net: wwan: t7xx: Infrastructure for early port configuration

To support cases such as FW update or Core dump, the t7xx
device is capable of signaling the host that a special port
needs to be created before the handshake phase.

Adds the infrastructure required to create the early ports
which also requires a different configuration of CLDMA queues.

Base on the v5 patch version of follow series:
'net: wwan: t7xx: fw flashing & coredump support'
(https://patchwork.kernel.org/project/netdevbpf/patch/3777bb382f4b0395cb594a602c5c79dbab86c9e0.1674307425.git.m.chetan.kumar@linux.intel.com/)

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Add sysfs attribute for device state machine

Add support for userspace to get/set the device mode, device's state
machine changes between (unknown/ready/reset/fastboot).

Get the device state mode:
- 'cat /sys/bus/pci/devices/${bdf}/t7xx_mode'

Set the device state mode:
- reset(cold reset): 'echo reset > /sys/bus/pci/devices/${bdf}/t7xx_mode'
- fastboot: 'echo fastboot_switching > /sys/bus/pci/devices/${bdf}/t7xx_mode'
Reload driver to get the new device state after setting operation.

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Ensure init is completed before system sleep

When the system attempts to sleep while mtk_t7xx is not ready, the driver
cannot put the device to sleep:
[ 12.472918] mtk_t7xx 0000:57:00.0: [PM] Exiting suspend, modem in invalid state
[ 12.472936] mtk_t7xx 0000:57:00.0: PM: pci_pm_suspend(): t7xx_pci_pm_suspend+0x0/0x20 [mtk_t7xx] returns -14
[ 12.473678] mtk_t7xx 0000:57:00.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1b0 returns -14
[ 12.473711] mtk_t7xx 0000:57:00.0: PM: failed to suspend async: error -14
[ 12.764776] PM: Some devices failed to suspend, or early wake event detected

Mediatek confirmed the device can take a rather long time to complete
its initialization, so wait for up to 20 seconds until init is done.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Fix Runtime PM initialization

For PCI devices the Runtime PM refcount is incremented twice:
1. During device enumeration with a call to pm_runtime_forbid.
2. Just before a driver probe logic is called.
Because of that in order to enable Runtime PM on a given device
we have to call both pm_runtime_allow and pm_runtime_put_noidle,
once it's ready to be runtime suspended.
The former was missing causing the pm refcount to never reach 0.

Fixes: d10b3a695ba0 ("net: wwan: t7xx: Runtime PM")
Signed-off-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "Merge branch 'wwan-t7xx-fw-flashing-and-coredump-support'"

This reverts commit 5417197dd516a8e115aa69f62a7b7554b0c3829c, reversing
changes made to 0630f64d25a0f0a8c6a9ce9fde8750b3b561e6f5.

Reverting to allow addressing review comments.

Link: https://lore.kernel.org/all/4c5dbea0-52a9-1c3d-7547-00ea54c90550@linux.intel.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: wwan: t7xx: Enable devlink based fw flashing and coredump collection

This patch brings-in support for t7xx wwan device firmware flashing &
coredump collection using devlink.

Driver Registers with Devlink framework.
Implements devlink ops flash_update callback that programs modem firmware.
Creates region & snapshot required for device coredump log collection.
On early detection of wwan device in fastboot mode driver sets up CLDMA0 HW
tx/rx queues for raw data transfer then registers with devlink framework.
Upon receiving firmware image & partition details driver sends fastboot
commands for flashing the firmware.

In this flow the fastboot command & response gets exchanged between driver
and device. Once firmware flashing is success completion status is reported
to user space application.

Below is the devlink command usage for firmware flashing

$devlink dev flash pci/$BDF file ABC.img component ABC

Note: ABC.img is the firmware to be programmed to "ABC" partition.

In case of coredump collection when wwan device encounters an exception
it reboots & stays in fastboot mode for coredump collection by host driver.
On detecting exception state driver collects the core dump, creates the
devlink region & reports an event to user space application for dump
collection. The user space application invokes devlink region read command
for dump collection.

Below are the devlink commands used for coredump collection.

devlink region new pci/$BDF/mr_dump
devlink region read pci/$BDF/mr_dump snapshot $ID address $ADD length $LEN
devlink region del pci/$BDF/mr_dump snapshot $ID

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: Devegowda Chandrashekar <chandrashekar.devegowda@intel.com>
Signed-off-by: Mishra Soumya Prakash <soumya.prakash.mishra@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: PCIe reset rescan

PCI rescan module implements "rescan work queue". In firmware flashing
or coredump collection procedure WWAN device is programmed to boot in
fastboot mode and a work item is scheduled for removal & detection.
The WWAN device is reset using APCI call as part driver removal flow.
Work queue rescans pci bus at fixed interval for device detection,
later when device is detect work queue exits.

Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
Co-developed-by: Madhusmita Sahu <madhusmita.sahu@intel.com>
Signed-off-by: Madhusmita Sahu <madhusmita.sahu@intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: Devegowda Chandrashekar <chandrashekar.devegowda@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Fix smatch errors

t7xx_request_irq() error: uninitialized symbol 'ret'.

t7xx_core_hk_handler() error: potentially dereferencing uninitialized 'event'.
If the condition to enter the loop that waits for the handshake event
is false on the first iteration then the uninitialized 'event' will be
dereferenced, fix this by initializing 'event' to NULL.

t7xx_port_proxy_recv_skb() warn: variable dereferenced before check 'skb'.
No need to check skb at t7xx_port_proxy_recv_skb() since we know it
is always called with a valid skb by t7xx_cldma_gpd_rx_from_q().

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Link: https://lore.kernel.org/r/20220518195529.126246-1-ricardo.martinez@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: wwan: t7xx: Device deep sleep lock/unlock

Introduce the mechanism to lock/unlock the device 'deep sleep' mode.
When the PCIe link state is L1.2 or L2, the host side still can keep
the device is in D0 state from the host side point of view. At the same
time, if the device's 'deep sleep' mode is unlocked, the device will
go to 'deep sleep' while it is still in D0 state on the host side.

Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Runtime PM

Enables runtime power management callbacks including runtime_suspend
and runtime_resume. Autosuspend is used to prevent overhead by frequent
wake-ups.

Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Co-developed-by: Eliot Lee <eliot.lee@intel.com>
Signed-off-by: Eliot Lee <eliot.lee@intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Introduce power management

Implements suspend, resumes, freeze, thaw, poweroff, and restore
`dev_pm_ops` callbacks.

From the host point of view, the t7xx driver is one entity. But, the
device has several modules that need to be addressed in different ways
during power management (PM) flows.
The driver uses the term 'PM entities' to refer to the 2 DPMA and
2 CLDMA HW blocks that need to be managed during PM flows.
When a dev_pm_ops function is called, the PM entities list is iterated
and the matching function is called for each entry in the list.

Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: t7xx: Add core components

Registers the t7xx device driver with the kernel. Setup all the core
components: PCIe layer, Modem Host Cross Core Interface (MHCCIF),
modem control operations, modem state machine, and build
infrastructure.

* PCIe layer code implements driver probe and removal.
* MHCCIF provides interrupt channels to communicate events
such as handshake, PM and port enumeration.
* Modem control implements the entry point for modem init,
reset and exit.
* The modem status monitor is a state machine used by modem control
to complete initialization and stop. It is used also to propagate
exception events reported by other components.

Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>