regulator: spm_regulator: Add snapshot of spm_regulator driver

This is snapshot of the spm_regulator driver as of
msm-5.15 'commit acd312e779517 ("regulator: spm_regulator:
Add snapshot of spm_regulator driver")'.

Change-Id: I3521caeaf6f6621c07a1cc34ba2d3faa20f4660a
Signed-off-by: Sai Kannan <quic_csaikann@quicinc.com>

drivers/regulator/Kconfig

@@ -65,6 +65,16 @@ config REGULATOR_VIRTUAL_CONSUMER
 
 	  If unsure, say no.
 
+config REGULATOR_SPM
+        bool "SPM regulator driver"
+        depends on SPMI
+        help
+          Enable support for the SPM regulator driver which is used for
+          setting voltages of processor supply regulators via the SPM module
+          found inside chips of Qualcomm Technologies Inc. The SPM regulator
+          driver can be used on QTI SoCs where the APSS processor cores are
+          supplied by their own PMIC regulator.
+
 config REGULATOR_USERSPACE_CONSUMER
 	tristate "Userspace regulator consumer support"
 	help

drivers/regulator/Makefile

@@ -196,5 +196,5 @@ obj-$(CONFIG_REGULATOR_STUB) += stub-regulator.o
 obj-$(CONFIG_REGULATOR_DEBUG_CONTROL) += debug-regulator.o
 obj-$(CONFIG_REGULATOR_QTI_OCP_NOTIFIER) += qti-ocp-notifier.o
 obj-$(CONFIG_VIRTIO_REGULATOR) += virtio_regulator.o
-
+obj-$(CONFIG_REGULATOR_SPM) += spm-regulator.o
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG

include/linux/regulator/spm-regulator.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2013-2014, 2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _LINUX_REGULATOR_SPM_H
+#define _LINUX_REGULATOR_SPM_H
+
+#include <linux/err.h>
+#include <linux/init.h>
+
+#ifdef CONFIG_REGULATOR_SPM
+int __init spm_regulator_init(void);
+#else
+static inline int __init spm_regulator_init(void) { return -ENODEV; }
+#endif
+
+#endif