// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2011-2017, The Linux Foundation
*/
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include "slimbus.h"
/**
* slim_msg_response() - Deliver Message response received from a device to the
* framework.
*
* @ctrl: Controller handle
* @reply: Reply received from the device
* @len: Length of the reply
* @tid: Transaction ID received with which framework can associate reply.
*
* Called by controller to inform framework about the response received.
* This helps in making the API asynchronous, and controller-driver doesn't need
* to manage 1 more table other than the one managed by framework mapping TID
* with buffers
*/
void slim_msg_response(struct slim_controller *ctrl, u8 *reply, u8 tid, u8 len)
{
struct slim_msg_txn *txn;
struct slim_val_inf *msg;
unsigned long flags;
spin_lock_irqsave(&ctrl->txn_lock, flags);
txn = idr_find(&ctrl->tid_idr, tid);
if (txn == NULL) {
spin_unlock_irqrestore(&ctrl->txn_lock, flags);
return;
}
msg = txn->msg;
if (msg == NULL || msg->rbuf == NULL) {
dev_err(ctrl->dev, "Got response to invalid TID:%d, len:%d\n",
tid, len);
spin_unlock_irqrestore(&ctrl->txn_lock, flags);
return;
}
idr_remove(&ctrl->tid_idr, tid);
spin_unlock_irqrestore(&ctrl->txn_lock, flags);
memcpy(msg->rbuf, reply, len);
if (txn->comp)
complete(txn->comp);
/* Remove runtime-pm vote now that response was received for TID txn */
pm_runtime_mark_last_busy(ctrl->dev);
pm_runtime_put_autosuspend(ctrl->dev);
}
EXPORT_SYMBOL_GPL(slim_msg_response);
/**
* slim_do_transfer() - Process a SLIMbus-messaging transaction
*
* @ctrl: Controller handle
* @txn: Transaction to be sent over SLIMbus
*
* Called by controller to transmit messaging transactions not dealing with
* Interface/Value elements. (e.g. transmittting a message to assign logical
* address to a slave device
*
* Return: -ETIMEDOUT: If transmission of this message timed out
* (e.g. due to bus lines not being clocked or driven by controller)
*/
int slim_do_transfer(struct slim_controller *ctrl, struct slim_msg_txn *txn)
{
DECLARE_COMPLETION_ONSTACK(done);
bool need_tid = false, clk_pause_msg = false;
unsigned long flags;
int ret, tid, timeout;
/*
* do not vote for runtime-PM if the transactions are part of clock
* pause sequence
*/
if (ctrl->sched.clk_state == SLIM_CLK_ENTERING_PAUSE &&
(txn->mt == SLIM_MSG_MT_CORE &&
txn->mc >= SLIM_MSG_MC_BEGIN_RECONFIGURATION &&
txn->mc <= SLIM_MSG_MC_RECONFIGURE_NOW))
clk_pause_msg = true;
if (!clk_pause_msg) {
ret = pm_runtime_get_sync(ctrl->dev);
if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
dev_err(ctrl->dev, "ctrl wrong state:%d, ret:%d\n",
ctrl->sched.clk_state, ret);
goto slim_xfer_err;
}
}
need_tid = slim_tid_txn(txn->mt, txn->mc);
if (need_tid) {
spin_lock_irqsave(&ctrl->txn_lock, flags);
tid = idr_alloc(&ctrl->tid_idr, txn, 0,
SLIM_MAX_TIDS, GFP_ATOMIC);
txn->tid = tid;
if (!txn->msg->comp)
txn->comp = &done;
else
txn->comp = txn->comp;
spin_unlock_irqrestore(&ctrl->txn_lock, flags);
if (tid < 0)
return tid;
}
ret = ctrl->xfer_msg(ctrl, txn);
if (ret && need_tid && !txn->msg->comp) {
unsigned long ms = txn->rl + HZ;
timeout = wait_for_completion_timeout(txn->comp,
msecs_to_jiffies(ms));
if (!timeout) {
ret = -ETIMEDOUT;
spin_lock_irqsave(&ctrl->txn_lock, flags);
idr_remove(&ctrl->tid_idr, tid);
spin_unlock_irqrestore(&ctrl->txn_lock, flags);
}
}
if (ret)
dev_err(ctrl->dev, "Tx:MT:0x%x, MC:0x%x, LA:0x%x failed:%d\n",
txn->mt, txn->mc, txn->la, ret);
slim_xfer_err:
if (!clk_pause_msg && (!need_tid || ret == -ETIMEDOUT)) {
/*
* remove runtime-pm vote if this was TX only, or
* if there was error during this transaction
*/
pm_runtime_mark_last_busy(ctrl->dev);
pm_runtime_mark_last_busy(ctrl->dev);
}
return ret;
}
EXPORT_SYMBOL_GPL(slim_do_transfer);
static int slim_val_inf_sanity(struct slim_controller *ctrl,
struct slim_val_inf *msg, u8 mc)
{
if (!msg || msg->num_bytes > 16 ||
(msg->start_offset + msg->num_bytes) > 0xC00)
goto reterr;
switch (mc) {
case SLIM_MSG_MC_REQUEST_VALUE:
case SLIM_MSG_MC_REQUEST_INFORMATION:
if (msg->rbuf != NULL)
return 0;
break;
case SLIM_MSG_MC_CHANGE_VALUE:
case SLIM_MSG_MC_CLEAR_INFORMATION:
if (msg->wbuf != NULL)
return 0;
break;
case SLIM_MSG_MC_REQUEST_CHANGE_VALUE:
case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION:
if (msg->rbuf != NULL && msg->wbuf != NULL)
return 0;
break;
}
reterr:
if (msg)
dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n",
msg->start_offset, mc);
return -EINVAL;
}
static u16 slim_slicesize(int code)
{
static const u8 sizetocode[16] = {
0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7
};
code = clamp(code, 1, (int)ARRAY_SIZE(sizetocode));
return sizetocode[code - 1];
}
/**
* slim_xfer_msg() - Transfer a value info message on slim device
*
* @sbdev: slim device to which this msg has to be transfered
* @msg: value info message pointer
* @mc: message code of the message
*
* Called by drivers which want to transfer a vlaue or info elements.
*
* Return: -ETIMEDOUT: If transmission of this message timed out
*/
int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg,
u8 mc)
{
DEFINE_SLIM_LDEST_TXN(txn_stack, mc, 6, sbdev->laddr, msg);
struct slim_msg_txn *txn = &txn_stack;
struct slim_controller *ctrl = sbdev->ctrl;
int ret;
u16 sl;
if (!ctrl)
return -EINVAL;
ret = slim_val_inf_sanity(ctrl, msg, mc);
if (ret)
return ret;
sl = slim_slicesize(msg->num_bytes);
dev_dbg(ctrl->dev, "SB xfer msg:os:%x, len:%d, MC:%x, sl:%x\n",
msg->start_offset, msg->num_bytes, mc, sl);
txn->ec = ((sl | (1 << 3)) | ((msg->start_offset & 0xFFF) << 4));
switch (mc) {
case SLIM_MSG_MC_REQUEST_CHANGE_VALUE:
case SLIM_MSG_MC_CHANGE_VALUE:
case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION:
case SLIM_MSG_MC_CLEAR_INFORMATION:
txn->rl += msg->num_bytes;
default:
break;
}
if (slim_tid_txn(txn->mt, txn->mc))
txn->rl++;
return slim_do_transfer(ctrl, txn);
}
EXPORT_SYMBOL_GPL(slim_xfer_msg);
static void slim_fill_msg(struct slim_val_inf *msg, u32 addr,
size_t count, u8 *rbuf, u8 *wbuf)
{
msg->start_offset = addr;
msg->num_bytes = count;
msg->rbuf = rbuf;
msg->wbuf = wbuf;
}
/**
* slim_read() - Read SLIMbus value element
*
* @sdev: client handle.
* @addr: address of value element to read.
* @count: number of bytes to read. Maximum bytes allowed are 16.
* @val: will return what the value element value was
*
* Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of
* this message timed out (e.g. due to bus lines not being clocked
* or driven by controller)
*/
int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val)
{
struct slim_val_inf msg;
slim_fill_msg(&msg, addr, count, val, NULL);
return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_REQUEST_VALUE);
}
EXPORT_SYMBOL_GPL(slim_read);
/**
* slim_readb() - Read byte from SLIMbus value element
*
* @sdev: client handle.
* @addr: address in the value element to read.
*
* Return: byte value of value element.
*/
int slim_readb(struct slim_device *sdev, u32 addr)
{
int ret;
u8 buf;
ret = slim_read(sdev, addr, 1, &buf);
if (ret < 0)
return ret;
else
return buf;
}
EXPORT_SYMBOL_GPL(slim_readb);
/**
* slim_write() - Write SLIMbus value element
*
* @sdev: client handle.
* @addr: address in the value element to write.
* @count: number of bytes to write. Maximum bytes allowed are 16.
* @val: value to write to value element
*
* Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of
* this message timed out (e.g. due to bus lines not being clocked
* or driven by controller)
*/
int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val)
{
struct slim_val_inf msg;
slim_fill_msg(&msg, addr, count, NULL, val);
return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_CHANGE_VALUE);
}
EXPORT_SYMBOL_GPL(slim_write);
/**
* slim_writeb() - Write byte to SLIMbus value element
*
* @sdev: client handle.
* @addr: address of value element to write.
* @value: value to write to value element
*
* Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of
* this message timed out (e.g. due to bus lines not being clocked
* or driven by controller)
*
*/
int slim_writeb(struct slim_device *sdev, u32 addr, u8 value)
{
return slim_write(sdev, addr, 1, &value);
}
EXPORT_SYMBOL_GPL(slim_writeb);
