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path: root/drivers/firmware/arm_scmi/reset.c
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Diffstat (limited to 'drivers/firmware/arm_scmi/reset.c')
-rw-r--r--drivers/firmware/arm_scmi/reset.c231
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);