From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evan Green Subject: Re: [PATCH V2 2/3] dt-bindings: mmc: sdhci-msm: Add entries for passing load values Date: Fri, 21 Sep 2018 13:06:54 -0700 Message-ID: References: <1537424558-17989-1-git-send-email-vbadigan@codeaurora.org> <1537424558-17989-3-git-send-email-vbadigan@codeaurora.org> <8f26b82c-b966-11d3-4fb6-0137a0a8cd4a@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <8f26b82c-b966-11d3-4fb6-0137a0a8cd4a@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: vbadigan@codeaurora.org Cc: adrian.hunter@intel.com, Ulf Hansson , robh+dt@kernel.org, linux-mmc@vger.kernel.org, asutoshd@codeaurora.org, riteshh@codeaurora.org, stummala@codeaurora.org, sayali , Doug Anderson , vviswana@codeaurora.org, mark.rutland@arm.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On Fri, Sep 21, 2018 at 3:32 AM Veerabhadrarao Badiganti wrote: > > Hi Evan, > > > On 9/21/2018 5:45 AM, Evan Green wrote: > > On Wed, Sep 19, 2018 at 11:24 PM Veerabhadrarao Badiganti > > wrote: > >> From: Vijay Viswanath > >> > >> 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 > >> Signed-off-by: Veerabhadrarao Badiganti > >> --- > >> 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,-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>; > >> -- > >> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project > >> > > 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