ARM: tegra: clk_m is the architected timer source clock

While clk_m and the oscillator run at the same frequencies on Tegra114
and Tegra124, clk_m is the proper source for the architected timer. On
more recent Tegra generations, Tegra210 and later, both the oscillator
and clk_m can run at different frequencies. clk_m will be divided down
from the oscillator.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/mach-tegra/tegra114/clock.c

@@ -679,8 +679,8 @@ void arch_timer_init(void)
 	struct sysctr_ctlr *sysctr = (struct sysctr_ctlr *)NV_PA_TSC_BASE;
 	u32 freq, val;
 
-	freq = clock_get_rate(CLOCK_ID_OSC);
-	debug("%s: osc freq is %dHz [0x%08X]\n", __func__, freq, freq);
+	freq = clock_get_rate(CLOCK_ID_CLK_M);
+	debug("%s: clk_m freq is %dHz [0x%08X]\n", __func__, freq, freq);
 
 	/* ARM CNTFRQ */
 	asm("mcr p15, 0, %0, c14, c0, 0\n" : : "r" (freq));

arch/arm/mach-tegra/tegra124/clock.c

@@ -859,8 +859,8 @@ void arch_timer_init(void)
 	struct sysctr_ctlr *sysctr = (struct sysctr_ctlr *)NV_PA_TSC_BASE;
 	u32 freq, val;
 
-	freq = clock_get_rate(CLOCK_ID_OSC);
-	debug("%s: osc freq is %dHz [0x%08X]\n", __func__, freq, freq);
+	freq = clock_get_rate(CLOCK_ID_CLK_M);
+	debug("%s: clk_m freq is %dHz [0x%08X]\n", __func__, freq, freq);
 
 	/* ARM CNTFRQ */
 	asm("mcr p15, 0, %0, c14, c0, 0\n" : : "r" (freq));

arch/arm/mach-tegra/tegra210/clock.c

@@ -1014,13 +1014,11 @@ void arch_timer_init(void)
 	struct sysctr_ctlr *sysctr = (struct sysctr_ctlr *)NV_PA_TSC_BASE;
 	u32 freq, val;
 
-	freq = clock_get_rate(CLOCK_ID_OSC);
-	debug("%s: osc freq is %dHz [0x%08X]\n", __func__, freq, freq);
+	freq = clock_get_rate(CLOCK_ID_CLK_M);
+	debug("%s: clk_m freq is %dHz [0x%08X]\n", __func__, freq, freq);
 
-	/* ARM CNTFRQ */
-#ifndef CONFIG_ARM64
-	asm("mcr p15, 0, %0, c14, c0, 0\n" : : "r" (freq));
-#endif
+	if (current_el() == 3)
+		asm("msr cntfrq_el0, %0\n" : : "r" (freq));
 
 	/* Only Tegra114+ has the System Counter regs */
 	debug("%s: setting CNTFID0 to 0x%08X\n", __func__, freq);