[PATCH 07/16] bus: mhi: core: Add support for basic PM operations

Manivannan Sadhasivam
2020-01-23T11:19:18Z

This commit adds support for basic MHI PM operations such as
mhi_async_power_up, mhi_sync_power_up, and mhi_power_down. These
routines places the MHI bus into respective power domain states
and calls the state_transition APIs when necessary. The MHI
controller driver is expected to call these PM routines for
MHI powerup and powerdown.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/989

Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[mani: splitted the pm patch and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
drivers/bus/mhi/core/Makefile | 2 +-
drivers/bus/mhi/core/boot.c | 89 +++++++++
drivers/bus/mhi/core/init.c | 313 ++++++++++++++++++++++++++++++++
drivers/bus/mhi/core/internal.h | 37 ++++
drivers/bus/mhi/core/main.c | 89 +++++++++
drivers/bus/mhi/core/pm.c | 218 ++++++++++++++++++++++
include/linux/mhi.h | 51 ++++++
7 files changed, 798 insertions(+), 1 deletion(-)
create mode 100644 drivers/bus/mhi/core/boot.c

diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index a0070f9cdfcd..66e2700c9032 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,3 +1,3 @@
obj-$(CONFIG_MHI_BUS) := mhi.o

-mhi-y := init.o main.o pm.o
+mhi-y := init.o main.o pm.o boot.o
diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
new file mode 100644
index 000000000000..0996f18c4281
--- /dev/null
+++ b/drivers/bus/mhi/core/boot.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#define dev_fmt(fmt) "MHI: " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include "internal.h"
+
+void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
+ struct image_info *image_info)
+{
+ int i;
+ struct mhi_buf *mhi_buf = image_info->mhi_buf;
+
+ for (i = 0; i < image_info->entries; i++, mhi_buf++)
+ mhi_free_coherent(mhi_cntrl, mhi_buf->len, mhi_buf->buf,
+ mhi_buf->dma_addr);
+
+ kfree(image_info->mhi_buf);
+ kfree(image_info);
+}
+
+int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
+ struct image_info **image_info,
+ size_t alloc_size)
+{
+ size_t seg_size = mhi_cntrl->seg_len;
+ int segments = DIV_ROUND_UP(alloc_size, seg_size) + 1;
+ int i;
+ struct image_info *img_info;
+ struct mhi_buf *mhi_buf;
+
+ img_info = kzalloc(sizeof(*img_info), GFP_KERNEL);
+ if (!img_info)
+ return -ENOMEM;
+
+ /* Allocate memory for entries */
+ img_info->mhi_buf = kcalloc(segments, sizeof(*img_info->mhi_buf),
+ GFP_KERNEL);
+ if (!img_info->mhi_buf)
+ goto error_alloc_mhi_buf;
+
+ /* Allocate and populate vector table */
+ mhi_buf = img_info->mhi_buf;
+ for (i = 0; i < segments; i++, mhi_buf++) {
+ size_t vec_size = seg_size;
+
+ /* Vector table is the last entry */
+ if (i == segments - 1)
+ vec_size = sizeof(struct bhi_vec_entry) * i;
+
+ mhi_buf->len = vec_size;
+ mhi_buf->buf = mhi_alloc_coherent(mhi_cntrl, vec_size,
+ &mhi_buf->dma_addr,
+ GFP_KERNEL);
+ if (!mhi_buf->buf)
+ goto error_alloc_segment;
+ }
+
+ img_info->bhi_vec = img_info->mhi_buf[segments - 1].buf;
+ img_info->entries = segments;
+ *image_info = img_info;
+
+ return 0;
+
+error_alloc_segment:
+ for (--i, --mhi_buf; i >= 0; i--, mhi_buf--)
+ mhi_free_coherent(mhi_cntrl, mhi_buf->len, mhi_buf->buf,
+ mhi_buf->dma_addr);
+
+error_alloc_mhi_buf:
+ kfree(img_info);
+
+ return -ENOMEM;
+}
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 83a03493c757..7fff92e9661b 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -75,6 +75,284 @@ const char *to_mhi_pm_state_str(enum mhi_pm_state state)
return mhi_pm_state_str[index];
}

+/* MHI protocol requires the transfer ring to be aligned with ring length */
+static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring,
+ u64 len)
+{
+ ring->alloc_size = len + (len - 1);
+ ring->pre_aligned = mhi_alloc_coherent(mhi_cntrl, ring->alloc_size,
+ &ring->dma_handle, GFP_KERNEL);
+ if (!ring->pre_aligned)
+ return -ENOMEM;
+
+ ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
+ ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
+
+ return 0;
+}
+
+void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
+{
+ int i;
+ struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
+
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+ if (mhi_event->offload_ev)
+ continue;
+
+ free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
+ }
+
+ free_irq(mhi_cntrl->irq[0], mhi_cntrl);
+}
+
+int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
+{
+ int i;
+ int ret;
+ struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
+
+ /* Setup BHI_INTVEC IRQ */
+ ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
+ mhi_intvec_threaded_handler,
+ IRQF_SHARED | IRQF_NO_SUSPEND,
+ "bhi", mhi_cntrl);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+ if (mhi_event->offload_ev)
+ continue;
+
+ ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
+ mhi_irq_handler,
+ IRQF_SHARED | IRQF_NO_SUSPEND,
+ "mhi", mhi_event);
+ if (ret) {
+ dev_err(mhi_cntrl->dev,
+ "Error requesting irq:%d for ev:%d\n",
+ mhi_cntrl->irq[mhi_event->irq], i);
+ goto error_request;
+ }
+ }
+
+ return 0;
+
+error_request:
+ for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
+ if (mhi_event->offload_ev)
+ continue;
+
+ free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
+ }
+ free_irq(mhi_cntrl->irq[0], mhi_cntrl);
+
+ return ret;
+}
+
+void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
+{
+ int i;
+ struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
+ struct mhi_cmd *mhi_cmd;
+ struct mhi_event *mhi_event;
+ struct mhi_ring *ring;
+
+ mhi_cmd = mhi_cntrl->mhi_cmd;
+ for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
+ ring = &mhi_cmd->ring;
+ mhi_free_coherent(mhi_cntrl, ring->alloc_size,
+ ring->pre_aligned, ring->dma_handle);
+ ring->base = NULL;
+ ring->iommu_base = 0;
+ }
+
+ mhi_free_coherent(mhi_cntrl,
+ sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
+ mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
+
+ mhi_event = mhi_cntrl->mhi_event;
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+ if (mhi_event->offload_ev)
+ continue;
+
+ ring = &mhi_event->ring;
+ mhi_free_coherent(mhi_cntrl, ring->alloc_size,
+ ring->pre_aligned, ring->dma_handle);
+ ring->base = NULL;
+ ring->iommu_base = 0;
+ }
+
+ mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
+ mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
+ mhi_ctxt->er_ctxt_addr);
+
+ mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
+ mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
+ mhi_ctxt->chan_ctxt_addr);
+
+ kfree(mhi_ctxt);
+ mhi_cntrl->mhi_ctxt = NULL;
+}
+
+int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
+{
+ struct mhi_ctxt *mhi_ctxt;
+ struct mhi_chan_ctxt *chan_ctxt;
+ struct mhi_event_ctxt *er_ctxt;
+ struct mhi_cmd_ctxt *cmd_ctxt;
+ struct mhi_chan *mhi_chan;
+ struct mhi_event *mhi_event;
+ struct mhi_cmd *mhi_cmd;
+ int ret = -ENOMEM, i;
+
+ atomic_set(&mhi_cntrl->dev_wake, 0);
+ atomic_set(&mhi_cntrl->alloc_size, 0);
+ atomic_set(&mhi_cntrl->pending_pkts, 0);
+
+ mhi_ctxt = kzalloc(sizeof(*mhi_ctxt), GFP_KERNEL);
+ if (!mhi_ctxt)
+ return -ENOMEM;
+
+ /* Setup channel ctxt */
+ mhi_ctxt->chan_ctxt = mhi_alloc_coherent(mhi_cntrl,
+ sizeof(*mhi_ctxt->chan_ctxt) *
+ mhi_cntrl->max_chan,
+ &mhi_ctxt->chan_ctxt_addr,
+ GFP_KERNEL);
+ if (!mhi_ctxt->chan_ctxt)
+ goto error_alloc_chan_ctxt;
+
+ mhi_chan = mhi_cntrl->mhi_chan;
+ chan_ctxt = mhi_ctxt->chan_ctxt;
+ for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
+ /* Skip if it is an offload channel */
+ if (mhi_chan->offload_ch)
+ continue;
+
+ chan_ctxt->chstate = MHI_CH_STATE_DISABLED;
+ chan_ctxt->brstmode = mhi_chan->db_cfg.brstmode;
+ chan_ctxt->pollcfg = mhi_chan->db_cfg.pollcfg;
+ chan_ctxt->chtype = mhi_chan->type;
+ chan_ctxt->erindex = mhi_chan->er_index;
+
+ mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
+ mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
+ }
+
+ /* Setup event context */
+ mhi_ctxt->er_ctxt = mhi_alloc_coherent(mhi_cntrl,
+ sizeof(*mhi_ctxt->er_ctxt) *
+ mhi_cntrl->total_ev_rings,
+ &mhi_ctxt->er_ctxt_addr,
+ GFP_KERNEL);
+ if (!mhi_ctxt->er_ctxt)
+ goto error_alloc_er_ctxt;
+
+ er_ctxt = mhi_ctxt->er_ctxt;
+ mhi_event = mhi_cntrl->mhi_event;
+ for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
+ mhi_event++) {
+ struct mhi_ring *ring = &mhi_event->ring;
+
+ /* Skip if it is an offload event */
+ if (mhi_event->offload_ev)
+ continue;
+
+ er_ctxt->intmodc = 0;
+ er_ctxt->intmodt = mhi_event->intmod;
+ er_ctxt->ertype = MHI_ER_TYPE_VALID;
+ er_ctxt->msivec = mhi_event->irq;
+ mhi_event->db_cfg.db_mode = true;
+
+ ring->el_size = sizeof(struct mhi_tre);
+ ring->len = ring->el_size * ring->elements;
+ ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
+ if (ret)
+ goto error_alloc_er;
+
+ /*
+ * If the read pointer equals to the write pointer, then the
+ * ring is empty
+ */
+ ring->rp = ring->wp = ring->base;
+ er_ctxt->rbase = ring->iommu_base;
+ er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
+ er_ctxt->rlen = ring->len;
+ ring->ctxt_wp = &er_ctxt->wp;
+ }
+
+ /* Setup cmd context */
+ mhi_ctxt->cmd_ctxt = mhi_alloc_coherent(mhi_cntrl,
+ sizeof(*mhi_ctxt->cmd_ctxt) *
+ NR_OF_CMD_RINGS,
+ &mhi_ctxt->cmd_ctxt_addr,
+ GFP_KERNEL);
+ if (!mhi_ctxt->cmd_ctxt)
+ goto error_alloc_er;
+
+ mhi_cmd = mhi_cntrl->mhi_cmd;
+ cmd_ctxt = mhi_ctxt->cmd_ctxt;
+ for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
+ struct mhi_ring *ring = &mhi_cmd->ring;
+
+ ring->el_size = sizeof(struct mhi_tre);
+ ring->elements = CMD_EL_PER_RING;
+ ring->len = ring->el_size * ring->elements;
+ ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
+ if (ret)
+ goto error_alloc_cmd;
+
+ ring->rp = ring->wp = ring->base;
+ cmd_ctxt->rbase = ring->iommu_base;
+ cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
+ cmd_ctxt->rlen = ring->len;
+ ring->ctxt_wp = &cmd_ctxt->wp;
+ }
+
+ mhi_cntrl->mhi_ctxt = mhi_ctxt;
+
+ return 0;
+
+error_alloc_cmd:
+ for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
+ struct mhi_ring *ring = &mhi_cmd->ring;
+
+ mhi_free_coherent(mhi_cntrl, ring->alloc_size,
+ ring->pre_aligned, ring->dma_handle);
+ }
+ mhi_free_coherent(mhi_cntrl,
+ sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
+ mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
+ i = mhi_cntrl->total_ev_rings;
+ mhi_event = mhi_cntrl->mhi_event + i;
+
+error_alloc_er:
+ for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
+ struct mhi_ring *ring = &mhi_event->ring;
+
+ if (mhi_event->offload_ev)
+ continue;
+
+ mhi_free_coherent(mhi_cntrl, ring->alloc_size,
+ ring->pre_aligned, ring->dma_handle);
+ }
+ mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
+ mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
+ mhi_ctxt->er_ctxt_addr);
+
+error_alloc_er_ctxt:
+ mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
+ mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
+ mhi_ctxt->chan_ctxt_addr);
+
+error_alloc_chan_ctxt:
+ kfree(mhi_ctxt);
+
+ return ret;
+}
+
int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
{
u32 val;
@@ -548,6 +826,41 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
}
EXPORT_SYMBOL_GPL(mhi_unregister_controller);

+int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
+{
+ int ret;
+
+ mutex_lock(&mhi_cntrl->pm_mutex);
+
+ ret = mhi_init_dev_ctxt(mhi_cntrl);
+ if (ret)
+ goto error_dev_ctxt;
+
+ mhi_cntrl->pre_init = true;
+
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+
+ return 0;
+
+error_dev_ctxt:
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
+
+void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
+{
+ if (mhi_cntrl->fbc_image) {
+ mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
+ mhi_cntrl->fbc_image = NULL;
+ }
+
+ mhi_deinit_dev_ctxt(mhi_cntrl);
+ mhi_cntrl->pre_init = false;
+}
+EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
+
static void mhi_release_device(struct device *dev)
{
struct mhi_device *mhi_dev = to_mhi_device(dev);
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 2dba4923482a..d920264ded21 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -575,6 +575,11 @@ static inline void mhi_dealloc_device(struct mhi_controller *mhi_cntrl,
int mhi_destroy_device(struct device *dev, void *data);
void mhi_create_devices(struct mhi_controller *mhi_cntrl);

+int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
+ struct image_info **image_info, size_t alloc_size);
+void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
+ struct image_info *image_info);
+
/* Power management APIs */
enum mhi_pm_state __must_check mhi_tryset_pm_state(
struct mhi_controller *mhi_cntrl,
@@ -616,5 +621,37 @@ void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,

/* Initialization methods */
int mhi_init_mmio(struct mhi_controller *mhi_cntrl);
+int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl);
+void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl);
+int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl);
+void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl);
+
+/* Memory allocation methods */
+static inline void *mhi_alloc_coherent(struct mhi_controller *mhi_cntrl,
+ size_t size,
+ dma_addr_t *dma_handle,
+ gfp_t gfp)
+{
+ void *buf = dma_alloc_coherent(mhi_cntrl->dev, size, dma_handle, gfp);
+
+ if (buf)
+ atomic_add(size, &mhi_cntrl->alloc_size);
+
+ return buf;
+}
+
+static inline void mhi_free_coherent(struct mhi_controller *mhi_cntrl,
+ size_t size,
+ void *vaddr,
+ dma_addr_t dma_handle)
+{
+ atomic_sub(size, &mhi_cntrl->alloc_size);
+ dma_free_coherent(mhi_cntrl->dev, size, vaddr, dma_handle);
+}
+
+/* ISR handlers */
+irqreturn_t mhi_irq_handler(int irq_number, void *dev);
+irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *dev);
+irqreturn_t mhi_intvec_handler(int irq_number, void *dev);

#endif /* _MHI_INT_H */
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index df980fb3b6db..453feba8f02a 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -144,6 +144,11 @@ enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl)
return ret ? MHI_STATE_MAX : state;
}

+static void *mhi_to_virtual(struct mhi_ring *ring, dma_addr_t addr)
+{
+ return (addr - ring->iommu_base) + ring->base;
+}
+
int mhi_destroy_device(struct device *dev, void *data)
{
struct mhi_device *mhi_dev;
@@ -248,3 +253,87 @@ void mhi_create_devices(struct mhi_controller *mhi_cntrl)
mhi_dealloc_device(mhi_cntrl, mhi_dev);
}
}
+
+irqreturn_t mhi_irq_handler(int irq_number, void *dev)
+{
+ struct mhi_event *mhi_event = dev;
+ struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
+ struct mhi_event_ctxt *er_ctxt =
+ &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
+ struct mhi_ring *ev_ring = &mhi_event->ring;
+ void *dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+
+ /* Only proceed if event ring has pending events */
+ if (ev_ring->rp == dev_rp)
+ return IRQ_HANDLED;
+
+ /* For client managed event ring, notify pending data */
+ if (mhi_event->cl_manage) {
+ struct mhi_chan *mhi_chan = mhi_event->mhi_chan;
+ struct mhi_device *mhi_dev = mhi_chan->mhi_dev;
+
+ if (mhi_dev)
+ mhi_notify(mhi_dev, MHI_CB_PENDING_DATA);
+ } else {
+ tasklet_schedule(&mhi_event->task);
+ }
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *dev)
+{
+ struct mhi_controller *mhi_cntrl = dev;
+ enum mhi_state state = MHI_STATE_MAX;
+ enum mhi_pm_state pm_state = 0;
+ enum mhi_ee_type ee = 0;
+
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
+ state = mhi_get_mhi_state(mhi_cntrl);
+ ee = mhi_cntrl->ee;
+ mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
+ }
+
+ if (state == MHI_STATE_SYS_ERR) {
+ dev_dbg(mhi_cntrl->dev, "System error detected\n");
+ pm_state = mhi_tryset_pm_state(mhi_cntrl,
+ MHI_PM_SYS_ERR_DETECT);
+ }
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+
+ /* If device in RDDM don't bother processing SYS error */
+ if (mhi_cntrl->ee == MHI_EE_RDDM) {
+ if (mhi_cntrl->ee != ee) {
+ mhi_cntrl->status_cb(mhi_cntrl, mhi_cntrl->priv_data,
+ MHI_CB_EE_RDDM);
+ wake_up_all(&mhi_cntrl->state_event);
+ }
+ goto exit_intvec;
+ }
+
+ if (pm_state == MHI_PM_SYS_ERR_DETECT) {
+ wake_up_all(&mhi_cntrl->state_event);
+
+ /* For fatal errors, we let controller decide next step */
+ if (MHI_IN_PBL(ee))
+ mhi_cntrl->status_cb(mhi_cntrl, mhi_cntrl->priv_data,
+ MHI_CB_FATAL_ERROR);
+ else
+ schedule_work(&mhi_cntrl->syserr_worker);
+ }
+
+exit_intvec:
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t mhi_intvec_handler(int irq_number, void *dev)
+{
+ struct mhi_controller *mhi_cntrl = dev;
+
+ /* Wake up events waiting for state change */
+ wake_up_all(&mhi_cntrl->state_event);
+
+ return IRQ_WAKE_THREAD;
+}
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 75d43b1039ea..b67ae2455fc5 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -140,6 +140,17 @@ void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum mhi_state 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 *mhi_cntrl)
+{
+ mhi_cntrl->wake_get(mhi_cntrl, false);
+ mhi_cntrl->wake_put(mhi_cntrl, true);
+}
+
/* Handle device ready state transition */
int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
{
@@ -683,3 +694,210 @@ int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)

return 0;
}
+
+/* Assert device wake db */
+static void mhi_assert_dev_wake(struct mhi_controller *mhi_cntrl, bool force)
+{
+ unsigned long flags;
+
+ /*
+ * If force flag is set, then increment the wake count value and
+ * ring wake db
+ */
+ if (unlikely(force)) {
+ spin_lock_irqsave(&mhi_cntrl->wlock, flags);
+ atomic_inc(&mhi_cntrl->dev_wake);
+ if (MHI_WAKE_DB_FORCE_SET_VALID(mhi_cntrl->pm_state) &&
+ !mhi_cntrl->wake_set) {
+ mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1);
+ mhi_cntrl->wake_set = true;
+ }
+ spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
+ } else {
+ /*
+ * If resources are already requested, then just increment
+ * the wake count value and return
+ */
+ if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, 1, 0)))
+ return;
+
+ spin_lock_irqsave(&mhi_cntrl->wlock, flags);
+ if ((atomic_inc_return(&mhi_cntrl->dev_wake) == 1) &&
+ MHI_WAKE_DB_SET_VALID(mhi_cntrl->pm_state) &&
+ !mhi_cntrl->wake_set) {
+ mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1);
+ mhi_cntrl->wake_set = true;
+ }
+ spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
+ }
+}
+
+/* De-assert device wake db */
+static void mhi_deassert_dev_wake(struct mhi_controller *mhi_cntrl,
+ bool override)
+{
+ unsigned long flags;
+
+ /*
+ * Only continue if there is a single resource, else just decrement
+ * and return
+ */
+ if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, -1, 1)))
+ return;
+
+ spin_lock_irqsave(&mhi_cntrl->wlock, flags);
+ if ((atomic_dec_return(&mhi_cntrl->dev_wake) == 0) &&
+ MHI_WAKE_DB_CLEAR_VALID(mhi_cntrl->pm_state) && !override &&
+ mhi_cntrl->wake_set) {
+ mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 0);
+ mhi_cntrl->wake_set = false;
+ }
+ spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
+}
+
+int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
+{
+ int ret;
+ u32 val;
+ enum mhi_ee_type current_ee;
+ enum dev_st_transition next_state;
+
+ dev_info(mhi_cntrl->dev, "Requested to power ON\n");
+
+ if (mhi_cntrl->nr_irqs < mhi_cntrl->total_ev_rings)
+ return -EINVAL;
+
+ /* Supply default wake routines if not provided by controller driver */
+ if (!mhi_cntrl->wake_get || !mhi_cntrl->wake_put ||
+ !mhi_cntrl->wake_toggle) {
+ mhi_cntrl->wake_get = mhi_assert_dev_wake;
+ mhi_cntrl->wake_put = mhi_deassert_dev_wake;
+ mhi_cntrl->wake_toggle = (mhi_cntrl->db_access & MHI_PM_M2) ?
+ mhi_toggle_dev_wake_nop : mhi_toggle_dev_wake;
+ }
+
+ mutex_lock(&mhi_cntrl->pm_mutex);
+ mhi_cntrl->pm_state = MHI_PM_DISABLE;
+
+ if (!mhi_cntrl->pre_init) {
+ /* Setup device context */
+ ret = mhi_init_dev_ctxt(mhi_cntrl);
+ if (ret)
+ goto error_dev_ctxt;
+ }
+
+ ret = mhi_init_irq_setup(mhi_cntrl);
+ if (ret)
+ goto error_setup_irq;
+
+ /* Setup BHI offset & INTVEC */
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &val);
+ if (ret) {
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ goto error_bhi_offset;
+ }
+
+ mhi_cntrl->bhi = mhi_cntrl->regs + val;
+
+ /* Setup BHIE offset */
+ if (mhi_cntrl->fbc_download) {
+ ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF, &val);
+ if (ret) {
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ dev_err(mhi_cntrl->dev, "Error reading BHIE offset\n");
+ goto error_bhi_offset;
+ }
+
+ mhi_cntrl->bhie = mhi_cntrl->regs + val;
+ }
+
+ mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
+ mhi_cntrl->pm_state = MHI_PM_POR;
+ mhi_cntrl->ee = MHI_EE_MAX;
+ current_ee = mhi_get_exec_env(mhi_cntrl);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+
+ /* Confirm that the device is in valid exec env */
+ if (!MHI_IN_PBL(current_ee) && current_ee != MHI_EE_AMSS) {
+ dev_err(mhi_cntrl->dev, "Not a valid EE for power on\n");
+ ret = -EIO;
+ goto error_bhi_offset;
+ }
+
+ /* Transition to next state */
+ next_state = MHI_IN_PBL(current_ee) ?
+ DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;
+
+ if (next_state == DEV_ST_TRANSITION_PBL)
+ schedule_work(&mhi_cntrl->fw_worker);
+
+ mhi_queue_state_transition(mhi_cntrl, next_state);
+
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+
+ dev_info(mhi_cntrl->dev, "Power on setup success\n");
+
+ return 0;
+
+error_bhi_offset:
+ mhi_deinit_free_irq(mhi_cntrl);
+
+error_setup_irq:
+ if (!mhi_cntrl->pre_init)
+ mhi_deinit_dev_ctxt(mhi_cntrl);
+
+error_dev_ctxt:
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_async_power_up);
+
+void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
+{
+ enum mhi_pm_state cur_state;
+
+ /* If it's not a graceful shutdown, force MHI to linkdown state */
+ if (!graceful) {
+ mutex_lock(&mhi_cntrl->pm_mutex);
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ cur_state = mhi_tryset_pm_state(mhi_cntrl,
+ MHI_PM_LD_ERR_FATAL_DETECT);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+ if (cur_state != MHI_PM_LD_ERR_FATAL_DETECT)
+ dev_dbg(mhi_cntrl->dev,
+ "Failed to move to state: %s from: %s\n",
+ to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT),
+ to_mhi_pm_state_str(mhi_cntrl->pm_state));
+ }
+ mhi_pm_disable_transition(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
+ mhi_deinit_free_irq(mhi_cntrl);
+
+ if (!mhi_cntrl->pre_init) {
+ /* Free all allocated resources */
+ if (mhi_cntrl->fbc_image) {
+ mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
+ mhi_cntrl->fbc_image = NULL;
+ }
+ mhi_deinit_dev_ctxt(mhi_cntrl);
+ }
+}
+EXPORT_SYMBOL_GPL(mhi_power_down);
+
+int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
+{
+ int ret = mhi_async_power_up(mhi_cntrl);
+
+ if (ret)
+ return ret;
+
+ wait_event_timeout(mhi_cntrl->state_event,
+ MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
+ MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
+ msecs_to_jiffies(mhi_cntrl->timeout_ms));
+
+ return (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -EIO;
+}
+EXPORT_SYMBOL(mhi_sync_power_up);
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 80633099b90d..04c500323214 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -83,6 +83,17 @@ enum mhi_ch_type {
MHI_CH_TYPE_INBOUND_COALESCED = 3,
};

+/**
+ * struct image_info - Firmware and RDDM table table
+ * @mhi_buf - Buffer for firmware and RDDM table
+ * @entries - # of entries in table
+ */
+struct image_info {
+ struct mhi_buf *mhi_buf;
+ struct bhi_vec_entry *bhi_vec;
+ u32 entries;
+};
+
/**
* enum mhi_ee_type - Execution environment types
* @MHI_EE_PBL: Primary Bootloader
@@ -272,6 +283,7 @@ struct mhi_controller_config {
* @bus_id: Physical bus instance used by the controller
* @regs: Base address of MHI MMIO register space
* @bhi: Points to base of MHI BHI register space
+ * @bhie: Points to base of MHI BHIe register space
* @wake_db: MHI WAKE doorbell register address
* @iova_start: IOMMU starting address for data
* @iova_stop: IOMMU stop address for data
@@ -280,6 +292,7 @@ struct mhi_controller_config {
* @fbc_download: MHI host needs to do complete image transfer
* @sbl_size: SBL image size
* @seg_len: BHIe vector size
+ * @fbc_image: Points to firmware image buffer
* @max_chan: Maximum number of channels the controller supports
* @mhi_chan: Points to the channel configuration table
* @lpm_chans: List of channels that require LPM notifications
@@ -335,6 +348,7 @@ struct mhi_controller {
u32 bus_id;
void __iomem *regs;
void __iomem *bhi;
+ void __iomem *bhie;
void __iomem *wake_db;

dma_addr_t iova_start;
@@ -344,6 +358,7 @@ struct mhi_controller {
bool fbc_download;
size_t sbl_size;
size_t seg_len;
+ struct image_info *fbc_image;
u32 max_chan;
struct mhi_chan *mhi_chan;
struct list_head lpm_chans;
@@ -532,4 +547,40 @@ void mhi_driver_unregister(struct mhi_driver *mhi_drv);
void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
enum mhi_state state);

+/**
+ * mhi_prepare_for_power_up - Do pre-initialization before power up.
+ * This is optional, call this before power up if
+ * the controller does not want bus framework to
+ * automatically free any allocated memory during
+ * shutdown process.
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl);
+
+/**
+ * mhi_async_power_up - Start MHI power up sequence
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_async_power_up(struct mhi_controller *mhi_cntrl);
+
+/**
+ * mhi_sync_power_up - Start MHI power up sequence and wait till the device
+ * device enters valid EE state
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_sync_power_up(struct mhi_controller *mhi_cntrl);
+
+/**
+ * mhi_power_down - Start MHI power down sequence
+ * @mhi_cntrl: MHI controller
+ * @graceful: Link is still accessible, so do a graceful shutdown process
+ */
+void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
+
+/**
+ * mhi_unprepare_after_power_down - Free any allocated memory after power down
+ * @mhi_cntrl: MHI controller
+ */
+void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl);
+
#endif /* _MHI_H_ */
--
2.17.1