On Fri, May 05, 2017 at 05:25:24PM +0200, John Crispin wrote:

Add support for the IPQ4019 PCIe controller. IPQ4019 supports Gen
1/2, one lane, one PCIe root complex with support for MSI and legacy
interrupts, and it conforms to PCI Express Base 2.1 specification.

The core init is the sames as for the MSM8996, however the clocks and
reset lines differ.

Signed-off-by: John Crispin <john@phrozen.org>
---
 .../devicetree/bindings/pci/qcom,pcie.txt          |  20 +-

For the binding:

Acked-by: Rob Herring <robh@kernel.org>

 drivers/pci/host/pcie-qcom.c                       | 304 +++++++++++++++++++++
 2 files changed, 323 insertions(+), 1 deletion(-)

+static int qcom_pcie_init_v3(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_v3 *res = &pcie->res.v3;
+	struct device *dev = pcie->pp.dev;
+	u32 val;
+	int ret;
+
+	ret = reset_control_assert(res->axi_m_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert axi master reset\n");

These all seem kind of verbose. Perhaps the error message should be in 
reset_control_assert function.

+		return ret;
+	}
+
+	ret = reset_control_assert(res->axi_s_reset);
+	if (ret) {
+		dev_err(dev, "cannot asser axi slave reset\n");
+		return ret;
+	}
+
+	usleep_range(10000, 12000);
+
+	ret = reset_control_assert(res->pipe_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert pipe reset\n");
+		return ret;
+	}
+
+	ret = reset_control_assert(res->pipe_sticky_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert pipe sticky reset\n");
+		return ret;
+	}
+
+	ret = reset_control_assert(res->phy_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert phy reset\n");
+		return ret;
+	}
+
+	ret = reset_control_assert(res->phy_ahb_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert phy ahb reset\n");
+		return ret;
+	}
+
+	usleep_range(10000, 12000);
+
+	ret = reset_control_assert(res->axi_m_sticky_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert axi master sticky reset\n");
+		return ret;
+	}
+
+	ret = reset_control_assert(res->pwr_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert power reset\n");
+		return ret;
+	}
+
+	ret = reset_control_assert(res->ahb_reset);
+	if (ret) {
+		dev_err(dev, "cannot assert ahb reset\n");
+		return ret;
+	}
+
+	usleep_range(10000, 12000);
+
+	ret = reset_control_deassert(res->phy_ahb_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert phy ahb reset\n");
+		return ret;
+	}
+
+	ret = reset_control_deassert(res->phy_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert phy reset\n");
+		goto err_rst_phy;
+	}
+
+	ret = reset_control_deassert(res->pipe_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert pipe reset\n");
+		goto err_rst_pipe;
+	}
+
+	ret = reset_control_deassert(res->pipe_sticky_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert pipe sticky reset\n");
+		goto err_rst_pipe_sticky;
+	}
+
+	usleep_range(10000, 12000);
+
+	ret = reset_control_deassert(res->axi_m_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert axi master reset\n");
+		goto err_rst_axi_m;
+	}
+
+	ret = reset_control_deassert(res->axi_m_sticky_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert axi master sticky reset\n");
+		goto err_rst_axi_m_sticky;
+	}
+
+	ret = reset_control_deassert(res->axi_s_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert axi slave reset\n");
+		goto err_rst_axi_s;
+	}
+
+	ret = reset_control_deassert(res->pwr_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert power reset\n");
+		goto err_rst_pwr;
+	}
+
+	ret = reset_control_deassert(res->ahb_reset);
+	if (ret) {
+		dev_err(dev, "cannot deassert ahb reset\n");
+		goto err_rst_ahb;
+	}
+
+	usleep_range(10000, 12000);
+
+	ret = clk_prepare_enable(res->aux_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable iface clock\n");
+		goto err_clk_aux;
+	}
+
+	ret = clk_prepare_enable(res->master_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable core clock\n");
+		goto err_clk_axi_m;
+	}
+
+	ret = clk_prepare_enable(res->slave_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable phy clock\n");
+		goto err_clk_axi_s;
+	}
+
+	/* enable PCIe clocks and resets */
+	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
+	val &= !BIT(0);
+	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
+	/* change DBI base address */
+	writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
+
+	/* MAC PHY_POWERDOWN MUX DISABLE  */
+	val = readl(pcie->parf + PCIE20_PARF_SYS_CTRL);
+	val &= ~BIT(29);
+	writel(val, pcie->parf + PCIE20_PARF_SYS_CTRL);
+
+	val = readl(pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+	val |= BIT(4);
+	writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+
+	val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
+	val |= BIT(31);
+	writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
+
+	return 0;
+
+err_clk_axi_s:
+	clk_disable_unprepare(res->master_clk);
+err_clk_axi_m:
+	clk_disable_unprepare(res->aux_clk);

In deinit you turn off the clocks last.