// SPDX-License-Identifier: GPL-2.0-only
/*
* PCIe PHY driver for Lantiq VRX200 and ARX300 SoCs.
*
* Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
*
* Based on the BSP (called "UGW") driver:
* Copyright (C) 2009-2015 Lei Chuanhua <chuanhua.lei@lantiq.com>
* Copyright (C) 2016 Intel Corporation
*
* TODO: PHY modes other than 36MHz (without "SSC")
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <dt-bindings/phy/phy-lantiq-vrx200-pcie.h>
#define PCIE_PHY_PLL_CTRL1 0x44
#define PCIE_PHY_PLL_CTRL2 0x46
#define PCIE_PHY_PLL_CTRL2_CONST_SDM_MASK GENMASK(7, 0)
#define PCIE_PHY_PLL_CTRL2_CONST_SDM_EN BIT(8)
#define PCIE_PHY_PLL_CTRL2_PLL_SDM_EN BIT(9)
#define PCIE_PHY_PLL_CTRL3 0x48
#define PCIE_PHY_PLL_CTRL3_EXT_MMD_DIV_RATIO_EN BIT(1)
#define PCIE_PHY_PLL_CTRL3_EXT_MMD_DIV_RATIO_MASK GENMASK(6, 4)
#define PCIE_PHY_PLL_CTRL4 0x4a
#define PCIE_PHY_PLL_CTRL5 0x4c
#define PCIE_PHY_PLL_CTRL6 0x4e
#define PCIE_PHY_PLL_CTRL7 0x50
#define PCIE_PHY_PLL_A_CTRL1 0x52
#define PCIE_PHY_PLL_A_CTRL2 0x54
#define PCIE_PHY_PLL_A_CTRL2_LF_MODE_EN BIT(14)
#define PCIE_PHY_PLL_A_CTRL3 0x56
#define PCIE_PHY_PLL_A_CTRL3_MMD_MASK GENMASK(15, 13)
#define PCIE_PHY_PLL_STATUS 0x58
#define PCIE_PHY_TX1_CTRL1 0x60
#define PCIE_PHY_TX1_CTRL1_FORCE_EN BIT(3)
#define PCIE_PHY_TX1_CTRL1_LOAD_EN BIT(4)
#define PCIE_PHY_TX1_CTRL2 0x62
#define PCIE_PHY_TX1_CTRL3 0x64
#define PCIE_PHY_TX1_A_CTRL1 0x66
#define PCIE_PHY_TX1_A_CTRL2 0x68
#define PCIE_PHY_TX1_MOD1 0x6a
#define PCIE_PHY_TX1_MOD2 0x6c
#define PCIE_PHY_TX1_MOD3 0x6e
#define PCIE_PHY_TX2_CTRL1 0x70
#define PCIE_PHY_TX2_CTRL1_LOAD_EN BIT(4)
#define PCIE_PHY_TX2_CTRL2 0x72
#define PCIE_PHY_TX2_A_CTRL1 0x76
#define PCIE_PHY_TX2_A_CTRL2 0x78
#define PCIE_PHY_TX2_MOD1 0x7a
#define PCIE_PHY_TX2_MOD2 0x7c
#define PCIE_PHY_TX2_MOD3 0x7e
#define PCIE_PHY_RX1_CTRL1 0xa0
#define PCIE_PHY_RX1_CTRL1_LOAD_EN BIT(1)
#define PCIE_PHY_RX1_CTRL2 0xa2
#define PCIE_PHY_RX1_CDR 0xa4
#define PCIE_PHY_RX1_EI 0xa6
#define PCIE_PHY_RX1_A_CTRL 0xaa
struct ltq_vrx200_pcie_phy_priv {
struct phy *phy;
unsigned int mode;
struct device *dev;
struct regmap *phy_regmap;
struct regmap *rcu_regmap;
struct clk *pdi_clk;
struct clk *phy_clk;
struct reset_control *phy_reset;
struct reset_control *pcie_reset;
u32 rcu_ahb_endian_offset;
u32 rcu_ahb_endian_big_endian_mask;
};
static void ltq_vrx200_pcie_phy_common_setup(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
/* PLL Setting */
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_A_CTRL1, 0x120e);
/* increase the bias reference voltage */
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_A_CTRL2, 0x39d7);
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_A_CTRL3, 0x0900);
/* Endcnt */
regmap_write(priv->phy_regmap, PCIE_PHY_RX1_EI, 0x0004);
regmap_write(priv->phy_regmap, PCIE_PHY_RX1_A_CTRL, 0x6803);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_TX1_CTRL1,
PCIE_PHY_TX1_CTRL1_FORCE_EN,
PCIE_PHY_TX1_CTRL1_FORCE_EN);
/* predrv_ser_en */
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_A_CTRL2, 0x0706);
/* ctrl_lim */
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_CTRL3, 0x1fff);
/* ctrl */
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_A_CTRL1, 0x0810);
/* predrv_ser_en */
regmap_update_bits(priv->phy_regmap, PCIE_PHY_TX2_A_CTRL2, 0x7f00,
0x4700);
/* RTERM */
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_CTRL2, 0x2e00);
/* Improved 100MHz clock output */
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_CTRL2, 0x3096);
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_A_CTRL2, 0x4707);
/* Reduced CDR BW to avoid glitches */
regmap_write(priv->phy_regmap, PCIE_PHY_RX1_CDR, 0x0235);
}
static void pcie_phy_36mhz_mode_setup(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_CTRL3,
PCIE_PHY_PLL_CTRL3_EXT_MMD_DIV_RATIO_EN, 0x0000);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_CTRL3,
PCIE_PHY_PLL_CTRL3_EXT_MMD_DIV_RATIO_MASK, 0x0000);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_CTRL2,
PCIE_PHY_PLL_CTRL2_PLL_SDM_EN,
PCIE_PHY_PLL_CTRL2_PLL_SDM_EN);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_CTRL2,
PCIE_PHY_PLL_CTRL2_CONST_SDM_EN,
PCIE_PHY_PLL_CTRL2_CONST_SDM_EN);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_A_CTRL3,
PCIE_PHY_PLL_A_CTRL3_MMD_MASK,
FIELD_PREP(PCIE_PHY_PLL_A_CTRL3_MMD_MASK, 0x1));
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_A_CTRL2,
PCIE_PHY_PLL_A_CTRL2_LF_MODE_EN, 0x0000);
/* const_sdm */
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_CTRL1, 0x38e4);
regmap_update_bits(priv->phy_regmap, PCIE_PHY_PLL_CTRL2,
PCIE_PHY_PLL_CTRL2_CONST_SDM_MASK,
FIELD_PREP(PCIE_PHY_PLL_CTRL2_CONST_SDM_MASK,
0xee));
/* pllmod */
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_CTRL7, 0x0002);
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_CTRL6, 0x3a04);
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_CTRL5, 0xfae3);
regmap_write(priv->phy_regmap, PCIE_PHY_PLL_CTRL4, 0x1b72);
}
static int ltq_vrx200_pcie_phy_wait_for_pll(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
unsigned int tmp;
int ret;
ret = regmap_read_poll_timeout(priv->phy_regmap, PCIE_PHY_PLL_STATUS,
tmp, ((tmp & 0x0070) == 0x0070), 10,
10000);
if (ret) {
dev_err(priv->dev, "PLL Link timeout, PLL status = 0x%04x\n",
tmp);
return ret;
}
return 0;
}
static void ltq_vrx200_pcie_phy_apply_workarounds(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
static const struct reg_default slices[] = {
{
.reg = PCIE_PHY_TX1_CTRL1,
.def = PCIE_PHY_TX1_CTRL1_LOAD_EN,
},
{
.reg = PCIE_PHY_TX2_CTRL1,
.def = PCIE_PHY_TX2_CTRL1_LOAD_EN,
},
{
.reg = PCIE_PHY_RX1_CTRL1,
.def = PCIE_PHY_RX1_CTRL1_LOAD_EN,
}
};
int i;
for (i = 0; i < ARRAY_SIZE(slices); i++) {
/* enable load_en */
regmap_update_bits(priv->phy_regmap, slices[i].reg,
slices[i].def, slices[i].def);
udelay(1);
/* disable load_en */
regmap_update_bits(priv->phy_regmap, slices[i].reg,
slices[i].def, 0x0);
}
for (i = 0; i < 5; i++) {
/* TX2 modulation */
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_MOD1, 0x1ffe);
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_MOD2, 0xfffe);
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_MOD3, 0x0601);
usleep_range(1000, 2000);
regmap_write(priv->phy_regmap, PCIE_PHY_TX2_MOD3, 0x0001);
/* TX1 modulation */
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_MOD1, 0x1ffe);
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_MOD2, 0xfffe);
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_MOD3, 0x0601);
usleep_range(1000, 2000);
regmap_write(priv->phy_regmap, PCIE_PHY_TX1_MOD3, 0x0001);
}
}
static int ltq_vrx200_pcie_phy_init(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
int ret;
if (of_device_is_big_endian(priv->dev->of_node))
regmap_update_bits(priv->rcu_regmap,
priv->rcu_ahb_endian_offset,
priv->rcu_ahb_endian_big_endian_mask,
priv->rcu_ahb_endian_big_endian_mask);
else
regmap_update_bits(priv->rcu_regmap,
priv->rcu_ahb_endian_offset,
priv->rcu_ahb_endian_big_endian_mask, 0x0);
ret = reset_control_assert(priv->phy_reset);
if (ret)
goto err;
udelay(1);
ret = reset_control_deassert(priv->phy_reset);
if (ret)
goto err;
udelay(1);
ret = reset_control_deassert(priv->pcie_reset);
if (ret)
goto err_assert_phy_reset;
/* Make sure PHY PLL is stable */
usleep_range(20, 40);
return 0;
err_assert_phy_reset:
reset_control_assert(priv->phy_reset);
err:
return ret;
}
static int ltq_vrx200_pcie_phy_exit(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
int ret;
ret = reset_control_assert(priv->pcie_reset);
if (ret)
return ret;
ret = reset_control_assert(priv->phy_reset);
if (ret)
return ret;
return 0;
}
static int ltq_vrx200_pcie_phy_power_on(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
int ret;
/* Enable PDI to access PCIe PHY register */
ret = clk_prepare_enable(priv->pdi_clk);
if (ret)
goto err;
/* Configure PLL and PHY clock */
ltq_vrx200_pcie_phy_common_setup(phy);
pcie_phy_36mhz_mode_setup(phy);
/* Enable the PCIe PHY and make PLL setting take effect */
ret = clk_prepare_enable(priv->phy_clk);
if (ret)
goto err_disable_pdi_clk;
/* Check if we are in "startup ready" status */
ret = ltq_vrx200_pcie_phy_wait_for_pll(phy);
if (ret)
goto err_disable_phy_clk;
ltq_vrx200_pcie_phy_apply_workarounds(phy);
return 0;
err_disable_phy_clk:
clk_disable_unprepare(priv->phy_clk);
err_disable_pdi_clk:
clk_disable_unprepare(priv->pdi_clk);
err:
return ret;
}
static int ltq_vrx200_pcie_phy_power_off(struct phy *phy)
{
struct ltq_vrx200_pcie_phy_priv *priv = phy_get_drvdata(phy);
clk_disable_unprepare(priv->phy_clk);
clk_disable_unprepare(priv->pdi_clk);
return 0;
}
static const struct phy_ops ltq_vrx200_pcie_phy_ops = {
.init = ltq_vrx200_pcie_phy_init,
.exit = ltq_vrx200_pcie_phy_exit,
.power_on = ltq_vrx200_pcie_phy_power_on,
.power_off = ltq_vrx200_pcie_phy_power_off,
.owner = THIS_MODULE,
};
static struct phy *ltq_vrx200_pcie_phy_xlate(struct device *dev,
struct of_phandle_args *args)
{
struct ltq_vrx200_pcie_phy_priv *priv = dev_get_drvdata(dev);
unsigned int mode;
if (args->args_count != 1) {
dev_err(dev, "invalid number of arguments\n");
return ERR_PTR(-EINVAL);
}
mode = args->args[0];
switch (mode) {
case LANTIQ_PCIE_PHY_MODE_36MHZ:
priv->mode = mode;
break;
case LANTIQ_PCIE_PHY_MODE_25MHZ:
case LANTIQ_PCIE_PHY_MODE_25MHZ_SSC:
case LANTIQ_PCIE_PHY_MODE_36MHZ_SSC:
case LANTIQ_PCIE_PHY_MODE_100MHZ:
case LANTIQ_PCIE_PHY_MODE_100MHZ_SSC:
dev_err(dev, "PHY mode not implemented yet: %u\n", mode);
return ERR_PTR(-EINVAL);
default:
dev_err(dev, "invalid PHY mode %u\n", mode);
return ERR_PTR(-EINVAL);
}
return priv->phy;
}
static int ltq_vrx200_pcie_phy_probe(struct platform_device *pdev)
{
static const struct regmap_config regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.reg_stride = 2,
.max_register = PCIE_PHY_RX1_A_CTRL,
};
struct ltq_vrx200_pcie_phy_priv *priv;
struct device *dev = &pdev->dev;
struct phy_provider *provider;
void __iomem *base;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
priv->phy_regmap = devm_regmap_init_mmio(dev, base, ®map_config);
if (IS_ERR(priv->phy_regmap))
return PTR_ERR(priv->phy_regmap);
priv->rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
"lantiq,rcu");
if (IS_ERR(priv->rcu_regmap))
return PTR_ERR(priv->rcu_regmap);
ret = device_property_read_u32(dev, "lantiq,rcu-endian-offset",
&priv->rcu_ahb_endian_offset);
if (ret) {
dev_err(dev,
"failed to parse the 'lantiq,rcu-endian-offset' property\n");
return ret;
}
ret = device_property_read_u32(dev, "lantiq,rcu-big-endian-mask",
&priv->rcu_ahb_endian_big_endian_mask);
if (ret) {
dev_err(dev,
"failed to parse the 'lantiq,rcu-big-endian-mask' property\n");
return ret;
}
priv->pdi_clk = devm_clk_get(dev, "pdi");
if (IS_ERR(priv->pdi_clk))
return PTR_ERR(priv->pdi_clk);
priv->phy_clk = devm_clk_get(dev, "phy");
if (IS_ERR(priv->phy_clk))
return PTR_ERR(priv->phy_clk);
priv->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
if (IS_ERR(priv->phy_reset))
return PTR_ERR(priv->phy_reset);
priv->pcie_reset = devm_reset_control_get_shared(dev, "pcie");
if (IS_ERR(priv->pcie_reset))
return PTR_ERR(priv->pcie_reset);
priv->dev = dev;
priv->phy = devm_phy_create(dev, dev->of_node,
<q_vrx200_pcie_phy_ops);
if (IS_ERR(priv->phy)) {
dev_err(dev, "failed to create PHY\n");
return PTR_ERR(priv->phy);
}
phy_set_drvdata(priv->phy, priv);
dev_set_drvdata(dev, priv);
provider = devm_of_phy_provider_register(dev,
ltq_vrx200_pcie_phy_xlate);
return PTR_ERR_OR_ZERO(provider);
}
static const struct of_device_id ltq_vrx200_pcie_phy_of_match[] = {
{ .compatible = "lantiq,vrx200-pcie-phy", },
{ .compatible = "lantiq,arx300-pcie-phy", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ltq_vrx200_pcie_phy_of_match);
static struct platform_driver ltq_vrx200_pcie_phy_driver = {
.probe = ltq_vrx200_pcie_phy_probe,
.driver = {
.name = "ltq-vrx200-pcie-phy",
.of_match_table = ltq_vrx200_pcie_phy_of_match,
}
};
module_platform_driver(ltq_vrx200_pcie_phy_driver);
MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
MODULE_DESCRIPTION("Lantiq VRX200 and ARX300 PCIe PHY driver");
MODULE_LICENSE("GPL v2");
