On 15-Apr-19 7:50 PM, Thierry Reding wrote:
> 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
I will take care of it in V2.
Manikanta
>
>> };
>>
>> 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
>>
