arch/sparc/cpu/leon3/cpu_init.c

   1 /* Initializes CPU and basic hardware such as memory
   2  * controllers, IRQ controller and system timer 0.
   3  *
   4  * (C) Copyright 2007, 2015
   5  * Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <asm/asi.h>
  12 #include <asm/leon.h>
  13 #include <asm/io.h>
  14 #include <asm/irq.h>
  15 #include <ambapp.h>
  16 #include <grlib/irqmp.h>
  17 #include <grlib/gptimer.h>
  18 #include <debug_uart.h>
  19
  20 #include <config.h>
  21
  22 /* Default Plug&Play I/O area */
  23 #ifndef CONFIG_AMBAPP_IOAREA
  24 #define CONFIG_AMBAPP_IOAREA AMBA_DEFAULT_IOAREA
  25 #endif
  26
  27 /* Select which TIMER that will become the time base */
  28 #ifndef CONFIG_SYS_GRLIB_GPTIMER_INDEX
  29 #define CONFIG_SYS_GRLIB_GPTIMER_INDEX 0
  30 #endif
  31
  32 #define TIMER_BASE_CLK 1000000
  33 #define US_PER_TICK (1000000 / CONFIG_SYS_HZ)
  34
  35 DECLARE_GLOBAL_DATA_PTR;
  36
  37 ambapp_dev_irqmp *irqmp = NULL;
  38
  39 /*
  40  * Breath some life into the CPU...
  41  *
  42  * Run from FLASH/PROM:
  43  *  - until memory controller is set up, only registers available
  44  *  - memory controller has already been setup up, stack can be used
  45  *  - no global variables available for writing
  46  *  - constants available
  47  */
  48 void cpu_init_f(void)
  49 {
  50 #ifdef CONFIG_DEBUG_UART
  51         debug_uart_init();
  52 #endif
  53 }
  54
  55 /* If cache snooping is available in hardware the result will be set
  56  * to 0x800000, otherwise 0.
  57  */
  58 static unsigned int snoop_detect(void)
  59 {
  60         unsigned int result;
  61         asm("lda [%%g0] 2, %0" : "=r"(result));
  62         return result & 0x00800000;
  63 }
  64
  65 int arch_cpu_init(void)
  66 {
  67         ambapp_apbdev apbdev;
  68         int index;
  69
  70         gd->cpu_clk = CONFIG_SYS_CLK_FREQ;
  71         gd->bus_clk = CONFIG_SYS_CLK_FREQ;
  72         gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
  73
  74         gd->arch.snooping_available = snoop_detect();
  75
  76         /* Initialize the AMBA Plug & Play bus structure, the bus
  77          * structure represents the AMBA bus that the CPU is located at.
  78          */
  79         ambapp_bus_init(CONFIG_AMBAPP_IOAREA, CONFIG_SYS_CLK_FREQ, &ambapp_plb);
  80
  81         /* Initialize/clear all the timers in the system.
  82          */
  83         for (index = 0; ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER,
  84                 GAISLER_GPTIMER, index, &apbdev) == 1; index++) {
  85                 ambapp_dev_gptimer *timer;
  86                 unsigned int bus_freq;
  87                 int i, ntimers;
  88
  89                 timer = (ambapp_dev_gptimer *)apbdev.address;
  90
  91                 /* Different buses may have different frequency, the
  92                  * frequency of the bus tell in which frequency the timer
  93                  * prescaler operates.
  94                  */
  95                 bus_freq = ambapp_bus_freq(&ambapp_plb, apbdev.ahb_bus_index);
  96
  97                 /* Initialize prescaler common to all timers to 1MHz */
  98                 timer->scalar = timer->scalar_reload =
  99                         (((bus_freq / 1000) + 500) / 1000) - 1;
 100
 101                 /* Clear all timers */
 102                 ntimers = timer->config & 0x7;
 103                 for (i = 0; i < ntimers; i++) {
 104                         timer->e[i].ctrl = GPTIMER_CTRL_IP;
 105                         timer->e[i].rld = 0;
 106                         timer->e[i].ctrl = GPTIMER_CTRL_LD;
 107                 }
 108         }
 109
 110         return 0;
 111 }
 112
 113 /*
 114  * initialize higher level parts of CPU like time base and timers
 115  */
 116 int cpu_init_r(void)
 117 {
 118         ambapp_apbdev apbdev;
 119         int cpu;
 120
 121         /*
 122          * Find AMBA APB IRQMP Controller,
 123          */
 124         if (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER,
 125                 GAISLER_IRQMP, 0, &apbdev) != 1) {
 126                 panic("%s: IRQ controller not found\n", __func__);
 127                 return -1;
 128         }
 129         irqmp = (ambapp_dev_irqmp *)apbdev.address;
 130
 131         /* initialize the IRQMP */
 132         irqmp->ilevel = 0xf;    /* all IRQ off */
 133         irqmp->iforce = 0;
 134         irqmp->ipend = 0;
 135         irqmp->iclear = 0xfffe; /* clear all old pending interrupts */
 136         for (cpu = 0; cpu < 16; cpu++) {
 137                 /* mask and clear force for all IRQs on CPU[N] */
 138                 irqmp->cpu_mask[cpu] = 0;
 139                 irqmp->cpu_force[cpu] = 0;
 140         }
 141
 142         return 0;
 143 }
 144
 145 /* Busy wait a number of ms */
 146 void cpu_wait_ms_busy(unsigned long ms)
 147 {
 148         unsigned int ms_delay;
 149         volatile unsigned int tmp;
 150
 151         /* ~10-20 cycles per decrement */
 152         ms_delay = leon_cpu_freq / (1000 * 10);
 153         do {
 154                 /* Wait ~1ms */
 155                 tmp = ms_delay;
 156                 while (tmp-- > 0)
 157                         ;
 158         } while (--ms > 0);
 159 }
 160
 161 /* Uses Timer 0 to get accurate
 162  * pauses. Max 2 raised to 32 ticks
 163  *
 164  */
 165 void cpu_wait_ticks(unsigned long ticks)
 166 {
 167         unsigned long start;
 168
 169         if (interrupt_is_enabled()) {
 170                 start = get_timer(0);
 171                 while (get_timer(start) < ticks)
 172                         ;
 173         } else {
 174                 /* Interrupts disabled, this means that we cannot
 175                  * use get_timer(), it relies on IRQ. Instead the
 176                  * CPU frequency is used.
 177                  */
 178                 cpu_wait_ms_busy(ticks2usec(ticks) / 1000);
 179         }
 180 }
 181
 182 int timer_interrupt_init_cpu(void)
 183 {
 184         return -1;
 185 }
 186
 187 /*
 188  * This function is intended for SHORT delays only.
 189  */
 190 unsigned long cpu_usec2ticks(unsigned long usec)
 191 {
 192         if (usec < US_PER_TICK)
 193                 return 1;
 194         return usec / US_PER_TICK;
 195 }
 196
 197 unsigned long cpu_ticks2usec(unsigned long ticks)
 198 {
 199         return ticks * US_PER_TICK;
 200 }
 201
 202 int timer_init(void)
 203 {
 204         ambapp_dev_gptimer_element *tmr;
 205         ambapp_dev_gptimer *gptimer;
 206         ambapp_apbdev apbdev;
 207         unsigned bus_freq;
 208
 209         if (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER, GAISLER_GPTIMER,
 210                 CONFIG_SYS_GRLIB_GPTIMER_INDEX, &apbdev) != 1) {
 211                 panic("%s: gptimer not found!\n", __func__);
 212                 return -1;
 213         }
 214
 215         gptimer = (ambapp_dev_gptimer *) apbdev.address;
 216
 217         /* Different buses may have different frequency, the
 218          * frequency of the bus tell in which frequency the timer
 219          * prescaler operates.
 220          */
 221         bus_freq = ambapp_bus_freq(&ambapp_plb, apbdev.ahb_bus_index);
 222
 223         /* initialize prescaler common to all timers to 1MHz */
 224         gptimer->scalar = gptimer->scalar_reload =
 225                 (((bus_freq / 1000) + 500) / 1000) - 1;
 226
 227         tmr = (ambapp_dev_gptimer_element *)&gptimer->e[0];
 228
 229         tmr->val = 0;
 230         tmr->rld = ~0;
 231         tmr->ctrl = GPTIMER_CTRL_EN | GPTIMER_CTRL_RS | GPTIMER_CTRL_LD;
 232
 233         CONFIG_SYS_TIMER_COUNTER = (void *)&tmr->val;
 234         return 0;
 235 }