linux/drivers/firmware/arm_scmi/base.c
Sudeep Holla aa90ac45bc firmware: arm_scmi: Use {get,put}_unaligned_le{32,64} accessors
Instead of type-casting the {tx,rx}.buf all over the place while
accessing them to read/write __le{32,64} from/to the firmware, let's
use the existing {get,put}_unaligned_le{32,64} accessors to hide all
the type cast ugliness.

Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-08-12 12:23:01 +01:00

259 lines
6.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Base Protocol
*
* Copyright (C) 2018 ARM Ltd.
*/
#include "common.h"
enum scmi_base_protocol_cmd {
BASE_DISCOVER_VENDOR = 0x3,
BASE_DISCOVER_SUB_VENDOR = 0x4,
BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
BASE_DISCOVER_AGENT = 0x7,
BASE_NOTIFY_ERRORS = 0x8,
};
struct scmi_msg_resp_base_attributes {
u8 num_protocols;
u8 num_agents;
__le16 reserved;
};
/**
* scmi_base_attributes_get() - gets the implementation details
* that are associated with the base protocol.
*
* @handle: SCMI entity handle
*
* Return: 0 on success, else appropriate SCMI error.
*/
static int scmi_base_attributes_get(const struct scmi_handle *handle)
{
int ret;
struct scmi_xfer *t;
struct scmi_msg_resp_base_attributes *attr_info;
struct scmi_revision_info *rev = handle->version;
ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
SCMI_PROTOCOL_BASE, 0, sizeof(*attr_info), &t);
if (ret)
return ret;
ret = scmi_do_xfer(handle, t);
if (!ret) {
attr_info = t->rx.buf;
rev->num_protocols = attr_info->num_protocols;
rev->num_agents = attr_info->num_agents;
}
scmi_xfer_put(handle, t);
return ret;
}
/**
* scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
*
* @handle: SCMI entity handle
* @sub_vendor: specify true if sub-vendor ID is needed
*
* Return: 0 on success, else appropriate SCMI error.
*/
static int
scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
{
u8 cmd;
int ret, size;
char *vendor_id;
struct scmi_xfer *t;
struct scmi_revision_info *rev = handle->version;
if (sub_vendor) {
cmd = BASE_DISCOVER_SUB_VENDOR;
vendor_id = rev->sub_vendor_id;
size = ARRAY_SIZE(rev->sub_vendor_id);
} else {
cmd = BASE_DISCOVER_VENDOR;
vendor_id = rev->vendor_id;
size = ARRAY_SIZE(rev->vendor_id);
}
ret = scmi_xfer_get_init(handle, cmd, SCMI_PROTOCOL_BASE, 0, size, &t);
if (ret)
return ret;
ret = scmi_do_xfer(handle, t);
if (!ret)
memcpy(vendor_id, t->rx.buf, size);
scmi_xfer_put(handle, t);
return ret;
}
/**
* scmi_base_implementation_version_get() - gets a vendor-specific
* implementation 32-bit version. The format of the version number is
* vendor-specific
*
* @handle: SCMI entity handle
*
* Return: 0 on success, else appropriate SCMI error.
*/
static int
scmi_base_implementation_version_get(const struct scmi_handle *handle)
{
int ret;
__le32 *impl_ver;
struct scmi_xfer *t;
struct scmi_revision_info *rev = handle->version;
ret = scmi_xfer_get_init(handle, BASE_DISCOVER_IMPLEMENT_VERSION,
SCMI_PROTOCOL_BASE, 0, sizeof(*impl_ver), &t);
if (ret)
return ret;
ret = scmi_do_xfer(handle, t);
if (!ret) {
impl_ver = t->rx.buf;
rev->impl_ver = le32_to_cpu(*impl_ver);
}
scmi_xfer_put(handle, t);
return ret;
}
/**
* scmi_base_implementation_list_get() - gets the list of protocols it is
* OSPM is allowed to access
*
* @handle: SCMI entity handle
* @protocols_imp: pointer to hold the list of protocol identifiers
*
* Return: 0 on success, else appropriate SCMI error.
*/
static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
u8 *protocols_imp)
{
u8 *list;
int ret, loop;
struct scmi_xfer *t;
__le32 *num_skip, *num_ret;
u32 tot_num_ret = 0, loop_num_ret;
struct device *dev = handle->dev;
ret = scmi_xfer_get_init(handle, BASE_DISCOVER_LIST_PROTOCOLS,
SCMI_PROTOCOL_BASE, sizeof(*num_skip), 0, &t);
if (ret)
return ret;
num_skip = t->tx.buf;
num_ret = t->rx.buf;
list = t->rx.buf + sizeof(*num_ret);
do {
/* Set the number of protocols to be skipped/already read */
*num_skip = cpu_to_le32(tot_num_ret);
ret = scmi_do_xfer(handle, t);
if (ret)
break;
loop_num_ret = le32_to_cpu(*num_ret);
if (tot_num_ret + loop_num_ret > MAX_PROTOCOLS_IMP) {
dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
break;
}
for (loop = 0; loop < loop_num_ret; loop++)
protocols_imp[tot_num_ret + loop] = *(list + loop);
tot_num_ret += loop_num_ret;
} while (loop_num_ret);
scmi_xfer_put(handle, t);
return ret;
}
/**
* scmi_base_discover_agent_get() - discover the name of an agent
*
* @handle: SCMI entity handle
* @id: Agent identifier
* @name: Agent identifier ASCII string
*
* An agent id of 0 is reserved to identify the platform itself.
* Generally operating system is represented as "OSPM"
*
* Return: 0 on success, else appropriate SCMI error.
*/
static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
int id, char *name)
{
int ret;
struct scmi_xfer *t;
ret = scmi_xfer_get_init(handle, BASE_DISCOVER_AGENT,
SCMI_PROTOCOL_BASE, sizeof(__le32),
SCMI_MAX_STR_SIZE, &t);
if (ret)
return ret;
put_unaligned_le32(id, t->tx.buf);
ret = scmi_do_xfer(handle, t);
if (!ret)
strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
scmi_xfer_put(handle, t);
return ret;
}
int scmi_base_protocol_init(struct scmi_handle *h)
{
int id, ret;
u8 *prot_imp;
u32 version;
char name[SCMI_MAX_STR_SIZE];
const struct scmi_handle *handle = h;
struct device *dev = handle->dev;
struct scmi_revision_info *rev = handle->version;
ret = scmi_version_get(handle, SCMI_PROTOCOL_BASE, &version);
if (ret)
return ret;
prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
if (!prot_imp)
return -ENOMEM;
rev->major_ver = PROTOCOL_REV_MAJOR(version),
rev->minor_ver = PROTOCOL_REV_MINOR(version);
scmi_base_attributes_get(handle);
scmi_base_vendor_id_get(handle, false);
scmi_base_vendor_id_get(handle, true);
scmi_base_implementation_version_get(handle);
scmi_base_implementation_list_get(handle, prot_imp);
scmi_setup_protocol_implemented(handle, prot_imp);
dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
rev->major_ver, rev->minor_ver, rev->vendor_id,
rev->sub_vendor_id, rev->impl_ver);
dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
rev->num_agents);
for (id = 0; id < rev->num_agents; id++) {
scmi_base_discover_agent_get(handle, id, name);
dev_dbg(dev, "Agent %d: %s\n", id, name);
}
return 0;
}