1 /* Initializes CPU and basic hardware such as memory
2 * controllers, IRQ controller and system timer 0.
4 * (C) Copyright 2007, 2015
5 * Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com
7 * SPDX-License-Identifier: GPL-2.0+
14 #include <grlib/irqmp.h>
15 #include <grlib/gptimer.h>
19 /* Default Plug&Play I/O area */
20 #ifndef CONFIG_AMBAPP_IOAREA
21 #define CONFIG_AMBAPP_IOAREA AMBA_DEFAULT_IOAREA
24 #define TIMER_BASE_CLK 1000000
25 #define US_PER_TICK (1000000 / CONFIG_SYS_HZ)
27 DECLARE_GLOBAL_DATA_PTR;
29 /* reset CPU (jump to 0, without reset) */
32 ambapp_dev_irqmp *irqmp = NULL;
33 ambapp_dev_gptimer *gptimer = NULL;
34 unsigned int gptimer_irq = 0;
35 int leon3_snooping_avail = 0;
43 * Breath some life into the CPU...
45 * Run from FLASH/PROM:
46 * - until memory controller is set up, only registers available
47 * - memory controller has already been setup up, stack can be used
48 * - no global variables available for writing
49 * - constants available
56 /* Routine called from start.S,
58 * Run from FLASH/PROM:
59 * - memory controller has already been setup up, stack can be used
60 * - global variables available for read/writing
61 * - constants avaiable
63 void cpu_init_f2(void)
65 /* Initialize the AMBA Plug & Play bus structure, the bus
66 * structure represents the AMBA bus that the CPU is located at.
68 ambapp_bus_init(CONFIG_AMBAPP_IOAREA, CONFIG_SYS_CLK_FREQ, &ambapp_plb);
72 * initialize higher level parts of CPU like time base and timers
78 ambapp_dev_gptimer *timer = NULL;
79 unsigned int bus_freq;
82 * Find AMBA APB IRQMP Controller,
84 if (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER,
85 GAISLER_IRQMP, 0, &apbdev) != 1) {
86 panic("%s: IRQ controller not found\n", __func__);
89 irqmp = (ambapp_dev_irqmp *)apbdev.address;
91 /* initialize the IRQMP */
92 irqmp->ilevel = 0xf; /* all IRQ off */
95 irqmp->iclear = 0xfffe; /* clear all old pending interrupts */
96 for (cpu = 0; cpu < 16; cpu++) {
97 /* mask and clear force for all IRQs on CPU[N] */
98 irqmp->cpu_mask[cpu] = 0;
99 irqmp->cpu_force[cpu] = 0;
104 while (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER, GAISLER_GPTIMER,
105 index, &apbdev) == 1) {
106 timer = (ambapp_dev_gptimer *)apbdev.address;
107 if (gptimer == NULL) {
109 gptimer_irq = apbdev.irq;
112 /* Different buses may have different frequency, the
113 * frequency of the bus tell in which frequency the timer
114 * prescaler operates.
116 bus_freq = ambapp_bus_freq(&ambapp_plb, apbdev.ahb_bus_index);
118 /* initialize prescaler common to all timers to 1MHz */
119 timer->scalar = timer->scalar_reload =
120 (((bus_freq / 1000) + 500) / 1000) - 1;
125 printf("%s: gptimer not found!\n", __func__);
131 /* Uses Timer 0 to get accurate
132 * pauses. Max 2 raised to 32 ticks
135 void cpu_wait_ticks(unsigned long ticks)
137 unsigned long start = get_timer(0);
138 while (get_timer(start) < ticks) ;
141 /* initiate and setup timer0 interrupt to configured HZ. Base clock is 1MHz.
142 * Return irq number for timer int or a negative number for
145 int timer_interrupt_init_cpu(void)
147 /* SYS_HZ ticks per second */
148 gptimer->e[0].val = 0;
149 gptimer->e[0].rld = (TIMER_BASE_CLK / CONFIG_SYS_HZ) - 1;
151 (GPTIMER_CTRL_EN | GPTIMER_CTRL_RS |
152 GPTIMER_CTRL_LD | GPTIMER_CTRL_IE);
157 ulong get_tbclk(void)
159 return TIMER_BASE_CLK;
163 * This function is intended for SHORT delays only.
165 unsigned long cpu_usec2ticks(unsigned long usec)
167 if (usec < US_PER_TICK)
169 return usec / US_PER_TICK;
172 unsigned long cpu_ticks2usec(unsigned long ticks)
174 return ticks * US_PER_TICK;