linux_dsm_epyc7002/drivers/firmware/arm_scmi/driver.c
Sudeep Holla 907b6d1491 firmware: arm_scmi: add per-protocol channels support using idr objects
In order to maintain the channel information per protocol, we need
some sort of list or hashtable to hold all this information. IDR
provides sparse array mapping of small integer ID numbers onto arbitrary
pointers. In this case the arbitrary pointers can be pointers to the
channel information.

This patch adds support for per-protocol channels using those idr
objects.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2018-02-28 16:37:57 +00:00

872 lines
23 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/mailbox_client.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/processor.h>
#include <linux/semaphore.h>
#include <linux/slab.h>
#include "common.h"
#define MSG_ID_SHIFT 0
#define MSG_ID_MASK 0xff
#define MSG_TYPE_SHIFT 8
#define MSG_TYPE_MASK 0x3
#define MSG_PROTOCOL_ID_SHIFT 10
#define MSG_PROTOCOL_ID_MASK 0xff
#define MSG_TOKEN_ID_SHIFT 18
#define MSG_TOKEN_ID_MASK 0x3ff
#define MSG_XTRACT_TOKEN(header) \
(((header) >> MSG_TOKEN_ID_SHIFT) & MSG_TOKEN_ID_MASK)
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);
/**
* 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;
/* protect transfer allocation */
spinlock_t xfer_lock;
};
/**
* struct scmi_desc - Description of SoC integration
*
* @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
* @max_msg: Maximum number of messages that can be pending
* simultaneously in the system
* @max_msg_size: Maximum size of data per message that can be handled.
*/
struct scmi_desc {
int max_rx_timeout_ms;
int max_msg;
int max_msg_size;
};
/**
* struct scmi_chan_info - Structure representing a SCMI channel informfation
*
* @cl: Mailbox Client
* @chan: Transmit/Receive mailbox channel
* @payload: Transmit/Receive mailbox channel payload area
* @dev: Reference to device in the SCMI hierarchy corresponding to this
* channel
*/
struct scmi_chan_info {
struct mbox_client cl;
struct mbox_chan *chan;
void __iomem *payload;
struct device *dev;
struct scmi_handle *handle;
};
/**
* struct scmi_info - Structure representing a SCMI instance
*
* @dev: Device pointer
* @desc: SoC description for this instance
* @handle: Instance of SCMI handle to send to clients
* @version: SCMI revision information containing protocol version,
* implementation version and (sub-)vendor identification.
* @minfo: Message info
* @tx_idr: IDR object to map protocol id to 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 minfo;
struct idr tx_idr;
u8 *protocols_imp;
struct list_head node;
int users;
};
#define client_to_scmi_chan_info(c) container_of(c, struct scmi_chan_info, cl)
#define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle)
/*
* SCMI specification requires all parameters, message headers, return
* arguments or any protocol data to be expressed in little endian
* format only.
*/
struct scmi_shared_mem {
__le32 reserved;
__le32 channel_status;
#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1)
#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0)
__le32 reserved1[2];
__le32 flags;
#define SCMI_SHMEM_FLAG_INTR_ENABLED BIT(0)
__le32 length;
__le32 msg_header;
u8 msg_payload[0];
};
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, "Command ID: %x Sequence ID: %x Protocol: %x\n",
hdr->id, hdr->seq, hdr->protocol_id);
}
static void scmi_fetch_response(struct scmi_xfer *xfer,
struct scmi_shared_mem __iomem *mem)
{
xfer->hdr.status = ioread32(mem->msg_payload);
/* Skip the length of header and statues in payload area i.e 8 bytes*/
xfer->rx.len = min_t(size_t, xfer->rx.len, ioread32(&mem->length) - 8);
/* Take a copy to the rx buffer.. */
memcpy_fromio(xfer->rx.buf, mem->msg_payload + 4, xfer->rx.len);
}
/**
* scmi_rx_callback() - mailbox client callback for receive messages
*
* @cl: client pointer
* @m: mailbox message
*
* 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.
*/
static void scmi_rx_callback(struct mbox_client *cl, void *m)
{
u16 xfer_id;
struct scmi_xfer *xfer;
struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
struct device *dev = cinfo->dev;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct scmi_xfers_info *minfo = &info->minfo;
struct scmi_shared_mem __iomem *mem = cinfo->payload;
xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
/*
* 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);
return;
}
xfer = &minfo->xfer_block[xfer_id];
scmi_dump_header_dbg(dev, &xfer->hdr);
/* Is the message of valid length? */
if (xfer->rx.len > info->desc->max_msg_size) {
dev_err(dev, "unable to handle %zu xfer(max %d)\n",
xfer->rx.len, info->desc->max_msg_size);
return;
}
scmi_fetch_response(xfer, mem);
complete(&xfer->done);
}
/**
* pack_scmi_header() - packs and returns 32-bit header
*
* @hdr: pointer to header containing all the information on message id,
* protocol id and sequence id.
*/
static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
{
return ((hdr->id & MSG_ID_MASK) << MSG_ID_SHIFT) |
((hdr->seq & MSG_TOKEN_ID_MASK) << MSG_TOKEN_ID_SHIFT) |
((hdr->protocol_id & MSG_PROTOCOL_ID_MASK) << MSG_PROTOCOL_ID_SHIFT);
}
/**
* scmi_tx_prepare() - mailbox client callback to prepare for the transfer
*
* @cl: client pointer
* @m: mailbox message
*
* This function prepares the shared memory which contains the header and the
* payload.
*/
static void scmi_tx_prepare(struct mbox_client *cl, void *m)
{
struct scmi_xfer *t = m;
struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
struct scmi_shared_mem __iomem *mem = cinfo->payload;
/* Mark channel busy + clear error */
iowrite32(0x0, &mem->channel_status);
iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,
&mem->flags);
iowrite32(sizeof(mem->msg_header) + t->tx.len, &mem->length);
iowrite32(pack_scmi_header(&t->hdr), &mem->msg_header);
if (t->tx.buf)
memcpy_toio(mem->msg_payload, t->tx.buf, t->tx.len);
}
/**
* scmi_one_xfer_get() - Allocate one message
*
* @handle: SCMI entity handle
*
* Helper function which is used by various command 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_one_xfer_get(const struct scmi_handle *handle)
{
u16 xfer_id;
struct scmi_xfer *xfer;
unsigned long flags, bit_pos;
struct scmi_info *info = handle_to_scmi_info(handle);
struct scmi_xfers_info *minfo = &info->minfo;
/* 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);
return xfer;
}
/**
* scmi_one_xfer_put() - Release a message
*
* @minfo: transfer info pointer
* @xfer: message that was reserved by scmi_one_xfer_get
*
* This holds a spinlock to maintain integrity of internal data structures.
*/
void scmi_one_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
{
unsigned long flags;
struct scmi_info *info = handle_to_scmi_info(handle);
struct scmi_xfers_info *minfo = &info->minfo;
/*
* 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 bool
scmi_xfer_poll_done(const struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
{
struct scmi_shared_mem __iomem *mem = cinfo->payload;
u16 xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
if (xfer->hdr.seq != xfer_id)
return false;
return ioread32(&mem->channel_status) &
(SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR |
SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
}
#define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC)
static bool scmi_xfer_done_no_timeout(const struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer, ktime_t stop)
{
ktime_t __cur = ktime_get();
return scmi_xfer_poll_done(cinfo, xfer) || ktime_after(__cur, stop);
}
/**
* scmi_do_xfer() - Do one transfer
*
* @info: Pointer to SCMI entity information
* @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;
ret = mbox_send_message(cinfo->chan, xfer);
if (ret < 0) {
dev_dbg(dev, "mbox send fail %d\n", ret);
return ret;
}
/* mbox_send_message returns non-negative value on success, so reset */
ret = 0;
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))
scmi_fetch_response(xfer, cinfo->payload);
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, "mbox 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);
/*
* NOTE: we might prefer not to need the mailbox ticker to manage the
* transfer queueing since the protocol layer queues things by itself.
* Unfortunately, we have to kick the mailbox framework after we have
* received our message.
*/
mbox_client_txdone(cinfo->chan, ret);
return ret;
}
/**
* scmi_one_xfer_init() - Allocate and initialise one message
*
* @handle: SCMI entity handle
* @msg_id: Message identifier
* @msg_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_one_xfer_get and
* initialise the header.
*
* Return: 0 if all went fine with @p pointing to message, else
* corresponding error.
*/
int scmi_one_xfer_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 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_one_xfer_get(handle);
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: Handle to SCMI entity information
*
* 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_one_xfer_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_one_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 const struct scmi_desc scmi_generic_desc = {
.max_rx_timeout_ms = 30, /* we may increase this if required */
.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
.max_msg_size = 128,
};
/* Each compatible listed below must have descriptor associated with it */
static const struct of_device_id scmi_of_match[] = {
{ .compatible = "arm,scmi", .data = &scmi_generic_desc },
{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, scmi_of_match);
static int scmi_xfer_info_init(struct scmi_info *sinfo)
{
int i;
struct scmi_xfer *xfer;
struct device *dev = sinfo->dev;
const struct scmi_desc *desc = sinfo->desc;
struct scmi_xfers_info *info = &sinfo->minfo;
/* Pre-allocated messages, no more than what hdr.seq can support */
if (WARN_ON(desc->max_msg >= (MSG_TOKEN_ID_MASK + 1))) {
dev_err(dev, "Maximum message of %d exceeds supported %d\n",
desc->max_msg, MSG_TOKEN_ID_MASK + 1);
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;
bitmap_zero(info->xfer_alloc_table, desc->max_msg);
/* 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_mailbox_check(struct device_node *np)
{
struct of_phandle_args arg;
return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg);
}
static int scmi_mbox_free_channel(int id, void *p, void *data)
{
struct scmi_chan_info *cinfo = p;
struct idr *idr = data;
if (!IS_ERR_OR_NULL(cinfo->chan)) {
mbox_free_channel(cinfo->chan);
cinfo->chan = NULL;
}
idr_remove(idr, id);
return 0;
}
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) {
/* Safe to free channels since no more users */
ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
idr_destroy(&info->tx_idr);
}
return ret;
}
static inline int
scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, int prot_id)
{
int ret;
struct resource res;
resource_size_t size;
struct device_node *shmem, *np = dev->of_node;
struct scmi_chan_info *cinfo;
struct mbox_client *cl;
if (scmi_mailbox_check(np)) {
cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
goto idr_alloc;
}
cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
cinfo->dev = dev;
cl = &cinfo->cl;
cl->dev = dev;
cl->rx_callback = scmi_rx_callback;
cl->tx_prepare = scmi_tx_prepare;
cl->tx_block = false;
cl->knows_txdone = true;
shmem = of_parse_phandle(np, "shmem", 0);
ret = of_address_to_resource(shmem, 0, &res);
of_node_put(shmem);
if (ret) {
dev_err(dev, "failed to get SCMI Tx payload mem resource\n");
return ret;
}
size = resource_size(&res);
cinfo->payload = devm_ioremap(info->dev, res.start, size);
if (!cinfo->payload) {
dev_err(dev, "failed to ioremap SCMI Tx payload\n");
return -EADDRNOTAVAIL;
}
/* Transmit channel is first entry i.e. index 0 */
cinfo->chan = mbox_request_channel(cl, 0);
if (IS_ERR(cinfo->chan)) {
ret = PTR_ERR(cinfo->chan);
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to request SCMI Tx mailbox\n");
return ret;
}
idr_alloc:
ret = idr_alloc(&info->tx_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 void
scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
int prot_id)
{
struct scmi_device *sdev;
sdev = scmi_device_create(np, info->dev, prot_id);
if (!sdev) {
dev_err(info->dev, "failed to create %d protocol device\n",
prot_id);
return;
}
if (scmi_mbox_chan_setup(info, &sdev->dev, prot_id)) {
dev_err(&sdev->dev, "failed to setup transport\n");
scmi_device_destroy(sdev);
}
/* setup handle now as the transport is ready */
scmi_set_handle(sdev);
}
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;
/* Only mailbox method supported, check for the presence of one */
if (scmi_mailbox_check(np)) {
dev_err(dev, "no mailbox found in %pOF\n", np);
return -EINVAL;
}
desc = of_match_device(scmi_of_match, dev)->data;
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->dev = dev;
info->desc = desc;
INIT_LIST_HEAD(&info->node);
ret = scmi_xfer_info_init(info);
if (ret)
return ret;
platform_set_drvdata(pdev, info);
idr_init(&info->tx_idr);
handle = &info->handle;
handle->dev = info->dev;
handle->version = &info->version;
ret = scmi_mbox_chan_setup(info, dev, SCMI_PROTOCOL_BASE);
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;
prot_id &= MSG_PROTOCOL_ID_MASK;
if (!scmi_is_protocol_implemented(handle, prot_id)) {
dev_err(dev, "SCMI protocol %d not implemented\n",
prot_id);
continue;
}
scmi_create_protocol_device(child, info, prot_id);
}
return 0;
}
static struct platform_driver scmi_driver = {
.driver = {
.name = "arm-scmi",
.of_match_table = scmi_of_match,
},
.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");