linux/drivers/firmware/arm_scmi/power.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * System Control and Management Interface (SCMI) Power Protocol
   4 *
   5 * Copyright (C) 2018 ARM Ltd.
   6 */
   7
   8#include "common.h"
   9
  10enum scmi_power_protocol_cmd {
  11        POWER_DOMAIN_ATTRIBUTES = 0x3,
  12        POWER_STATE_SET = 0x4,
  13        POWER_STATE_GET = 0x5,
  14        POWER_STATE_NOTIFY = 0x6,
  15};
  16
  17struct scmi_msg_resp_power_attributes {
  18        __le16 num_domains;
  19        __le16 reserved;
  20        __le32 stats_addr_low;
  21        __le32 stats_addr_high;
  22        __le32 stats_size;
  23};
  24
  25struct scmi_msg_resp_power_domain_attributes {
  26        __le32 flags;
  27#define SUPPORTS_STATE_SET_NOTIFY(x)    ((x) & BIT(31))
  28#define SUPPORTS_STATE_SET_ASYNC(x)     ((x) & BIT(30))
  29#define SUPPORTS_STATE_SET_SYNC(x)      ((x) & BIT(29))
  30            u8 name[SCMI_MAX_STR_SIZE];
  31};
  32
  33struct scmi_power_set_state {
  34        __le32 flags;
  35#define STATE_SET_ASYNC         BIT(0)
  36        __le32 domain;
  37        __le32 state;
  38};
  39
  40struct scmi_power_state_notify {
  41        __le32 domain;
  42        __le32 notify_enable;
  43};
  44
  45struct power_dom_info {
  46        bool state_set_sync;
  47        bool state_set_async;
  48        bool state_set_notify;
  49        char name[SCMI_MAX_STR_SIZE];
  50};
  51
  52struct scmi_power_info {
  53        int num_domains;
  54        u64 stats_addr;
  55        u32 stats_size;
  56        struct power_dom_info *dom_info;
  57};
  58
  59static int scmi_power_attributes_get(const struct scmi_handle *handle,
  60                                     struct scmi_power_info *pi)
  61{
  62        int ret;
  63        struct scmi_xfer *t;
  64        struct scmi_msg_resp_power_attributes *attr;
  65
  66        ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
  67                                 SCMI_PROTOCOL_POWER, 0, sizeof(*attr), &t);
  68        if (ret)
  69                return ret;
  70
  71        attr = t->rx.buf;
  72
  73        ret = scmi_do_xfer(handle, t);
  74        if (!ret) {
  75                pi->num_domains = le16_to_cpu(attr->num_domains);
  76                pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
  77                                (u64)le32_to_cpu(attr->stats_addr_high) << 32;
  78                pi->stats_size = le32_to_cpu(attr->stats_size);
  79        }
  80
  81        scmi_xfer_put(handle, t);
  82        return ret;
  83}
  84
  85static int
  86scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
  87                                 struct power_dom_info *dom_info)
  88{
  89        int ret;
  90        struct scmi_xfer *t;
  91        struct scmi_msg_resp_power_domain_attributes *attr;
  92
  93        ret = scmi_xfer_get_init(handle, POWER_DOMAIN_ATTRIBUTES,
  94                                 SCMI_PROTOCOL_POWER, sizeof(domain),
  95                                 sizeof(*attr), &t);
  96        if (ret)
  97                return ret;
  98
  99        *(__le32 *)t->tx.buf = cpu_to_le32(domain);
 100        attr = t->rx.buf;
 101
 102        ret = scmi_do_xfer(handle, t);
 103        if (!ret) {
 104                u32 flags = le32_to_cpu(attr->flags);
 105
 106                dom_info->state_set_notify = SUPPORTS_STATE_SET_NOTIFY(flags);
 107                dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
 108                dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
 109                strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 110        }
 111
 112        scmi_xfer_put(handle, t);
 113        return ret;
 114}
 115
 116static int
 117scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
 118{
 119        int ret;
 120        struct scmi_xfer *t;
 121        struct scmi_power_set_state *st;
 122
 123        ret = scmi_xfer_get_init(handle, POWER_STATE_SET, SCMI_PROTOCOL_POWER,
 124                                 sizeof(*st), 0, &t);
 125        if (ret)
 126                return ret;
 127
 128        st = t->tx.buf;
 129        st->flags = cpu_to_le32(0);
 130        st->domain = cpu_to_le32(domain);
 131        st->state = cpu_to_le32(state);
 132
 133        ret = scmi_do_xfer(handle, t);
 134
 135        scmi_xfer_put(handle, t);
 136        return ret;
 137}
 138
 139static int
 140scmi_power_state_get(const struct scmi_handle *handle, u32 domain, u32 *state)
 141{
 142        int ret;
 143        struct scmi_xfer *t;
 144
 145        ret = scmi_xfer_get_init(handle, POWER_STATE_GET, SCMI_PROTOCOL_POWER,
 146                                 sizeof(u32), sizeof(u32), &t);
 147        if (ret)
 148                return ret;
 149
 150        *(__le32 *)t->tx.buf = cpu_to_le32(domain);
 151
 152        ret = scmi_do_xfer(handle, t);
 153        if (!ret)
 154                *state = le32_to_cpu(*(__le32 *)t->rx.buf);
 155
 156        scmi_xfer_put(handle, t);
 157        return ret;
 158}
 159
 160static int scmi_power_num_domains_get(const struct scmi_handle *handle)
 161{
 162        struct scmi_power_info *pi = handle->power_priv;
 163
 164        return pi->num_domains;
 165}
 166
 167static char *scmi_power_name_get(const struct scmi_handle *handle, u32 domain)
 168{
 169        struct scmi_power_info *pi = handle->power_priv;
 170        struct power_dom_info *dom = pi->dom_info + domain;
 171
 172        return dom->name;
 173}
 174
 175static struct scmi_power_ops power_ops = {
 176        .num_domains_get = scmi_power_num_domains_get,
 177        .name_get = scmi_power_name_get,
 178        .state_set = scmi_power_state_set,
 179        .state_get = scmi_power_state_get,
 180};
 181
 182static int scmi_power_protocol_init(struct scmi_handle *handle)
 183{
 184        int domain;
 185        u32 version;
 186        struct scmi_power_info *pinfo;
 187
 188        scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
 189
 190        dev_dbg(handle->dev, "Power Version %d.%d\n",
 191                PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 192
 193        pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
 194        if (!pinfo)
 195                return -ENOMEM;
 196
 197        scmi_power_attributes_get(handle, pinfo);
 198
 199        pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
 200                                       sizeof(*pinfo->dom_info), GFP_KERNEL);
 201        if (!pinfo->dom_info)
 202                return -ENOMEM;
 203
 204        for (domain = 0; domain < pinfo->num_domains; domain++) {
 205                struct power_dom_info *dom = pinfo->dom_info + domain;
 206
 207                scmi_power_domain_attributes_get(handle, domain, dom);
 208        }
 209
 210        handle->power_ops = &power_ops;
 211        handle->power_priv = pinfo;
 212
 213        return 0;
 214}
 215
 216static int __init scmi_power_init(void)
 217{
 218        return scmi_protocol_register(SCMI_PROTOCOL_POWER,
 219                                      &scmi_power_protocol_init);
 220}
 221subsys_initcall(scmi_power_init);
 222