[PATCH] pci: pci_mvebu: Add support for reset-gpios

[Pali Rohár]

On Friday 05 August 2022 13:01:27 Stefan Roese wrote:
> On 28.07.22 15:03, Pali Rohár wrote:
> > Release PERST# signal via GPIO when "reset-gpios" is defined in device tree.
> > 
> > Signed-off-by: Pali Rohár <pali at kernel.org>
> > ---
> >   drivers/pci/pci_mvebu.c | 14 ++++++++++++++
> >   1 file changed, 14 insertions(+)
> > 
> > diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
> > index d80f87e0cfc6..269c027db204 100644
> > --- a/drivers/pci/pci_mvebu.c
> > +++ b/drivers/pci/pci_mvebu.c
> > @@ -22,6 +22,7 @@
> >   #include <asm/io.h>
> >   #include <asm/arch/cpu.h>
> >   #include <asm/arch/soc.h>
> > +#include <asm-generic/gpio.h>
> >   #include <linux/bitops.h>
> >   #include <linux/delay.h>
> >   #include <linux/errno.h>
> > @@ -60,6 +61,7 @@ struct mvebu_pcie {
> >   	struct resource mem;
> >   	void __iomem *iobase;
> >   	struct resource io;
> > +	struct gpio_desc reset_gpio;
> >   	u32 intregs;
> >   	u32 port;
> >   	u32 lane;
> > @@ -416,6 +418,14 @@ static int mvebu_pcie_probe(struct udevice *dev)
> >   	struct udevice *ctlr = pci_get_controller(dev);
> >   	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
> >   	u32 reg;
> > +	int ret;
> > +
> > +	/* Request for optional PERST# GPIO */
> > +	ret = gpio_request_by_name(dev, "reset-gpios", 0, &pcie->reset_gpio, GPIOD_IS_OUT);
> > +	if (ret && ret != -ENOENT) {
> > +		printf("%s: unable to request reset-gpios: %d\n", pcie->name, ret);
> > +		return ret;
> > +	}
> >   	/*
> >   	 * Change Class Code of PCI Bridge device to PCI Bridge (0x600400)
> > @@ -537,6 +547,10 @@ static int mvebu_pcie_probe(struct udevice *dev)
> >   	pcie->cfgcache[(PCI_PREF_MEMORY_BASE - 0x10) / 4] =
> >   		PCI_PREF_RANGE_TYPE_64 | (PCI_PREF_RANGE_TYPE_64 << 16);
> > +	/* Release PERST# via GPIO when it was defined */
> > +	if (dm_gpio_is_valid(&pcie->reset_gpio))
> > +		dm_gpio_set_value(&pcie->reset_gpio, 0);
> > +
> >   	mvebu_pcie_wait_for_link(pcie);
> >   	return 0;
> 
> While running some build tests, this error shows on some Kirkwood
> boards:
> 
> $ make pogo_v4_defconfig
> $ make -s -j20
> ===================== WARNING ======================
> This board does not use CONFIG_TIMER (Driver Model
> for Timer drivers). Please update the board to use
> CONFIG_TIMER before the v2023.01 release. Failure to
> update by the deadline may result in board removal.
> See doc/develop/driver-model/migration.rst for more info.
> ====================================================
> ===================== WARNING ======================
> This board does not use CONFIG_DM_SERIAL (Driver Model
> for Serial drivers). Please update the board to use
> CONFIG_DM_SERIAL before the v2023.04 release. Failure to
> update by the deadline may result in board removal.
> See doc/develop/driver-model/migration.rst for more info.
> ====================================================
> /opt/kernel.org/gcc-11.1.0-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-ld.bfd:
> drivers/pci/pci_mvebu.o: in function `mvebu_pcie_probe':
> /home/stefan/git/u-boot/u-boot-marvell/drivers/pci/pci_mvebu.c:424:
> undefined reference to `gpio_request_by_name'
> /opt/kernel.org/gcc-11.1.0-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-ld.bfd:
> /home/stefan/git/u-boot/u-boot-marvell/drivers/pci/pci_mvebu.c:552:
> undefined reference to `dm_gpio_set_value'
> make: *** [Makefile:1818: u-boot] Error 1
> 
> Could you please take a look and make sure, that world build succeeds?
> 
> Thanks,
> Stefan

There is probably missing DM_GPIO. Now I started CI test on github:
https://github.com/u-boot/u-boot/pull/204
After that I will send v2.