| // 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 <s>_pipe_clksrc generated by PHY goes to the GCC that gate |
| * controls it. The <s>_pipe_clk coming out of the GCC is requested |
| * by the PHY driver for its operations. |
| * We register the <s>_pipe_clksrc here. The gcc driver takes care |
| * of assigning this <s>_pipe_clksrc as parent to <s>_pipe_clk. |
| * Below picture shows this relationship. |
| * |
| * +---------------+ |
| * | PHY block |<<---------------------------------------+ |
| * | | | |
| * | +-------+ | +-----+ | |
| * I/P---^-->| PLL |---^--->pipe_clksrc--->| GCC |--->pipe_clk---+ |
| * clk | +-------+ | +-----+ |
| * +---------------+ |
| */ |
| static int phy_pipe_clksrc_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; |
| |
| ret = devm_clk_hw_register(qphy->dev, &fixed->hw); |
| if (ret < 0) |
| return ret; |
| |
| return devm_of_clk_add_hw_provider(qphy->dev, of_clk_hw_simple_get, &fixed->hw); |
| } |
| |
| static int qcom_pcie2_phy_probe(struct platform_device *pdev) |
| { |
| struct phy_provider *phy_provider; |
| struct qcom_phy *qphy; |
| 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; |
| qphy->base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(qphy->base)) |
| return PTR_ERR(qphy->base); |
| |
| ret = phy_pipe_clksrc_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 = "phy-qcom-pcie2", |
| .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"); |