diff options
Diffstat (limited to 'drivers/phy/socionext/phy-uniphier-pcie.c')
| -rw-r--r-- | drivers/phy/socionext/phy-uniphier-pcie.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/phy/socionext/phy-uniphier-pcie.c b/drivers/phy/socionext/phy-uniphier-pcie.c new file mode 100644 index 000000000000..93ffbd2940fa --- /dev/null +++ b/drivers/phy/socionext/phy-uniphier-pcie.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * phy-uniphier-pcie.c - PHY driver for UniPhier PCIe controller + * Copyright 2018, Socionext Inc. + * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> + */ + +#include <linux/bitops.h> +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/iopoll.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/reset.h> +#include <linux/resource.h> + +/* PHY */ +#define PCL_PHY_TEST_I 0x2000 +#define PCL_PHY_TEST_O 0x2004 +#define TESTI_DAT_MASK GENMASK(13, 6) +#define TESTI_ADR_MASK GENMASK(5, 1) +#define TESTI_WR_EN BIT(0) + +#define PCL_PHY_RESET 0x200c +#define PCL_PHY_RESET_N_MNMODE BIT(8) /* =1:manual */ +#define PCL_PHY_RESET_N BIT(0) /* =1:deasssert */ + +/* SG */ +#define SG_USBPCIESEL 0x590 +#define SG_USBPCIESEL_PCIE BIT(0) + +#define PCL_PHY_R00 0 +#define RX_EQ_ADJ_EN BIT(3) /* enable for EQ adjustment */ +#define PCL_PHY_R06 6 +#define RX_EQ_ADJ GENMASK(5, 0) /* EQ adjustment value */ +#define RX_EQ_ADJ_VAL 0 +#define PCL_PHY_R26 26 +#define VCO_CTRL GENMASK(7, 4) /* Tx VCO adjustment value */ +#define VCO_CTRL_INIT_VAL 5 + +struct uniphier_pciephy_priv { + void __iomem *base; + struct device *dev; + struct clk *clk; + struct reset_control *rst; + const struct uniphier_pciephy_soc_data *data; +}; + +struct uniphier_pciephy_soc_data { + bool has_syscon; +}; + +static void uniphier_pciephy_testio_write(struct uniphier_pciephy_priv *priv, + u32 data) +{ + /* need to read TESTO twice after accessing TESTI */ + writel(data, priv->base + PCL_PHY_TEST_I); + readl(priv->base + PCL_PHY_TEST_O); + readl(priv->base + PCL_PHY_TEST_O); +} + +static void uniphier_pciephy_set_param(struct uniphier_pciephy_priv *priv, + u32 reg, u32 mask, u32 param) +{ + u32 val; + + /* read previous data */ + val = FIELD_PREP(TESTI_DAT_MASK, 1); + val |= FIELD_PREP(TESTI_ADR_MASK, reg); + uniphier_pciephy_testio_write(priv, val); + val = readl(priv->base + PCL_PHY_TEST_O); + + /* update value */ + val &= ~FIELD_PREP(TESTI_DAT_MASK, mask); + val = FIELD_PREP(TESTI_DAT_MASK, mask & param); + val |= FIELD_PREP(TESTI_ADR_MASK, reg); + uniphier_pciephy_testio_write(priv, val); + uniphier_pciephy_testio_write(priv, val | TESTI_WR_EN); + uniphier_pciephy_testio_write(priv, val); + + /* read current data as dummy */ + val = FIELD_PREP(TESTI_DAT_MASK, 1); + val |= FIELD_PREP(TESTI_ADR_MASK, reg); + uniphier_pciephy_testio_write(priv, val); + readl(priv->base + PCL_PHY_TEST_O); +} + +static void uniphier_pciephy_assert(struct uniphier_pciephy_priv *priv) +{ + u32 val; + + val = readl(priv->base + PCL_PHY_RESET); + val &= ~PCL_PHY_RESET_N; + val |= PCL_PHY_RESET_N_MNMODE; + writel(val, priv->base + PCL_PHY_RESET); +} + +static void uniphier_pciephy_deassert(struct uniphier_pciephy_priv *priv) +{ + u32 val; + + val = readl(priv->base + PCL_PHY_RESET); + val |= PCL_PHY_RESET_N_MNMODE | PCL_PHY_RESET_N; + writel(val, priv->base + PCL_PHY_RESET); +} + +static int uniphier_pciephy_init(struct phy *phy) +{ + struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy); + int ret; + + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + + ret = reset_control_deassert(priv->rst); + if (ret) + goto out_clk_disable; + + uniphier_pciephy_set_param(priv, PCL_PHY_R00, + RX_EQ_ADJ_EN, RX_EQ_ADJ_EN); + uniphier_pciephy_set_param(priv, PCL_PHY_R06, RX_EQ_ADJ, + FIELD_PREP(RX_EQ_ADJ, RX_EQ_ADJ_VAL)); + uniphier_pciephy_set_param(priv, PCL_PHY_R26, VCO_CTRL, + FIELD_PREP(VCO_CTRL, VCO_CTRL_INIT_VAL)); + usleep_range(1, 10); + + uniphier_pciephy_deassert(priv); + usleep_range(1, 10); + + return 0; + +out_clk_disable: + clk_disable_unprepare(priv->clk); + + return ret; +} + +static int uniphier_pciephy_exit(struct phy *phy) +{ + struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy); + + uniphier_pciephy_assert(priv); + reset_control_assert(priv->rst); + clk_disable_unprepare(priv->clk); + + return 0; +} + +static const struct phy_ops uniphier_pciephy_ops = { + .init = uniphier_pciephy_init, + .exit = uniphier_pciephy_exit, + .owner = THIS_MODULE, +}; + +static int uniphier_pciephy_probe(struct platform_device *pdev) +{ + struct uniphier_pciephy_priv *priv; + struct phy_provider *phy_provider; + struct device *dev = &pdev->dev; + struct regmap *regmap; + struct resource *res; + struct phy *phy; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->data = of_device_get_match_data(dev); + if (WARN_ON(!priv->data)) + return -EINVAL; + + priv->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) + return PTR_ERR(priv->clk); + + priv->rst = devm_reset_control_get_shared(dev, NULL); + if (IS_ERR(priv->rst)) + return PTR_ERR(priv->rst); + + phy = devm_phy_create(dev, dev->of_node, &uniphier_pciephy_ops); + if (IS_ERR(phy)) + return PTR_ERR(phy); + + regmap = syscon_regmap_lookup_by_phandle(dev->of_node, + "socionext,syscon"); + if (!IS_ERR(regmap) && priv->data->has_syscon) + regmap_update_bits(regmap, SG_USBPCIESEL, + SG_USBPCIESEL_PCIE, SG_USBPCIESEL_PCIE); + + phy_set_drvdata(phy, priv); + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static const struct uniphier_pciephy_soc_data uniphier_ld20_data = { + .has_syscon = true, +}; + +static const struct uniphier_pciephy_soc_data uniphier_pxs3_data = { + .has_syscon = false, +}; + +static const struct of_device_id uniphier_pciephy_match[] = { + { + .compatible = "socionext,uniphier-ld20-pcie-phy", + .data = &uniphier_ld20_data, + }, + { + .compatible = "socionext,uniphier-pxs3-pcie-phy", + .data = &uniphier_pxs3_data, + }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, uniphier_pciephy_match); + +static struct platform_driver uniphier_pciephy_driver = { + .probe = uniphier_pciephy_probe, + .driver = { + .name = "uniphier-pcie-phy", + .of_match_table = uniphier_pciephy_match, + }, +}; +module_platform_driver(uniphier_pciephy_driver); + +MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>"); +MODULE_DESCRIPTION("UniPhier PHY driver for PCIe controller"); +MODULE_LICENSE("GPL v2"); |