ARM: tegra: Implement clk_m

On currently supported SoCs, clk_m always runs at the same frequency as
the oscillator input. However newer SoC generations such as Tegra210 no
longer have that restriction. Prepare for that by separating clk_m from
the oscillator clock and allow SoC code to override the clk_m rate.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra210/clock.c b/arch/arm/mach-tegra/tegra210/clock.c
index 830a33ffc9..146bb6453a 100644
--- a/arch/arm/mach-tegra/tegra210/clock.c
+++ b/arch/arm/mach-tegra/tegra210/clock.c
@@ -998,6 +998,17 @@ void clock_early_init(void)
 	udelay(2);
 }
 
+unsigned int clk_m_get_rate(unsigned parent_rate)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 value, div;
+
+	value = readl(&clkrst->crc_spare_reg0);
+	div = ((value >> 2) & 0x3) + 1;
+
+	return parent_rate / div;
+}
+
 void arch_timer_init(void)
 {
 	struct sysctr_ctlr *sysctr = (struct sysctr_ctlr *)NV_PA_TSC_BASE;