Merge tag 'scmi-voltage-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep...
authorSudeep Holla <sudeep.holla@arm.com>
Mon, 23 Nov 2020 16:37:27 +0000 (16:37 +0000)
committerSudeep Holla <sudeep.holla@arm.com>
Mon, 23 Nov 2020 16:37:27 +0000 (16:37 +0000)
SCMI voltage domain management protocol support for v5.11

SCMI v3.0 voltage domain protocol support to discover the voltage levels
supported by the domains and to set/get the configuration and voltage
level of any given domain.

* tag 'scmi-voltage-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Add support to enumerated SCMI voltage domain device
  firmware: arm_scmi: Add voltage domain management protocol support
  dt-bindings: arm: Add support for SCMI Regulators

Documentation/devicetree/bindings/arm/arm,scmi.txt
drivers/firmware/arm_scmi/Makefile
drivers/firmware/arm_scmi/common.h
drivers/firmware/arm_scmi/driver.c
drivers/firmware/arm_scmi/voltage.c [new file with mode: 0644]
include/linux/scmi_protocol.h

index 55deb68..6e011ca 100644 (file)
@@ -62,6 +62,29 @@ Required properties:
  - #power-domain-cells : Should be 1. Contains the device or the power
                         domain ID value used by SCMI commands.
 
+Regulator bindings for the SCMI Regulator based on SCMI Message Protocol
+------------------------------------------------------------
+An SCMI Regulator is permanently bound to a well defined SCMI Voltage Domain,
+and should be always positioned as a root regulator.
+It does not support any current operation.
+
+SCMI Regulators are grouped under a 'regulators' node which in turn is a child
+of the SCMI Voltage protocol node inside the desired SCMI instance node.
+
+This binding uses the common regulator binding[6] but, due to SCMI abstractions,
+supports only a subset of its properties as specified below amongst Optional
+properties.
+
+Required properties:
+ - reg : shall identify an existent SCMI Voltage Domain.
+
+Optional properties:
+ - regulator-name
+ - regulator-min-microvolt / regulator-max-microvolt
+ - regulator-always-on / regulator-boot-on
+ - regulator-max-step-microvolt
+ - regulator-coupled-with / regulator-coupled-max-spread
+
 Sensor bindings for the sensors based on SCMI Message Protocol
 --------------------------------------------------------------
 SCMI provides an API to access the various sensors on the SoC.
@@ -105,6 +128,7 @@ Required sub-node properties:
 [3] Documentation/devicetree/bindings/thermal/thermal*.yaml
 [4] Documentation/devicetree/bindings/sram/sram.yaml
 [5] Documentation/devicetree/bindings/reset/reset.txt
+[6] Documentation/devicetree/bindings/regulator/regulator.yaml
 
 Example:
 
@@ -169,6 +193,25 @@ firmware {
                        reg = <0x16>;
                        #reset-cells = <1>;
                };
+
+               scmi_voltage: protocol@17 {
+                       reg = <0x17>;
+
+                       regulators {
+                               regulator_devX: regulator@0 {
+                                       reg = <0x0>;
+                                       regulator-max-microvolt = <3300000>;
+                               };
+
+                               regulator_devY: regulator@9 {
+                                       reg = <0x9>;
+                                       regulator-min-microvolt = <500000>;
+                                       regulator-max-microvolt = <4200000>;
+                               };
+
+                               ...
+                       };
+               };
        };
 };
 
index bc0d54f..6a2ef63 100644 (file)
@@ -4,7 +4,7 @@ scmi-driver-y = driver.o notify.o
 scmi-transport-y = shmem.o
 scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
 scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
-scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o
+scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o
 scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \
                    $(scmi-transport-y)
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
index 65063fa..c0fb45e 100644 (file)
@@ -169,6 +169,7 @@ DECLARE_SCMI_REGISTER_UNREGISTER(perf);
 DECLARE_SCMI_REGISTER_UNREGISTER(power);
 DECLARE_SCMI_REGISTER_UNREGISTER(reset);
 DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
+DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
 DECLARE_SCMI_REGISTER_UNREGISTER(system);
 
 #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \
index 3dfd8b6..5392e1f 100644 (file)
@@ -743,6 +743,7 @@ static struct scmi_prot_devnames devnames[] = {
        { SCMI_PROTOCOL_CLOCK,  { "clocks" },},
        { SCMI_PROTOCOL_SENSOR, { "hwmon" },},
        { SCMI_PROTOCOL_RESET,  { "reset" },},
+       { SCMI_PROTOCOL_VOLTAGE,  { "regulator" },},
 };
 
 static inline void
@@ -946,6 +947,7 @@ static int __init scmi_driver_init(void)
        scmi_power_register();
        scmi_reset_register();
        scmi_sensors_register();
+       scmi_voltage_register();
        scmi_system_register();
 
        return platform_driver_register(&scmi_driver);
@@ -961,6 +963,7 @@ static void __exit scmi_driver_exit(void)
        scmi_power_unregister();
        scmi_reset_unregister();
        scmi_sensors_unregister();
+       scmi_voltage_unregister();
        scmi_system_unregister();
 
        platform_driver_unregister(&scmi_driver);
diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c
new file mode 100644 (file)
index 0000000..e794e43
--- /dev/null
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Voltage Protocol
+ *
+ * Copyright (C) 2020 ARM Ltd.
+ */
+
+#include <linux/scmi_protocol.h>
+
+#include "common.h"
+
+#define VOLTAGE_DOMS_NUM_MASK          GENMASK(15, 0)
+#define REMAINING_LEVELS_MASK          GENMASK(31, 16)
+#define RETURNED_LEVELS_MASK           GENMASK(11, 0)
+
+enum scmi_voltage_protocol_cmd {
+       VOLTAGE_DOMAIN_ATTRIBUTES = 0x3,
+       VOLTAGE_DESCRIBE_LEVELS = 0x4,
+       VOLTAGE_CONFIG_SET = 0x5,
+       VOLTAGE_CONFIG_GET = 0x6,
+       VOLTAGE_LEVEL_SET = 0x7,
+       VOLTAGE_LEVEL_GET = 0x8,
+};
+
+#define NUM_VOLTAGE_DOMAINS(x) ((u16)(FIELD_GET(VOLTAGE_DOMS_NUM_MASK, (x))))
+
+struct scmi_msg_resp_domain_attributes {
+       __le32 attr;
+       u8 name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_msg_cmd_describe_levels {
+       __le32 domain_id;
+       __le32 level_index;
+};
+
+struct scmi_msg_resp_describe_levels {
+       __le32 flags;
+#define NUM_REMAINING_LEVELS(f)        ((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
+#define NUM_RETURNED_LEVELS(f) ((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
+#define SUPPORTS_SEGMENTED_LEVELS(f)   ((f) & BIT(12))
+       __le32 voltage[];
+};
+
+struct scmi_msg_cmd_config_set {
+       __le32 domain_id;
+       __le32 config;
+};
+
+struct scmi_msg_cmd_level_set {
+       __le32 domain_id;
+       __le32 flags;
+       __le32 voltage_level;
+};
+
+struct voltage_info {
+       unsigned int version;
+       unsigned int num_domains;
+       struct scmi_voltage_info *domains;
+};
+
+static int scmi_protocol_attributes_get(const struct scmi_handle *handle,
+                                       struct voltage_info *vinfo)
+{
+       int ret;
+       struct scmi_xfer *t;
+
+       ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
+                                SCMI_PROTOCOL_VOLTAGE, 0, sizeof(__le32), &t);
+       if (ret)
+               return ret;
+
+       ret = scmi_do_xfer(handle, t);
+       if (!ret)
+               vinfo->num_domains =
+                       NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));
+
+       scmi_xfer_put(handle, t);
+       return ret;
+}
+
+static int scmi_init_voltage_levels(struct device *dev,
+                                   struct scmi_voltage_info *v,
+                                   u32 num_returned, u32 num_remaining,
+                                   bool segmented)
+{
+       u32 num_levels;
+
+       num_levels = num_returned + num_remaining;
+       /*
+        * segmented levels entries are represented by a single triplet
+        * returned all in one go.
+        */
+       if (!num_levels ||
+           (segmented && (num_remaining || num_returned != 3))) {
+               dev_err(dev,
+                       "Invalid level descriptor(%d/%d/%d) for voltage dom %d\n",
+                       num_levels, num_returned, num_remaining, v->id);
+               return -EINVAL;
+       }
+
+       v->levels_uv = devm_kcalloc(dev, num_levels, sizeof(u32), GFP_KERNEL);
+       if (!v->levels_uv)
+               return -ENOMEM;
+
+       v->num_levels = num_levels;
+       v->segmented = segmented;
+
+       return 0;
+}
+
+static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
+                                       struct voltage_info *vinfo)
+{
+       int ret, dom;
+       struct scmi_xfer *td, *tl;
+       struct device *dev = handle->dev;
+       struct scmi_msg_resp_domain_attributes *resp_dom;
+       struct scmi_msg_resp_describe_levels *resp_levels;
+
+       ret = scmi_xfer_get_init(handle, VOLTAGE_DOMAIN_ATTRIBUTES,
+                                SCMI_PROTOCOL_VOLTAGE, sizeof(__le32),
+                                sizeof(*resp_dom), &td);
+       if (ret)
+               return ret;
+       resp_dom = td->rx.buf;
+
+       ret = scmi_xfer_get_init(handle, VOLTAGE_DESCRIBE_LEVELS,
+                                SCMI_PROTOCOL_VOLTAGE, sizeof(__le64), 0, &tl);
+       if (ret)
+               goto outd;
+       resp_levels = tl->rx.buf;
+
+       for (dom = 0; dom < vinfo->num_domains; dom++) {
+               u32 desc_index = 0;
+               u16 num_returned = 0, num_remaining = 0;
+               struct scmi_msg_cmd_describe_levels *cmd;
+               struct scmi_voltage_info *v;
+
+               /* Retrieve domain attributes at first ... */
+               put_unaligned_le32(dom, td->tx.buf);
+               ret = scmi_do_xfer(handle, td);
+               /* Skip domain on comms error */
+               if (ret)
+                       continue;
+
+               v = vinfo->domains + dom;
+               v->id = dom;
+               v->attributes = le32_to_cpu(resp_dom->attr);
+               strlcpy(v->name, resp_dom->name, SCMI_MAX_STR_SIZE);
+
+               cmd = tl->tx.buf;
+               /* ...then retrieve domain levels descriptions */
+               do {
+                       u32 flags;
+                       int cnt;
+
+                       cmd->domain_id = cpu_to_le32(v->id);
+                       cmd->level_index = desc_index;
+                       ret = scmi_do_xfer(handle, tl);
+                       if (ret)
+                               break;
+
+                       flags = le32_to_cpu(resp_levels->flags);
+                       num_returned = NUM_RETURNED_LEVELS(flags);
+                       num_remaining = NUM_REMAINING_LEVELS(flags);
+
+                       /* Allocate space for num_levels if not already done */
+                       if (!v->num_levels) {
+                               ret = scmi_init_voltage_levels(dev, v,
+                                                              num_returned,
+                                                              num_remaining,
+                                             SUPPORTS_SEGMENTED_LEVELS(flags));
+                               if (ret)
+                                       break;
+                       }
+
+                       if (desc_index + num_returned > v->num_levels) {
+                               dev_err(handle->dev,
+                                       "No. of voltage levels can't exceed %d\n",
+                                       v->num_levels);
+                               ret = -EINVAL;
+                               break;
+                       }
+
+                       for (cnt = 0; cnt < num_returned; cnt++) {
+                               s32 val;
+
+                               val =
+                                   (s32)le32_to_cpu(resp_levels->voltage[cnt]);
+                               v->levels_uv[desc_index + cnt] = val;
+                               if (val < 0)
+                                       v->negative_volts_allowed = true;
+                       }
+
+                       desc_index += num_returned;
+
+                       scmi_reset_rx_to_maxsz(handle, tl);
+                       /* check both to avoid infinite loop due to buggy fw */
+               } while (num_returned && num_remaining);
+
+               if (ret) {
+                       v->num_levels = 0;
+                       devm_kfree(dev, v->levels_uv);
+               }
+
+               scmi_reset_rx_to_maxsz(handle, td);
+       }
+
+       scmi_xfer_put(handle, tl);
+outd:
+       scmi_xfer_put(handle, td);
+
+       return ret;
+}
+
+static int __scmi_voltage_get_u32(const struct scmi_handle *handle,
+                                 u8 cmd_id, u32 domain_id, u32 *value)
+{
+       int ret;
+       struct scmi_xfer *t;
+       struct voltage_info *vinfo = handle->voltage_priv;
+
+       if (domain_id >= vinfo->num_domains)
+               return -EINVAL;
+
+       ret = scmi_xfer_get_init(handle, cmd_id,
+                                SCMI_PROTOCOL_VOLTAGE,
+                                sizeof(__le32), 0, &t);
+       if (ret)
+               return ret;
+
+       put_unaligned_le32(domain_id, t->tx.buf);
+       ret = scmi_do_xfer(handle, t);
+       if (!ret)
+               *value = get_unaligned_le32(t->rx.buf);
+
+       scmi_xfer_put(handle, t);
+       return ret;
+}
+
+static int scmi_voltage_config_set(const struct scmi_handle *handle,
+                                  u32 domain_id, u32 config)
+{
+       int ret;
+       struct scmi_xfer *t;
+       struct voltage_info *vinfo = handle->voltage_priv;
+       struct scmi_msg_cmd_config_set *cmd;
+
+       if (domain_id >= vinfo->num_domains)
+               return -EINVAL;
+
+       ret = scmi_xfer_get_init(handle, VOLTAGE_CONFIG_SET,
+                                SCMI_PROTOCOL_VOLTAGE,
+                                sizeof(*cmd), 0, &t);
+       if (ret)
+               return ret;
+
+       cmd = t->tx.buf;
+       cmd->domain_id = cpu_to_le32(domain_id);
+       cmd->config = cpu_to_le32(config & GENMASK(3, 0));
+
+       ret = scmi_do_xfer(handle, t);
+
+       scmi_xfer_put(handle, t);
+       return ret;
+}
+
+static int scmi_voltage_config_get(const struct scmi_handle *handle,
+                                  u32 domain_id, u32 *config)
+{
+       return __scmi_voltage_get_u32(handle, VOLTAGE_CONFIG_GET,
+                                     domain_id, config);
+}
+
+static int scmi_voltage_level_set(const struct scmi_handle *handle,
+                                 u32 domain_id, u32 flags, s32 volt_uV)
+{
+       int ret;
+       struct scmi_xfer *t;
+       struct voltage_info *vinfo = handle->voltage_priv;
+       struct scmi_msg_cmd_level_set *cmd;
+
+       if (domain_id >= vinfo->num_domains)
+               return -EINVAL;
+
+       ret = scmi_xfer_get_init(handle, VOLTAGE_LEVEL_SET,
+                                SCMI_PROTOCOL_VOLTAGE,
+                                sizeof(*cmd), 0, &t);
+       if (ret)
+               return ret;
+
+       cmd = t->tx.buf;
+       cmd->domain_id = cpu_to_le32(domain_id);
+       cmd->flags = cpu_to_le32(flags);
+       cmd->voltage_level = cpu_to_le32(volt_uV);
+
+       ret = scmi_do_xfer(handle, t);
+
+       scmi_xfer_put(handle, t);
+       return ret;
+}
+
+static int scmi_voltage_level_get(const struct scmi_handle *handle,
+                                 u32 domain_id, s32 *volt_uV)
+{
+       return __scmi_voltage_get_u32(handle, VOLTAGE_LEVEL_GET,
+                                     domain_id, (u32 *)volt_uV);
+}
+
+static const struct scmi_voltage_info * __must_check
+scmi_voltage_info_get(const struct scmi_handle *handle, u32 domain_id)
+{
+       struct voltage_info *vinfo = handle->voltage_priv;
+
+       if (domain_id >= vinfo->num_domains ||
+           !vinfo->domains[domain_id].num_levels)
+               return NULL;
+
+       return vinfo->domains + domain_id;
+}
+
+static int scmi_voltage_domains_num_get(const struct scmi_handle *handle)
+{
+       struct voltage_info *vinfo = handle->voltage_priv;
+
+       return vinfo->num_domains;
+}
+
+static struct scmi_voltage_ops voltage_ops = {
+       .num_domains_get = scmi_voltage_domains_num_get,
+       .info_get = scmi_voltage_info_get,
+       .config_set = scmi_voltage_config_set,
+       .config_get = scmi_voltage_config_get,
+       .level_set = scmi_voltage_level_set,
+       .level_get = scmi_voltage_level_get,
+};
+
+static int scmi_voltage_protocol_init(struct scmi_handle *handle)
+{
+       int ret;
+       u32 version;
+       struct voltage_info *vinfo;
+
+       ret = scmi_version_get(handle, SCMI_PROTOCOL_VOLTAGE, &version);
+       if (ret)
+               return ret;
+
+       dev_dbg(handle->dev, "Voltage Version %d.%d\n",
+               PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+       vinfo = devm_kzalloc(handle->dev, sizeof(*vinfo), GFP_KERNEL);
+       if (!vinfo)
+               return -ENOMEM;
+       vinfo->version = version;
+
+       ret = scmi_protocol_attributes_get(handle, vinfo);
+       if (ret)
+               return ret;
+
+       if (vinfo->num_domains) {
+               vinfo->domains = devm_kcalloc(handle->dev, vinfo->num_domains,
+                                             sizeof(*vinfo->domains),
+                                             GFP_KERNEL);
+               if (!vinfo->domains)
+                       return -ENOMEM;
+               ret = scmi_voltage_descriptors_get(handle, vinfo);
+               if (ret)
+                       return ret;
+       } else {
+               dev_warn(handle->dev, "No Voltage domains found.\n");
+       }
+
+       handle->voltage_ops = &voltage_ops;
+       handle->voltage_priv = vinfo;
+
+       return 0;
+}
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_VOLTAGE, voltage)
index be0be5f..dd9e948 100644 (file)
@@ -480,6 +480,64 @@ struct scmi_reset_ops {
        int (*deassert)(const struct scmi_handle *handle, u32 domain);
 };
 
+/**
+ * struct scmi_voltage_info - describe one available SCMI Voltage Domain
+ *
+ * @id: the domain ID as advertised by the platform
+ * @segmented: defines the layout of the entries of array @levels_uv.
+ *            - when True the entries are to be interpreted as triplets,
+ *              each defining a segment representing a range of equally
+ *              space voltages: <lowest_volts>, <highest_volt>, <step_uV>
+ *            - when False the entries simply represent a single discrete
+ *              supported voltage level
+ * @negative_volts_allowed: True if any of the entries of @levels_uv represent
+ *                         a negative voltage.
+ * @attributes: represents Voltage Domain advertised attributes
+ * @name: name assigned to the Voltage Domain by platform
+ * @num_levels: number of total entries in @levels_uv.
+ * @levels_uv: array of entries describing the available voltage levels for
+ *            this domain.
+ */
+struct scmi_voltage_info {
+       unsigned int id;
+       bool segmented;
+       bool negative_volts_allowed;
+       unsigned int attributes;
+       char name[SCMI_MAX_STR_SIZE];
+       unsigned int num_levels;
+#define SCMI_VOLTAGE_SEGMENT_LOW       0
+#define SCMI_VOLTAGE_SEGMENT_HIGH      1
+#define SCMI_VOLTAGE_SEGMENT_STEP      2
+       int *levels_uv;
+};
+
+/**
+ * struct scmi_voltage_ops - represents the various operations provided
+ * by SCMI Voltage Protocol
+ *
+ * @num_domains_get: get the count of voltage domains provided by SCMI
+ * @info_get: get the information of the specified domain
+ * @config_set: set the config for the specified domain
+ * @config_get: get the config of the specified domain
+ * @level_set: set the voltage level for the specified domain
+ * @level_get: get the voltage level of the specified domain
+ */
+struct scmi_voltage_ops {
+       int (*num_domains_get)(const struct scmi_handle *handle);
+       const struct scmi_voltage_info __must_check *(*info_get)
+               (const struct scmi_handle *handle, u32 domain_id);
+       int (*config_set)(const struct scmi_handle *handle, u32 domain_id,
+                         u32 config);
+#define        SCMI_VOLTAGE_ARCH_STATE_OFF             0x0
+#define        SCMI_VOLTAGE_ARCH_STATE_ON              0x7
+       int (*config_get)(const struct scmi_handle *handle, u32 domain_id,
+                         u32 *config);
+       int (*level_set)(const struct scmi_handle *handle, u32 domain_id,
+                        u32 flags, s32 volt_uV);
+       int (*level_get)(const struct scmi_handle *handle, u32 domain_id,
+                        s32 *volt_uV);
+};
+
 /**
  * struct scmi_notify_ops  - represents notifications' operations provided by
  * SCMI core
@@ -533,6 +591,7 @@ struct scmi_notify_ops {
  * @clk_ops: pointer to set of clock protocol operations
  * @sensor_ops: pointer to set of sensor protocol operations
  * @reset_ops: pointer to set of reset protocol operations
+ * @voltage_ops: pointer to set of voltage protocol operations
  * @notify_ops: pointer to set of notifications related operations
  * @perf_priv: pointer to private data structure specific to performance
  *     protocol(for internal use only)
@@ -544,6 +603,8 @@ struct scmi_notify_ops {
  *     protocol(for internal use only)
  * @reset_priv: pointer to private data structure specific to reset
  *     protocol(for internal use only)
+ * @voltage_priv: pointer to private data structure specific to voltage
+ *     protocol(for internal use only)
  * @notify_priv: pointer to private data structure specific to notifications
  *     (for internal use only)
  */
@@ -555,6 +616,7 @@ struct scmi_handle {
        const struct scmi_power_ops *power_ops;
        const struct scmi_sensor_ops *sensor_ops;
        const struct scmi_reset_ops *reset_ops;
+       const struct scmi_voltage_ops *voltage_ops;
        const struct scmi_notify_ops *notify_ops;
        /* for protocol internal use */
        void *perf_priv;
@@ -562,6 +624,7 @@ struct scmi_handle {
        void *power_priv;
        void *sensor_priv;
        void *reset_priv;
+       void *voltage_priv;
        void *notify_priv;
        void *system_priv;
 };
@@ -574,6 +637,7 @@ enum scmi_std_protocol {
        SCMI_PROTOCOL_CLOCK = 0x14,
        SCMI_PROTOCOL_SENSOR = 0x15,
        SCMI_PROTOCOL_RESET = 0x16,
+       SCMI_PROTOCOL_VOLTAGE = 0x17,
 };
 
 enum scmi_system_events {