regulator: add QCOM RPMh regulator driver

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.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 779 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 347351e79b1e..329cdd33ed62 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -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
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 18bfed61e7fe..801d9a34a203 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -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
diff --git a/drivers/regulator/qcom-rpmh-regulator.c b/drivers/regulator/qcom-rpmh-regulator.c
new file mode 100644
index 000000000000..9f27daebd8c8
--- /dev/null
+++ b/drivers/regulator/qcom-rpmh-regulator.c
@@ -0,0 +1,769 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018, The Linux Foundation. All rights reserved.
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+
+#include <soc/qcom/cmd-db.h>
+#include <soc/qcom/rpmh.h>
+
+#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
+
+/**
+ * enum rpmh_regulator_type - supported RPMh accelerator types
+ * %VRM:        RPMh VRM accelerator which supports voting on enable, voltage,
+ *              and mode of LDO, SMPS, and BOB type PMIC regulators.
+ * %XOB:        RPMh XOB accelerator which supports voting on the enable state
+ *              of PMIC regulators.
+ */
+enum rpmh_regulator_type {
+        VRM,
+        XOB,
+};
+
+#define RPMH_REGULATOR_REG_VRM_VOLTAGE          0x0
+#define RPMH_REGULATOR_REG_ENABLE               0x4
+#define RPMH_REGULATOR_REG_VRM_MODE             0x8
+
+#define PMIC4_LDO_MODE_RETENTION                4
+#define PMIC4_LDO_MODE_LPM                      5
+#define PMIC4_LDO_MODE_HPM                      7
+
+#define PMIC4_SMPS_MODE_RETENTION               4
+#define PMIC4_SMPS_MODE_PFM                     5
+#define PMIC4_SMPS_MODE_AUTO                    6
+#define PMIC4_SMPS_MODE_PWM                     7
+
+#define PMIC4_BOB_MODE_PASS                     0
+#define PMIC4_BOB_MODE_PFM                      1
+#define PMIC4_BOB_MODE_AUTO                     2
+#define PMIC4_BOB_MODE_PWM                      3
+
+/**
+ * struct rpmh_vreg_hw_data - RPMh regulator hardware configurations
+ * @regulator_type:             RPMh accelerator type used to manage this
+ *                              regulator
+ * @ops:                        Pointer to regulator ops callback structure
+ * @voltage_range:              The single range of voltages supported by this
+ *                              PMIC regulator type
+ * @n_voltages:                 The number of unique voltage set points defined
+ *                              by voltage_range
+ * @hpm_min_load_uA:            Minimum load current in microamps that requires
+ *                              high power mode (HPM) operation.  This is used
+ *                              for LDO hardware type regulators only.
+ * @pmic_mode_map:              Array indexed by regulator framework mode
+ *                              containing PMIC hardware modes.  Must be large
+ *                              enough to index all framework modes supported
+ *                              by this regulator hardware type.
+ * @of_map_mode:                Maps an RPMH_REGULATOR_MODE_* mode value defined
+ *                              in device tree to a regulator framework mode
+ */
+struct rpmh_vreg_hw_data {
+        enum rpmh_regulator_type                regulator_type;
+        const struct regulator_ops              *ops;
+        const struct regulator_linear_range     voltage_range;
+        int                                     n_voltages;
+        int                                     hpm_min_load_uA;
+        const int                               *pmic_mode_map;
+        unsigned int                          (*of_map_mode)(unsigned int mode);
+};
+
+/**
+ * struct rpmh_vreg - individual RPMh regulator data structure encapsulating a
+ *              single regulator device
+ * @dev:                        Device pointer for the top-level PMIC RPMh
+ *                              regulator parent device.  This is used as a
+ *                              handle in RPMh write requests.
+ * @addr:                       Base address of the regulator resource within
+ *                              an RPMh accelerator
+ * @rdesc:                      Regulator descriptor
+ * @hw_data:                    PMIC regulator configuration data for this RPMh
+ *                              regulator
+ * @always_wait_for_ack:        Boolean flag indicating if a request must always
+ *                              wait for an ACK from RPMh before continuing even
+ *                              if it corresponds to a strictly lower power
+ *                              state (e.g. enabled --> disabled).
+ * @enabled:                    Flag indicating if the regulator is enabled or
+ *                              not
+ * @bypassed:                   Boolean indicating if the regulator is in
+ *                              bypass (pass-through) mode or not.  This is
+ *                              only used by BOB rpmh-regulator resources.
+ * @voltage_selector:           Selector used for get_voltage_sel() and
+ *                              set_voltage_sel() callbacks
+ * @mode:                       RPMh VRM regulator current framework mode
+ */
+struct rpmh_vreg {
+        struct device                   *dev;
+        u32                             addr;
+        struct regulator_desc           rdesc;
+        const struct rpmh_vreg_hw_data  *hw_data;
+        bool                            always_wait_for_ack;
+
+        int                             enabled;
+        bool                            bypassed;
+        int                             voltage_selector;
+        unsigned int                    mode;
+};
+
+/**
+ * struct rpmh_vreg_init_data - initialization data for an RPMh regulator
+ * @name:                       Name for the regulator which also corresponds
+ *                              to the device tree subnode name of the regulator
+ * @resource_name:              RPMh regulator resource name format string.
+ *                              This must include exactly one field: '%s' which
+ *                              is filled at run-time with the PMIC ID provided
+ *                              by device tree property qcom,pmic-id.  Example:
+ *                              "ldo%s1" for RPMh resource "ldoa1".
+ * @supply_name:                Parent supply regulator name
+ * @hw_data:                    Configuration data for this PMIC regulator type
+ */
+struct rpmh_vreg_init_data {
+        const char                      *name;
+        const char                      *resource_name;
+        const char                      *supply_name;
+        const struct rpmh_vreg_hw_data  *hw_data;
+};
+
+/**
+ * rpmh_regulator_send_request() - send the request to RPMh
+ * @vreg:               Pointer to the RPMh regulator
+ * @cmd:                Pointer to the RPMh command to send
+ * @wait_for_ack:       Boolean indicating if execution must wait until the
+ *                      request has been acknowledged as complete
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_send_request(struct rpmh_vreg *vreg,
+                        struct tcs_cmd *cmd, bool wait_for_ack)
+{
+        int ret;
+
+        if (wait_for_ack || vreg->always_wait_for_ack)
+                ret = rpmh_write(vreg->dev, RPMH_ACTIVE_ONLY_STATE, cmd, 1);
+        else
+                ret = rpmh_write_async(vreg->dev, RPMH_ACTIVE_ONLY_STATE, cmd,
+                                        1);