On Thu, Apr 11, 2019 at 10:33:54PM +0530, Manikanta Maddireddy wrote:
> Add support for GPIO based PERST# instead of SFIO mode controller by AFI.
> GPIO number comes from per port PCIe device tree node.
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
> ---
> drivers/pci/controller/pci-tegra.c | 37 +++++++++++++++++++++++++-----
> 1 file changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
> index 4a91c9fb3a9d..75873e6627f9 100644
> --- a/drivers/pci/controller/pci-tegra.c
> +++ b/drivers/pci/controller/pci-tegra.c
> @@ -17,6 +17,7 @@
> #include <linux/debugfs.h>
> #include <linux/delay.h>
> #include <linux/export.h>
> +#include <linux/gpio.h>
> #include <linux/interrupt.h>
> #include <linux/iopoll.h>
> #include <linux/irq.h>
> @@ -26,6 +27,7 @@
> #include <linux/module.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/pci.h>
> @@ -406,6 +408,7 @@ struct tegra_pcie_port {
>
> int n_gpios;
> int *gpios;
> + int rst_gpio;
This should be using GPIO descriptor APIs.
Thierry
> };
>
> struct tegra_pcie_bus {
> @@ -589,15 +592,23 @@ static void tegra_pcie_port_reset(struct tegra_pcie_port *port)
> unsigned long value;
>
> /* pulse reset signal */
> - value = afi_readl(port->pcie, ctrl);
> - value &= ~AFI_PEX_CTRL_RST;
> - afi_writel(port->pcie, value, ctrl);
> + if (gpio_is_valid(port->rst_gpio)) {
> + gpio_set_value(port->rst_gpio, 0);
> + } else {
> + value = afi_readl(port->pcie, ctrl);
> + value &= ~AFI_PEX_CTRL_RST;
> + afi_writel(port->pcie, value, ctrl);
> + }
>
> usleep_range(1000, 2000);
>
> - value = afi_readl(port->pcie, ctrl);
> - value |= AFI_PEX_CTRL_RST;
> - afi_writel(port->pcie, value, ctrl);
> + if (gpio_is_valid(port->rst_gpio)) {
> + gpio_set_value(port->rst_gpio, 1);
> + } else {
> + value = afi_readl(port->pcie, ctrl);
> + value |= AFI_PEX_CTRL_RST;
> + afi_writel(port->pcie, value, ctrl);
> + }
> }
>
> static void tegra_pcie_enable_rp_features(struct tegra_pcie_port *port)
> @@ -2241,6 +2252,20 @@ static int tegra_pcie_parse_plat_dt(struct tegra_pcie_port *port,
> }
> }
>
> + port->rst_gpio = of_get_named_gpio(np, "nvidia,rst-gpio", 0);
> + if (gpio_is_valid(port->rst_gpio)) {
> + err = devm_gpio_request(dev, port->rst_gpio, "pex_rst_gpio");
> + if (err < 0) {
> + dev_err(dev, "rst_gpio request failed: %d\n", err);
> + return err;
> + }
> + err = gpio_direction_output(port->rst_gpio, 0);
> + if (err < 0) {
> + dev_err(dev, "rst_gpio set o/p failed: %d\n", err);
> + return err;
> + }
> + }
> +
> return 0;
> }
>
> --
> 2.17.1
>
Attachment:
signature.asc
Description: PGP signature
