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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019 Daniel Golle <daniel@makrotopia.org>
*
*/
#include <dt-bindings/phy/phy.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/mfd/syscon.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#define ADDR_VAL(val) ((val) & 0xFFFF)
#define DATA_VAL(val) ((val) & 0xFFFF)
#define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114
enum {
HCSL_BIAS_ON = BIT(0),
HCSL_PCIE_EN = BIT(1),
HCSL_PCIEA_EN = BIT(2),
HCSL_PCIEB_EN = BIT(3),
};
enum {
/* pcie phy reg offset */
PHY_ADDR = 0,
PHY_DATA = 4,
/* phy data reg bits */
READ_EN = BIT(16),
WRITE_EN = BIT(17),
CAP_DATA = BIT(18),
};
struct oxnas_pcie_phy {
struct device *dev;
void __iomem *membase;
const struct phy_ops *ops;
struct regmap *sys_ctrl;
};
static int oxnas_pcie_phy_init(struct phy *phy)
{
struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);
struct reset_control *rstc;
int ret;
/* generate clocks from HCSL buffers, shared parts */
regmap_write(pciephy->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);
/* Ensure PCIe PHY is properly reset */
rstc = reset_control_get(pciephy->dev, "phy");
if (IS_ERR(rstc)) {
ret = PTR_ERR(rstc);
} else {
ret = reset_control_reset(rstc);
reset_control_put(rstc);
}
if (ret) {
dev_err(pciephy->dev, "phy reset failed %d\n", ret);
return ret;
}
return 0;
}
static int oxnas_pcie_phy_power_on(struct phy *phy)
{
struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);
/* Enable PCIe Pre-Emphasis: What these value means? */
writel(ADDR_VAL(0x0014), pciephy->membase + PHY_ADDR);
writel(DATA_VAL(0xce10) | CAP_DATA, pciephy->membase + PHY_DATA);
writel(DATA_VAL(0xce10) | WRITE_EN, pciephy->membase + PHY_DATA);
writel(ADDR_VAL(0x2004), pciephy->membase + PHY_ADDR);
writel(DATA_VAL(0x82c7) | CAP_DATA, pciephy->membase + PHY_DATA);
writel(DATA_VAL(0x82c7) | WRITE_EN, pciephy->membase + PHY_DATA);
return 0;
}
static const struct phy_ops ops = {
.init = oxnas_pcie_phy_init,
.power_on = oxnas_pcie_phy_power_on,
.owner = THIS_MODULE,
};
static int oxnas_pcie_phy_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct phy *generic_phy;
struct phy_provider *phy_provider;
struct oxnas_pcie_phy *pciephy;
struct regmap *sys_ctrl;
void __iomem *membase;
membase = of_iomap(np, 0);
if (IS_ERR(membase))
return PTR_ERR(membase);
sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
if (IS_ERR(sys_ctrl)) {
dev_err(dev, "Cannot find OX820 SYSCRTL\n");
return PTR_ERR(sys_ctrl);
}
pciephy = devm_kzalloc(dev, sizeof(*pciephy), GFP_KERNEL);
if (!pciephy)
return -ENOMEM;
pciephy->sys_ctrl = sys_ctrl;
pciephy->membase = membase;
pciephy->dev = dev;
pciephy->ops = &ops;
generic_phy = devm_phy_create(dev, dev->of_node, pciephy->ops);
if (IS_ERR(generic_phy)) {
dev_err(dev, "failed to create PHY\n");
return PTR_ERR(generic_phy);
}
phy_set_drvdata(generic_phy, pciephy);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
return PTR_ERR_OR_ZERO(phy_provider);
}
static const struct of_device_id oxnas_pcie_phy_id_table[] = {
{ .compatible = "oxsemi,ox820-pcie-phy" },
{ },
};
static struct platform_driver oxnas_pcie_phy_driver = {
.probe = oxnas_pcie_phy_probe,
.driver = {
.name = "ox820-pcie-phy",
.of_match_table = oxnas_pcie_phy_id_table,
},
};
builtin_platform_driver(oxnas_pcie_phy_driver);
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