| Message ID | 20250325071832.21229-3-mike.looijmans@topic.nl (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] pcie-xilinx: Wait for link-up status during initialization | expand |
On Tue, Mar 25, 2025 at 08:18:27AM +0100, Mike Looijmans wrote: > Support providing the PERST# reset signal through a devicetree binding. > Thus the system no longer relies on external components to perform the > bus reset. > > Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> > --- > > Changes in v2: > Split into "reset GPIO" and "wait for link" patches > Handle GPIO defer and/or errors > > drivers/pci/controller/pcie-xilinx.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/pci/controller/pcie-xilinx.c b/drivers/pci/controller/pcie-xilinx.c > index 2e59b91f43e0..e191ab95d669 100644 > --- a/drivers/pci/controller/pcie-xilinx.c > +++ b/drivers/pci/controller/pcie-xilinx.c > @@ -18,6 +18,7 @@ > #include <linux/iopoll.h> > #include <linux/msi.h> > #include <linux/of_address.h> > +#include <linux/of_gpio.h> Correct header is: #include <linux/gpio/consumer.h> > #include <linux/of_pci.h> > #include <linux/of_platform.h> > #include <linux/of_irq.h> > @@ -577,11 +578,17 @@ static int xilinx_pcie_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct xilinx_pcie *pcie; > struct pci_host_bridge *bridge; > + struct gpio_desc *perst_gpio; > int err; > > if (!dev->of_node) > return -ENODEV; > > + perst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); > + if (IS_ERR(perst_gpio)) > + return dev_err_probe(dev, PTR_ERR(perst_gpio), > + "reset-gpios request failed\n"); 'Failed to request reset GPIO' > + > bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie)); > if (!bridge) > return -ENODEV; > @@ -596,6 +603,13 @@ static int xilinx_pcie_probe(struct platform_device *pdev) > return err; > } > > + if (perst_gpio) { > + usleep_range(10, 20); /* Assert the reset for ~10 us */ Delay should be PCIE_T_PVPERL_MS. > + gpiod_set_value_cansleep(perst_gpio, 0); > + /* Initial delay to provide endpoint time to restart */ s/restart/initialize - Mani
diff --git a/drivers/pci/controller/pcie-xilinx.c b/drivers/pci/controller/pcie-xilinx.c index 2e59b91f43e0..e191ab95d669 100644 --- a/drivers/pci/controller/pcie-xilinx.c +++ b/drivers/pci/controller/pcie-xilinx.c @@ -18,6 +18,7 @@ #include <linux/iopoll.h> #include <linux/msi.h> #include <linux/of_address.h> +#include <linux/of_gpio.h> #include <linux/of_pci.h> #include <linux/of_platform.h> #include <linux/of_irq.h> @@ -577,11 +578,17 @@ static int xilinx_pcie_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct xilinx_pcie *pcie; struct pci_host_bridge *bridge; + struct gpio_desc *perst_gpio; int err; if (!dev->of_node) return -ENODEV; + perst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(perst_gpio)) + return dev_err_probe(dev, PTR_ERR(perst_gpio), + "reset-gpios request failed\n"); + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie)); if (!bridge) return -ENODEV; @@ -596,6 +603,13 @@ static int xilinx_pcie_probe(struct platform_device *pdev) return err; } + if (perst_gpio) { + usleep_range(10, 20); /* Assert the reset for ~10 us */ + gpiod_set_value_cansleep(perst_gpio, 0); + /* Initial delay to provide endpoint time to restart */ + usleep_range(1000, 2000); + } + xilinx_pcie_init_port(pcie); err = xilinx_pcie_init_irq_domain(pcie);
Support providing the PERST# reset signal through a devicetree binding. Thus the system no longer relies on external components to perform the bus reset. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> --- Changes in v2: Split into "reset GPIO" and "wait for link" patches Handle GPIO defer and/or errors drivers/pci/controller/pcie-xilinx.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)