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Diffstat (limited to '')
-rw-r--r-- | drivers/phy/qualcomm/phy-qcom-pcie2.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/phy/qualcomm/phy-qcom-pcie2.c b/drivers/phy/qualcomm/phy-qcom-pcie2.c new file mode 100644 index 000000000..5407e59bb --- /dev/null +++ b/drivers/phy/qualcomm/phy-qcom-pcie2.c @@ -0,0 +1,328 @@ +// 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; + + 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 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"); |