[U-Boot] [PATCH 2/6] ARM: tegra: Implement clk_m

Thierry Reding
2015-08-20T09:42:19Z

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>
---
arch/arm/include/asm/arch-tegra/clock.h | 3 +++
arch/arm/include/asm/arch-tegra114/clock-tables.h | 1 +
arch/arm/include/asm/arch-tegra124/clock-tables.h | 1 +
arch/arm/include/asm/arch-tegra20/clock-tables.h | 1 +
arch/arm/include/asm/arch-tegra210/clock-tables.h | 1 +
arch/arm/include/asm/arch-tegra30/clock-tables.h | 1 +
arch/arm/mach-tegra/clock.c | 10 ++++++++++
arch/arm/mach-tegra/tegra210/clock.c | 11 +++++++++++
8 files changed, 29 insertions(+)

diff --git a/arch/arm/include/asm/arch-tegra/clock.h b/arch/arm/include/asm/arch-tegra/clock.h
index d570d7f134a8..eb07c4a07522 100644
--- a/arch/arm/include/asm/arch-tegra/clock.h
+++ b/arch/arm/include/asm/arch-tegra/clock.h
@@ -44,6 +44,9 @@ enum {
/* return the current oscillator clock frequency */
enum clock_osc_freq clock_get_osc_freq(void);

+/* return the clk_m frequency */
+unsigned int clk_m_get_rate(unsigned int parent_rate);
+
/**
* Start PLL using the provided configuration parameters.
*
diff --git a/arch/arm/include/asm/arch-tegra114/clock-tables.h b/arch/arm/include/asm/arch-tegra114/clock-tables.h
index d8fa0e1d2cee..3f910f5ae8b9 100644
--- a/arch/arm/include/asm/arch-tegra114/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra114/clock-tables.h
@@ -38,6 +38,7 @@ enum clock_id {
/* These are the base clocks (inputs to the Tegra SOC) */
CLOCK_ID_32KHZ,
CLOCK_ID_OSC,
+ CLOCK_ID_CLK_M,

CLOCK_ID_COUNT, /* number of PLLs */
CLOCK_ID_DISPLAY2, /* placeholder */
diff --git a/arch/arm/include/asm/arch-tegra124/clock-tables.h b/arch/arm/include/asm/arch-tegra124/clock-tables.h
index 3c67e72afe89..9466b4ffb33e 100644
--- a/arch/arm/include/asm/arch-tegra124/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra124/clock-tables.h
@@ -30,6 +30,7 @@ enum clock_id {
/* These are the base clocks (inputs to the Tegra SoC) */
CLOCK_ID_32KHZ,
CLOCK_ID_OSC,
+ CLOCK_ID_CLK_M,

CLOCK_ID_COUNT, /* number of PLLs */

diff --git a/arch/arm/include/asm/arch-tegra20/clock-tables.h b/arch/arm/include/asm/arch-tegra20/clock-tables.h
index 894be088cde2..812e8760d0cd 100644
--- a/arch/arm/include/asm/arch-tegra20/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra20/clock-tables.h
@@ -29,6 +29,7 @@ enum clock_id {
/* These are the base clocks (inputs to the Tegra SOC) */
CLOCK_ID_32KHZ,
CLOCK_ID_OSC,
+ CLOCK_ID_CLK_M,

CLOCK_ID_COUNT, /* number of clocks */
CLOCK_ID_NONE = -1,
diff --git a/arch/arm/include/asm/arch-tegra210/clock-tables.h b/arch/arm/include/asm/arch-tegra210/clock-tables.h
index 175040dae618..a612485d8e23 100644
--- a/arch/arm/include/asm/arch-tegra210/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra210/clock-tables.h
@@ -30,6 +30,7 @@ enum clock_id {
/* These are the base clocks (inputs to the Tegra SoC) */
CLOCK_ID_32KHZ,
CLOCK_ID_OSC,
+ CLOCK_ID_CLK_M,

CLOCK_ID_COUNT, /* number of PLLs */

diff --git a/arch/arm/include/asm/arch-tegra30/clock-tables.h b/arch/arm/include/asm/arch-tegra30/clock-tables.h
index cb619f1f2d61..f7c7af80faaf 100644
--- a/arch/arm/include/asm/arch-tegra30/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra30/clock-tables.h
@@ -38,6 +38,7 @@ enum clock_id {
/* These are the base clocks (inputs to the Tegra SOC) */
CLOCK_ID_32KHZ,
CLOCK_ID_OSC,
+ CLOCK_ID_CLK_M,

CLOCK_ID_COUNT, /* number of PLLs */
CLOCK_ID_DISPLAY2, /* Tegra3, placeholder */
diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c
index f9dfcd04115a..41e7de95a2e3 100644
--- a/arch/arm/mach-tegra/clock.c
+++ b/arch/arm/mach-tegra/clock.c
@@ -461,6 +461,11 @@ void reset_cmplx_set_enable(int cpu, int which, int reset)
writel(mask, &clkrst->crc_cpu_cmplx_clr);
}

+unsigned int __weak clk_m_get_rate(unsigned int parent_rate)
+{
+ return parent_rate;
+}
+
unsigned clock_get_rate(enum clock_id clkid)
{
struct clk_pll *pll;
@@ -472,6 +477,9 @@ unsigned clock_get_rate(enum clock_id clkid)
if (clkid == CLOCK_ID_OSC)
return parent_rate;

+ if (clkid == CLOCK_ID_CLK_M)
+ return clk_m_get_rate(parent_rate);
+
pll = get_pll(clkid);
if (!pll)
return 0;
@@ -613,8 +621,10 @@ void clock_init(void)
pll_rate[CLOCK_ID_XCPU] = clock_get_rate(CLOCK_ID_XCPU);
pll_rate[CLOCK_ID_SFROM32KHZ] = 32768;
pll_rate[CLOCK_ID_OSC] = clock_get_rate(CLOCK_ID_OSC);
+ pll_rate[CLOCK_ID_CLK_M] = clock_get_rate(CLOCK_ID_CLK_M);

debug("Osc = %d\n", pll_rate[CLOCK_ID_OSC]);
+ debug("CLKM = %d\n", pll_rate[CLOCK_ID_CLK_M]);
debug("PLLC = %d\n", pll_rate[CLOCK_ID_CGENERAL]);
debug("PLLM = %d\n", pll_rate[CLOCK_ID_MEMORY]);
debug("PLLP = %d\n", pll_rate[CLOCK_ID_PERIPH]);
diff --git a/arch/arm/mach-tegra/tegra210/clock.c b/arch/arm/mach-tegra/tegra210/clock.c
index 830a33ffc938..146bb6453a19 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;
--
2.4.5