[PATCH v3 2/3] PCI: qcom: add support to msm8996 PCIE controller

From: Srinivas Kandagatla
Date: Fri Nov 04 2016 - 09:01:38 EST


This patch adds support to msm8996/apq8096 pcie, MSM8996 supports
Gen 1/2, One lane, 3 pcie root-complex with support to MSI and
legacy interrupts and it conforms to PCI Express Base 2.1 specification.

This patch adds post_init callback to qcom_pcie_ops, as this is pcie
pipe clocks are only setup after the phy is powered on.
It also adds ltssm_enable callback as it is very much different to other
supported SOCs in the driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
.../devicetree/bindings/pci/qcom,pcie.txt | 68 +++++++-
drivers/pci/host/pcie-qcom.c | 177 ++++++++++++++++++++-
2 files changed, 239 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.txt b/Documentation/devicetree/bindings/pci/qcom,pcie.txt
index 4059a6f..4a0538d 100644
--- 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 +93,16 @@
- "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
+ - "aux" Auxiliary (AUX) clock.
+ - "bus_master" Master AXI clock.
+ - "bus_slave" Slave AXI clock.
+ - "pipe" Pipe Clock driving internal logic.
+ - "cfg" Configuration clk.
- resets:
Usage: required
Value type: <prop-encoded-array>
@@ -115,7 +126,7 @@
- "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
@@ -231,3 +242,58 @@
pinctrl-0 = <&pcie0_pins_default>;
pinctrl-names = "default";
};
+
+* Example for apq8096:
+
+ pcie@00608000{
+ compatible = "qcom,pcie-msm8996", "snps,dw-pcie";
+ power-domains = <&gcc PCIE1_GDSC>;
+ bus-range = <0x00 0xff>;
+ num-lanes = <1>;
+
+ status = "disabled";
+
+ reg = <0x00608000 0x2000>,
+ <0x0d000000 0xf1d>,
+ <0x0d000f20 0xa8>,
+ <0x0d100000 0x100000>;
+
+ reg-names = "parf", "dbi", "elbi", "config";
+
+ phys = <&pcie_phy 1>;
+ phy-names = "pciephy";
+
+ #address-cells = <3>;
+ #size-cells = <2>;
+ ranges = <0x01000000 0x0 0x0d200000 0x0d200000 0x0 0x100000>,
+ <0x02000000 0x0 0x0d300000 0x0d300000 0x0 0xd00000>;
+
+ interrupts = <GIC_SPI 413 IRQ_TYPE_NONE>;
+ interrupt-names = "msi";
+ #interrupt-cells = <1>;
+ interrupt-map-mask = <0 0 0 0x7>;
+ interrupt-map = <0 0 0 1 &intc 0 272 IRQ_TYPE_LEVEL_HIGH>, /* int_a */
+ <0 0 0 2 &intc 0 273 IRQ_TYPE_LEVEL_HIGH>, /* int_b */
+ <0 0 0 3 &intc 0 274 IRQ_TYPE_LEVEL_HIGH>, /* int_c */
+ <0 0 0 4 &intc 0 275 IRQ_TYPE_LEVEL_HIGH>; /* int_d */
+
+ pinctrl-names = "default", "sleep";
+ pinctrl-0 = <&pcie1_clkreq_default &pcie1_perst_default &pcie1_wake_default>;
+ pinctrl-1 = <&pcie1_clkreq_sleep &pcie1_perst_default &pcie1_wake_sleep>;
+
+ vdda-1p8-supply = <&pm8994_l12>;
+ vdda-supply = <&pm8994_l28>;
+ linux,pci-domain = <1>;
+
+ clocks = <&gcc GCC_PCIE_1_PIPE_CLK>,
+ <&gcc GCC_PCIE_1_AUX_CLK>,
+ <&gcc GCC_PCIE_1_CFG_AHB_CLK>,
+ <&gcc GCC_PCIE_1_MSTR_AXI_CLK>,
+ <&gcc GCC_PCIE_1_SLV_AXI_CLK>;
+
+ clock-names = "pipe",
+ "aux",
+ "cfg",
+ "bus_master",
+ "bus_slave";
+ };
diff --git a/drivers/pci/host/pcie-qcom.c b/drivers/pci/host/pcie-qcom.c
index 3593640..f37c690 100644
--- a/drivers/pci/host/pcie-qcom.c
+++ b/drivers/pci/host/pcie-qcom.c
@@ -36,11 +36,19 @@

#include "pcie-designware.h"

+#define PCIE20_PARF_DBI_BASE_ADDR 0x168
+
+#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_MHI_CLOCK_RESET_CTRL 0x174
#define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT 0x178
+#define MSM8996_PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT 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 +80,18 @@ 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 +99,9 @@ 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 +135,33 @@ 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 @@ static int qcom_pcie_init_v1(struct qcom_pcie *pcie)
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 = 0;
+
+ 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 + MSM8996_PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
+ val |= BIT(31);
+ writel(val, pcie->parf + MSM8996_PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
+
+ 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->slave_clk);
+ clk_disable_unprepare(res->master_clk);
+ clk_disable_unprepare(res->cfg_clk);
+ clk_disable_unprepare(res->aux_clk);
+ clk_disable_unprepare(res->pipe_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 },
{ }
};

--
2.10.1