diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/reset.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/reset.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c new file mode 100644 index 000000000000..64cc81915581 --- /dev/null +++ b/drivers/firmware/arm_scmi/reset.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Management Interface (SCMI) Reset Protocol + * + * Copyright (C) 2019 ARM Ltd. + */ + +#include "common.h" + +enum scmi_reset_protocol_cmd { + RESET_DOMAIN_ATTRIBUTES = 0x3, + RESET = 0x4, + RESET_NOTIFY = 0x5, +}; + +enum scmi_reset_protocol_notify { + RESET_ISSUED = 0x0, +}; + +#define NUM_RESET_DOMAIN_MASK 0xffff +#define RESET_NOTIFY_ENABLE BIT(0) + +struct scmi_msg_resp_reset_domain_attributes { + __le32 attributes; +#define SUPPORTS_ASYNC_RESET(x) ((x) & BIT(31)) +#define SUPPORTS_NOTIFY_RESET(x) ((x) & BIT(30)) + __le32 latency; + u8 name[SCMI_MAX_STR_SIZE]; +}; + +struct scmi_msg_reset_domain_reset { + __le32 domain_id; + __le32 flags; +#define AUTONOMOUS_RESET BIT(0) +#define EXPLICIT_RESET_ASSERT BIT(1) +#define ASYNCHRONOUS_RESET BIT(2) + __le32 reset_state; +#define ARCH_RESET_TYPE BIT(31) +#define COLD_RESET_STATE BIT(0) +#define ARCH_COLD_RESET (ARCH_RESET_TYPE | COLD_RESET_STATE) +}; + +struct reset_dom_info { + bool async_reset; + bool reset_notify; + u32 latency_us; + char name[SCMI_MAX_STR_SIZE]; +}; + +struct scmi_reset_info { + int num_domains; + struct reset_dom_info *dom_info; +}; + +static int scmi_reset_attributes_get(const struct scmi_handle *handle, + struct scmi_reset_info *pi) +{ + int ret; + struct scmi_xfer *t; + u32 attr; + + ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES, + SCMI_PROTOCOL_RESET, 0, sizeof(attr), &t); + if (ret) + return ret; + + ret = scmi_do_xfer(handle, t); + if (!ret) { + attr = get_unaligned_le32(t->rx.buf); + pi->num_domains = attr & NUM_RESET_DOMAIN_MASK; + } + + scmi_xfer_put(handle, t); + return ret; +} + +static int +scmi_reset_domain_attributes_get(const struct scmi_handle *handle, u32 domain, + struct reset_dom_info *dom_info) +{ + int ret; + struct scmi_xfer *t; + struct scmi_msg_resp_reset_domain_attributes *attr; + + ret = scmi_xfer_get_init(handle, RESET_DOMAIN_ATTRIBUTES, + SCMI_PROTOCOL_RESET, sizeof(domain), + sizeof(*attr), &t); + if (ret) + return ret; + + put_unaligned_le32(domain, t->tx.buf); + attr = t->rx.buf; + + ret = scmi_do_xfer(handle, t); + if (!ret) { + u32 attributes = le32_to_cpu(attr->attributes); + + dom_info->async_reset = SUPPORTS_ASYNC_RESET(attributes); + dom_info->reset_notify = SUPPORTS_NOTIFY_RESET(attributes); + dom_info->latency_us = le32_to_cpu(attr->latency); + if (dom_info->latency_us == U32_MAX) + dom_info->latency_us = 0; + strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE); + } + + scmi_xfer_put(handle, t); + return ret; +} + +static int scmi_reset_num_domains_get(const struct scmi_handle *handle) +{ + struct scmi_reset_info *pi = handle->reset_priv; + + return pi->num_domains; +} + +static char *scmi_reset_name_get(const struct scmi_handle *handle, u32 domain) +{ + struct scmi_reset_info *pi = handle->reset_priv; + struct reset_dom_info *dom = pi->dom_info + domain; + + return dom->name; +} + +static int scmi_reset_latency_get(const struct scmi_handle *handle, u32 domain) +{ + struct scmi_reset_info *pi = handle->reset_priv; + struct reset_dom_info *dom = pi->dom_info + domain; + + return dom->latency_us; +} + +static int scmi_domain_reset(const struct scmi_handle *handle, u32 domain, + u32 flags, u32 state) +{ + int ret; + struct scmi_xfer *t; + struct scmi_msg_reset_domain_reset *dom; + struct scmi_reset_info *pi = handle->reset_priv; + struct reset_dom_info *rdom = pi->dom_info + domain; + + if (rdom->async_reset) + flags |= ASYNCHRONOUS_RESET; + + ret = scmi_xfer_get_init(handle, RESET, SCMI_PROTOCOL_RESET, + sizeof(*dom), 0, &t); + if (ret) + return ret; + + dom = t->tx.buf; + dom->domain_id = cpu_to_le32(domain); + dom->flags = cpu_to_le32(flags); + dom->domain_id = cpu_to_le32(state); + + if (rdom->async_reset) + ret = scmi_do_xfer_with_response(handle, t); + else + ret = scmi_do_xfer(handle, t); + + scmi_xfer_put(handle, t); + return ret; +} + +static int scmi_reset_domain_reset(const struct scmi_handle *handle, u32 domain) +{ + return scmi_domain_reset(handle, domain, AUTONOMOUS_RESET, + ARCH_COLD_RESET); +} + +static int +scmi_reset_domain_assert(const struct scmi_handle *handle, u32 domain) +{ + return scmi_domain_reset(handle, domain, EXPLICIT_RESET_ASSERT, + ARCH_COLD_RESET); +} + +static int +scmi_reset_domain_deassert(const struct scmi_handle *handle, u32 domain) +{ + return scmi_domain_reset(handle, domain, 0, ARCH_COLD_RESET); +} + +static struct scmi_reset_ops reset_ops = { + .num_domains_get = scmi_reset_num_domains_get, + .name_get = scmi_reset_name_get, + .latency_get = scmi_reset_latency_get, + .reset = scmi_reset_domain_reset, + .assert = scmi_reset_domain_assert, + .deassert = scmi_reset_domain_deassert, +}; + +static int scmi_reset_protocol_init(struct scmi_handle *handle) +{ + int domain; + u32 version; + struct scmi_reset_info *pinfo; + + scmi_version_get(handle, SCMI_PROTOCOL_RESET, &version); + + dev_dbg(handle->dev, "Reset Version %d.%d\n", + PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version)); + + pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL); + if (!pinfo) + return -ENOMEM; + + scmi_reset_attributes_get(handle, pinfo); + + pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains, + sizeof(*pinfo->dom_info), GFP_KERNEL); + if (!pinfo->dom_info) + return -ENOMEM; + + for (domain = 0; domain < pinfo->num_domains; domain++) { + struct reset_dom_info *dom = pinfo->dom_info + domain; + + scmi_reset_domain_attributes_get(handle, domain, dom); + } + + handle->reset_ops = &reset_ops; + handle->reset_priv = pinfo; + + return 0; +} + +static int __init scmi_reset_init(void) +{ + return scmi_protocol_register(SCMI_PROTOCOL_RESET, + &scmi_reset_protocol_init); +} +subsys_initcall(scmi_reset_init); |