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/mpc8xx.h>
  22 #include <asm/8xx_immap.h>
  23 #include <asm/prom.h>
  24 #include <asm/fs_pd.h>
  25 #include <mm/mmu_decl.h>
  26
  27 #include <sysdev/mpc8xx_pic.h>
  28
  29 #include "mpc8xx.h"
  30
  31 struct mpc8xx_pcmcia_ops m8xx_pcmcia_ops;
  32
  33 extern int cpm_pic_init(void);
  34 extern int cpm_get_irq(void);
  35
  36 /* A place holder for time base interrupts, if they are ever enabled. */
  37 static irqreturn_t timebase_interrupt(int irq, void *dev)
  38 {
  39         printk ("timebase_interrupt()\n");
  40
  41         return IRQ_HANDLED;
  42 }
  43
  44 static struct irqaction tbint_irqaction = {
  45         .handler = timebase_interrupt,
  46         .name = "tbint",
  47 };
  48
  49 /* per-board overridable init_internal_rtc() function. */
  50 void __init __attribute__ ((weak))
  51 init_internal_rtc(void)
  52 {
  53         sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
  54
  55         /* Disable the RTC one second and alarm interrupts. */
  56         clrbits16(&sys_tmr->sit_rtcsc, (RTCSC_SIE | RTCSC_ALE));
  57
  58         /* Enable the RTC */
  59         setbits16(&sys_tmr->sit_rtcsc, (RTCSC_RTF | RTCSC_RTE));
  60         immr_unmap(sys_tmr);
  61 }
  62
  63 static int __init get_freq(char *name, unsigned long *val)
  64 {
  65         struct device_node *cpu;
  66         const unsigned int *fp;
  67         int found = 0;
  68
  69         /* The cpu node should have timebase and clock frequency properties */
  70         cpu = of_find_node_by_type(NULL, "cpu");
  71
  72         if (cpu) {
  73                 fp = of_get_property(cpu, name, NULL);
  74                 if (fp) {
  75                         found = 1;
  76                         *val = *fp;
  77                 }
  78
  79                 of_node_put(cpu);
  80         }
  81
  82         return found;
  83 }
  84
  85 /* The decrementer counts at the system (internal) clock frequency divided by
  86  * sixteen, or external oscillator divided by four.  We force the processor
  87  * to use system clock divided by sixteen.
  88  */
  89 void __init mpc8xx_calibrate_decr(void)
  90 {
  91         struct device_node *cpu;
  92         cark8xx_t __iomem *clk_r1;
  93         car8xx_t __iomem *clk_r2;
  94         sitk8xx_t __iomem *sys_tmr1;
  95         sit8xx_t __iomem *sys_tmr2;
  96         int irq, virq;
  97
  98         clk_r1 = immr_map(im_clkrstk);
  99
 100         /* Unlock the SCCR. */
 101         out_be32(&clk_r1->cark_sccrk, ~KAPWR_KEY);
 102         out_be32(&clk_r1->cark_sccrk, KAPWR_KEY);
 103         immr_unmap(clk_r1);
 104
 105         /* Force all 8xx processors to use divide by 16 processor clock. */
 106         clk_r2 = immr_map(im_clkrst);
 107         setbits32(&clk_r2->car_sccr, 0x02000000);
 108         immr_unmap(clk_r2);
 109
 110         /* Processor frequency is MHz.
 111          */
 112         ppc_proc_freq = 50000000;
 113         if (!get_freq("clock-frequency", &ppc_proc_freq))
 114                 printk(KERN_ERR "WARNING: Estimating processor frequency "
 115                                 "(not found)\n");
 116
 117         ppc_tb_freq = ppc_proc_freq / 16;
 118         printk("Decrementer Frequency = 0x%lx\n", ppc_tb_freq);
 119
 120         /* Perform some more timer/timebase initialization.  This used
 121          * to be done elsewhere, but other changes caused it to get
 122          * called more than once....that is a bad thing.
 123          *
 124          * First, unlock all of the registers we are going to modify.
 125          * To protect them from corruption during power down, registers
 126          * that are maintained by keep alive power are "locked".  To
 127          * modify these registers we have to write the key value to
 128          * the key location associated with the register.
 129          * Some boards power up with these unlocked, while others
 130          * are locked.  Writing anything (including the unlock code?)
 131          * to the unlocked registers will lock them again.  So, here
 132          * we guarantee the registers are locked, then we unlock them
 133          * for our use.
 134          */
 135         sys_tmr1 = immr_map(im_sitk);
 136         out_be32(&sys_tmr1->sitk_tbscrk, ~KAPWR_KEY);
 137         out_be32(&sys_tmr1->sitk_rtcsck, ~KAPWR_KEY);
 138         out_be32(&sys_tmr1->sitk_tbk, ~KAPWR_KEY);
 139         out_be32(&sys_tmr1->sitk_tbscrk, KAPWR_KEY);
 140         out_be32(&sys_tmr1->sitk_rtcsck, KAPWR_KEY);
 141         out_be32(&sys_tmr1->sitk_tbk, KAPWR_KEY);
 142         immr_unmap(sys_tmr1);
 143
 144         init_internal_rtc();
 145
 146         /* Enabling the decrementer also enables the timebase interrupts
 147          * (or from the other point of view, to get decrementer interrupts
 148          * we have to enable the timebase).  The decrementer interrupt
 149          * is wired into the vector table, nothing to do here for that.
 150          */
 151         cpu = of_find_node_by_type(NULL, "cpu");
 152         virq= irq_of_parse_and_map(cpu, 0);
 153         irq = irq_map[virq].hwirq;
 154
 155         sys_tmr2 = immr_map(im_sit);
 156         out_be16(&sys_tmr2->sit_tbscr, ((1 << (7 - (irq/2))) << 8) |
 157                                         (TBSCR_TBF | TBSCR_TBE));
 158         immr_unmap(sys_tmr2);
 159
 160         if (setup_irq(virq, &tbint_irqaction))
 161                 panic("Could not allocate timer IRQ!");
 162 }
 163
 164 /* The RTC on the MPC8xx is an internal register.
 165  * We want to protect this during power down, so we need to unlock,
 166  * modify, and re-lock.
 167  */
 168
 169 int mpc8xx_set_rtc_time(struct rtc_time *tm)
 170 {
 171         sitk8xx_t __iomem *sys_tmr1;
 172         sit8xx_t __iomem *sys_tmr2;
 173         int time;
 174
 175         sys_tmr1 = immr_map(im_sitk);
 176         sys_tmr2 = immr_map(im_sit);
 177         time = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
 178                       tm->tm_hour, tm->tm_min, tm->tm_sec);
 179
 180         out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
 181         out_be32(&sys_tmr2->sit_rtc, time);
 182         out_be32(&sys_tmr1->sitk_rtck, ~KAPWR_KEY);
 183
 184         immr_unmap(sys_tmr2);
 185         immr_unmap(sys_tmr1);
 186         return 0;
 187 }
 188
 189 void mpc8xx_get_rtc_time(struct rtc_time *tm)
 190 {
 191         unsigned long data;
 192         sit8xx_t __iomem *sys_tmr = immr_map(im_sit);
 193
 194         /* Get time from the RTC. */
 195         data = in_be32(&sys_tmr->sit_rtc);
 196         to_tm(data, tm);
 197         tm->tm_year -= 1900;
 198         tm->tm_mon -= 1;
 199         immr_unmap(sys_tmr);
 200         return;
 201 }
 202
 203 void mpc8xx_restart(char *cmd)
 204 {
 205         car8xx_t __iomem *clk_r = immr_map(im_clkrst);
 206
 207
 208         local_irq_disable();
 209
 210         setbits32(&clk_r->car_plprcr, 0x00000080);
 211         /* Clear the ME bit in MSR to cause checkstop on machine check
 212         */
 213         mtmsr(mfmsr() & ~0x1000);
 214
 215         in_8(&clk_r->res[0]);
 216         panic("Restart failed\n");
 217 }
 218
 219 static void cpm_cascade(unsigned int irq, struct irq_desc *desc)
 220 {
 221         struct irq_chip *chip;
 222         int cascade_irq;
 223
 224         if ((cascade_irq = cpm_get_irq()) >= 0) {
 225                 struct irq_desc *cdesc = irq_to_desc(cascade_irq);
 226
 227                 generic_handle_irq(cascade_irq);
 228
 229                 chip = get_irq_desc_chip(cdesc);
 230                 chip->irq_eoi(&cdesc->irq_data);
 231         }
 232
 233         chip = get_irq_desc_chip(desc);
 234         chip->irq_eoi(&desc->irq_data);
 235 }
 236
 237 /* Initialize the internal interrupt controllers.  The number of
 238  * interrupts supported can vary with the processor type, and the
 239  * 82xx family can have up to 64.
 240  * External interrupts can be either edge or level triggered, and
 241  * need to be initialized by the appropriate driver.
 242  */
 243 void __init mpc8xx_pics_init(void)
 244 {
 245         int irq;
 246
 247         if (mpc8xx_pic_init()) {
 248                 printk(KERN_ERR "Failed interrupt 8xx controller  initialization\n");
 249                 return;
 250         }
 251
 252         irq = cpm_pic_init();
 253         if (irq != NO_IRQ)
 254                 set_irq_chained_handler(irq, cpm_cascade);
 255 }