PCI: mt7621: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/linux-pci/20230321193208.366561-12-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

PCI: mt7621: Use dev_info() to log PCIe card detection

When there is no card plugged on a PCIe port a log reporting that
the port will be disabled is flagged as an error (dev_err()).

Since this is not an error at all, change the log level by using
dev_info() instead.

Link: https://lore.kernel.org/r/20230324073733.1596231-1-sergio.paracuellos@gmail.com
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

PCI: mt7621: Delay phy ports initialization

Some devices like ZBT WE1326 and ZBT WF3526-P and some Netgear models need
to delay phy port initialization after calling the mt7621_pcie_init_port()
driver function to get into reliable boots for both warm and hard resets.

The delay required to detect the ports seems to be in the range [75-100]
milliseconds.

If the ports are not detected the controller is not functional.

There is no datasheet or something similar to really understand why this
extra delay is needed only for these devices and it is not for most of
the boards that are built on mt7621 SoC.

This issue has been reported by openWRT community and the complete
discussion is in [0]. The 100 milliseconds delay has been tested in all
devices to validate it.

Add the extra 100 milliseconds delay to fix the issue.

[0]: https://github.com/openwrt/openwrt/pull/11220

Link: https://lore.kernel.org/r/20221231074041.264738-1-sergio.paracuellos@gmail.com
Fixes: 2bdd5238e756 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver")
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

PCI: mt7621: Add sentinel to quirks table

Current driver is missing a sentinel in the struct soc_device_attribute
array, which causes an oops when assessed by the
soc_device_match(mt7621_pcie_quirks_match) call.

This was only exposed once the CONFIG_SOC_MT7621 mt7621 soc_dev_attr
was fixed to register the SOC as a device, in:

commit 7c18b64bba3b ("mips: ralink: mt7621: do not use kzalloc too early")

Fix it by adding the required sentinel.

Link: https://lore.kernel.org/lkml/26ebbed1-0fe9-4af9-8466-65f841d0b382@app.fastmail.com
Link: https://lore.kernel.org/r/20221205204645.301301-1-git@johnthomson.fastmail.com.au
Fixes: b483b4e4d3f6 ("staging: mt7621-pci: add quirks for 'E2' revision using 'soc_device_attribute'")
Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

PCI: mt7621: Use PCI_CONF1_EXT_ADDRESS() macro

Simplify pcie-mt7621.c driver code and use new PCI_CONF1_EXT_ADDRESS()
macro for accessing PCIe config space.

Link: https://lore.kernel.org/r/20220924092404.31776-4-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

PCI: mt7621: Remove unused function pcie_rmw()

Function pcie_rmw() is not being used at all and can be deleted. Hence get
rid of it, which fixes this warning:

drivers/pci/controller/pcie-mt7621.c:112:20: warning: unused function 'pcie_rmw' [-Wunused-function]

Fixes: 2bdd5238e756 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver")
Link: https://lore.kernel.org/r/20220124113003.406224-3-sergio.paracuellos@gmail.com
Link: https://lore.kernel.org/all/202201241754.igtHzgHv-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: mt7621: Drop of_match_ptr() to avoid unused variable

We have stubs for most OF interfaces even when CONFIG_OF is not set, so we
allow building of pcie-mt7621.c in that case for compile testing.

When CONFIG_OF is not set, "of_match_ptr(mt7621_pcie_ids)" compiles to
NULL, which leaves mt7621_pcie_ids unused:

$ make W=1
drivers/pci/controller/pcie-mt7621.c:549:34: warning: unused variable 'mt7621_pcie_ids' [-Wunused-const-variable]

Drop of_match_ptr() to avoid the unused variable warning.

[bhelgaas: commit log]
Fixes: 2bdd5238e756 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver")
Link: https://lore.kernel.org/r/20220124113003.406224-2-sergio.paracuellos@gmail.com
Link: https://lore.kernel.org/r/202201241754.igtHzgHv-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: mt7621: Add missing MODULE_LICENSE()

The MT7621 PCIe host controller driver can be built as a module, but it
lacks a MODULE_LICENSE(), which causes a build error:

ERROR: modpost: missing MODULE_LICENSE() in drivers/pci/controller/pcie-mt7621.o

Add MODULE_LICENSE() to the driver.

Fixes: 2bdd5238e756 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver")
Link: https://lore.kernel.org/r/20211207104924.21327-5-sergio.paracuellos@gmail.com
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

PCI: mt7621: Move MIPS setup to pcibios_root_bridge_prepare()

On the MIPS ralink mt7621 platform, we need to set up I/O coherency units
based on the host bridge apertures.

To remove this arch dependency from the driver itself, move the coherency
setup from the driver to pcibios_root_bridge_prepare().

[bhelgaas: squash add/remove into one patch, commit log]
Link: https://lore.kernel.org/r/20211207104924.21327-3-sergio.paracuellos@gmail.com
Link: https://lore.kernel.org/r/20211207104924.21327-4-sergio.paracuellos@gmail.com
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net> # arch/mips
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> # arch/mips

PCI: mt7621: Declare mt7621_pci_ops static

Sparse complains about mt7621_pci_ops symbol is not declared and asks if
it should be declared as static instead. Sparse is right. Hence declare
symbol as static.

Link: https://lore.kernel.org/r/20211117152952.12271-1-sergio.paracuellos@gmail.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

PCI: mt7621: Rename mt7621_pci_ to mt7621_pcie_

Rename mt7621_pci_* structs and functions to mt7621_pcie_* for consistency
with the rest of the file.

Link: https://lore.kernel.org/r/20211223011054.1227810-18-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>

PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver

Add driver for the PCIe controller of the MT7621 SoC.

[bhelgaas: rename from pci-mt7621.c to pcie-mt7621.c; also rename Kconfig
symbol from PCI_MT7621 to PCIE_MT7621]
Link: https://lore.kernel.org/r/20210922050035.18162-3-sergio.paracuellos@gmail.com
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>