Re: [PATCH v2] pci: pci_mvebu: Add support for reset-gpios

Stefan Roese
2022-08-05T14:15:15Z

On 05.08.22 16:03, Pali Rohár wrote:
> Release PERST# signal via GPIO when "reset-gpios" is defined in device tree.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Stefan Roese <sr@denx.de>
> ---
> Changes in v2:
> * select DM_GPIO
> * use asm/gpio.h

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan

> ---
> drivers/pci/Kconfig | 1 +
> drivers/pci/pci_mvebu.c | 14 ++++++++++++++
> 2 files changed, 15 insertions(+)
>
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index 436acca898e4..22f4995453ed 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -301,6 +301,7 @@ config PCI_MVEBU
> depends on (ARCH_KIRKWOOD || ARCH_MVEBU)
> select MISC
> select DM_RESET
> + select DM_GPIO
> help
> Say Y here if you want to enable PCIe controller support on
> Kirkwood and Armada 370/XP/375/38x SoCs.
> diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
> index d80f87e0cfc6..5bd340a421b8 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/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;

Viele Grüße,
Stefan Roese

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