diff options
author | Cristian Marussi <cristian.marussi@arm.com> | 2020-11-19 19:10:47 +0000 |
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committer | Sudeep Holla <sudeep.holla@arm.com> | 2020-11-20 14:55:48 +0000 |
commit | 2add5cacff3531e54c50b0832128299faa9f0563 (patch) | |
tree | fe2228fd2fcafb65452256b27e487503a9478ead /drivers/firmware/arm_scmi/voltage.c | |
parent | 0f80fcec08e9c50b8d2992cf26495673765ebaba (diff) | |
download | linux-2add5cacff3531e54c50b0832128299faa9f0563.tar.bz2 |
firmware: arm_scmi: Add voltage domain management protocol support
SCMI v3.0 introduces voltage domain protocol which provides commands to:
- Discover the voltage levels supported by a domain
- Get the configuration and voltage level of a domain
- Set the configuration and voltage level of a domain
Let us add support for the same.
Link: https://lore.kernel.org/r/20201119191051.46363-2-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware/arm_scmi/voltage.c')
-rw-r--r-- | drivers/firmware/arm_scmi/voltage.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c new file mode 100644 index 000000000000..e794e4349ae6 --- /dev/null +++ b/drivers/firmware/arm_scmi/voltage.c @@ -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) |