[PATCH v7 0/7] PCI: brcmstb: have host-bridge turn on sub-device power

Jim Quinlan
2021-11-03T18:51:46Z

v7 -- RobH suggested putting the "vpcixxx-supply" property under the
bridge-node rather than the endpoint device node. Also, he said to
use the pci-ops add_bus/remove methods. Doing so simplifies the
code greatly and three commits were dropped. Thanks!

-- Rob also suggested (I think) having this patchset be a general
feature which is activated by an OF property under the bridge node.
I tried to do that but realized that our root complex driver
controls the regulators with its dev_pm_ops and there is no way to
transfer this control when using general mechanism. Note that
although the regulator core deals with suspend, our RC driver wants
the right to sometimes to preclude this for WOL scenarios.

-- One commit was added to change the response to the return value of
the pci_ops add_bus() method. Currently, an error causes a WARNING,
a dev_err(...), and continues to return the child bus. The
modification was, for returning -ENOLINK only, to skip WARNING &
dev_err() and return NULL. This is necessary for our RC HW, as if
the code continues on it will do a pci_read_config_dword() for the
vendor/id, and our HW flags a CPU abort (instead of returning
0xffffffff) when the is no pcie-link established.

[NOTE: MarkB, I did not add one of your two "Reviewed-by"s
because the commit had a decent amount of change.]

v6 -- Dropped the idea of a placeholder regulator
property (brcm-ep-a-supply). (MarkB)
-- device_initialize() now called once. Two
commits were added for this. (GKH)
-- In two cases, separated a single function
into two or more functions (MarkB)
-- "(void)foo();" => "foo()". Note that although
foo() returns an int, in this instance it is being
invoked within a function returning void, and foo()
already executes a dev_err() on error. (MarkB)
-- Added a commit to correct PCIe interrupts in YAML.
-- Removed "device_type = "pci";" for the EP node
in the YAML example.
-- Updated the URL related to the voltage regulator
names on GitHub. Note that I added vpciev3v3aux.

v5 [NOTE: It has been a while since v4. Sorry]
-- See "PCI: allow for callback to prepare nascent subdev"
commit message for the cornerstone of this patchset
and the reasons behind it. This is a new commit.
-- The RC driver now looks into its DT children and
turns on regulators for a sub-device, and this occurs
prior to PCIe link as it must.
-- Dropped commits not related to the focus of this patchset.

v4 [NOTE: I'm not sure this fixes RobH and MarkB constraints but I'd
like to use this pullreq as a basis for future discussion.]
[Commit: Add bindings for ...]
-- Fix syntax error in YAML bindings example (RobH)
-- {vpcie12v,vpcie3v3}-supply props are back in root complex DT node
(I believe RobH said this was okay)
[Commit: Add control of ..]
-- Do not do global search for regulator; now we look specifically
for the property {vpcie12v,vpcie3v3}-supply in the root complex
DT node and then call devm_regulator_bulk_get() (MarkB)
-- Use devm_regulator_bulk_get() (Bjorn)
-- s/EP/slot0 device/ (Bjorn)
-- Spelling, capitalization (Bjorn)
-- Have brcm_phy_stop() return a void (Bjorn)
[Commit: Do not turn off ...]
-- Capitalization (Bjorn)
[Commit: Check return value ...]
-- Commit message content (Bjorn)
-- Move 6/6 hunk to 2/6 where it belongs (Bjorn)
-- Move the rest of 6/6 before all other commits (Bjorn)

v3 -- Driver now searches for EP DT subnode for any regulators to turn on.
If present, these regulators have the property names
"vpcie12v-supply" and "vpcie3v3-supply". The existence of these
regulators in the EP subnode are currently pending as a pullreq
in pci-bus.yaml at
https://github.com/devicetree-org/dt-schema/pull/54
(MarkB, RobH).
-- Check return of brcm_set_regulators() (Florian)
-- Specify one regulator string per line for easier update (Florian)
-- Author/Committer/Signoff email changed from that of V2 from
'james.quinlan@broadcom.com' to 'jim2101024@gmail.com'.

v2 -- Use regulator bulk API rather than multiple calls (MarkB).

v1 -- Bindings are added for fixed regulators that may power the EP device.
-- The brcmstb RC driver is modified to control these regulators
during probe, suspend, and resume.
-- 7216 type SOCs have additional error reporting HW and a
panic handler is added to dump its info.
-- A missing return value check is added.

Jim Quinlan (7):
dt-bindings: PCI: Correct brcmstb interrupts, interrupt-map.
dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators
PCI: brcmstb: Split brcm_pcie_setup() into two funcs
PCI: pci_alloc_child_bus() return NULL if ->add_bus() returns -ENOLINK
PCI: brcmstb: Add control of subdevice voltage regulators
PCI: brcmstb: Do not turn off regulators if EP can wake up
PCI: brcmstb: Change brcm_phy_stop() to return void

.../bindings/pci/brcm,stb-pcie.yaml | 31 ++-
drivers/pci/controller/pcie-brcmstb.c | 233 ++++++++++++++++--
drivers/pci/probe.c | 3 +
3 files changed, 250 insertions(+), 17 deletions(-)

base-commit: 8e37395c3a5dceff62a5010ebbbc107f4145935c