linux/drivers/firmware/arm_scmi/driver.c
Sudeep Holla bad0d73b65 firmware: arm_scmi: Use signed integer to report transfer status
Currently the trace event 'scmi_xfer_end' reports the status of the
transfer using the unsigned status field read from the firmware which
may not be easy to interpret. It may also miss to emit any timeouts
that happen in the driver resulting in emitting garbage in the status
field in those scenarios.

Let us use signed integer so that error values are emitted out after
they are mapped from firmware error formats to standard linux error
codes. While at this, also include any timeouts in the driver itself.

Link: https://lore.kernel.org/r/20200609134503.55860-1-sudeep.holla@arm.com
Cc: Jim Quinlan <james.quinlan@broadcom.com>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-06-30 14:07:08 +01:00

927 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Message Protocol driver
*
* SCMI Message Protocol is used between the System Control Processor(SCP)
* and the Application Processors(AP). The Message Handling Unit(MHU)
* provides a mechanism for inter-processor communication between SCP's
* Cortex M3 and AP.
*
* SCP offers control and management of the core/cluster power states,
* various power domain DVFS including the core/cluster, certain system
* clocks configuration, thermal sensors and many others.
*
* Copyright (C) 2018 ARM Ltd.
*/
#include <linux/bitmap.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/processor.h>
#include <linux/slab.h>
#include "common.h"
#define CREATE_TRACE_POINTS
#include <trace/events/scmi.h>
enum scmi_error_codes {
SCMI_SUCCESS = 0, /* Success */
SCMI_ERR_SUPPORT = -1, /* Not supported */
SCMI_ERR_PARAMS = -2, /* Invalid Parameters */
SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */
SCMI_ERR_ENTRY = -4, /* Not found */
SCMI_ERR_RANGE = -5, /* Value out of range */
SCMI_ERR_BUSY = -6, /* Device busy */
SCMI_ERR_COMMS = -7, /* Communication Error */
SCMI_ERR_GENERIC = -8, /* Generic Error */
SCMI_ERR_HARDWARE = -9, /* Hardware Error */
SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
SCMI_ERR_MAX
};
/* List of all SCMI devices active in system */
static LIST_HEAD(scmi_list);
/* Protection for the entire list */
static DEFINE_MUTEX(scmi_list_mutex);
/* Track the unique id for the transfers for debug & profiling purpose */
static atomic_t transfer_last_id;
/**
* struct scmi_xfers_info - Structure to manage transfer information
*
* @xfer_block: Preallocated Message array
* @xfer_alloc_table: Bitmap table for allocated messages.
* Index of this bitmap table is also used for message
* sequence identifier.
* @xfer_lock: Protection for message allocation
*/
struct scmi_xfers_info {
struct scmi_xfer *xfer_block;
unsigned long *xfer_alloc_table;
spinlock_t xfer_lock;
};
/**
* struct scmi_info - Structure representing a SCMI instance
*
* @dev: Device pointer
* @desc: SoC description for this instance
* @version: SCMI revision information containing protocol version,
* implementation version and (sub-)vendor identification.
* @handle: Instance of SCMI handle to send to clients
* @tx_minfo: Universal Transmit Message management info
* @rx_minfo: Universal Receive Message management info
* @tx_idr: IDR object to map protocol id to Tx channel info pointer
* @rx_idr: IDR object to map protocol id to Rx channel info pointer
* @protocols_imp: List of protocols implemented, currently maximum of
* MAX_PROTOCOLS_IMP elements allocated by the base protocol
* @node: List head
* @users: Number of users of this instance
*/
struct scmi_info {
struct device *dev;
const struct scmi_desc *desc;
struct scmi_revision_info version;
struct scmi_handle handle;
struct scmi_xfers_info tx_minfo;
struct scmi_xfers_info rx_minfo;
struct idr tx_idr;
struct idr rx_idr;
u8 *protocols_imp;
struct list_head node;
int users;
};
#define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle)
static const int scmi_linux_errmap[] = {
/* better than switch case as long as return value is continuous */
0, /* SCMI_SUCCESS */
-EOPNOTSUPP, /* SCMI_ERR_SUPPORT */
-EINVAL, /* SCMI_ERR_PARAM */
-EACCES, /* SCMI_ERR_ACCESS */
-ENOENT, /* SCMI_ERR_ENTRY */
-ERANGE, /* SCMI_ERR_RANGE */
-EBUSY, /* SCMI_ERR_BUSY */
-ECOMM, /* SCMI_ERR_COMMS */
-EIO, /* SCMI_ERR_GENERIC */
-EREMOTEIO, /* SCMI_ERR_HARDWARE */
-EPROTO, /* SCMI_ERR_PROTOCOL */
};
static inline int scmi_to_linux_errno(int errno)
{
if (errno < SCMI_SUCCESS && errno > SCMI_ERR_MAX)
return scmi_linux_errmap[-errno];
return -EIO;
}
/**
* scmi_dump_header_dbg() - Helper to dump a message header.
*
* @dev: Device pointer corresponding to the SCMI entity
* @hdr: pointer to header.
*/
static inline void scmi_dump_header_dbg(struct device *dev,
struct scmi_msg_hdr *hdr)
{
dev_dbg(dev, "Message ID: %x Sequence ID: %x Protocol: %x\n",
hdr->id, hdr->seq, hdr->protocol_id);
}
/**
* scmi_xfer_get() - Allocate one message
*
* @handle: Pointer to SCMI entity handle
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Helper function which is used by various message functions that are
* exposed to clients of this driver for allocating a message traffic event.
*
* This function can sleep depending on pending requests already in the system
* for the SCMI entity. Further, this also holds a spinlock to maintain
* integrity of internal data structures.
*
* Return: 0 if all went fine, else corresponding error.
*/
static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
struct scmi_xfers_info *minfo)
{
u16 xfer_id;
struct scmi_xfer *xfer;
unsigned long flags, bit_pos;
struct scmi_info *info = handle_to_scmi_info(handle);
/* Keep the locked section as small as possible */
spin_lock_irqsave(&minfo->xfer_lock, flags);
bit_pos = find_first_zero_bit(minfo->xfer_alloc_table,
info->desc->max_msg);
if (bit_pos == info->desc->max_msg) {
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return ERR_PTR(-ENOMEM);
}
set_bit(bit_pos, minfo->xfer_alloc_table);
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
xfer_id = bit_pos;
xfer = &minfo->xfer_block[xfer_id];
xfer->hdr.seq = xfer_id;
reinit_completion(&xfer->done);
xfer->transfer_id = atomic_inc_return(&transfer_last_id);
return xfer;
}
/**
* __scmi_xfer_put() - Release a message
*
* @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer: message that was reserved by scmi_xfer_get
*
* This holds a spinlock to maintain integrity of internal data structures.
*/
static void
__scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
{
unsigned long flags;
/*
* Keep the locked section as small as possible
* NOTE: we might escape with smp_mb and no lock here..
* but just be conservative and symmetric.
*/
spin_lock_irqsave(&minfo->xfer_lock, flags);
clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
}
static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
{
struct scmi_xfer *xfer;
struct device *dev = cinfo->dev;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct scmi_xfers_info *minfo = &info->rx_minfo;
xfer = scmi_xfer_get(cinfo->handle, minfo);
if (IS_ERR(xfer)) {
dev_err(dev, "failed to get free message slot (%ld)\n",
PTR_ERR(xfer));
info->desc->ops->clear_channel(cinfo);
return;
}
unpack_scmi_header(msg_hdr, &xfer->hdr);
scmi_dump_header_dbg(dev, &xfer->hdr);
info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size,
xfer);
trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq,
MSG_TYPE_NOTIFICATION);
__scmi_xfer_put(minfo, xfer);
info->desc->ops->clear_channel(cinfo);
}
static void scmi_handle_response(struct scmi_chan_info *cinfo,
u16 xfer_id, u8 msg_type)
{
struct scmi_xfer *xfer;
struct device *dev = cinfo->dev;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct scmi_xfers_info *minfo = &info->tx_minfo;
/* Are we even expecting this? */
if (!test_bit(xfer_id, minfo->xfer_alloc_table)) {
dev_err(dev, "message for %d is not expected!\n", xfer_id);
info->desc->ops->clear_channel(cinfo);
return;
}
xfer = &minfo->xfer_block[xfer_id];
/*
* Even if a response was indeed expected on this slot at this point,
* a buggy platform could wrongly reply feeding us an unexpected
* delayed response we're not prepared to handle: bail-out safely
* blaming firmware.
*/
if (unlikely(msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done)) {
dev_err(dev,
"Delayed Response for %d not expected! Buggy F/W ?\n",
xfer_id);
info->desc->ops->clear_channel(cinfo);
/* It was unexpected, so nobody will clear the xfer if not us */
__scmi_xfer_put(minfo, xfer);
return;
}
scmi_dump_header_dbg(dev, &xfer->hdr);
info->desc->ops->fetch_response(cinfo, xfer);
trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq,
msg_type);
if (msg_type == MSG_TYPE_DELAYED_RESP) {
info->desc->ops->clear_channel(cinfo);
complete(xfer->async_done);
} else {
complete(&xfer->done);
}
}
/**
* scmi_rx_callback() - callback for receiving messages
*
* @cinfo: SCMI channel info
* @msg_hdr: Message header
*
* Processes one received message to appropriate transfer information and
* signals completion of the transfer.
*
* NOTE: This function will be invoked in IRQ context, hence should be
* as optimal as possible.
*/
void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr)
{
u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr);
u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
switch (msg_type) {
case MSG_TYPE_NOTIFICATION:
scmi_handle_notification(cinfo, msg_hdr);
break;
case MSG_TYPE_COMMAND:
case MSG_TYPE_DELAYED_RESP:
scmi_handle_response(cinfo, xfer_id, msg_type);
break;
default:
WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type);
break;
}
}
/**
* scmi_xfer_put() - Release a transmit message
*
* @handle: Pointer to SCMI entity handle
* @xfer: message that was reserved by scmi_xfer_get
*/
void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(handle);
__scmi_xfer_put(&info->tx_minfo, xfer);
}
#define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC)
static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer, ktime_t stop)
{
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
return info->desc->ops->poll_done(cinfo, xfer) ||
ktime_after(ktime_get(), stop);
}
/**
* scmi_do_xfer() - Do one transfer
*
* @handle: Pointer to SCMI entity handle
* @xfer: Transfer to initiate and wait for response
*
* Return: -ETIMEDOUT in case of no response, if transmit error,
* return corresponding error, else if all goes well,
* return 0.
*/
int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
{
int ret;
int timeout;
struct scmi_info *info = handle_to_scmi_info(handle);
struct device *dev = info->dev;
struct scmi_chan_info *cinfo;
cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id);
if (unlikely(!cinfo))
return -EINVAL;
trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq,
xfer->hdr.poll_completion);
ret = info->desc->ops->send_message(cinfo, xfer);
if (ret < 0) {
dev_dbg(dev, "Failed to send message %d\n", ret);
return ret;
}
if (xfer->hdr.poll_completion) {
ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS);
spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
if (ktime_before(ktime_get(), stop))
info->desc->ops->fetch_response(cinfo, xfer);
else
ret = -ETIMEDOUT;
} else {
/* And we wait for the response. */
timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
if (!wait_for_completion_timeout(&xfer->done, timeout)) {
dev_err(dev, "timed out in resp(caller: %pS)\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
}
}
if (!ret && xfer->hdr.status)
ret = scmi_to_linux_errno(xfer->hdr.status);
if (info->desc->ops->mark_txdone)
info->desc->ops->mark_txdone(cinfo, ret);
trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq, ret);
return ret;
}
#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC)
/**
* scmi_do_xfer_with_response() - Do one transfer and wait until the delayed
* response is received
*
* @handle: Pointer to SCMI entity handle
* @xfer: Transfer to initiate and wait for response
*
* Return: -ETIMEDOUT in case of no delayed response, if transmit error,
* return corresponding error, else if all goes well, return 0.
*/
int scmi_do_xfer_with_response(const struct scmi_handle *handle,
struct scmi_xfer *xfer)
{
int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
DECLARE_COMPLETION_ONSTACK(async_response);
xfer->async_done = &async_response;
ret = scmi_do_xfer(handle, xfer);
if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout))
ret = -ETIMEDOUT;
xfer->async_done = NULL;
return ret;
}
/**
* scmi_xfer_get_init() - Allocate and initialise one message for transmit
*
* @handle: Pointer to SCMI entity handle
* @msg_id: Message identifier
* @prot_id: Protocol identifier for the message
* @tx_size: transmit message size
* @rx_size: receive message size
* @p: pointer to the allocated and initialised message
*
* This function allocates the message using @scmi_xfer_get and
* initialise the header.
*
* Return: 0 if all went fine with @p pointing to message, else
* corresponding error.
*/
int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
size_t tx_size, size_t rx_size, struct scmi_xfer **p)
{
int ret;
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(handle);
struct scmi_xfers_info *minfo = &info->tx_minfo;
struct device *dev = info->dev;
/* Ensure we have sane transfer sizes */
if (rx_size > info->desc->max_msg_size ||
tx_size > info->desc->max_msg_size)
return -ERANGE;
xfer = scmi_xfer_get(handle, minfo);
if (IS_ERR(xfer)) {
ret = PTR_ERR(xfer);
dev_err(dev, "failed to get free message slot(%d)\n", ret);
return ret;
}
xfer->tx.len = tx_size;
xfer->rx.len = rx_size ? : info->desc->max_msg_size;
xfer->hdr.id = msg_id;
xfer->hdr.protocol_id = prot_id;
xfer->hdr.poll_completion = false;
*p = xfer;
return 0;
}
/**
* scmi_version_get() - command to get the revision of the SCMI entity
*
* @handle: Pointer to SCMI entity handle
* @protocol: Protocol identifier for the message
* @version: Holds returned version of protocol.
*
* Updates the SCMI information in the internal data structure.
*
* Return: 0 if all went fine, else return appropriate error.
*/
int scmi_version_get(const struct scmi_handle *handle, u8 protocol,
u32 *version)
{
int ret;
__le32 *rev_info;
struct scmi_xfer *t;
ret = scmi_xfer_get_init(handle, PROTOCOL_VERSION, protocol, 0,
sizeof(*version), &t);
if (ret)
return ret;
ret = scmi_do_xfer(handle, t);
if (!ret) {
rev_info = t->rx.buf;
*version = le32_to_cpu(*rev_info);
}
scmi_xfer_put(handle, t);
return ret;
}
void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
u8 *prot_imp)
{
struct scmi_info *info = handle_to_scmi_info(handle);
info->protocols_imp = prot_imp;
}
static bool
scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id)
{
int i;
struct scmi_info *info = handle_to_scmi_info(handle);
if (!info->protocols_imp)
return false;
for (i = 0; i < MAX_PROTOCOLS_IMP; i++)
if (info->protocols_imp[i] == prot_id)
return true;
return false;
}
/**
* scmi_handle_get() - Get the SCMI handle for a device
*
* @dev: pointer to device for which we want SCMI handle
*
* NOTE: The function does not track individual clients of the framework
* and is expected to be maintained by caller of SCMI protocol library.
* scmi_handle_put must be balanced with successful scmi_handle_get
*
* Return: pointer to handle if successful, NULL on error
*/
struct scmi_handle *scmi_handle_get(struct device *dev)
{
struct list_head *p;
struct scmi_info *info;
struct scmi_handle *handle = NULL;
mutex_lock(&scmi_list_mutex);
list_for_each(p, &scmi_list) {
info = list_entry(p, struct scmi_info, node);
if (dev->parent == info->dev) {
handle = &info->handle;
info->users++;
break;
}
}
mutex_unlock(&scmi_list_mutex);
return handle;
}
/**
* scmi_handle_put() - Release the handle acquired by scmi_handle_get
*
* @handle: handle acquired by scmi_handle_get
*
* NOTE: The function does not track individual clients of the framework
* and is expected to be maintained by caller of SCMI protocol library.
* scmi_handle_put must be balanced with successful scmi_handle_get
*
* Return: 0 is successfully released
* if null was passed, it returns -EINVAL;
*/
int scmi_handle_put(const struct scmi_handle *handle)
{
struct scmi_info *info;
if (!handle)
return -EINVAL;
info = handle_to_scmi_info(handle);
mutex_lock(&scmi_list_mutex);
if (!WARN_ON(!info->users))
info->users--;
mutex_unlock(&scmi_list_mutex);
return 0;
}
static int __scmi_xfer_info_init(struct scmi_info *sinfo,
struct scmi_xfers_info *info)
{
int i;
struct scmi_xfer *xfer;
struct device *dev = sinfo->dev;
const struct scmi_desc *desc = sinfo->desc;
/* Pre-allocated messages, no more than what hdr.seq can support */
if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) {
dev_err(dev, "Maximum message of %d exceeds supported %ld\n",
desc->max_msg, MSG_TOKEN_MAX);
return -EINVAL;
}
info->xfer_block = devm_kcalloc(dev, desc->max_msg,
sizeof(*info->xfer_block), GFP_KERNEL);
if (!info->xfer_block)
return -ENOMEM;
info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(desc->max_msg),
sizeof(long), GFP_KERNEL);
if (!info->xfer_alloc_table)
return -ENOMEM;
/* Pre-initialize the buffer pointer to pre-allocated buffers */
for (i = 0, xfer = info->xfer_block; i < desc->max_msg; i++, xfer++) {
xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size,
GFP_KERNEL);
if (!xfer->rx.buf)
return -ENOMEM;
xfer->tx.buf = xfer->rx.buf;
init_completion(&xfer->done);
}
spin_lock_init(&info->xfer_lock);
return 0;
}
static int scmi_xfer_info_init(struct scmi_info *sinfo)
{
int ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo);
if (!ret && idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE))
ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo);
return ret;
}
static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
int prot_id, bool tx)
{
int ret, idx;
struct scmi_chan_info *cinfo;
struct idr *idr;
/* Transmit channel is first entry i.e. index 0 */
idx = tx ? 0 : 1;
idr = tx ? &info->tx_idr : &info->rx_idr;
/* check if already allocated, used for multiple device per protocol */
cinfo = idr_find(idr, prot_id);
if (cinfo)
return 0;
if (!info->desc->ops->chan_available(dev, idx)) {
cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
return -EINVAL;
goto idr_alloc;
}
cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
cinfo->dev = dev;
ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
if (ret)
return ret;
idr_alloc:
ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
if (ret != prot_id) {
dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret);
return ret;
}
cinfo->handle = &info->handle;
return 0;
}
static inline int
scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
{
int ret = scmi_chan_setup(info, dev, prot_id, true);
if (!ret) /* Rx is optional, hence no error check */
scmi_chan_setup(info, dev, prot_id, false);
return ret;
}
static inline void
scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
int prot_id, const char *name)
{
struct scmi_device *sdev;
sdev = scmi_device_create(np, info->dev, prot_id, name);
if (!sdev) {
dev_err(info->dev, "failed to create %d protocol device\n",
prot_id);
return;
}
if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
dev_err(&sdev->dev, "failed to setup transport\n");
scmi_device_destroy(sdev);
return;
}
/* setup handle now as the transport is ready */
scmi_set_handle(sdev);
}
#define MAX_SCMI_DEV_PER_PROTOCOL 2
struct scmi_prot_devnames {
int protocol_id;
char *names[MAX_SCMI_DEV_PER_PROTOCOL];
};
static struct scmi_prot_devnames devnames[] = {
{ SCMI_PROTOCOL_POWER, { "genpd" },},
{ SCMI_PROTOCOL_PERF, { "cpufreq" },},
{ SCMI_PROTOCOL_CLOCK, { "clocks" },},
{ SCMI_PROTOCOL_SENSOR, { "hwmon" },},
{ SCMI_PROTOCOL_RESET, { "reset" },},
};
static inline void
scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info,
int prot_id)
{
int loop, cnt;
for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) {
if (devnames[loop].protocol_id != prot_id)
continue;
for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) {
const char *name = devnames[loop].names[cnt];
if (name)
scmi_create_protocol_device(np, info, prot_id,
name);
}
}
}
static int scmi_probe(struct platform_device *pdev)
{
int ret;
struct scmi_handle *handle;
const struct scmi_desc *desc;
struct scmi_info *info;
struct device *dev = &pdev->dev;
struct device_node *child, *np = dev->of_node;
desc = of_device_get_match_data(dev);
if (!desc)
return -EINVAL;
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->dev = dev;
info->desc = desc;
INIT_LIST_HEAD(&info->node);
platform_set_drvdata(pdev, info);
idr_init(&info->tx_idr);
idr_init(&info->rx_idr);
handle = &info->handle;
handle->dev = info->dev;
handle->version = &info->version;
ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
if (ret)
return ret;
ret = scmi_xfer_info_init(info);
if (ret)
return ret;
ret = scmi_base_protocol_init(handle);
if (ret) {
dev_err(dev, "unable to communicate with SCMI(%d)\n", ret);
return ret;
}
mutex_lock(&scmi_list_mutex);
list_add_tail(&info->node, &scmi_list);
mutex_unlock(&scmi_list_mutex);
for_each_available_child_of_node(np, child) {
u32 prot_id;
if (of_property_read_u32(child, "reg", &prot_id))
continue;
if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id))
dev_err(dev, "Out of range protocol %d\n", prot_id);
if (!scmi_is_protocol_implemented(handle, prot_id)) {
dev_err(dev, "SCMI protocol %d not implemented\n",
prot_id);
continue;
}
scmi_create_protocol_devices(child, info, prot_id);
}
return 0;
}
void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
{
idr_remove(idr, id);
}
static int scmi_remove(struct platform_device *pdev)
{
int ret = 0;
struct scmi_info *info = platform_get_drvdata(pdev);
struct idr *idr = &info->tx_idr;
mutex_lock(&scmi_list_mutex);
if (info->users)
ret = -EBUSY;
else
list_del(&info->node);
mutex_unlock(&scmi_list_mutex);
if (ret)
return ret;
/* Safe to free channels since no more users */
ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
idr_destroy(&info->tx_idr);
idr = &info->rx_idr;
ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
idr_destroy(&info->rx_idr);
return ret;
}
static ssize_t protocol_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%u.%u\n", info->version.major_ver,
info->version.minor_ver);
}
static DEVICE_ATTR_RO(protocol_version);
static ssize_t firmware_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "0x%x\n", info->version.impl_ver);
}
static DEVICE_ATTR_RO(firmware_version);
static ssize_t vendor_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%s\n", info->version.vendor_id);
}
static DEVICE_ATTR_RO(vendor_id);
static ssize_t sub_vendor_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%s\n", info->version.sub_vendor_id);
}
static DEVICE_ATTR_RO(sub_vendor_id);
static struct attribute *versions_attrs[] = {
&dev_attr_firmware_version.attr,
&dev_attr_protocol_version.attr,
&dev_attr_vendor_id.attr,
&dev_attr_sub_vendor_id.attr,
NULL,
};
ATTRIBUTE_GROUPS(versions);
/* Each compatible listed below must have descriptor associated with it */
static const struct of_device_id scmi_of_match[] = {
{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
#ifdef CONFIG_ARM_PSCI_FW
{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
#endif
{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, scmi_of_match);
static struct platform_driver scmi_driver = {
.driver = {
.name = "arm-scmi",
.of_match_table = scmi_of_match,
.dev_groups = versions_groups,
},
.probe = scmi_probe,
.remove = scmi_remove,
};
module_platform_driver(scmi_driver);
MODULE_ALIAS("platform: arm-scmi");
MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCMI protocol driver");
MODULE_LICENSE("GPL v2");