On 9/22/2018 1:36 AM, Evan Green wrote:
On Fri, Sep 21, 2018 at 3:32 AM Veerabhadrarao Badiganti
<vbadigan@xxxxxxxxxxxxxx> wrote:
Hi Evan,
On 9/21/2018 5:45 AM, Evan Green wrote:
On Wed, Sep 19, 2018 at 11:24 PM Veerabhadrarao Badiganti
<vbadigan@xxxxxxxxxxxxxx> wrote:
From: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
The load a particular sdhc controller should request from a regulator
is device specific and hence each device should individually vote for
the required load.
Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 502b3b8..3720385 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -26,6 +26,11 @@ Required properties:
"cal" - reference clock for RCLK delay calibration (optional)
"sleep" - sleep clock for RCLK delay calibration (optional)
+Optional properties:
+- qcom,<supply>-current-level-microamp - specifies load levels for supply during BUS_ON and
+ BUS_OFF states in power irq. Should be specified in
+ pairs (lpm, hpm), for BUS_OFF and BUS_ON respectively.
+ Units uA.
Example:
sdhc_1: sdhci@f9824900 {
@@ -37,6 +42,7 @@ Example:
vmmc-supply = <&pm8941_l20>;
vqmmc-supply = <&pm8941_s3>;
+ qcom,vqmmc-current-level-microamp = <200 22000>;
pinctrl-names = "default";
pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
--
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Aren't the regulator load levels pretty coarse? Would it be safe to
say that pretty much all sd/mmc devices need the high powered mode, or
are there really some devices that can get by with LPM all the time?
-Evan
The load levels here are min and max supported by the regulator. To
cover all devices
we do set it to max load. We can't make any assumptions on this, as
peak current may vary
from device to device.
Hi Veera,
If it were up to me, I would just assume all devices need high power
mode for BUS_ON and low power mode for BUS_OFF, and skip adding this
binding until you actually came up with a device that needed lower
power mode for BUS_ON, or high power mode for BUS_OFF (when would that
be, anyway?) Are there any actual use cases you've seen that need
different values in here?
-Evan
Hi Evan,
With the present implementation if these load values are not supplied in
dt, its not setting
any load at all. Without setting load, I'm observing CRC/timeout/tuning
errors.
I can update the code to fallback to default values when these are not
supplied in dt, but these values
will be different from SD card and eMMC devices.
So, this dt binding is needed.
Thanks
Veera
