PCI: qcom: Add support for MSM8996 PCIe controller

Add support for the MSM8996/APQ8096 PCIe controller.  MSM8996 supports Gen
1/2, one lane, 3 PCIe root complexes with support for MSI and legacy
interrupts, and it conforms to PCI Express Base 2.1 specification.

Add a post_init callback to qcom_pcie_ops, as the PCIe pipe clocks are only
setup after the phy is powered on.  It also adds an ltssm_enable callback
as it is very much different from other supported SoCs in the driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.txt b/Documentation/devicetree/bindings/pci/qcom,pcie.txt
index 4059a6f..e15f9b1 100644 (file)
--- a/Documentation/devicetree/bindings/pci/qcom,pcie.txt
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie.txt
@@ -7,6 +7,7 @@
                        - "qcom,pcie-ipq8064" for ipq8064
                        - "qcom,pcie-apq8064" for apq8064
                        - "qcom,pcie-apq8084" for apq8084
+                       - "qcom,pcie-msm8996" for msm8996 or apq8096
 
 - reg:
        Usage: required
@@ -92,6 +93,17 @@
                        - "aux"         Auxiliary (AUX) clock
                        - "bus_master"  Master AXI clock
                        - "bus_slave"   Slave AXI clock
+
+- clock-names:
+       Usage: required for msm8996/apq8096
+       Value type: <stringlist>
+       Definition: Should contain the following entries
+                       - "pipe"        Pipe Clock driving internal logic
+                       - "aux"         Auxiliary (AUX) clock
+                       - "cfg"         Configuration clock
+                       - "bus_master"  Master AXI clock
+                       - "bus_slave"   Slave AXI clock
+
 - resets:
        Usage: required
        Value type: <prop-encoded-array>
@@ -115,7 +127,7 @@
                        - "core" Core reset
 
 - power-domains:
-       Usage: required for apq8084
+       Usage: required for apq8084 and msm8996/apq8096
        Value type: <prop-encoded-array>
        Definition: A phandle and power domain specifier pair to the
                    power domain which is responsible for collapsing

diff --git a/drivers/pci/host/pcie-qcom.c b/drivers/pci/host/pcie-qcom.c
index ef0a84c..8b02db2 100644 (file)
--- a/drivers/pci/host/pcie-qcom.c
+++ b/drivers/pci/host/pcie-qcom.c
@@ -36,11 +36,17 @@
 
 #include "pcie-designware.h"
 
+#define PCIE20_PARF_SYS_CTRL                   0x00
 #define PCIE20_PARF_PHY_CTRL                   0x40
 #define PCIE20_PARF_PHY_REFCLK                 0x4C
 #define PCIE20_PARF_DBI_BASE_ADDR              0x168
-#define PCIE20_PARF_SLV_ADDR_SPACE_SIZE                0x16c
+#define PCIE20_PARF_SLV_ADDR_SPACE_SIZE                0x16C
+#define PCIE20_PARF_MHI_CLOCK_RESET_CTRL       0x174
 #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT      0x178
+#define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2   0x1A8
+#define PCIE20_PARF_LTSSM                      0x1B0
+#define PCIE20_PARF_SID_OFFSET                 0x234
+#define PCIE20_PARF_BDF_TRANSLATE_CFG          0x24C
 
 #define PCIE20_ELBI_SYS_CTRL                   0x04
 #define PCIE20_ELBI_SYS_CTRL_LT_ENABLE         BIT(0)
@@ -72,9 +78,18 @@ struct qcom_pcie_resources_v1 {
        struct regulator *vdda;
 };
 
+struct qcom_pcie_resources_v2 {
+       struct clk *aux_clk;
+       struct clk *master_clk;
+       struct clk *slave_clk;
+       struct clk *cfg_clk;
+       struct clk *pipe_clk;
+};
+
 union qcom_pcie_resources {
        struct qcom_pcie_resources_v0 v0;
        struct qcom_pcie_resources_v1 v1;
+       struct qcom_pcie_resources_v2 v2;
 };
 
 struct qcom_pcie;
@@ -82,7 +97,9 @@ struct qcom_pcie;
 struct qcom_pcie_ops {
        int (*get_resources)(struct qcom_pcie *pcie);
        int (*init)(struct qcom_pcie *pcie);
+       int (*post_init)(struct qcom_pcie *pcie);
        void (*deinit)(struct qcom_pcie *pcie);
+       void (*ltssm_enable)(struct qcom_pcie *pcie);
 };
 
 struct qcom_pcie {
@@ -116,17 +133,35 @@ static irqreturn_t qcom_pcie_msi_irq_handler(int irq, void *arg)
        return dw_handle_msi_irq(pp);
 }
 
-static int qcom_pcie_establish_link(struct qcom_pcie *pcie)
+static void qcom_pcie_v0_v1_ltssm_enable(struct qcom_pcie *pcie)
 {
        u32 val;
 
-       if (dw_pcie_link_up(&pcie->pp))
-               return 0;
-
        /* enable link training */
        val = readl(pcie->elbi + PCIE20_ELBI_SYS_CTRL);
        val |= PCIE20_ELBI_SYS_CTRL_LT_ENABLE;
        writel(val, pcie->elbi + PCIE20_ELBI_SYS_CTRL);
+}
+
+static void qcom_pcie_v2_ltssm_enable(struct qcom_pcie *pcie)
+{
+       u32 val;
+
+       /* enable link training */
+       val = readl(pcie->parf + PCIE20_PARF_LTSSM);
+       val |= BIT(8);
+       writel(val, pcie->parf + PCIE20_PARF_LTSSM);
+}
+
+static int qcom_pcie_establish_link(struct qcom_pcie *pcie)
+{
+
+       if (dw_pcie_link_up(&pcie->pp))
+               return 0;
+
+       /* Enable Link Training state machine */
+       if (pcie->ops->ltssm_enable)
+               pcie->ops->ltssm_enable(pcie);
 
        return dw_pcie_wait_for_link(&pcie->pp);
 }
@@ -421,6 +456,113 @@ err_res:
        return ret;
 }
 
+static int qcom_pcie_get_resources_v2(struct qcom_pcie *pcie)
+{
+       struct qcom_pcie_resources_v2 *res = &pcie->res.v2;
+       struct device *dev = pcie->pp.dev;
+
+       res->aux_clk = devm_clk_get(dev, "aux");
+       if (IS_ERR(res->aux_clk))
+               return PTR_ERR(res->aux_clk);
+
+       res->cfg_clk = devm_clk_get(dev, "cfg");
+       if (IS_ERR(res->cfg_clk))
+               return PTR_ERR(res->cfg_clk);
+
+       res->master_clk = devm_clk_get(dev, "bus_master");
+       if (IS_ERR(res->master_clk))
+               return PTR_ERR(res->master_clk);
+
+       res->slave_clk = devm_clk_get(dev, "bus_slave");
+       if (IS_ERR(res->slave_clk))
+               return PTR_ERR(res->slave_clk);
+
+       res->pipe_clk = devm_clk_get(dev, "pipe");
+       if (IS_ERR(res->pipe_clk))
+               return PTR_ERR(res->pipe_clk);
+
+       return 0;
+}
+
+static int qcom_pcie_init_v2(struct qcom_pcie *pcie)
+{
+       struct qcom_pcie_resources_v2 *res = &pcie->res.v2;
+       struct device *dev = pcie->pp.dev;
+       u32 val;
+       int ret;
+
+       ret = clk_prepare_enable(res->aux_clk);
+       if (ret) {
+               dev_err(dev, "cannot prepare/enable aux clock\n");
+               return ret;
+       }
+
+       ret = clk_prepare_enable(res->cfg_clk);
+       if (ret) {
+               dev_err(dev, "cannot prepare/enable cfg clock\n");
+               goto err_cfg_clk;
+       }
+
+       ret = clk_prepare_enable(res->master_clk);
+       if (ret) {
+               dev_err(dev, "cannot prepare/enable master clock\n");
+               goto err_master_clk;
+       }
+
+       ret = clk_prepare_enable(res->slave_clk);
+       if (ret) {
+               dev_err(dev, "cannot prepare/enable slave clock\n");
+               goto err_slave_clk;
+       }
+
+       /* 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_slave_clk:
+       clk_disable_unprepare(res->master_clk);
+err_master_clk:
+       clk_disable_unprepare(res->cfg_clk);
+err_cfg_clk:
+       clk_disable_unprepare(res->aux_clk);
+
+       return ret;
+}
+
+static int qcom_pcie_post_init_v2(struct qcom_pcie *pcie)
+{
+       struct qcom_pcie_resources_v2 *res = &pcie->res.v2;
+       struct device *dev = pcie->pp.dev;
+       int ret;
+
+       ret = clk_prepare_enable(res->pipe_clk);
+       if (ret) {
+               dev_err(dev, "cannot prepare/enable pipe clock\n");
+               return ret;
+       }
+
+       return 0;
+}
+
 static int qcom_pcie_link_up(struct pcie_port *pp)
 {
        struct qcom_pcie *pcie = to_qcom_pcie(pp);
@@ -429,6 +571,17 @@ static int qcom_pcie_link_up(struct pcie_port *pp)
        return !!(val & PCI_EXP_LNKSTA_DLLLA);
 }
 
+static void qcom_pcie_deinit_v2(struct qcom_pcie *pcie)
+{
+       struct qcom_pcie_resources_v2 *res = &pcie->res.v2;
+
+       clk_disable_unprepare(res->pipe_clk);
+       clk_disable_unprepare(res->slave_clk);
+       clk_disable_unprepare(res->master_clk);
+       clk_disable_unprepare(res->cfg_clk);
+       clk_disable_unprepare(res->aux_clk);
+}
+
 static void qcom_pcie_host_init(struct pcie_port *pp)
 {
        struct qcom_pcie *pcie = to_qcom_pcie(pp);
@@ -444,6 +597,9 @@ static void qcom_pcie_host_init(struct pcie_port *pp)
        if (ret)
                goto err_deinit;
 
+       if (pcie->ops->post_init)
+               pcie->ops->post_init(pcie);
+
        dw_pcie_setup_rc(pp);
 
        if (IS_ENABLED(CONFIG_PCI_MSI))
@@ -487,12 +643,22 @@ static const struct qcom_pcie_ops ops_v0 = {
        .get_resources = qcom_pcie_get_resources_v0,
        .init = qcom_pcie_init_v0,
        .deinit = qcom_pcie_deinit_v0,
+       .ltssm_enable = qcom_pcie_v0_v1_ltssm_enable,
 };
 
 static const struct qcom_pcie_ops ops_v1 = {
        .get_resources = qcom_pcie_get_resources_v1,
        .init = qcom_pcie_init_v1,
        .deinit = qcom_pcie_deinit_v1,
+       .ltssm_enable = qcom_pcie_v0_v1_ltssm_enable,
+};
+
+static const struct qcom_pcie_ops ops_v2 = {
+       .get_resources = qcom_pcie_get_resources_v2,
+       .init = qcom_pcie_init_v2,
+       .post_init = qcom_pcie_post_init_v2,
+       .deinit = qcom_pcie_deinit_v2,
+       .ltssm_enable = qcom_pcie_v2_ltssm_enable,
 };
 
 static int qcom_pcie_probe(struct platform_device *pdev)
@@ -572,6 +738,7 @@ static const struct of_device_id qcom_pcie_match[] = {
        { .compatible = "qcom,pcie-ipq8064", .data = &ops_v0 },
        { .compatible = "qcom,pcie-apq8064", .data = &ops_v0 },
        { .compatible = "qcom,pcie-apq8084", .data = &ops_v1 },
+       { .compatible = "qcom,pcie-msm8996", .data = &ops_v2 },
        { }
 };