// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
*
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/mhi.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include "internal.h"
/*
* Not all MHI state transitions are synchronous. Transitions like Linkdown,
* SYS_ERR, and shutdown can happen anytime asynchronously. This function will
* transition to a new state only if we're allowed to.
*
* Priority increases as we go down. For instance, from any state in L0, the
* transition can be made to states in L1, L2 and L3. A notable exception to
* this rule is state DISABLE. From DISABLE state we can only transition to
* POR state. Also, while in L2 state, user cannot jump back to previous
* L1 or L0 states.
*
* Valid transitions:
* L0: DISABLE <--> POR
* POR <--> POR
* POR -> M0 -> M2 --> M0
* POR -> FW_DL_ERR
* FW_DL_ERR <--> FW_DL_ERR
* M0 <--> M0
* M0 -> FW_DL_ERR
* M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0
* L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR
* L2: SHUTDOWN_PROCESS -> DISABLE
* L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT
* LD_ERR_FATAL_DETECT -> SHUTDOWN_PROCESS
*/
static struct mhi_pm_transitions const dev_state_transitions[] = {
/* L0 States */
{
MHI_PM_DISABLE,
MHI_PM_POR
},
{
MHI_PM_POR,
MHI_PM_POR | MHI_PM_DISABLE | MHI_PM_M0 |
MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
},
{
MHI_PM_M0,
MHI_PM_M0 | MHI_PM_M2 | MHI_PM_M3_ENTER |
MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
},
{
MHI_PM_M2,
MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT
},
{
MHI_PM_M3_ENTER,
MHI_PM_M3 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT
},
{
MHI_PM_M3,
MHI_PM_M3_EXIT | MHI_PM_SYS_ERR_DETECT |
MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
},
{
MHI_PM_M3_EXIT,
MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT
},
{
MHI_PM_FW_DL_ERR,
MHI_PM_FW_DL_ERR | MHI_PM_SYS_ERR_DETECT |
MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
},
/* L1 States */
{
MHI_PM_SYS_ERR_DETECT,
MHI_PM_SYS_ERR_PROCESS | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT
},
{
MHI_PM_SYS_ERR_PROCESS,
MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS |
MHI_PM_LD_ERR_FATAL_DETECT
},
/* L2 States */
{
MHI_PM_SHUTDOWN_PROCESS,
MHI_PM_DISABLE | MHI_PM_LD_ERR_FATAL_DETECT
},
/* L3 States */
{
MHI_PM_LD_ERR_FATAL_DETECT,
MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_SHUTDOWN_PROCESS
},
};
enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cntrl,
enum mhi_pm_state state)
{
unsigned long cur_state = mhi_cntrl->pm_state;
int index = find_last_bit(&cur_state, 32);
if (unlikely(index >= ARRAY_SIZE(dev_state_transitions)))
return cur_state;
if (unlikely(dev_state_transitions[index].from_state != cur_state))
return cur_state;
if (unlikely(!(dev_state_transitions[index].to_states & state)))
return cur_state;
mhi_cntrl->pm_state = state;
return mhi_cntrl->pm_state;
}
void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum mhi_state state)
{
if (state == MHI_STATE_RESET) {
mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 1);
} else {
mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
MHICTRL_MHISTATE_MASK,
MHICTRL_MHISTATE_SHIFT, state);
}
}
/* NOP for backward compatibility, host allowed to ring DB in M2 state */
static void mhi_toggle_dev_wake_nop(struct mhi_controller *mhi_cntrl)
{
}
static void mhi_toggle_dev_wake(struct mhi_controller