Patchwork [V2,5/6] clk: tegra114: implement wait_for_reset and disable_clock for tegra_cpu_car_ops

login
register
mail settings
Submitter Joseph Lo
Date May 20, 2013, 10:39 a.m.
Message ID <1369046369-12489-6-git-send-email-josephl@nvidia.com>
Download mbox | patch
Permalink /patch/244886/
State Accepted, archived
Headers show

Comments

Joseph Lo - May 20, 2013, 10:39 a.m.
The conventional CPU hotplug sequence on the other Tegra chips, we will also
clock gate the CPU in tegra_cpu_kill() after the CPU was power gated. For
Tegra114, the flow controller will clock gate the CPU after the power down
sequence. But we still need to implement a empty function for disable_clock
to avoid kernel warning message.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
---
V2:
* no change
---
 drivers/clk/tegra/clk-tegra114.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
index d78e16e..40d939d 100644
--- a/drivers/clk/tegra/clk-tegra114.c
+++ b/drivers/clk/tegra/clk-tegra114.c
@@ -250,6 +250,9 @@ 
 #define CLK_SOURCE_XUSB_DEV_SRC 0x60c
 #define CLK_SOURCE_EMC 0x19c
 
+/* Tegra CPU clock and reset control regs */
+#define CLK_RST_CONTROLLER_CPU_CMPLX_STATUS	0x470
+
 static int periph_clk_enb_refcnt[CLK_OUT_ENB_NUM * 32];
 
 static void __iomem *clk_base;
@@ -2000,7 +2003,25 @@  static __init void tegra114_periph_clk_init(void __iomem *clk_base)
 	}
 }
 
-static struct tegra_cpu_car_ops tegra114_cpu_car_ops;
+/* Tegra114 CPU clock and reset control functions */
+static void tegra114_wait_cpu_in_reset(u32 cpu)
+{
+	unsigned int reg;
+
+	do {
+		reg = readl(clk_base + CLK_RST_CONTROLLER_CPU_CMPLX_STATUS);
+		cpu_relax();
+	} while (!(reg & (1 << cpu)));  /* check CPU been reset or not */
+}
+static void tegra114_disable_cpu_clock(u32 cpu)
+{
+	/* flow controller would take care in the power sequence. */
+}
+
+static struct tegra_cpu_car_ops tegra114_cpu_car_ops = {
+	.wait_for_reset	= tegra114_wait_cpu_in_reset,
+	.disable_clock	= tegra114_disable_cpu_clock,
+};
 
 static const struct of_device_id pmc_match[] __initconst = {
 	{ .compatible = "nvidia,tegra114-pmc" },