diff options
| author | Alex Frid <afrid@nvidia.com> | 2013-09-19 22:45:09 -0700 |
|---|---|---|
| committer | Ajay Nandakumar <anandakumarm@nvidia.com> | 2013-10-03 19:17:28 +0530 |
| commit | 2760eca910ae0ee2f983b6f5f091aeb804f01a6c (patch) | |
| tree | a8e828e0b3ec75540299b457cd21a39f3a83a0c8 /arch/arm/mach-tegra/dvfs.c | |
| parent | 0b2cb04e9f86865f507d92e677b9443849d845aa (diff) | |
ARM: tegra: dvfs: Handle zero GPU rail voltage
Preserved voltage of the rail with in-band enable / disable control
when all clocks associated with dvfs rail are disabled, and "0"
voltage is requested. The rail will be turned off via explicit call
to regulator interface - applicable to GPU rail.
No changes if "0" voltage is requested for rail with side-band control,
and jump-to-zero property - CPU rail: allow to pass "0" through,
mainly for statistical purpose. Added warning and preserve voltage
if "0" requested for core rail - must never happen (core system clocks
are never disabled at run-time).
Change-Id: I724ea9373d0731d6f115ecde1e3b8dd8e7ff2884
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/278180
Reviewed-by: Automatic_Commit_Validation_User
Tested-by: Prashant Malani <pmalani@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
(cherry picked from commit fab7582bcae0c63a645aa2cbb9e1e001b4b5603c)
Signed-off-by: Ajay Nandakumar <anandakumarm@nvidia.com>
Diffstat (limited to 'arch/arm/mach-tegra/dvfs.c')
| -rw-r--r-- | arch/arm/mach-tegra/dvfs.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/arm/mach-tegra/dvfs.c b/arch/arm/mach-tegra/dvfs.c index 91ddef4692f8..7c16170b0997 100644 --- a/arch/arm/mach-tegra/dvfs.c +++ b/arch/arm/mach-tegra/dvfs.c @@ -408,6 +408,15 @@ static int dvfs_rail_update(struct dvfs_rail *rail) /* Apply offset and min/max limits if any clock is requesting voltage */ if (millivolts) millivolts = dvfs_rail_apply_limits(rail, millivolts); + /* Keep current voltage if regulator is to be disabled via explicitly */ + else if (rail->in_band_pm) + return 0; + /* Keep current voltage if regulator must not be disabled at run time */ + else if (!rail->jmp_to_zero) { + WARN(1, "%s cannot be turned off by dvfs\n"); + return 0; + } + /* else: fall thru if regulator is turned off by side band signaling */ /* retry update if limited by from-relationship to account for circular dependencies */ @@ -1524,7 +1533,8 @@ static int dvfs_tree_show(struct seq_file *s, void *data) list_for_each_entry(rail, &dvfs_rail_list, node) { int thermal_mv_floor = 0; - seq_printf(s, "%s %d mV%s:\n", rail->reg_id, rail->millivolts, + seq_printf(s, "%s %d mV%s:\n", rail->reg_id, + rail->stats.off ? 0 : rail->millivolts, rail->dfll_mode ? " dfll mode" : rail->disabled ? " disabled" : ""); list_for_each_entry(rel, &rail->relationships_from, from_node) { |