From: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
For AXS103, certain bitfile configurations may not work with stock
"clock-frequency" specified in DT. Instead of duplicating the DT files, we
fixup the DT in-place.
This used to be done differently - as in top level "clock-frequency" was
read very early from FDT and exported using arc_{get|set}_core_freq()
also used in setting up clockevent/clocksource timers
This homebrew clk API served well for legacy timer probe (non DT)
However TIMERS are now probed from DT and use "core_clk" defined in DT,
and thus can no longer use the top level "clock-frequency".
This change reduces the number of users of ARC clk hack and paves way
for removal.
Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
[vgupta: broken out of from bigger patch]
Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
---
arch/arc/kernel/setup.c | 12 +++++++-----
arch/arc/plat-axs10x/axs10x.c | 27 +++++++++++++++++++++------
2 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index b2921a3bd924..6fff28be695d 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -23,7 +23,6 @@
#include <asm/page.h>
#include <asm/irq.h>
#include <asm/unwind.h>
-#include <asm/clk.h>
#include <asm/mach_desc.h>
#include <asm/smp.h>
@@ -229,10 +228,6 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
if (tbl->info.id == 0)
n += scnprintf(buf + n, len - n, "UNKNOWN ARC Processor\n");
- n += scnprintf(buf + n, len - n, "CPU speed\t: %u.%02u Mhz\n",
- (unsigned int)(arc_get_core_freq() / 1000000),
- (unsigned int)(arc_get_core_freq() / 10000) % 100);
-
n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s%s%s\nISA Extn\t: ",
IS_AVAIL1(cpu->extn.timer0, "Timer0 "),
IS_AVAIL1(cpu->extn.timer1, "Timer1 "),
@@ -487,6 +482,10 @@ static int show_cpuinfo(struct seq_file *m, void *v)
{
char *str;
int cpu_id = ptr_to_cpu(v);
+ struct device_node *pll = of_find_node_by_name(NULL, "core_clk");
+ u32 freq;
+
+ of_property_read_u32(pll, "clock-frequency", &freq);
if (!cpu_online(cpu_id)) {
seq_printf(m, "processor [%d]\t: Offline\n", cpu_id);
@@ -498,6 +497,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
goto done;
seq_printf(m, arc_cpu_mumbojumbo(cpu_id, str, PAGE_SIZE));
+ seq_printf(m, "CPU speed\t: %u.%02u Mhz\n",
+ (unsigned int)(freq / 1000000),
+ (unsigned int)(freq / 10000) % 100);
seq_printf(m, "Bogo MIPS\t: %lu.%02lu\n",
loops_per_jiffy / (500000 / HZ),
diff --git a/arch/arc/plat-axs10x/axs10x.c b/arch/arc/plat-axs10x/axs10x.c
index 1b0f0f458a2b..9701c93f315d 100644
--- a/arch/arc/plat-axs10x/axs10x.c
+++ b/arch/arc/plat-axs10x/axs10x.c
@@ -14,10 +14,11 @@
*
*/
+#include <linux/of_fdt.h>
#include <linux/of_platform.h>
+#include <linux/libfdt.h>
#include <asm/asm-offsets.h>
-#include <asm/clk.h>
#include <asm/io.h>
#include <asm/mach_desc.h>
#include <asm/mcip.h>
@@ -389,6 +390,13 @@ axs103_set_freq(unsigned int id, unsigned int fd, unsigned int od)
static void __init axs103_early_init(void)
{
+ int offset = fdt_path_offset(initial_boot_params, "/cpu_card/core_clk");
+ const struct fdt_property *prop = fdt_get_property(initial_boot_params,
+ offset,
+ "clock-frequency",
+ NULL);
+ u32 freq = be32_to_cpu(*(u32*)(prop->data)) / 1000000, orig = freq;
+
/*
* AXS103 configurations for SMP/QUAD configurations share device tree
* which defaults to 90 MHz. However recent failures of Quad config
@@ -401,12 +409,12 @@ static void __init axs103_early_init(void)
#ifdef CONFIG_ARC_MCIP
unsigned int num_cores = (read_aux_reg(ARC_REG_MCIP_BCR) >> 16) & 0x3F;
if (num_cores > 2)
- arc_set_core_freq(50 * 1000000);
+ freq = 50;
else if (num_cores == 2)
- arc_set_core_freq(75 * 1000000);
+ freq = 75;
#endif
- switch (arc_get_core_freq()/1000000) {
+ switch (freq) {
case 33:
axs103_set_freq(1, 1, 1);
break;
@@ -431,11 +439,18 @@ static void __init axs103_early_init(void)
* DT "clock-frequency" might not match with board value.
* Hence update it to match the board value.
*/
- arc_set_core_freq(axs103_get_freq() * 1000000);
+ freq = axs103_get_freq();
break;
}
- pr_info("Freq is %dMHz\n", axs103_get_freq());
+ pr_info("Freq is %dMHz\n", freq);
+
+ /* Patching .dtb in-place with new core clock value */
+ if (freq != orig ) {
+ freq = cpu_to_be32(freq * 1000000);
+ fdt_setprop_inplace(initial_boot_params, offset,
+ "clock-frequency", &freq, sizeof(freq));
+ }
/* Memory maps already config in pre-bootloader */
--
2.5.0
