[PATCH 3/7] phy: qcom: Add Qualcomm PCIe2 PHY driver

Bjorn Andersson
2019-01-25T23:45:05Z

The Qualcomm PCIe2 PHY is based on design from Synopsys and found in
several different platforms where the QMP PHY isn't used.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
drivers/phy/qualcomm/Kconfig | 8 +
drivers/phy/qualcomm/Makefile | 1 +
drivers/phy/qualcomm/phy-qcom-pcie2.c | 331 ++++++++++++++++++++++++++
3 files changed, 340 insertions(+)
create mode 100644 drivers/phy/qualcomm/phy-qcom-pcie2.c

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index 32f7d34eb784..0edb5316972f 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -24,6 +24,14 @@ config PHY_QCOM_IPQ806X_SATA
depends on OF
select GENERIC_PHY

+config PHY_QCOM_PCIE2
+ tristate "Qualcomm PCIe PHY Driver"
+ depends on OF && COMMON_CLK && (ARCH_QCOM || COMPILE_TEST)
+ select GENERIC_PHY
+ help
+ Enable this to support the Qualcomm PCIe PHY, used with the Synopsys
+ based PCIe controller.
+
config PHY_QCOM_QMP
tristate "Qualcomm QMP PHY Driver"
depends on OF && COMMON_CLK && (ARCH_QCOM || COMPILE_TEST)
diff --git a/drivers/phy/qualcomm/Makefile b/drivers/phy/qualcomm/Makefile
index c56efd3af205..283251d6a5d9 100644
--- a/drivers/phy/qualcomm/Makefile
+++ b/drivers/phy/qualcomm/Makefile
@@ -2,6 +2,7 @@
obj-$(CONFIG_PHY_ATH79_USB) += phy-ath79-usb.o
obj-$(CONFIG_PHY_QCOM_APQ8064_SATA) += phy-qcom-apq8064-sata.o
obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA) += phy-qcom-ipq806x-sata.o
+obj-$(CONFIG_PHY_QCOM_PCIE2) += phy-qcom-pcie2.o
obj-$(CONFIG_PHY_QCOM_QMP) += phy-qcom-qmp.o
obj-$(CONFIG_PHY_QCOM_QUSB2) += phy-qcom-qusb2.o
obj-$(CONFIG_PHY_QCOM_UFS) += phy-qcom-ufs.o
diff --git a/drivers/phy/qualcomm/phy-qcom-pcie2.c b/drivers/phy/qualcomm/phy-qcom-pcie2.c
new file mode 100644
index 000000000000..2fa891c18b6f
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-pcie2.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2019, Linaro Ltd.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/phy/phy.h>
+
+#define PCIE20_PARF_PHY_STTS 0x3c
+#define PCIE2_PHY_RESET_CTRL 0x44
+#define PCIE20_PARF_PHY_REFCLK_CTRL2 0xa0
+#define PCIE20_PARF_PHY_REFCLK_CTRL3 0xa4
+#define PCIE20_PARF_PCS_SWING_CTRL1 0x88
+#define PCIE20_PARF_PCS_SWING_CTRL2 0x8c
+#define PCIE20_PARF_PCS_DEEMPH1 0x74
+#define PCIE20_PARF_PCS_DEEMPH2 0x78
+#define PCIE20_PARF_PCS_DEEMPH3 0x7c
+#define PCIE20_PARF_CONFIGBITS 0x84
+#define PCIE20_PARF_PHY_CTRL3 0x94
+#define PCIE20_PARF_PCS_CTRL 0x80
+
+#define TX_AMP_VAL 120
+#define PHY_RX0_EQ_GEN1_VAL 0
+#define PHY_RX0_EQ_GEN2_VAL 4
+#define TX_DEEMPH_GEN1_VAL 24
+#define TX_DEEMPH_GEN2_3_5DB_VAL 26
+#define TX_DEEMPH_GEN2_6DB_VAL 36
+#define PHY_TX0_TERM_OFFST_VAL 0
+
+struct qcom_phy {
+ struct device *dev;
+ void __iomem *base;
+
+ struct regulator_bulk_data vregs[2];
+
+ struct reset_control *phy_reset;
+ struct reset_control *pipe_reset;
+ struct clk *pipe_clk;
+};
+
+static int qcom_pcie2_phy_init(struct phy *phy)
+{
+ struct qcom_phy *qphy = phy_get_drvdata(phy);
+ int ret;
+
+ ret = reset_control_deassert(qphy->phy_reset);
+ if (ret) {
+ dev_err(qphy->dev, "cannot deassert pipe reset\n");
+ return ret;
+ }
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
+ if (ret)
+ reset_control_assert(qphy->phy_reset);
+
+ return ret;
+}
+
+static int qcom_pcie2_phy_power_on(struct phy *phy)
+{
+ struct qcom_phy *qphy = phy_get_drvdata(phy);
+ int ret;
+ u32 val;
+
+ /* Program REF_CLK source */
+ val = readl(qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL2);
+ val &= ~BIT(1);
+ writel(val, qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL2);
+
+ usleep_range(1000, 2000);
+
+ /* Don't use PAD for refclock */
+ val = readl(qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL2);
+ val &= ~BIT(0);
+ writel(val, qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL2);
+
+ /* Program SSP ENABLE */
+ val = readl(qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL3);
+ val |= BIT(0);
+ writel(val, qphy->base + PCIE20_PARF_PHY_REFCLK_CTRL3);
+
+ usleep_range(1000, 2000);
+
+ /* Assert Phy SW Reset */
+ val = readl(qphy->base + PCIE2_PHY_RESET_CTRL);
+ val |= BIT(0);
+ writel(val, qphy->base + PCIE2_PHY_RESET_CTRL);
+
+ /* Program Tx Amplitude */
+ val = readl(qphy->base + PCIE20_PARF_PCS_SWING_CTRL1);
+ val &= ~0x7f;
+ val |= TX_AMP_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PCS_SWING_CTRL1);
+
+ val = readl(qphy->base + PCIE20_PARF_PCS_SWING_CTRL2);
+ val &= ~0x7f;
+ val |= TX_AMP_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PCS_SWING_CTRL2);
+
+ /* Program De-Emphasis */
+ val = readl(qphy->base + PCIE20_PARF_PCS_DEEMPH1);
+ val &= ~0x3f;
+ val |= TX_DEEMPH_GEN2_6DB_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PCS_DEEMPH1);
+
+ val = readl(qphy->base + PCIE20_PARF_PCS_DEEMPH2);
+ val &= ~0x3f;
+ val |= TX_DEEMPH_GEN2_3_5DB_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PCS_DEEMPH2);
+
+ val = readl(qphy->base + PCIE20_PARF_PCS_DEEMPH3);
+ val &= ~0x3f;
+ val |= TX_DEEMPH_GEN1_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PCS_DEEMPH3);
+
+ /* Program Rx_Eq */
+ val = readl(qphy->base + PCIE20_PARF_CONFIGBITS);
+ val &= ~0x7;
+ val |= PHY_RX0_EQ_GEN2_VAL;
+ writel(val, qphy->base + PCIE20_PARF_CONFIGBITS);
+
+ /* Program Tx0_term_offset */
+ val = readl(qphy->base + PCIE20_PARF_PHY_CTRL3);
+ val &= ~0x1f;
+ val |= PHY_TX0_TERM_OFFST_VAL;
+ writel(val, qphy->base + PCIE20_PARF_PHY_CTRL3);
+
+ /* disable Tx2Rx Loopback */
+ val = readl(qphy->base + PCIE20_PARF_PCS_CTRL);
+ val &= ~BIT(1);
+ writel(val, qphy->base + PCIE20_PARF_PCS_CTRL);
+
+ /* De-assert Phy SW Reset */
+ val = readl(qphy->base + PCIE2_PHY_RESET_CTRL);
+ val &= ~BIT(0);
+ writel(val, qphy->base + PCIE2_PHY_RESET_CTRL);
+
+ usleep_range(1000, 2000);
+
+ ret = reset_control_deassert(qphy->pipe_reset);
+ if (ret) {
+ dev_err(qphy->dev, "cannot deassert pipe reset\n");
+ goto out;
+ }
+
+ clk_set_rate(qphy->pipe_clk, 250000000);
+
+ ret = clk_prepare_enable(qphy->pipe_clk);
+ if (ret) {
+ dev_err(qphy->dev, "failed to enable pipe clock\n");
+ goto out;
+ }
+
+ ret = readl_poll_timeout(qphy->base + PCIE20_PARF_PHY_STTS, val,
+ !(val & BIT(0)), 1000, 10);
+ if (ret)
+ dev_err(qphy->dev, "phy initialization failed\n");
+
+out:
+ return ret;
+}
+
+static int qcom_pcie2_phy_power_off(struct phy *phy)
+{
+ struct qcom_phy *qphy = phy_get_drvdata(phy);
+ u32 val;
+
+ val = readl(qphy->base + PCIE2_PHY_RESET_CTRL);
+ val |= BIT(0);
+ writel(val, qphy->base + PCIE2_PHY_RESET_CTRL);
+
+ clk_disable_unprepare(qphy->pipe_clk);
+ reset_control_assert(qphy->pipe_reset);
+
+ return 0;
+}
+
+static int qcom_pcie2_phy_exit(struct phy *phy)
+{
+ struct qcom_phy *qphy = phy_get_drvdata(phy);
+
+ regulator_bulk_disable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
+ reset_control_assert(qphy->phy_reset);
+
+ return 0;
+}
+
+static const struct phy_ops qcom_pcie2_ops = {
+ .init = qcom_pcie2_phy_init,
+ .power_on = qcom_pcie2_phy_power_on,
+ .power_off = qcom_pcie2_phy_power_off,
+ .exit = qcom_pcie2_phy_exit,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Register a fixed rate pipe clock.
+ *
+ * The _pipe_clksrc generated by PHY goes to the GCC that gate
+ * controls it. The _pipe_clk coming out of the GCC is requested
+ * by the PHY driver for its operations.
+ * We register the _pipe_clksrc here. The gcc driver takes care
+ * of assigning this _pipe_clksrc as parent to _pipe_clk.
+ * Below picture shows this relationship.
+ *
+ * +---------------+
+ * | PHY block |<<---------------------------------------+
+ * | | |
+ * | +-------+ | +-----+ |
+ * I/P---^-->| PLL |---^--->pipe_clksrc--->| GCC |--->pipe_clk---+
+ * clk | +-------+ | +-----+
+ * +---------------+
+ */
+static int phy_pipe_clk_register(struct qcom_phy *qphy)
+{
+ struct device_node *np = qphy->dev->of_node;
+ struct clk_fixed_rate *fixed;
+ struct clk_init_data init = { };
+ int ret;
+
+ ret = of_property_read_string(np, "clock-output-names", &init.name);
+ if (ret) {
+ dev_err(qphy->dev, "%s: No clock-output-names\n", np->name);
+ return ret;
+ }
+
+ fixed = devm_kzalloc(qphy->dev, sizeof(*fixed), GFP_KERNEL);
+ if (!fixed)
+ return -ENOMEM;
+
+ init.ops = &clk_fixed_rate_ops;
+
+ /* controllers using QMP phys use 250MHz pipe clock interface */
+ fixed->fixed_rate = 250000000;
+ fixed->hw.init = &init;
+
+ return devm_clk_hw_register(qphy->dev, &fixed->hw);
+}
+
+static int qcom_pcie2_phy_probe(struct platform_device *pdev)
+{
+ struct phy_provider *phy_provider;
+ struct qcom_phy *qphy;
+ struct resource *res;
+ struct device *dev = &pdev->dev;
+ struct phy *phy;
+ int ret;
+
+ qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
+ if (!qphy)
+ return -ENOMEM;
+
+ qphy->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ qphy->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(qphy->base))
+ return PTR_ERR(qphy->base);
+
+ ret = phy_pipe_clk_register(qphy);
+ if (ret) {
+ dev_err(dev, "failed to register pipe_clk\n");
+ return ret;
+ }
+
+ qphy->vregs[0].supply = "vdda-vp";
+ qphy->vregs[1].supply = "vdda-vph";
+ ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(qphy->vregs), qphy->vregs);
+ if (ret < 0)
+ return ret;
+
+ qphy->pipe_clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(qphy->pipe_clk)) {
+ dev_err(dev, "failed to acquire pipe clock\n");
+ return PTR_ERR(qphy->pipe_clk);
+ }
+
+ qphy->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
+ if (IS_ERR(qphy->phy_reset)) {
+ dev_err(dev, "failed to acquire phy reset\n");
+ return PTR_ERR(qphy->phy_reset);
+ }
+
+ qphy->pipe_reset = devm_reset_control_get_exclusive(dev, "pipe");
+ if (IS_ERR(qphy->pipe_reset)) {
+ dev_err(dev, "failed to acquire pipe reset\n");
+ return PTR_ERR(qphy->pipe_reset);
+ }
+
+ phy = devm_phy_create(dev, dev->of_node, &qcom_pcie2_ops);
+ if (IS_ERR(phy)) {
+ dev_err(dev, "failed to create phy\n");
+ return PTR_ERR(phy);
+ }
+
+ phy_set_drvdata(phy, qphy);
+
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(phy_provider))
+ dev_err(dev, "failed to register phy provider\n");
+
+ return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id qcom_pcie2_phy_match_table[] = {
+ { .compatible = "qcom,pcie2-phy" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, qcom_pcie2_phy_match_table);
+
+static struct platform_driver qcom_pcie2_phy_driver = {
+ .probe = qcom_pcie2_phy_probe,
+ .driver = {
+ .name = "qcom-pcie2-phy",
+ .of_match_table = qcom_pcie2_phy_match_table,
+ },
+};
+
+module_platform_driver(qcom_pcie2_phy_driver);
+
+MODULE_DESCRIPTION("Qualcomm PCIe PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.18.0