, ~KAPWR_KEY);
 181
 182         immr_unmap(sys_tmr2);
 183         immr_unmap(sys_tmr1);
 184         return 0;
 185 }
 186
 187 void mpc8xx_get_rtc_time(struct rtc_time *tm)
 188 {
 189         unsigned long data;
 190         sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
 191
 192         /* Get time from the RTC. */
 193         data = in_be32(&sys_tmr->sit_rtc);
 194         to_tm(data, tm);
 195         tm->tm_year -= 1900;
 196         tm->tm_mon -= 1;
 197         immr_unmap(sys_tmr);
 198         return;
 199 }
 200
 201 void mpc8xx_restart(char *cmd)
 202 {
 203         car8xx_t __iomem *clk_r = immr_map(im_clkrst);
 204
 205
 206         local_irq_disable();
 207
 208         setbits32(&clk_r->car_plprcr, 0x00000080);
 209         /* Clear the ME bit in MSR to cause checkstop on machine check
 210         */
 211         mtmsr(mfmsr() & ~0x1000);
 212
 213         in_8(&clk_r->res[0]);
 214         panic("Restart failed\n");
 215 }
 216
 217 static void cpm_cascade(unsigned int irq, struct irq_desc *desc)
 218 {
 219         struct irq_chip *chip = irq_desc_get_chip(desc);
 220         int cascade_irq = cpm_get_irq();
 221
 222         if (cascade_irq >= 0)
 223                 generic_handle_irq(cascade_irq);
 224
 225         chip->irq_eoi(&desc->irq_data);
 226 }
 227
 228 /* Initialize the internal interrupt controllers.  The number of
 229  * interrupts supported can vary with the processor type, and the
 230  * 82xx family can have up to 64.
 231  * External interrupts can be either edge or level triggered, and
 232  * need to be initialized by the appropriate driver.
 233  */
 234 void __init mpc8xx_pics_init(void)
 235 {
 236         int irq;
 237
 238         if (mpc8xx_pic_init()) {
 239                 printk(KERN_ERR "Failed interrupt 8xx controller  initialization\n");
 240                 return;
 241         }
 242
 243         irq = cpm_pic_init();
 244         if (irq != NO_IRQ)
 245                 irq_set_chained_handler(irq, cpm_cascade);
 246 }