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

Pali Rohár
2022-07-28T13:04:23Z

Release PERST# signal via GPIO when "reset-gpios" is defined in device tree.

Signed-off-by: Pali Rohár <pali@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;
--
2.20.1