[PATCH v6 09/10] PCI: dw-rockchip: Add system PM support

[Manivannan Sadhasivam]

On 2026-09-08 16:51 +0200, Sebastian Reichel wrote:
> Add system PM support for Rockchip PCIe Designware Controllers.
> 
> I've tested this on the Rockchip RK3576 EVB1, the Radxa ROCK 4D
> and the ArmSom Sige5 boards.
> 
> While I haven't experienced any issues, most of my tests have been done
> without any devices attached (i.e. default board without any extras), so
> there _might_ still be some problems. As system suspend does not work at
> all right now, I think it makes sense to get at least the basic
> configurations working as soon as possible as it will allow us to catch
> regressions by enabling system suspend in CI systems like KernelCI.
> 
> Co-developed-by: Shawn Lin <shawn.lin at rock-chips.com>
> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
> Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
> ---
>  drivers/pci/controller/dwc/pcie-dw-rockchip.c | 100 ++++++++++++++++++++++++++
>  1 file changed, 100 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> index 47d9cab909bc..e675918ba184 100644
> --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> @@ -120,6 +120,7 @@ struct rockchip_pcie {
>  	struct gpio_desc *rst_gpio;
>  	struct regulator *vpcie3v3;
>  	struct irq_domain *irq_domain;
> +	u32 intx;
>  	const struct rockchip_pcie_of_data *data;
>  	bool supports_clkreq;
>  	struct delayed_work trace_work;
> @@ -1042,6 +1043,99 @@ static int rockchip_pcie_rc_reset_root_port(struct pci_host_bridge *bridge,
>  	return ret;
>  }
>  
> +static int rockchip_pcie_suspend(struct device *dev)
> +{
> +	struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> +	struct dw_pcie *pci = &rockchip->pci;
> +	int ret;
> +
> +	if (rockchip->data->mode == DW_PCIE_EP_TYPE) {
> +		dev_err(dev, "suspend is not supported in EP mode\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	rockchip->intx = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_MASK_LEGACY);
> +
> +	ret = dw_pcie_suspend_noirq(pci);
> +	if (ret)
> +		return ret;
> +
> +	gpiod_set_value_cansleep(rockchip->rst_gpio, 0);
> +	rockchip_pcie_phy_deinit(rockchip);
> +	clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
> +	reset_control_assert(rockchip->rst);
> +	if (rockchip->vpcie3v3)
> +		regulator_disable(rockchip->vpcie3v3);
> +
> +	return 0;
> +}
> +
> +static int rockchip_pcie_resume(struct device *dev)
> +{
> +	struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> +	struct dw_pcie *pci = &rockchip->pci;
> +	int ret;
> +
> +	if (rockchip->data->mode == DW_PCIE_EP_TYPE) {
> +		dev_err(dev, "resume is not supported in EP mode\n");
> +		return -EOPNOTSUPP;
> +	}

This is going to regress the EP system suspend. If the EP suspend used to work
before this patch, then you can safely return 0 here.

> +
> +	ret = clk_bulk_prepare_enable(rockchip->clk_cnt, rockchip->clks);
> +	if (ret) {
> +		dev_err(dev, "clock init failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (rockchip->vpcie3v3) {
> +		ret = regulator_enable(rockchip->vpcie3v3);
> +		if (ret)
> +			goto err_disable_clk;
> +	}
> +
> +	ret = rockchip_pcie_phy_init(rockchip);
> +	if (ret) {
> +		dev_err(dev, "phy init failed: %d\n", ret);
> +		goto err_disable_regulator;
> +	}
> +
> +	reset_control_deassert(rockchip->rst);
> +
> +	rockchip_pcie_writel_apb(rockchip, FIELD_PREP_WM16(0xffff, rockchip->intx),
> +				 PCIE_CLIENT_INTR_MASK_LEGACY);
> +
> +	rockchip_pcie_enable_enhanced_ltssm_control_mode(rockchip, 0);
> +	rockchip_pcie_set_controller_mode(rockchip, PCIE_CLIENT_MODE_RC);
> +	rockchip_pcie_unmask_dll_indicator(rockchip);
> +
> +	gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
> +
> +	ret = dw_pcie_resume_noirq(pci);
> +	if (ret) {
> +		dev_err(dev, "failed to resume: %d\n", ret);
> +		/*
> +		 * During resume, dw_pcie_wait_for_link() is called and when
> +		 * there is no device connected at all it returns -EIO with
> +		 * the message "Device found, but not active". Ignore it for
> +		 * now.
> +		 */

This is not correct. When there is no device connected, -ENODEV will be
returned.

- Mani