lkml.org 
[lkml]   [2020]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 02/16] bus: mhi: core: Add support for registering MHI controllers
    From
    Date
    On 1/23/2020 4:18 AM, Manivannan Sadhasivam wrote:
    > This commit adds support for registering MHI controller drivers with
    > the MHI stack. MHI controller drivers manages the interaction with the
    > MHI client devices such as the external modems and WiFi chipsets. They
    > are also the MHI bus master in charge of managing the physical link
    > between the host and client device.
    >
    > This is based on the patch submitted by Sujeev Dias:
    > https://lkml.org/lkml/2018/7/9/987
    >
    > Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
    > Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
    > [jhugo: added static config for controllers and fixed several bugs]
    > Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
    > [mani: removed DT dependency, splitted and cleaned up for upstream]
    > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
    > ---
    > drivers/bus/Kconfig | 1 +
    > drivers/bus/Makefile | 3 +
    > drivers/bus/mhi/Kconfig | 14 +
    > drivers/bus/mhi/Makefile | 2 +
    > drivers/bus/mhi/core/Makefile | 3 +
    > drivers/bus/mhi/core/init.c | 404 +++++++++++++++++++++++++++++
    > drivers/bus/mhi/core/internal.h | 169 ++++++++++++
    > include/linux/mhi.h | 438 ++++++++++++++++++++++++++++++++
    > include/linux/mod_devicetable.h | 12 +
    > 9 files changed, 1046 insertions(+)
    > create mode 100644 drivers/bus/mhi/Kconfig
    > create mode 100644 drivers/bus/mhi/Makefile
    > create mode 100644 drivers/bus/mhi/core/Makefile
    > create mode 100644 drivers/bus/mhi/core/init.c
    > create mode 100644 drivers/bus/mhi/core/internal.h
    > create mode 100644 include/linux/mhi.h
    >
    > diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
    > index 50200d1c06ea..383934e54786 100644
    > --- a/drivers/bus/Kconfig
    > +++ b/drivers/bus/Kconfig
    > @@ -202,5 +202,6 @@ config DA8XX_MSTPRI
    > peripherals.
    >
    > source "drivers/bus/fsl-mc/Kconfig"
    > +source "drivers/bus/mhi/Kconfig"
    >
    > endmenu
    > diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
    > index 1320bcf9fa9d..05f32cd694a4 100644
    > --- a/drivers/bus/Makefile
    > +++ b/drivers/bus/Makefile
    > @@ -34,3 +34,6 @@ obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
    > obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
    >
    > obj-$(CONFIG_DA8XX_MSTPRI) += da8xx-mstpri.o
    > +
    > +# MHI
    > +obj-$(CONFIG_MHI_BUS) += mhi/
    > diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
    > new file mode 100644
    > index 000000000000..a8bd9bd7db7c
    > --- /dev/null
    > +++ b/drivers/bus/mhi/Kconfig
    > @@ -0,0 +1,14 @@
    > +# SPDX-License-Identifier: GPL-2.0

    first time I noticed this, although I suspect this will need to be
    corrected "everywhere" -
    Per the SPDX website, the "GPL-2.0" label is deprecated. It's
    replacement is "GPL-2.0-only".
    I think all instances should be updated to "GPL-2.0-only"

    > +#
    > +# MHI bus
    > +#
    > +# Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
    > +#
    > +
    > +config MHI_BUS
    > + tristate "Modem Host Interface (MHI) bus"
    > + help
    > + Bus driver for MHI protocol. Modem Host Interface (MHI) is a
    > + communication protocol used by the host processors to control
    > + and communicate with modem devices over a high speed peripheral
    > + bus or shared memory.
    > diff --git a/drivers/bus/mhi/Makefile b/drivers/bus/mhi/Makefile
    > new file mode 100644
    > index 000000000000..19e6443b72df
    > --- /dev/null
    > +++ b/drivers/bus/mhi/Makefile
    > @@ -0,0 +1,2 @@
    > +# core layer
    > +obj-y += core/
    > diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
    > new file mode 100644
    > index 000000000000..2db32697c67f
    > --- /dev/null
    > +++ b/drivers/bus/mhi/core/Makefile
    > @@ -0,0 +1,3 @@
    > +obj-$(CONFIG_MHI_BUS) := mhi.o
    > +
    > +mhi-y := init.o
    > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
    > new file mode 100644
    > index 000000000000..5b817ec250e0
    > --- /dev/null
    > +++ b/drivers/bus/mhi/core/init.c
    > @@ -0,0 +1,404 @@
    > +// SPDX-License-Identifier: GPL-2.0
    > +/*
    > + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
    > + *
    > + */
    > +
    > +#define dev_fmt(fmt) "MHI: " fmt
    > +
    > +#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/mod_devicetable.h>
    > +#include <linux/module.h>
    > +#include <linux/slab.h>
    > +#include <linux/vmalloc.h>
    > +#include <linux/wait.h>
    > +#include "internal.h"
    > +
    > +static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
    > + struct mhi_controller_config *config)
    > +{
    > + int i, num;
    > + struct mhi_event *mhi_event;
    > + struct mhi_event_config *event_cfg;
    > +
    > + num = config->num_events;
    > + mhi_cntrl->total_ev_rings = num;
    > + mhi_cntrl->mhi_event = kcalloc(num, sizeof(*mhi_cntrl->mhi_event),
    > + GFP_KERNEL);
    > + if (!mhi_cntrl->mhi_event)
    > + return -ENOMEM;
    > +
    > + /* Populate event ring */
    > + mhi_event = mhi_cntrl->mhi_event;
    > + for (i = 0; i < num; i++) {
    > + event_cfg = &config->event_cfg[i];
    > +
    > + mhi_event->er_index = i;
    > + mhi_event->ring.elements = event_cfg->num_elements;
    > + mhi_event->intmod = event_cfg->irq_moderation_ms;
    > + mhi_event->irq = event_cfg->irq;
    > +
    > + if (event_cfg->channel != U32_MAX) {
    > + /* This event ring has a dedicated channel */
    > + mhi_event->chan = event_cfg->channel;
    > + if (mhi_event->chan >= mhi_cntrl->max_chan) {
    > + dev_err(mhi_cntrl->dev,
    > + "Event Ring channel not available\n");
    > + goto error_ev_cfg;
    > + }
    > +
    > + mhi_event->mhi_chan =
    > + &mhi_cntrl->mhi_chan[mhi_event->chan];
    > + }
    > +
    > + /* Priority is fixed to 1 for now */
    > + mhi_event->priority = 1;
    > +
    > + mhi_event->db_cfg.brstmode = event_cfg->mode;
    > + if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
    > + goto error_ev_cfg;
    > +
    > + mhi_event->data_type = event_cfg->data_type;
    > +
    > + mhi_event->hw_ring = event_cfg->hardware_event;
    > + if (mhi_event->hw_ring)
    > + mhi_cntrl->hw_ev_rings++;
    > + else
    > + mhi_cntrl->sw_ev_rings++;
    > +
    > + mhi_event->cl_manage = event_cfg->client_managed;
    > + mhi_event->offload_ev = event_cfg->offload_channel;
    > + mhi_event++;
    > + }
    > +
    > + /* We need IRQ for each event ring + additional one for BHI */
    > + mhi_cntrl->nr_irqs_req = mhi_cntrl->total_ev_rings + 1;
    > +
    > + return 0;
    > +
    > +error_ev_cfg:
    > +
    > + kfree(mhi_cntrl->mhi_event);
    > + return -EINVAL;
    > +}
    > +
    > +static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
    > + struct mhi_controller_config *config)
    > +{
    > + int i;
    > + u32 chan;
    > + struct mhi_channel_config *ch_cfg;
    > +
    > + mhi_cntrl->max_chan = config->max_channels;
    > +
    > + /*
    > + * The allocation of MHI channels can exceed 32KB in some scenarios,
    > + * so to avoid any memory possible allocation failures, vzalloc is
    > + * used here
    > + */
    > + mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
    > + sizeof(*mhi_cntrl->mhi_chan));
    > + if (!mhi_cntrl->mhi_chan)
    > + return -ENOMEM;
    > +
    > + INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);
    > +
    > + /* Populate channel configurations */
    > + for (i = 0; i < config->num_channels; i++) {
    > + struct mhi_chan *mhi_chan;
    > +
    > + ch_cfg = &config->ch_cfg[i];
    > +
    > + chan = ch_cfg->num;
    > + if (chan >= mhi_cntrl->max_chan) {
    > + dev_err(mhi_cntrl->dev,
    > + "Channel %d not available\n", chan);
    > + goto error_chan_cfg;
    > + }
    > +
    > + mhi_chan = &mhi_cntrl->mhi_chan[chan];
    > + mhi_chan->name = ch_cfg->name;
    > + mhi_chan->chan = chan;
    > +
    > + mhi_chan->tre_ring.elements = ch_cfg->num_elements;
    > + if (!mhi_chan->tre_ring.elements)
    > + goto error_chan_cfg;
    > +
    > + /*
    > + * For some channels, local ring length should be bigger than
    > + * the transfer ring length due to internal logical channels
    > + * in device. So host can queue much more buffers than transfer
    > + * ring length. Example, RSC channels should have a larger local
    > + * channel length than transfer ring length.
    > + */
    > + mhi_chan->buf_ring.elements = ch_cfg->local_elements;
    > + if (!mhi_chan->buf_ring.elements)
    > + mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
    > + mhi_chan->er_index = ch_cfg->event_ring;
    > + mhi_chan->dir = ch_cfg->dir;
    > +
    > + /*
    > + * For most channels, chtype is identical to channel directions.
    > + * So, if it is not defined then assign channel direction to
    > + * chtype
    > + */
    > + mhi_chan->type = ch_cfg->type;
    > + if (!mhi_chan->type)
    > + mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;
    > +
    > + mhi_chan->ee_mask = ch_cfg->ee_mask;
    > +
    > + mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
    > + mhi_chan->xfer_type = ch_cfg->data_type;
    > +
    > + mhi_chan->lpm_notify = ch_cfg->lpm_notify;
    > + mhi_chan->offload_ch = ch_cfg->offload_channel;
    > + mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
    > + mhi_chan->pre_alloc = ch_cfg->auto_queue;
    > + mhi_chan->auto_start = ch_cfg->auto_start;
    > +
    > + /*
    > + * If MHI host allocates buffers, then the channel direction
    > + * should be DMA_FROM_DEVICE and the buffer type should be
    > + * MHI_BUF_RAW
    > + */
    > + if (mhi_chan->pre_alloc && (mhi_chan->dir != DMA_FROM_DEVICE ||
    > + mhi_chan->xfer_type != MHI_BUF_RAW)) {
    > + dev_err(mhi_cntrl->dev,
    > + "Invalid channel configuration\n");
    > + goto error_chan_cfg;
    > + }
    > +
    > + /*
    > + * Bi-directional and direction less channel must be an
    > + * offload channel
    > + */
    > + if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
    > + mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
    > + dev_err(mhi_cntrl->dev,
    > + "Invalid channel configuration\n");
    > + goto error_chan_cfg;
    > + }
    > +
    > + if (!mhi_chan->offload_ch) {
    > + mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
    > + if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
    > + dev_err(mhi_cntrl->dev,
    > + "Invalid Door bell mode\n");
    > + goto error_chan_cfg;
    > + }
    > + }
    > +
    > + mhi_chan->configured = true;
    > +
    > + if (mhi_chan->lpm_notify)
    > + list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
    > + }
    > +
    > + return 0;
    > +
    > +error_chan_cfg:
    > + vfree(mhi_cntrl->mhi_chan);
    > +
    > + return -EINVAL;
    > +}
    > +
    > +static int parse_config(struct mhi_controller *mhi_cntrl,
    > + struct mhi_controller_config *config)
    > +{
    > + int ret;
    > +
    > + /* Parse MHI channel configuration */
    > + ret = parse_ch_cfg(mhi_cntrl, config);
    > + if (ret)
    > + return ret;
    > +
    > + /* Parse MHI event configuration */
    > + ret = parse_ev_cfg(mhi_cntrl, config);
    > + if (ret)
    > + goto error_ev_cfg;
    > +
    > + mhi_cntrl->timeout_ms = config->timeout_ms;
    > + if (!mhi_cntrl->timeout_ms)
    > + mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
    > +
    > + mhi_cntrl->bounce_buf = config->use_bounce_buf;
    > + mhi_cntrl->buffer_len = config->buf_len;
    > + if (!mhi_cntrl->buffer_len)
    > + mhi_cntrl->buffer_len = MHI_MAX_MTU;
    > +
    > + return 0;
    > +
    > +error_ev_cfg:
    > + vfree(mhi_cntrl->mhi_chan);
    > +
    > + return ret;
    > +}
    > +
    > +int mhi_register_controller(struct mhi_controller *mhi_cntrl,
    > + struct mhi_controller_config *config)
    > +{
    > + int ret;
    > + int i;
    > + struct mhi_event *mhi_event;
    > + struct mhi_chan *mhi_chan;
    > + struct mhi_cmd *mhi_cmd;
    > + struct mhi_device *mhi_dev;
    > +
    > + if (!mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put)
    > + return -EINVAL;
    > +
    > + if (!mhi_cntrl->status_cb || !mhi_cntrl->link_status)
    > + return -EINVAL;
    > +
    > + ret = parse_config(mhi_cntrl, config);
    > + if (ret)
    > + return -EINVAL;
    > +
    > + mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
    > + sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
    > + if (!mhi_cntrl->mhi_cmd) {
    > + ret = -ENOMEM;
    > + goto error_alloc_cmd;
    > + }
    > +
    > + INIT_LIST_HEAD(&mhi_cntrl->transition_list);
    > + spin_lock_init(&mhi_cntrl->transition_lock);
    > + spin_lock_init(&mhi_cntrl->wlock);
    > + init_waitqueue_head(&mhi_cntrl->state_event);
    > +
    > + mhi_cmd = mhi_cntrl->mhi_cmd;
    > + for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
    > + spin_lock_init(&mhi_cmd->lock);
    > +
    > + mhi_event = mhi_cntrl->mhi_event;
    > + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
    > + /* Skip for offload events */
    > + if (mhi_event->offload_ev)
    > + continue;
    > +
    > + mhi_event->mhi_cntrl = mhi_cntrl;
    > + spin_lock_init(&mhi_event->lock);
    > + }
    > +
    > + mhi_chan = mhi_cntrl->mhi_chan;
    > + for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
    > + mutex_init(&mhi_chan->mutex);
    > + init_completion(&mhi_chan->completion);
    > + rwlock_init(&mhi_chan->lock);
    > + }
    > +
    > + /* Register controller with MHI bus */
    > + mhi_dev = mhi_alloc_device(mhi_cntrl);
    > + if (IS_ERR(mhi_dev)) {
    > + dev_err(mhi_cntrl->dev, "Failed to allocate device\n");
    > + ret = PTR_ERR(mhi_dev);
    > + goto error_alloc_dev;
    > + }
    > +
    > + mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
    > + mhi_dev->mhi_cntrl = mhi_cntrl;
    > + dev_set_name(&mhi_dev->dev, "%s", mhi_cntrl->name);
    > +
    > + /* Init wakeup source */
    > + device_init_wakeup(&mhi_dev->dev, true);
    > +
    > + ret = device_add(&mhi_dev->dev);
    > + if (ret)
    > + goto error_add_dev;
    > +
    > + mhi_cntrl->mhi_dev = mhi_dev;
    > +
    > + return 0;
    > +
    > +error_add_dev:
    > + mhi_dealloc_device(mhi_cntrl, mhi_dev);
    > +
    > +error_alloc_dev:
    > + kfree(mhi_cntrl->mhi_cmd);
    > +
    > +error_alloc_cmd:
    > + vfree(mhi_cntrl->mhi_chan);
    > + kfree(mhi_cntrl->mhi_event);
    > +
    > + return ret;
    > +}
    > +EXPORT_SYMBOL_GPL(mhi_register_controller);
    > +
    > +void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
    > +{
    > + struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
    > +
    > + kfree(mhi_cntrl->mhi_cmd);
    > + kfree(mhi_cntrl->mhi_event);
    > + vfree(mhi_cntrl->mhi_chan);
    > +
    > + device_del(&mhi_dev->dev);
    > + put_device(&mhi_dev->dev);
    > +}
    > +EXPORT_SYMBOL_GPL(mhi_unregister_controller);
    > +
    > +static void mhi_release_device(struct device *dev)
    > +{
    > + struct mhi_device *mhi_dev = to_mhi_device(dev);
    > +
    > + if (mhi_dev->ul_chan)
    > + mhi_dev->ul_chan->mhi_dev = NULL;
    > +
    > + if (mhi_dev->dl_chan)
    > + mhi_dev->dl_chan->mhi_dev = NULL;
    > +
    > + kfree(mhi_dev);
    > +}
    > +
    > +struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
    > +{
    > + struct mhi_device *mhi_dev;
    > + struct device *dev;
    > +
    > + mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL);
    > + if (!mhi_dev)
    > + return ERR_PTR(-ENOMEM);
    > +
    > + dev = &mhi_dev->dev;
    > + device_initialize(dev);
    > + dev->bus = &mhi_bus_type;
    > + dev->release = mhi_release_device;
    > + dev->parent = mhi_cntrl->dev;
    > + mhi_dev->mhi_cntrl = mhi_cntrl;
    > + atomic_set(&mhi_dev->dev_wake, 0);
    > +
    > + return mhi_dev;
    > +}
    > +
    > +static int mhi_match(struct device *dev, struct device_driver *drv)
    > +{
    > + return 0;
    > +};
    > +
    > +struct bus_type mhi_bus_type = {
    > + .name = "mhi",
    > + .dev_name = "mhi",
    > + .match = mhi_match,
    > +};
    > +
    > +static int __init mhi_init(void)
    > +{
    > + return bus_register(&mhi_bus_type);
    > +}
    > +
    > +static void __exit mhi_exit(void)
    > +{
    > + bus_unregister(&mhi_bus_type);
    > +}
    > +
    > +postcore_initcall(mhi_init);
    > +module_exit(mhi_exit);
    > +
    > +MODULE_LICENSE("GPL v2");
    > +MODULE_DESCRIPTION("MHI Host Interface");
    > diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
    > new file mode 100644
    > index 000000000000..21f686d3a140
    > --- /dev/null
    > +++ b/drivers/bus/mhi/core/internal.h
    > @@ -0,0 +1,169 @@
    > +/* SPDX-License-Identifier: GPL-2.0 */
    > +/*
    > + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
    > + *
    > + */
    > +
    > +#ifndef _MHI_INT_H
    > +#define _MHI_INT_H
    > +
    > +extern struct bus_type mhi_bus_type;
    > +
    > +/* MHI transfer completion events */
    > +enum mhi_ev_ccs {
    > + MHI_EV_CC_INVALID = 0x0,
    > + MHI_EV_CC_SUCCESS = 0x1,
    > + MHI_EV_CC_EOT = 0x2,
    > + MHI_EV_CC_OVERFLOW = 0x3,
    > + MHI_EV_CC_EOB = 0x4,
    > + MHI_EV_CC_OOB = 0x5,
    > + MHI_EV_CC_DB_MODE = 0x6,
    > + MHI_EV_CC_UNDEFINED_ERR = 0x10,
    > + MHI_EV_CC_BAD_TRE = 0x11,

    Perhaps a quick comment expanding the "EOT", "EOB", "OOB" acronyms? I
    feel like those might not be obvious to someone not familiar with the
    protocol.

    > +};
    > +
    > +enum mhi_ch_state {
    > + MHI_CH_STATE_DISABLED = 0x0,
    > + MHI_CH_STATE_ENABLED = 0x1,
    > + MHI_CH_STATE_RUNNING = 0x2,
    > + MHI_CH_STATE_SUSPENDED = 0x3,
    > + MHI_CH_STATE_STOP = 0x4,
    > + MHI_CH_STATE_ERROR = 0x5,
    > +};
    > +
    > +#define MHI_INVALID_BRSTMODE(mode) (mode != MHI_DB_BRST_DISABLE && \
    > + mode != MHI_DB_BRST_ENABLE)
    > +
    > +#define NR_OF_CMD_RINGS 1
    > +#define CMD_EL_PER_RING 128
    > +#define PRIMARY_CMD_RING 0
    > +#define MHI_MAX_MTU 0xffff
    > +
    > +enum mhi_er_type {
    > + MHI_ER_TYPE_INVALID = 0x0,
    > + MHI_ER_TYPE_VALID = 0x1,
    > +};
    > +
    > +enum mhi_ch_ee_mask {
    > + MHI_CH_EE_PBL = BIT(MHI_EE_PBL),

    MHI_EE_PBL does not appear to be defined. Are you perhaps missing an
    include?

    > + MHI_CH_EE_SBL = BIT(MHI_EE_SBL),
    > + MHI_CH_EE_AMSS = BIT(MHI_EE_AMSS),
    > + MHI_CH_EE_RDDM = BIT(MHI_EE_RDDM),
    > + MHI_CH_EE_PTHRU = BIT(MHI_EE_PTHRU),
    > + MHI_CH_EE_WFW = BIT(MHI_EE_WFW),
    > + MHI_CH_EE_EDL = BIT(MHI_EE_EDL),
    > +};
    > +
    > +struct db_cfg {
    > + bool reset_req;
    > + bool db_mode;
    > + u32 pollcfg;
    > + enum mhi_db_brst_mode brstmode;
    > + dma_addr_t db_val;
    > + void (*process_db)(struct mhi_controller *mhi_cntrl,
    > + struct db_cfg *db_cfg, void __iomem *io_addr,
    > + dma_addr_t db_val);
    > +};
    > +
    > +struct mhi_ring {
    > + dma_addr_t dma_handle;
    > + dma_addr_t iommu_base;
    > + u64 *ctxt_wp; /* point to ctxt wp */
    > + void *pre_aligned;
    > + void *base;
    > + void *rp;
    > + void *wp;
    > + size_t el_size;
    > + size_t len;
    > + size_t elements;
    > + size_t alloc_size;
    > + void __iomem *db_addr;
    > +};
    > +
    > +struct mhi_cmd {
    > + struct mhi_ring ring;
    > + spinlock_t lock;
    > +};
    > +
    > +struct mhi_buf_info {
    > + dma_addr_t p_addr;
    > + void *v_addr;
    > + void *bb_addr;
    > + void *wp;
    > + size_t len;
    > + void *cb_buf;
    > + enum dma_data_direction dir;
    > +};
    > +
    > +struct mhi_event {
    > + u32 er_index;
    > + u32 intmod;
    > + u32 irq;
    > + int chan; /* this event ring is dedicated to a channel (optional) */
    > + u32 priority;
    > + enum mhi_er_data_type data_type;
    > + struct mhi_ring ring;
    > + struct db_cfg db_cfg;
    > + bool hw_ring;
    > + bool cl_manage;
    > + bool offload_ev; /* managed by a device driver */
    > + spinlock_t lock;
    > + struct mhi_chan *mhi_chan; /* dedicated to channel */
    > + struct tasklet_struct task;
    > + int (*process_event)(struct mhi_controller *mhi_cntrl,
    > + struct mhi_event *mhi_event,
    > + u32 event_quota);
    > + struct mhi_controller *mhi_cntrl;
    > +};
    > +
    > +struct mhi_chan {
    > + u32 chan;
    > + const char *name;
    > + /*
    > + * Important: When consuming, increment tre_ring first and when
    > + * releasing, decrement buf_ring first. If tre_ring has space, buf_ring
    > + * is guranteed to have space so we do not need to check both rings.
    > + */
    > + struct mhi_ring buf_ring;
    > + struct mhi_ring tre_ring;
    > + u32 er_index;
    > + u32 intmod;
    > + enum mhi_ch_type type;
    > + enum dma_data_direction dir;
    > + struct db_cfg db_cfg;
    > + enum mhi_ch_ee_mask ee_mask;
    > + enum mhi_buf_type xfer_type;
    > + enum mhi_ch_state ch_state;
    > + enum mhi_ev_ccs ccs;
    > + bool lpm_notify;
    > + bool configured;
    > + bool offload_ch;
    > + bool pre_alloc;
    > + bool auto_start;
    > + int (*gen_tre)(struct mhi_controller *mhi_cntrl,
    > + struct mhi_chan *mhi_chan, void *buf, void *cb,
    > + size_t len, enum mhi_flags flags);
    > + int (*queue_xfer)(struct mhi_device *mhi_dev, struct mhi_chan *mhi_chan,
    > + void *buf, size_t len, enum mhi_flags mflags);
    > + struct mhi_device *mhi_dev;
    > + void (*xfer_cb)(struct mhi_device *mhi_dev, struct mhi_result *result);
    > + struct mutex mutex;
    > + struct completion completion;
    > + rwlock_t lock;
    > + struct list_head node;
    > +};
    > +
    > +/* Default MHI timeout */
    > +#define MHI_TIMEOUT_MS (1000)
    > +
    > +struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl);
    > +static inline void mhi_dealloc_device(struct mhi_controller *mhi_cntrl,
    > + struct mhi_device *mhi_dev)
    > +{
    > + kfree(mhi_dev);
    > +}
    > +
    > +int mhi_destroy_device(struct device *dev, void *data);
    > +void mhi_create_devices(struct mhi_controller *mhi_cntrl);
    > +
    > +#endif /* _MHI_INT_H */
    > diff --git a/include/linux/mhi.h b/include/linux/mhi.h
    > new file mode 100644
    > index 000000000000..69cf9a4b06c7
    > --- /dev/null
    > +++ b/include/linux/mhi.h
    > @@ -0,0 +1,438 @@
    > +/* SPDX-License-Identifier: GPL-2.0 */
    > +/*
    > + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
    > + *
    > + */
    > +#ifndef _MHI_H_
    > +#define _MHI_H_
    > +
    > +#include <linux/device.h>
    > +#include <linux/dma-direction.h>
    > +#include <linux/mutex.h>
    > +#include <linux/rwlock_types.h>
    > +#include <linux/slab.h>
    > +#include <linux/spinlock_types.h>
    > +#include <linux/wait.h>
    > +#include <linux/workqueue.h>
    > +
    > +struct mhi_chan;
    > +struct mhi_event;
    > +struct mhi_ctxt;
    > +struct mhi_cmd;
    > +struct mhi_buf_info;
    > +
    > +/**
    > + * enum mhi_callback - MHI callback
    > + * @MHI_CB_IDLE: MHI entered idle state
    > + * @MHI_CB_PENDING_DATA: New data available for client to process
    > + * @MHI_CB_LPM_ENTER: MHI host entered low power mode
    > + * @MHI_CB_LPM_EXIT: MHI host about to exit low power mode
    > + * @MHI_CB_EE_RDDM: MHI device entered RDDM exec env
    > + * @MHI_CB_EE_MISSION_MODE: MHI device entered Mission Mode exec env
    > + * @MHI_CB_SYS_ERROR: MHI device entered error state (may recover)
    > + * @MHI_CB_FATAL_ERROR: MHI device entered fatal error state
    > + */
    > +enum mhi_callback {
    > + MHI_CB_IDLE,
    > + MHI_CB_PENDING_DATA,
    > + MHI_CB_LPM_ENTER,
    > + MHI_CB_LPM_EXIT,
    > + MHI_CB_EE_RDDM,
    > + MHI_CB_EE_MISSION_MODE,
    > + MHI_CB_SYS_ERROR,
    > + MHI_CB_FATAL_ERROR,
    > +};
    > +
    > +/**
    > + * enum mhi_flags - Transfer flags
    > + * @MHI_EOB: End of buffer for bulk transfer
    > + * @MHI_EOT: End of transfer
    > + * @MHI_CHAIN: Linked transfer
    > + */
    > +enum mhi_flags {
    > + MHI_EOB,
    > + MHI_EOT,
    > + MHI_CHAIN,
    > +};
    > +
    > +/**
    > + * enum mhi_device_type - Device types
    > + * @MHI_DEVICE_XFER: Handles data transfer
    > + * @MHI_DEVICE_TIMESYNC: Use for timesync feature
    > + * @MHI_DEVICE_CONTROLLER: Control device
    > + */
    > +enum mhi_device_type {
    > + MHI_DEVICE_XFER,
    > + MHI_DEVICE_TIMESYNC,
    > + MHI_DEVICE_CONTROLLER,
    > +};
    > +
    > +/**
    > + * enum mhi_ch_type - Channel types
    > + * @MHI_CH_TYPE_INVALID: Invalid channel type
    > + * @MHI_CH_TYPE_OUTBOUND: Outbound channel to the device
    > + * @MHI_CH_TYPE_INBOUND: Inbound channel from the device
    > + * @MHI_CH_TYPE_INBOUND_COALESCED: Coalesced channel for the device to combine
    > + * multiple packets and send them as a single
    > + * large packet to reduce CPU consumption
    > + */
    > +enum mhi_ch_type {
    > + MHI_CH_TYPE_INVALID = 0,
    > + MHI_CH_TYPE_OUTBOUND = DMA_TO_DEVICE,
    > + MHI_CH_TYPE_INBOUND = DMA_FROM_DEVICE,
    > + MHI_CH_TYPE_INBOUND_COALESCED = 3,
    > +};
    > +
    > +/**
    > + * enum mhi_ee_type - Execution environment types
    > + * @MHI_EE_PBL: Primary Bootloader
    > + * @MHI_EE_SBL: Secondary Bootloader
    > + * @MHI_EE_AMSS: Modem, aka the primary runtime EE
    > + * @MHI_EE_RDDM: Ram dump download mode
    > + * @MHI_EE_WFW: WLAN firmware mode
    > + * @MHI_EE_PTHRU: Passthrough
    > + * @MHI_EE_EDL: Embedded downloader
    > + */
    > +enum mhi_ee_type {
    > + MHI_EE_PBL,
    > + MHI_EE_SBL,
    > + MHI_EE_AMSS,
    > + MHI_EE_RDDM,
    > + MHI_EE_WFW,
    > + MHI_EE_PTHRU,
    > + MHI_EE_EDL,
    > + MHI_EE_MAX_SUPPORTED = MHI_EE_EDL,
    > + MHI_EE_DISABLE_TRANSITION, /* local EE, not related to mhi spec */
    > + MHI_EE_NOT_SUPPORTED,
    > + MHI_EE_MAX,
    > +};
    > +
    > +/**
    > + * enum mhi_buf_type - Accepted buffer type for the channel
    > + * @MHI_BUF_RAW: Raw buffer
    > + * @MHI_BUF_SKB: SKB struct
    > + * @MHI_BUF_SCLIST: Scatter-gather list
    > + * @MHI_BUF_NOP: CPU offload channel, host does not accept transfer
    > + * @MHI_BUF_DMA: Receive DMA address mapped by client
    > + * @MHI_BUF_RSC_DMA: RSC type premapped buffer

    Maybe its just me, but what is "RSC"?

    > + */
    > +enum mhi_buf_type {
    > + MHI_BUF_RAW,
    > + MHI_BUF_SKB,
    > + MHI_BUF_SCLIST,
    > + MHI_BUF_NOP,
    > + MHI_BUF_DMA,
    > + MHI_BUF_RSC_DMA,
    > +};
    > +
    > +/**
    > + * enum mhi_er_data_type - Event ring data types
    > + * @MHI_ER_DATA: Only client data over this ring
    > + * @MHI_ER_CTRL: MHI control data and client data
    > + * @MHI_ER_TSYNC: Time sync events
    > + */
    > +enum mhi_er_data_type {
    > + MHI_ER_DATA,
    > + MHI_ER_CTRL,
    > + MHI_ER_TSYNC,
    > +};
    > +
    > +/**
    > + * enum mhi_db_brst_mode - Doorbell mode
    > + * @MHI_DB_BRST_DISABLE: Burst mode disable
    > + * @MHI_DB_BRST_ENABLE: Burst mode enable
    > + */
    > +enum mhi_db_brst_mode {
    > + MHI_DB_BRST_DISABLE = 0x2,
    > + MHI_DB_BRST_ENABLE = 0x3,
    > +};
    > +
    > +/**
    > + * struct mhi_channel_config - Channel configuration structure for controller
    > + * @num: The number assigned to this channel
    > + * @name: The name of this channel
    > + * @num_elements: The number of elements that can be queued to this channel
    > + * @local_elements: The local ring length of the channel
    > + * @event_ring: The event rung index that services this channel
    > + * @dir: Direction that data may flow on this channel
    > + * @type: Channel type
    > + * @ee_mask: Execution Environment mask for this channel

    But the mask defines are in internal.h, so how is a client suposed to
    know what they are?

    > + * @pollcfg: Polling configuration for burst mode. 0 is default. milliseconds
    > + for UL channels, multiple of 8 ring elements for DL channels
    > + * @data_type: Data type accepted by this channel
    > + * @doorbell: Doorbell mode
    > + * @lpm_notify: The channel master requires low power mode notifications
    > + * @offload_channel: The client manages the channel completely
    > + * @doorbell_mode_switch: Channel switches to doorbell mode on M0 transition
    > + * @auto_queue: Framework will automatically queue buffers for DL traffic
    > + * @auto_start: Automatically start (open) this channel
    > + */
    > +struct mhi_channel_config {
    > + u32 num;
    > + char *name;
    > + u32 num_elements;
    > + u32 local_elements;
    > + u32 event_ring;
    > + enum dma_data_direction dir;
    > + enum mhi_ch_type type;
    > + u32 ee_mask;
    > + u32 pollcfg;
    > + enum mhi_buf_type data_type;
    > + enum mhi_db_brst_mode doorbell;
    > + bool lpm_notify;
    > + bool offload_channel;
    > + bool doorbell_mode_switch;
    > + bool auto_queue;
    > + bool auto_start;
    > +};
    > +
    > +/**
    > + * struct mhi_event_config - Event ring configuration structure for controller
    > + * @num_elements: The number of elements that can be queued to this ring
    > + * @irq_moderation_ms: Delay irq for additional events to be aggregated
    > + * @irq: IRQ associated with this ring
    > + * @channel: Dedicated channel number. U32_MAX indicates a non-dedicated ring
    > + * @mode: Doorbell mode
    > + * @data_type: Type of data this ring will process
    > + * @hardware_event: This ring is associated with hardware channels
    > + * @client_managed: This ring is client managed
    > + * @offload_channel: This ring is associated with an offloaded channel
    > + * @priority: Priority of this ring. Use 1 for now
    > + */
    > +struct mhi_event_config {
    > + u32 num_elements;
    > + u32 irq_moderation_ms;
    > + u32 irq;
    > + u32 channel;
    > + enum mhi_db_brst_mode mode;
    > + enum mhi_er_data_type data_type;
    > + bool hardware_event;
    > + bool client_managed;
    > + bool offload_channel;
    > + u32 priority;
    > +};
    > +
    > +/**
    > + * struct mhi_controller_config - Root MHI controller configuration
    > + * @max_channels: Maximum number of channels supported
    > + * @timeout_ms: Timeout value for operations. 0 means use default
    > + * @use_bounce_buf: Use a bounce buffer pool due to limited DDR access
    > + * @m2_no_db: Host is not allowed to ring DB in M2 state
    > + * @buf_len: Size of automatically allocated buffers. 0 means use default
    > + * @num_channels: Number of channels defined in @ch_cfg
    > + * @ch_cfg: Array of defined channels
    > + * @num_events: Number of event rings defined in @event_cfg
    > + * @event_cfg: Array of defined event rings
    > + */
    > +struct mhi_controller_config {
    > + u32 max_channels;
    > + u32 timeout_ms;
    > + bool use_bounce_buf;
    > + bool m2_no_db;
    > + u32 buf_len;
    > + u32 num_channels;
    > + struct mhi_channel_config *ch_cfg;
    > + u32 num_events;
    > + struct mhi_event_config *event_cfg;
    > +};
    > +
    > +/**
    > + * struct mhi_controller - Master MHI controller structure
    > + * @name: Name of the controller
    > + * @dev: Driver model device node for the controller
    > + * @mhi_dev: MHI device instance for the controller
    > + * @dev_id: Device ID of the controller
    > + * @bus_id: Physical bus instance used by the controller
    > + * @regs: Base address of MHI MMIO register space
    > + * @iova_start: IOMMU starting address for data
    > + * @iova_stop: IOMMU stop address for data
    > + * @fw_image: Firmware image name for normal booting
    > + * @edl_image: Firmware image name for emergency download mode
    > + * @fbc_download: MHI host needs to do complete image transfer
    > + * @sbl_size: SBL image size
    > + * @seg_len: BHIe vector size
    > + * @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
    > + * @total_ev_rings: Total # of event rings allocated
    > + * @hw_ev_rings: Number of hardware event rings
    > + * @sw_ev_rings: Number of software event rings
    > + * @nr_irqs_req: Number of IRQs required to operate
    > + * @nr_irqs: Number of IRQ allocated by bus master
    > + * @irq: base irq # to request
    > + * @mhi_event: MHI event ring configurations table
    > + * @mhi_cmd: MHI command ring configurations table
    > + * @mhi_ctxt: MHI device context, shared memory between host and device
    > + * @timeout_ms: Timeout in ms for state transitions
    > + * @pm_mutex: Mutex for suspend/resume operation
    > + * @pre_init: MHI host needs to do pre-initialization before power up
    > + * @pm_lock: Lock for protecting MHI power management state
    > + * @pm_state: MHI power management state
    > + * @db_access: DB access states
    > + * @ee: MHI device execution environment
    > + * @wake_set: Device wakeup set flag
    > + * @dev_wake: Device wakeup count
    > + * @alloc_size: Total memory allocations size of the controller
    > + * @pending_pkts: Pending packets for the controller
    > + * @transition_list: List of MHI state transitions
    > + * @wlock: Lock for protecting device wakeup
    > + * @M0: M0 state counter for debugging
    > + * @M2: M2 state counter for debugging
    > + * @M3: M3 state counter for debugging
    > + * @M3_FAST: M3 Fast state counter for debugging
    > + * @st_worker: State transition worker
    > + * @fw_worker: Firmware download worker
    > + * @syserr_worker: System error worker
    > + * @state_event: State change event
    > + * @status_cb: CB function to notify various power states to bus master
    > + * @link_status: CB function to query link status of the device
    > + * @wake_get: CB function to assert device wake
    > + * @wake_put: CB function to de-assert device wake
    > + * @wake_toggle: CB function to assert and deasset (toggle) device wake
    > + * @runtime_get: CB function to controller runtime resume
    > + * @runtimet_put: CB function to decrement pm usage
    > + * @lpm_disable: CB function to request disable link level low power modes
    > + * @lpm_enable: CB function to request enable link level low power modes again
    > + * @bounce_buf: Use of bounce buffer
    > + * @buffer_len: Bounce buffer length
    > + * @priv_data: Points to bus master's private data
    > + */
    > +struct mhi_controller {
    > + const char *name;
    > + struct device *dev;
    > + struct mhi_device *mhi_dev;
    > + u32 dev_id;
    > + u32 bus_id;
    > + void __iomem *regs;
    > + dma_addr_t iova_start;
    > + dma_addr_t iova_stop;
    > + const char *fw_image;
    > + const char *edl_image;
    > + bool fbc_download;
    > + size_t sbl_size;
    > + size_t seg_len;
    > + u32 max_chan;
    > + struct mhi_chan *mhi_chan;
    > + struct list_head lpm_chans;
    > + u32 total_ev_rings;
    > + u32 hw_ev_rings;
    > + u32 sw_ev_rings;
    > + u32 nr_irqs_req;
    > + u32 nr_irqs;
    > + int *irq;
    > +
    > + struct mhi_event *mhi_event;
    > + struct mhi_cmd *mhi_cmd;
    > + struct mhi_ctxt *mhi_ctxt;
    > +
    > + u32 timeout_ms;
    > + struct mutex pm_mutex;
    > + bool pre_init;
    > + rwlock_t pm_lock;
    > + u32 pm_state;
    > + u32 db_access;
    > + enum mhi_ee_type ee;
    > + bool wake_set;
    > + atomic_t dev_wake;
    > + atomic_t alloc_size;
    > + atomic_t pending_pkts;
    > + struct list_head transition_list;
    > + spinlock_t transition_lock;
    > + spinlock_t wlock;
    > + u32 M0, M2, M3, M3_FAST;
    > + struct work_struct st_worker;
    > + struct work_struct fw_worker;
    > + struct work_struct syserr_worker;
    > + wait_queue_head_t state_event;
    > +
    > + void (*status_cb)(struct mhi_controller *mhi_cntrl, void *priv,
    > + enum mhi_callback cb);
    > + int (*link_status)(struct mhi_controller *mhi_cntrl, void *priv);
    > + void (*wake_get)(struct mhi_controller *mhi_cntrl, bool override);
    > + void (*wake_put)(struct mhi_controller *mhi_cntrl, bool override);
    > + void (*wake_toggle)(struct mhi_controller *mhi_cntrl);
    > + int (*runtime_get)(struct mhi_controller *mhi_cntrl, void *priv);
    > + void (*runtime_put)(struct mhi_controller *mhi_cntrl, void *priv);
    > + void (*lpm_disable)(struct mhi_controller *mhi_cntrl, void *priv);
    > + void (*lpm_enable)(struct mhi_controller *mhi_cntrl, void *priv);
    > +
    > + bool bounce_buf;
    > + size_t buffer_len;
    > + void *priv_data;
    > +};
    > +
    > +/**
    > + * struct mhi_device - Structure representing a MHI device which binds
    > + * to channels
    > + * @dev: Driver model device node for the MHI device
    > + * @tiocm: Device current terminal settings
    > + * @id: Pointer to MHI device ID struct
    > + * @chan_name: Name of the channel to which the device binds
    > + * @mhi_cntrl: Controller the device belongs to
    > + * @ul_chan: UL channel for the device
    > + * @dl_chan: DL channel for the device
    > + * @dev_wake: Device wakeup counter
    > + * @dev_type: MHI device type
    > + */
    > +struct mhi_device {
    > + struct device dev;
    > + u32 tiocm;
    > + const struct mhi_device_id *id;
    > + const char *chan_name;
    > + struct mhi_controller *mhi_cntrl;
    > + struct mhi_chan *ul_chan;
    > + struct mhi_chan *dl_chan;
    > + atomic_t dev_wake;
    > + enum mhi_device_type dev_type;
    > +};
    > +
    > +/**
    > + * struct mhi_result - Completed buffer information
    > + * @buf_addr: Address of data buffer
    > + * @dir: Channel direction
    > + * @bytes_xfer: # of bytes transferred
    > + * @transaction_status: Status of last transaction
    > + */
    > +struct mhi_result {
    > + void *buf_addr;
    > + enum dma_data_direction dir;
    > + size_t bytes_xferd;

    Desription says this is named "bytes_xfer"

    > + int transaction_status;
    > +};
    > +
    > +#define to_mhi_device(dev) container_of(dev, struct mhi_device, dev)
    > +
    > +/**
    > + * mhi_controller_set_devdata - Set MHI controller private data
    > + * @mhi_cntrl: MHI controller to set data
    > + */
    > +static inline void mhi_controller_set_devdata(struct mhi_controller *mhi_cntrl,
    > + void *priv)
    > +{
    > + mhi_cntrl->priv_data = priv;
    > +}
    > +
    > +/**
    > + * mhi_controller_get_devdata - Get MHI controller private data
    > + * @mhi_cntrl: MHI controller to get data
    > + */
    > +static inline void *mhi_controller_get_devdata(struct mhi_controller *mhi_cntrl)
    > +{
    > + return mhi_cntrl->priv_data;
    > +}
    > +
    > +/**
    > + * mhi_register_controller - Register MHI controller
    > + * @mhi_cntrl: MHI controller to register
    > + * @config: Configuration to use for the controller
    > + */
    > +int mhi_register_controller(struct mhi_controller *mhi_cntrl,
    > + struct mhi_controller_config *config);
    > +
    > +/**
    > + * mhi_unregister_controller - Unregister MHI controller
    > + * @mhi_cntrl: MHI controller to unregister
    > + */
    > +void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
    > +
    > +#endif /* _MHI_H_ */
    > diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
    > index e3596db077dc..be15e997fe39 100644
    > --- a/include/linux/mod_devicetable.h
    > +++ b/include/linux/mod_devicetable.h
    > @@ -821,4 +821,16 @@ struct wmi_device_id {
    > const void *context;
    > };
    >
    > +#define MHI_NAME_SIZE 32
    > +
    > +/**
    > + * struct mhi_device_id - MHI device identification
    > + * @chan: MHI channel name
    > + * @driver_data: driver data;
    > + */
    > +struct mhi_device_id {
    > + const char chan[MHI_NAME_SIZE];
    > + kernel_ulong_t driver_data;
    > +};
    > +
    > #endif /* LINUX_MOD_DEVICETABLE_H */
    >


    --
    Jeffrey Hugo
    Qualcomm Technologies, Inc. is a member of the
    Code Aurora Forum, a Linux Foundation Collaborative Project.

    \
     
     \ /
      Last update: 2020-01-23 18:07    [W:2.574 / U:0.328 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site