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 = irq_desc_get_chip(cdesc); 230 chip->irq_eoi(&cdesc->irq_data); 231 } 232 233 chip = irq_desc_get_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 irq_set_chained_handler(irq, cpm_cascade); 255 } 256