ARM: tegra: introduce tegra_cpu_car_ops structures

The tegra_cpu_car_ops provide the interface for CPU to control
it's clock gating and reset status. The other drivers should use
this for CPU control. And should not directly access CAR registers
to control CPU.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra20_clocks.c b/arch/arm/mach-tegra/tegra20_clocks.c
index 840ab262272a..9273b0dffc66 100644
--- a/arch/arm/mach-tegra/tegra20_clocks.c
+++ b/arch/arm/mach-tegra/tegra20_clocks.c
@@ -33,6 +33,7 @@
 #include "clock.h"
 #include "fuse.h"
 #include "tegra2_emc.h"
+#include "tegra_cpu_car.h"
 
 #define RST_DEVICES			0x004
 #define RST_DEVICES_SET			0x300
@@ -152,6 +153,14 @@
 #define PMC_BLINK_TIMER_DATA_OFF_SHIFT	16
 #define PMC_BLINK_TIMER_DATA_OFF_MASK	0xffff
 
+/* Tegra CPU clock and reset control regs */
+#define TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX		0x4c
+#define TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET	0x340
+#define TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR	0x344
+
+#define CPU_CLOCK(cpu)	(0x1 << (8 + cpu))
+#define CPU_RESET(cpu)	(0x1111ul << (cpu))
+
 static void __iomem *reg_clk_base = IO_ADDRESS(TEGRA_CLK_RESET_BASE);
 static void __iomem *reg_pmc_base = IO_ADDRESS(TEGRA_PMC_BASE);
 
@@ -1553,3 +1562,64 @@ struct clk_ops tegra_cdev_clk_ops = {
 	.disable = tegra20_cdev_clk_disable,
 	.recalc_rate = tegra20_cdev_recalc_rate,
 };
+
+/* Tegra20 CPU clock and reset control functions */
+static void tegra20_wait_cpu_in_reset(u32 cpu)
+{
+	unsigned int reg;
+
+	do {
+		reg = readl(reg_clk_base +
+			    TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET);
+		cpu_relax();
+	} while (!(reg & (1 << cpu)));	/* check CPU been reset or not */
+
+	return;
+}
+
+static void tegra20_put_cpu_in_reset(u32 cpu)
+{
+	writel(CPU_RESET(cpu),
+	       reg_clk_base + TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET);
+	dmb();
+}
+
+static void tegra20_cpu_out_of_reset(u32 cpu)
+{
+	writel(CPU_RESET(cpu),
+	       reg_clk_base + TEGRA_CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR);
+	wmb();
+}
+
+static void tegra20_enable_cpu_clock(u32 cpu)
+{
+	unsigned int reg;
+
+	reg = readl(reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+	writel(reg & ~CPU_CLOCK(cpu),
+	       reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+	barrier();
+	reg = readl(reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+}
+
+static void tegra20_disable_cpu_clock(u32 cpu)
+{
+	unsigned int reg;
+
+	reg = readl(reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+	writel(reg | CPU_CLOCK(cpu),
+	       reg_clk_base + TEGRA_CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+}
+
+static struct tegra_cpu_car_ops tegra20_cpu_car_ops = {
+	.wait_for_reset	= tegra20_wait_cpu_in_reset,
+	.put_in_reset	= tegra20_put_cpu_in_reset,
+	.out_of_reset	= tegra20_cpu_out_of_reset,
+	.enable_clock	= tegra20_enable_cpu_clock,
+	.disable_clock	= tegra20_disable_cpu_clock,
+};
+
+void __init tegra20_cpu_car_ops_init(void)
+{
+	tegra_cpu_car_ops = &tegra20_cpu_car_ops;
+}