/*
* Copyright (c) 2017 embedded brains GmbH. All rights reserved.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <bsp.h>
#include <bsp/bootcard.h>
#include <bsp/fatal.h>
#include <bsp/fdt.h>
#include <bsp/irq-generic.h>
#include <bsp/linker-symbols.h>
#include <dev/clock/arm-generic-timer.h>
#include <libcpu/arm-cp15.h>
#include <libfdt.h>
#define MAGIC_IRQ_OFFSET 32
void *imx_get_reg_of_node(const void *fdt, int node)
{
int len;
const uint32_t *val;
val = fdt_getprop(fdt, node, "reg", &len);
if (val == NULL || len < 4) {
return NULL;
}
return (void *) fdt32_to_cpu(val[0]);
}
rtems_vector_number imx_get_irq_of_node(
const void *fdt,
int node,
size_t index
)
{
int len;
const uint32_t *val;
val = fdt_getprop(fdt, node, "interrupts", &len);
if (val == NULL || len < (int) ((index + 1) * 12)) {
return BSP_INTERRUPT_VECTOR_INVALID;
}
return fdt32_to_cpu(val[index * 3 + 1]) + MAGIC_IRQ_OFFSET;
}
uint32_t bsp_fdt_map_intr(const uint32_t *intr, size_t icells)
{
return intr[1] + MAGIC_IRQ_OFFSET;
}
static bool imx_is_imx6(const void *fdt)
{
/*
* At the moment: Check for some compatible strings that should be there
* somewhere in every fdt.
*
* FIXME: It would be nice if some CPU-ID could be used instead. But I didn't
* find one.
*/
int node;
node = fdt_node_offset_by_compatible(fdt, -1, "fsl,imx6ul");
if (node >= 0) {
return true;
}
node = fdt_node_offset_by_compatible(fdt, -1, "fsl,imx6ull");
if (node >= 0) {
return true;
}
return false;
}
#define SYSCNT_CNTCR (0x0)
#define SYSCNT_CNTCR_ENABLE (1 << 0)
#define SYSCNT_CNTCR_HDBG (1 << 1)
#define SYSCNT_CNTCR_FCREQ(n) (1 << (8 + (n)))
#define SYSCNT_CNTFID(n) (0x20 + 4 * (n))
static uint32_t imx_syscnt_enable_and_return_frequency(const void *fdt)
{
uint32_t freq;
volatile void *syscnt_base;
/* That's not in the usual FDTs. Sorry for falling back to a magic value. */
if (imx_is_imx6(fdt)) {
syscnt_base = (void *)0x021dc000;
} else {
syscnt_base = (void *)0x306c0000;
}
freq = *(uint32_t *)(syscnt_base + SYSCNT_CNTFID(0));
arm_cp15_set_counter_frequency(freq);
*(uint32_t *)(syscnt_base + SYSCNT_CNTCR) =
SYSCNT_CNTCR_ENABLE |
SYSCNT_CNTCR_HDBG |
SYSCNT_CNTCR_FCREQ(0);
return freq;
}
void arm_generic_timer_get_config(
uint32_t *frequency,
uint32_t *irq
)
{
const void *fdt;
int node;
int len;
const uint32_t *val;
fdt = bsp_fdt_get();
node = fdt_path_offset(fdt, "/timer");
val = fdt_getprop(fdt, node, "clock-frequency", &len);
if (val != NULL && len >= 4) {
*frequency = fdt32_to_cpu(val[0]);
} else {
/*
* Normally clock-frequency would be provided by the boot loader. If it
* didn't add one, we have to initialize the system counter ourself.
*/
*frequency = imx_syscnt_enable_and_return_frequency(fdt);
}
/* FIXME: Figure out how Linux gets a proper IRQ number */
*irq = imx_get_irq_of_node(fdt, node, 0) - 16;
}
uintptr_t imx_gic_dist_base;
static void imx_find_gic(const void *fdt)
{
int node;
node = fdt_path_offset(fdt, "/interrupt-controller");
if (node < 0) {
node = fdt_path_offset(fdt, "/soc/interrupt-controller");
}
imx_gic_dist_base = (uintptr_t) imx_get_reg_of_node(fdt, node);
#if defined(RTEMS_SMP)
/*
* Secondary processors start with a disabled data cache and use the GIC to
* deterine if they can continue the initialization, see
* arm_gic_irq_initialize_secondary_cpu().
*/
rtems_cache_flush_multiple_data_lines(
&imx_gic_dist_base,
sizeof(imx_gic_dist_base)
);
#endif
}
void bsp_start(void)
{
imx_find_gic(bsp_fdt_get());
bsp_interrupt_initialize();
rtems_cache_coherent_add_area(
bsp_section_nocacheheap_begin,
(uintptr_t) bsp_section_nocacheheap_size
);
}