On Tue, Jan 07, 2020 at 08:12:56PM +0800, Shawn Guo wrote:
> It switches GPIO reset code to use gpio_desc, so that the code becomes
> simpler and cleaner. Also the GPIO signal should be implemented as
> a pulse to trigger a reset, let's correct that in the meantime.
The changelog makes it sound like this is a cleanup + a bug fix. If
so, please put them in separate patches and describe the effect of the
bug, e.g., "reset doesn't work before this fix" or whatever.
Capitalize the subject ("PCI: histb: Improve...").
> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-histb.c | 35 ++++++++++---------------
> 1 file changed, 14 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-histb.c b/drivers/pci/controller/dwc/pcie-histb.c
> index 811b5c6d62ea..d47a8e6d6fa3 100644
> --- a/drivers/pci/controller/dwc/pcie-histb.c
> +++ b/drivers/pci/controller/dwc/pcie-histb.c
> @@ -60,7 +60,7 @@ struct histb_pcie {
> struct reset_control *sys_reset;
> struct reset_control *bus_reset;
> void __iomem *ctrl;
> - int reset_gpio;
> + struct gpio_desc *reset_gpio;
> struct regulator *vpcie;
> };
>
> @@ -219,9 +219,6 @@ static void histb_pcie_host_disable(struct histb_pcie *hipcie)
> clk_disable_unprepare(hipcie->sys_clk);
> clk_disable_unprepare(hipcie->bus_clk);
>
> - if (gpio_is_valid(hipcie->reset_gpio))
> - gpio_set_value_cansleep(hipcie->reset_gpio, 0);
> -
> if (hipcie->vpcie)
> regulator_disable(hipcie->vpcie);
> }
> @@ -242,9 +239,6 @@ static int histb_pcie_host_enable(struct pcie_port *pp)
> }
> }
>
> - if (gpio_is_valid(hipcie->reset_gpio))
> - gpio_set_value_cansleep(hipcie->reset_gpio, 1);
> -
> ret = clk_prepare_enable(hipcie->bus_clk);
> if (ret) {
> dev_err(dev, "cannot prepare/enable bus clk\n");
> @@ -278,6 +272,14 @@ static int histb_pcie_host_enable(struct pcie_port *pp)
> reset_control_assert(hipcie->bus_reset);
> reset_control_deassert(hipcie->bus_reset);
>
> + if (hipcie->reset_gpio) {
> + gpiod_set_value_cansleep(hipcie->reset_gpio, 1);
> + usleep_range(100, 200);
> + gpiod_set_value_cansleep(hipcie->reset_gpio, 0);
> + /* wait for 1ms */
> + usleep_range(1000, 2000);
> + }
> +
> return 0;
>
> err_aux_clk:
> @@ -305,10 +307,7 @@ static int histb_pcie_probe(struct platform_device *pdev)
> struct dw_pcie *pci;
> struct pcie_port *pp;
> struct resource *res;
> - struct device_node *np = pdev->dev.of_node;
> struct device *dev = &pdev->dev;
> - enum of_gpio_flags of_flags;
> - unsigned long flag = GPIOF_DIR_OUT;
> int ret;
>
> hipcie = devm_kzalloc(dev, sizeof(*hipcie), GFP_KERNEL);
> @@ -345,17 +344,11 @@ static int histb_pcie_probe(struct platform_device *pdev)
> hipcie->vpcie = NULL;
> }
>
> - hipcie->reset_gpio = of_get_named_gpio_flags(np,
> - "reset-gpios", 0, &of_flags);
> - if (of_flags & OF_GPIO_ACTIVE_LOW)
> - flag |= GPIOF_ACTIVE_LOW;
> - if (gpio_is_valid(hipcie->reset_gpio)) {
> - ret = devm_gpio_request_one(dev, hipcie->reset_gpio,
> - flag, "PCIe device power control");
> - if (ret) {
> - dev_err(dev, "unable to request gpio\n");
> - return ret;
> - }
> + hipcie->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(hipcie->reset_gpio)) {
> + ret = PTR_ERR(hipcie->reset_gpio);
> + return ret;
> }
>
> hipcie->aux_clk = devm_clk_get(dev, "aux");
> --
> 2.17.1
>
