ARM: tegra: power: Add dynamic CPU regulator mode control

Operational mode of CPU voltage regulator depends on load current.
Commonly on Tegra platforms this dependency was handled by regulator
h/w itself. There are exceptions, however, introduced on some Tegra12
designs that requires s/w control of the mode.

In order to dynamically control regulator mode based on load,
s/w has to

(a) estimate load based on CPU frequency, number of on-line CPU cores,
and temperature
(b) compare load estimation with regulator specific threshold whenever
any of the above factors changes
(c) change regulator mode when the respective threshold is crossed

This commit adds layer (b) in cpu-tegra driver. It expects existing
Tegra CPU load calculator in EDP driver to implement (a), and provide
look-up table of frequency thresholds for each combination of on-line
CPU cores and temperature ranges. When the respective threshold is
crossed standard regulator mode change interface is called to carry
on (c).

Only switching between IDLE and NORMAL regulator modes is supported.
The respective EDP calculator functions are just stubbed, for now.

Bug 1302884

Change-Id: Iaea42a101aaea239643c0c80a7ad165ece3b1e36
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/301520
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/edp.c b/arch/arm/mach-tegra/edp.c
index 8435a915a5a7..83bd03be36a2 100644
--- a/arch/arm/mach-tegra/edp.c
+++ b/arch/arm/mach-tegra/edp.c
@@ -42,6 +42,8 @@ static unsigned int regulator_cur;
 /* Value to subtract from regulator current limit */
 static unsigned int edp_reg_override_mA = OVERRIDE_DEFAULT;
 
+static struct tegra_edp_limits *reg_mode_limits;
+
 static const unsigned int *system_edp_limits;
 
 static struct tegra_system_edp_entry *power_edp_limits;
@@ -507,6 +509,18 @@ void tegra_get_cpu_edp_limits(const struct tegra_edp_limits **limits, int *size)
 	*size = edp_limits_size;
 }
 
+void __init tegra_init_cpu_reg_mode_limits(unsigned int regulator_mA,
+					   unsigned int mode)
+{
+}
+
+void tegra_get_cpu_reg_mode_limits(const struct tegra_edp_limits **limits,
+				   int *size, unsigned int mode)
+{
+	*limits = reg_mode_limits;
+	*size = edp_limits_size;
+}
+
 void tegra_get_system_edp_limits(const unsigned int **limits)
 {
 	*limits = system_edp_limits;