regulator: add QCOM RPMh regulator driver

This patch series adds a driver and device tree binding documentation for PMIC regulator control via Resource Power Manager-hardened (RPMh) on some Qualcomm Technologies, Inc. SoCs such as SDM845. RPMh is a hardware block which contains several accelerators which are used to manage various hardware resources that are shared between the processors of the SoC. The final hardware state of a regulator is determined within RPMh by performing max aggregation of the requests made by all of the processors.

The RPMh regulator driver depends upon the RPMh driver [1] and command DB driver [2] which are both still undergoing review. It also depends upon three recent regulator patches: [3], [4], and [5] as well as an RPMh helper patch [6].

Changes since v8 [7]:
- Used C++ style comment for qcom-rpmh-regulator.c copyright
- Removed RPMH_REGULATOR_MODE_COUNT
- Changed ternary operator to if else statement in rpmh_regulator_vrm_set_mode_bypass()
- Changed LDO mode mappings to use REGULATOR_MODE_NORMAL for HPM instead of REGULATOR_MODE_FAST
- Replaced mapping arrays with switch case statements in of_map_mode callback functions

Changes since v7 [8]:
- Removed the cmd_db_ready() call from the driver probe function as it is now handled by the RPMh driver itself [6]
- Added Reviewed-by tag for driver patch 2/2

Changes since v6 [9]:
- Removed 'count' parameter from rpmh_regulator_send_request() since it is always 1
- Fixed _rpmh_regulator_vrm_set_voltage_sel() return value
- Added a helper function to capture common code between rpmh_regulator_enable() and rpmh_regulator_disable()
- Added an iterator for pmic_rpmh_data in rpmh_regulator_init_vreg()
- Added Reviewed-by tag for both patches

Changes since v5 [10]:
- Removed unused constants
- Added Reviewed-by tag for DT patch 1/2

Changes since v4 [11]:
- Removed support for DT properties qcom,regulator-drms-modes and qcom,drms-mode-max-microamps
- Specified fixed DRMS high power mode minimum limits for LDO type regulators
- Removed DRMS support for SMPS and BOB type regulators
- Simplified voltage caching logic

Changes since v3 [12]:
- Removed support for DT properties qcom,regulator-initial-microvolt and qcom,headroom-microvolt
- Renamed DT property qcom,allowed-drms-modes to be qcom,regulator-drms-modes
- Updated DT binding documentation to mention which common regulator bindings can be used for qcom-rpmh-regulator devices
- Added voltage caching so that voltage requests are only sent to RPMh after the regulator has been enabled at least once
- Changed 'voltage_selector' default value to be -ENOTRECOVERABLE to interact with [5]
- Initialized 'enabled' to -EINVAL so that unused regulators are disabled by regulator_late_cleanup()
- Removed rpmh_regulator_load_default_parameters() as it is no longer needed
- Updated the mode usage description in qcom,rpmh-regulator.h

Changes since v2 [13]:
- Replaced '_' with '-' in device tree supply property names
- Renamed qcom_rpmh-regulator.c to be qcom-rpmh-regulator.c
- Updated various DT property names to use "microvolt" and "microamp"
- Moved allowed modes constraint specification out of the driver [4]
- Replaced rpmh_client with device pointer to match new RPMh API [1]
- Corrected drms mode threshold checking
- Initialized voltage_selector to -EINVAL when not specified in DT
- Added constants for PMIC regulator hardware modes
- Corrected type sign of mode mapping tables
- Made variable names for mode arrays plural
- Simplified Kconfig depends on
- Removed unnecessary constants and struct fields
- Added some descriptive comments

Changes since v1 [14]:
- Addressed review feedback from Doug, Mark, and Stephen
- Replaced set_voltage()/get_voltage() callbacks with set_voltage_sel()/ get_voltage_sel()
- Added set_bypass()/get_bypass() callbacks for BOB pass-through mode control
- Removed top-level PMIC data structures
- Removed initialization variables from structs and passed them as function parameters
- Removed various comments and error messages
- Simplified mode handling
- Refactored per-PMIC rpmh-regulator data specification
- Simplified probe function
- Moved header into DT patch
- Removed redundant property listings from DT binding documentation

[1]: https://lkml.org/lkml/2018/6/20/519
[2]: https://lkml.org/lkml/2018/4/10/714
[3]: https://lkml.org/lkml/2018/4/18/556
[4]: https://lkml.org/lkml/2018/5/11/696
[5]: https://lkml.org/lkml/2018/5/15/1005
[6]: https://lkml.org/lkml/2018/6/18/1188
[7]: https://lkml.org/lkml/2018/6/22/935
[8]: https://lkml.org/lkml/2018/6/8/573
[9]: https://lkml.org/lkml/2018/6/4/879
[10]: https://lkml.org/lkml/2018/6/1/895
[11]: https://lkml.org/lkml/2018/5/22/1168
[12]: https://lkml.org/lkml/2018/5/11/701
[13]: https://lkml.org/lkml/2018/4/13/687
[14]: https://lkml.org/lkml/2018/3/16/1431

David Collins (2):
regulator: dt-bindings: add QCOM RPMh regulator bindings
regulator: add QCOM RPMh regulator driver

 .../bindings/regulator/qcom,rpmh-regulator.txt     | 160 +++++
 drivers/regulator/Kconfig                          |   9 +
 drivers/regulator/Makefile                         |   1 +
 drivers/regulator/qcom-rpmh-regulator.c            | 769 +++++++++++++++++++++
 .../dt-bindings/regulator/qcom,rpmh-regulator.h    |  36 +
 5 files changed, 975 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt
 create mode 100644 drivers/regulator/qcom-rpmh-regulator.c
 create mode 100644 include/dt-bindings/regulator/qcom,rpmh-regulator.h

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Introduce bindings for RPMh regulator devices found on some Qualcomm Technlogies, Inc. SoCs. These devices allow a given processor within the SoC to make PMIC regulator requests which are aggregated within the RPMh hardware block along with requests from other processors in the SoC to determine the final PMIC regulator hardware state.

---
 .../bindings/regulator/qcom,rpmh-regulator.txt     | 160 +++++++++++++++++++++
 .../dt-bindings/regulator/qcom,rpmh-regulator.h    |  36 +++++
 2 files changed, 196 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt
 create mode 100644 include/dt-bindings/regulator/qcom,rpmh-regulator.h

new file mode 100644
index 0000000..7ef2dbe
@@ -0,0 +1,160 @@
+Qualcomm Technologies, Inc. RPMh Regulators
+
+rpmh-regulator devices support PMIC regulator management via the Voltage
+Regulator Manager (VRM) and Oscillator Buffer (XOB) RPMh accelerators.  The APPS
+processor communicates with these hardware blocks via a Resource State
+Coordinator (RSC) using command packets.  The VRM allows changing three
+parameters for a given regulator: enable state, output voltage, and operating
+mode.  The XOB allows changing only a single parameter for a given regulator:
+its enable state.  Despite its name, the XOB is capable of controlling the
+enable state of any PMIC peripheral.  It is used for clock buffers, low-voltage
+switches, and LDO/SMPS regulators which have a fixed voltage and mode.
+
+=======================
+Required Node Structure
+=======================
+
+RPMh regulators must be described in two levels of device nodes.  The first
+level describes the PMIC containing the regulators and must reside within an
+RPMh device node.  The second level describes each regulator within the PMIC
+which is to be used on the board.  Each of these regulators maps to a single
+RPMh resource.
+
+The names used for regulator nodes must match those supported by a given PMIC.
+Supported regulator node names:
+	PM8998:		smps1 - smps13, ldo1 - ldo28, lvs1 - lvs2
+	PMI8998:	bob
+	PM8005:		smps1 - smps4
+
+========================
+First Level Nodes - PMIC
+========================
+
+- compatible
+	Usage:      required
+	Value type: <string>
+	Definition: Must be one of: "qcom,pm8998-rpmh-regulators",
+		    "qcom,pmi8998-rpmh-regulators" or
+		    "qcom,pm8005-rpmh-regulators".
+
+- qcom,pmic-id
+	Usage:      required
+	Value type: <string>
+	Definition: RPMh resource name suffix used for the regulators found on
+		    this PMIC.  Typical values: "a", "b", "c", "d", "e", "f".
+
+- vdd-s1-supply
+- vdd-s2-supply
+- vdd-s3-supply
+- vdd-s4-supply
+	Usage:      optional (PM8998 and PM8005 only)
+	Value type: <phandle>
+	Definition: phandle of the parent supply regulator of one or more of the
+		    regulators for this PMIC.
+
+- vdd-s5-supply
+- vdd-s6-supply
+- vdd-s7-supply
+- vdd-s8-supply
+- vdd-s9-supply
+- vdd-s10-supply
+- vdd-s11-supply
+- vdd-s12-supply
+- vdd-s13-supply
+- vdd-l1-l27-supply
+- vdd-l2-l8-l17-supply
+- vdd-l3-l11-supply
+- vdd-l4-l5-supply
+- vdd-l6-supply
+- vdd-l7-l12-l14-l15-supply
+- vdd-l9-supply
+- vdd-l10-l23-l25-supply
+- vdd-l13-l19-l21-supply
+- vdd-l16-l28-supply
+- vdd-l18-l22-supply
+- vdd-l20-l24-supply
+- vdd-l26-supply
+- vin-lvs-1-2-supply
+	Usage:      optional (PM8998 only)
+	Value type: <phandle>
+	Definition: phandle of the parent supply regulator of one or more of the
+		    regulators for this PMIC.
+
+- vdd-bob-supply
+	Usage:      optional (PMI8998 only)
+	Value type: <phandle>
+	Definition: BOB regulator parent supply phandle
+
+===============================
+Second Level Nodes - Regulators
+===============================
+
+- qcom,always-wait-for-ack
+	Usage:      optional
+	Value type: <empty>
+	Definition: Boolean flag which indicates that the application processor
+		    must wait for an ACK or a NACK from RPMh for every request
+		    sent for this regulator including those which are for a
+		    strictly lower power state.
+
+Other properties defined in Documentation/devicetree/bindings/regulator.txt
+may also be used.  regulator-initial-mode and regulator-allowed-modes may be
+specified for VRM regulators using mode values from
+include/dt-bindings/regulator/qcom,rpmh-regulator.h.  regulator-allow-bypass
+may be specified for BOB type regulators managed via VRM.
+regulator-allow-set-load may be specified for LDO type regulators managed via
+VRM.
+
+========
+Examples
+========
+
+#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
+
+&apps_rsc {
+	pm8998-rpmh-regulators {
+		compatible = "qcom,pm8998-rpmh-regulators";
+		qcom,pmic-id = "a";
+
+		vdd-l7-l12-l14-l15-supply = <&pm8998_s5>;
+
+		smps2 {
+			regulator-min-microvolt = <1100000>;
+			regulator-max-microvolt = <1100000>;
+		};
+
+		pm8998_s5: smps5 {
+			regulator-min-microvolt = <1904000>;
+			regulator-max-microvolt = <2040000>;
+		};
+
+		ldo7 {
+			regulator-min-microvolt = <1800000>;
+			regulator-max-microvolt = <1800000>;
+			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
+			regulator-allowed-modes =
+				<RPMH_REGULATOR_MODE_LPM
+				 RPMH_REGULATOR_MODE_HPM>;
+			regulator-allow-set-load;
+		};
+
+		lvs1 {
+			regulator-min-microvolt = <1800000>;
+			regulator-max-microvolt = <1800000>;
+		};
+	};
+
+	pmi8998-rpmh-regulators {
+		compatible = "qcom,pmi8998-rpmh-regulators";
+		qcom,pmic-id = "b";
+
+		bob {
+			regulator-min-microvolt = <3312000>;
+			regulator-max-microvolt = <3600000>;
+			regulator-allowed-modes =
+				<RPMH_REGULATOR_MODE_AUTO
+				 RPMH_REGULATOR_MODE_HPM>;
+			regulator-initial-mode = <RPMH_REGULATOR_MODE_AUTO>;
+		};
+	};
+};

new file mode 100644
index 0000000..86713dc
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved. */
+
+#ifndef __QCOM_RPMH_REGULATOR_H
+#define __QCOM_RPMH_REGULATOR_H
+
+/*
+ * These mode constants may be used to specify modes for various RPMh regulator
+ * device tree properties (e.g. regulator-initial-mode).  Each type of regulator
+ * supports a subset of the possible modes.
+ *
+ * %RPMH_REGULATOR_MODE_RET:	Retention mode in which only an extremely small
+ *				load current is allowed.  This mode is supported
+ *				by LDO and SMPS type regulators.
+ * %RPMH_REGULATOR_MODE_LPM:	Low power mode in which a small load current is
+ *				allowed.  This mode corresponds to PFM for SMPS
+ *				and BOB type regulators.  This mode is supported
+ *				by LDO, HFSMPS, BOB, and PMIC4 FTSMPS type
+ *				regulators.
+ * %RPMH_REGULATOR_MODE_AUTO:	Auto mode in which the regulator hardware
+ *				automatically switches between LPM and HPM based
+ *				upon the real-time load current.  This mode is
+ *				supported by HFSMPS, BOB, and PMIC4 FTSMPS type
+ *				regulators.
+ * %RPMH_REGULATOR_MODE_HPM:	High power mode in which the full rated current
+ *				of the regulator is allowed.  This mode
+ *				corresponds to PWM for SMPS and BOB type
+ *				regulators.  This mode is supported by all types
+ *				of regulators.
+ */
+#define RPMH_REGULATOR_MODE_RET		0
+#define RPMH_REGULATOR_MODE_LPM		1
+#define RPMH_REGULATOR_MODE_AUTO	2
+#define RPMH_REGULATOR_MODE_HPM		3
+
+#endif

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Hi Mark,

I know you are still looking for time to review the RPMh-regulator driver and that's fine. One idea I had though: if the bindings look OK to you and are less controversial, is there any chance they could land in the meantime?

Specifically it would be very handy to be able to post up device tree files that refer to regulators and even get those landed, but they can't land without the bindings.

If that's not possible then no worries, but I figured I'd check.

-Doug

This appears to have a bunch of dependencies which I've got no idea what's going on with the merging of and no idea if they'll affect the bindings or anything, nobody's said anything and last I looked it was unclear what was going on. I'm kind of hoping that things might have sorted themselves out of the merge window.

Some of the decisions in the code have flowed out into the bindings
before so I'm not keen to merge the bindings separately, and if the
driver for the thing used to communicate with the device is still in
review then that's definitely a red flag.
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Hi,

RPMh itself landed in Andy's tree and he sent a pull request on Saturday. Feel free to refer to the request ("[GIT PULL] Qualcomm Driver updates for 4.19") AKA
<https://patchwork.kernel.org/patch/10539125/>.

It doesn't look like arm-soc has picked up Andy's pull request yet though. If having it in arm-soc is a requirement then I'm happy to monitor arm-soc and ping this thread again when it's there.

Fair point. I was thinking that we had pared the driver down enough now that the bindings were no longer anything other than just boilerplate bits describing the hardware, but it's obviously your decision when you're happy to land them.

As per above it's been landed, so hopefully this red flag is removed?

-Doug

There was also some other thing called command DB as well which was a
separate series. Ideally there'd be a branch I could pull as there's a
build dependency on rpmh so I can't apply until the code has landed in
my tree, don't know what command DB is exactly.
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Hi,

Yup. That one landed in May and is already in mainline Linux. Refer to commit 312416d9171a ("drivers: qcom: add command DB driver").

Adding Andy to this thread (I guess he wasn't on it?). Hopefully he can provide you with the branch.

-Doug

That's good at least - the cover letter said it was still under review, guess it just hadn't been updated.

Andy?
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+ olof

Mark,

The arm-soc guys merged the Qualcomm pull requests. So you can just use my qcom-drivers-for-4.19 tag. That won't change at this point.

git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux.git
qcom-drivers-for-4.19

Regards,
Andy

Mark,

Did Andy's idea of using the above tag work for you? It appears that there are a few patches you don't need there, but it shouldn't hurt to pick them up too I think? Here's what I see:

---

$ git log --oneline linux/master..qcom-drivers-for-4.19
78ee559d7fc6 (tag: qcom-drivers-for-4.19) soc: qcom: rmtfs-mem: fix
memleak in probe error paths
4da3b0452bc6 soc: qcom: llc-slice: Add missing MODULE_LICENSE()
6c805adf17d4 drivers: qcom: rpmh: fix unwanted error check for get_tcs_of_type()
efa1c257b3fc drivers: qcom: rpmh-rsc: fix the loop index check in
get_req_from_tcs
a0b1561f8461 firmware: qcom: scm: add a dummy qcom_scm_assign_mem()
fdd102b52cfd drivers: qcom: rpmh-rsc: Check cmd_db_ready() to help children
2de4b8d33eab drivers: qcom: rpmh-rsc: allow active requests from wake TCS
c8790cb6da58 drivers: qcom: rpmh: add support for batch RPMH request
564b5e24ccd4 drivers: qcom: rpmh: allow requests to be sent asynchronously
600513dfeef3 drivers: qcom: rpmh: cache sleep/wake state requests
9a3afcfbc0cc drivers: qcom: rpmh-rsc: allow invalidation of sleep/wake TCS
fa460e453a83 drivers: qcom: rpmh-rsc: write sleep/wake requests to TCS
c1038456b02b drivers: qcom: rpmh: add RPMH helper functions
fc087fe5a45e drivers: qcom: rpmh-rsc: log RPMH requests in FTRACE
2e4690a09fca dt-bindings: introduce RPMH RSC bindings for Qualcomm SoCs
658628e7ef78 drivers: qcom: rpmh-rsc: add RPMH controller for QCOM SoCs
a3134fb09e0b drivers: soc: Add LLCC driver
7e5700ae64f6 dt-bindings: Documentation for qcom, llcc
0b65c59e3a54 soc: qcom: smem: Correct check for global partition

---

It seems like it's too late to land RPMh-regulator for 4.19, so I guess we'll have to aim for 4.20. I'm not sure if that means you're going to want to wait until 4.20-rc1 comes out to use as a base before thinking about landing RPMh-regulator? If so then I guess we've got ~3 weeks before something could land and we could start landing device tree bits using RPMh-regulator. If that's the plan then we'll probably just start landing things in the Chrome OS tree now and suck up the extra work of trying to resolve differences later...

Thanks!

-Doug

It does make my pull request look larger which is hard to get enthused about.

Stuff like this jumped out for example.

If I apply it after the merge window it's going to be based on -rc1. If
I get to it this week I guess I'll have to pull in the drivers tag.
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Add the QCOM RPMh regulator driver to manage PMIC regulators which are controlled via RPMh on some Qualcomm Technologies, Inc. SoCs. RPMh is a hardware block which contains several accelerators which are used to manage various hardware resources that are shared between the processors of the SoC. The final hardware state of a regulator is determined within RPMh by performing max aggregation of the requests made by all of the processors.

Add support for PMIC regulator control via the voltage regulator manager (VRM) and oscillator buffer (XOB) RPMh accelerators. VRM supports manipulation of enable state, voltage, and mode. XOB supports manipulation of enable state.

---
 drivers/regulator/Kconfig               |   9 +
 drivers/regulator/Makefile              |   1 +
 drivers/regulator/qcom-rpmh-regulator.c | 769 ++++++++++++++++++++++++++++++++
 3 files changed, 779 insertions(+)
 create mode 100644 drivers/regulator/qcom-rpmh-regulator.c

index 8233dc7..c5154b8 100644
@@ -682,6 +682,15 @@ config REGULATOR_QCOM_RPM
 	  Qualcomm RPM as a module. The module will be named
 	  "qcom_rpm-regulator".
 
+config REGULATOR_QCOM_RPMH
+	tristate "Qualcomm Technologies, Inc. RPMh regulator driver"
+	depends on QCOM_RPMH || COMPILE_TEST
+	help
+	  This driver supports control of PMIC regulators via the RPMh hardware
+	  block found on Qualcomm Technologies Inc. SoCs.  RPMh regulator
+	  control allows for voting on regulator state between multiple
+	  processors within the SoC.
+
 config REGULATOR_QCOM_SMD_RPM
 	tristate "Qualcomm SMD based RPM regulator driver"
 	depends on QCOM_SMD_RPM

index b7839f4..8d115e3 100644
@@ -78,6 +78,7 @@ obj-$(CONFIG_REGULATOR_MT6323)	+= mt6323-regulator.o
 obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
 obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_SPMI) += qcom_spmi-regulator.o
 obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Hi,

Hopefully <https://lore.kernel.org/lkml/[email protected]/>
addresses this?

Thanks!

-Doug