[PATCH 3/4] mfd: twl4030power: Add a configuration to turn off oscillator during off-idle

Tony Lindgren
2014-04-24T00:40:37Z

Some oscillators can be turned off during off-idle saving few
a little bit power at the cost of the oscillator start up
latency.

If you board can do this, you can now enable it by using the
ti,twl4030-power-idle-osc-off compatible flag.

Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
.../devicetree/bindings/mfd/twl4030-power.txt | 6 ++++++
drivers/mfd/twl4030-power.c | 19 +++++++++++++++++++
2 files changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/twl4030-power.txt b/Documentation/devicetree/bindings/mfd/twl4030-power.txt
index bbd6603..b9ee7b9 100644
--- a/Documentation/devicetree/bindings/mfd/twl4030-power.txt
+++ b/Documentation/devicetree/bindings/mfd/twl4030-power.txt
@@ -9,6 +9,7 @@ Required properties:
"ti,twl4030-power"
"ti,twl4030-power-reset"
"ti,twl4030-power-idle"
+ "ti,twl4030-power-idle-osc-off"

The use of ti,twl4030-power-reset is recommended at least on
3530 that needs a special configuration for warm reset to work.
@@ -16,6 +17,11 @@ The use of ti,twl4030-power-reset is recommended at least on
When using ti,twl4030-power-idle, the TI recommended configuration
for idle modes is loaded to the tlw4030 PMIC.

+When using ti,twl4030-power-idle-osc-off, the TI recommended
+configuration is used with the external oscillator being shut
+down during off-idle. Note that this does not work on all boards
+depending on how the external oscillator is wired.
+
Optional properties:
- ti,use_poweroff: With this flag, the chip will initiates an ACTIVE-to-OFF or
SLEEP-to-OFF transition when the system poweroffs.
diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
index 89c6b1a..12e4abe 100644
--- a/drivers/mfd/twl4030-power.c
+++ b/drivers/mfd/twl4030-power.c
@@ -777,6 +777,21 @@ static struct twl4030_power_data omap3_idle = {
.resource_config = omap3_idle_rconfig,
};

+/* Disable 32 KiHz oscillator during idle */
+static struct twl4030_resconfig osc_off_rconfig[] = {
+ { .resource = RES_CLKEN, .devgroup = DEV_GRP_P1 | DEV_GRP_P3,
+ .type = 3, .type2 = 2, .remap_off = TWL_REMAP_OFF,
+ .remap_sleep = TWL_REMAP_SLEEP, },
+ { /* Terminator */ },
+};
+
+static struct twl4030_power_data osc_off_idle = {
+ .scripts = omap3_idle_scripts,
+ .num = ARRAY_SIZE(omap3_idle_scripts),
+ .resource_config = omap3_idle_rconfig,
+ .board_config = osc_off_rconfig,
+};
+
static struct of_device_id twl4030_power_of_match[] = {
{
.compatible = "ti,twl4030-power-reset",
@@ -786,6 +801,10 @@ static struct of_device_id twl4030_power_of_match[] = {
.compatible = "ti,twl4030-power-idle",
.data = &omap3_idle,
},
+ {
+ .compatible = "ti,twl4030-power-idle-osc-off",
+ .data = &osc_off_idle,
+ },
{ },
};
MODULE_DEVICE_TABLE(of, twl4030_power_of_match);
--
1.8.1.1