phy-qcom-qusb2.c
/*
* Copyright (c) 2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/slab.h>
#define QUSB2PHY_PLL_TEST 0x04
#define CLK_REF_SEL BIT(7)
#define QUSB2PHY_PLL_TUNE 0x08
#define QUSB2PHY_PLL_USER_CTL1 0x0c
#define QUSB2PHY_PLL_USER_CTL2 0x10
#define QUSB2PHY_PLL_AUTOPGM_CTL1 0x1c
#define QUSB2PHY_PLL_PWR_CTRL 0x18
#define QUSB2PHY_PLL_STATUS 0x38
#define PLL_LOCKED BIT(5)
#define QUSB2PHY_PORT_TUNE1 0x80
#define QUSB2PHY_PORT_TUNE2 0x84
#define QUSB2PHY_PORT_TUNE3 0x88
#define QUSB2PHY_PORT_TUNE4 0x8c
#define QUSB2PHY_PORT_TUNE5 0x90
#define QUSB2PHY_PORT_TEST2 0x9c
#define QUSB2PHY_PORT_POWERDOWN 0xb4
#define CLAMP_N_EN BIT(5)
#define FREEZIO_N BIT(1)
#define POWER_DOWN BIT(0)
#define QUSB2PHY_REFCLK_ENABLE BIT(0)
#define PHY_CLK_SCHEME_SEL BIT(0)
struct qusb2_phy_init_tbl {
unsigned int offset;
unsigned int val;
};
#define QUSB2_PHY_INIT_CFG(o, v) \
{ \
.offset = o, \
.val = v, \
}
static const struct qusb2_phy_init_tbl msm8996_init_tbl[] = {
QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE1, 0xf8),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE2, 0xb3),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE3, 0x83),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TUNE4, 0xc0),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_TUNE, 0x30),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL1, 0x79),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_USER_CTL2, 0x21),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PORT_TEST2, 0x14),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_AUTOPGM_CTL1, 0x9f),
QUSB2_PHY_INIT_CFG(QUSB2PHY_PLL_PWR_CTRL, 0x00),
};
struct qusb2_phy_cfg {
const struct qusb2_phy_init_tbl *tbl;
/* number of entries in the table */
unsigned int tbl_num;
/* offset to PHY_CLK_SCHEME register in TCSR map */
unsigned int clk_scheme_offset;
};
static const struct qusb2_phy_cfg msm8996_phy_cfg = {
.tbl = msm8996_init_tbl,
.tbl_num = ARRAY_SIZE(msm8996_init_tbl),
};
static const char * const qusb2_phy_vreg_names[] = {
"vdda-pll", "vdda-phy-dpdm",
};
#define QUSB2_NUM_VREGS ARRAY_SIZE(qusb2_phy_vreg_names)
/**
* struct qusb2_phy - structure holding qusb2 phy attributes
*
* @phy: generic phy
* @base: iomapped memory space for qubs2 phy
*
* @cfg_ahb_clk: AHB2PHY interface clock
* @ref_clk: phy reference clock
* @iface_clk: phy interface clock
* @phy_reset: phy reset control
* @vregs: regulator supplies bulk data
*
* @tcsr: TCSR syscon register map
* @cell: nvmem cell containing phy tuning value
*
* @cfg: phy config data
* @has_se_clk_scheme: indicate if PHY has single-ended ref clock scheme
*/
struct qusb2_phy {
struct phy *phy;
void __iomem *base;
struct clk *cfg_ahb_clk;
struct clk *ref_clk;
struct clk *iface_clk;
struct reset_control *phy_reset;
struct regulator_bulk_data vregs[QUSB2_NUM_VREGS];
struct regmap *tcsr;
struct nvmem_cell *cell;
const struct qusb2_phy_cfg *cfg;
bool has_se_clk_scheme;
};
static inline void qusb2_setbits(void __iomem *base, u32 offset, u32 val)
{
u32 reg;
reg = readl(base + offset);
reg |= val;
writel(reg, base + offset);
/* Ensure above write is completed */
readl(base + offset);
}
static inline void qusb2_clrbits(void __iomem *base, u32 offset, u32 val)
{
u32 reg;
reg = readl(base + offset);
reg &= ~val;
writel(reg, base + offset);
/* Ensure above write is completed */
readl(base + offset);
}
static inline
void qcom_qusb2_phy_configure(void __iomem *base,
const struct qusb2_phy_init_tbl tbl[], int num)
{
int i;
for (i = 0; i < num; i++)
writel(tbl[i].val, base + tbl[i].offset);
}
/*
* Fetches HS Tx tuning value from nvmem and sets the
* QUSB2PHY_PORT_TUNE2 register.
* For error case, skip setting the value and use the default value.
*/
static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
{
struct device *dev = &qphy->phy->dev;
u8 *val;
/*
* Read efuse register having TUNE2 parameter's high nibble.
* If efuse register shows value as 0x0, or if we fail to find
* a valid efuse register settings, then use default value
* as 0xB for high nibble that we have already set while
* configuring phy.
*/
val = nvmem_cell_read(qphy->cell, NULL);
if (IS_ERR(val) || !val[0]) {
dev_dbg(dev, "failed to read a valid hs-tx trim value\n");
return;
}
/* Fused TUNE2 value is the higher nibble only */
qusb2_setbits(qphy->base, QUSB2PHY_PORT_TUNE2, val[0] << 0x4);
}
static int qusb2_phy_poweron(struct phy *phy)
{
struct qusb2_phy *qphy = phy_get_drvdata(phy);
int num = ARRAY_SIZE(qphy->vregs);
int ret;
dev_vdbg(&phy->dev, "%s(): Powering-on QUSB2 phy\n", __func__);
/* turn on regulator supplies */
ret = regulator_bulk_enable(num, qphy->vregs);
if (ret)
return ret;
ret = clk_prepare_enable(qphy->iface_clk);
if (ret) {
dev_err(&phy->dev, "failed to enable iface_clk, %d\n", ret);
regulator_bulk_disable(num, qphy->vregs);
return ret;
}
return 0;
}
static int qusb2_phy_poweroff(struct phy *phy)
{
struct qusb2_phy *qphy = phy_get_drvdata(phy);
clk_disable_unprepare(qphy->iface_clk);
regulator_bulk_disable(ARRAY_SIZE(qphy->vregs), qphy->vregs);
return 0;
}
static int qusb2_phy_init(struct phy *phy)
{
struct qusb2_phy *qphy = phy_get_drvdata(phy);
unsigned int val;
unsigned int clk_scheme;
int ret;
dev_vdbg(&phy->dev, "%s(): Initializing QUSB2 phy\n", __func__);
/* enable ahb interface clock to program phy */
ret = clk_prepare_enable(qphy->cfg_ahb_clk);
if (ret) {
dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
return ret;
}
/* Perform phy reset */
ret = reset_control_assert(qphy->phy_reset);
if (ret) {
dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret);
goto disable_ahb_clk;
}
/* 100 us delay to keep PHY in reset mode */
usleep_range(100, 150);
ret = reset_control_deassert(qphy->phy_reset);
if (ret) {
dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret);
goto disable_ahb_clk;
}
/* Disable the PHY */
qusb2_setbits(qphy->base, QUSB2PHY_PORT_POWERDOWN,
CLAMP_N_EN | FREEZIO_N | POWER_DOWN);
/* save reset value to override reference clock scheme later */
val = readl(qphy->base + QUSB2PHY_PLL_TEST);
qcom_qusb2_phy_configure(qphy->base, qphy->cfg->tbl,
qphy->cfg->tbl_num);
/* Set efuse value for tuning the PHY */
qusb2_phy_set_tune2_param(qphy);
/* Enable the PHY */
qusb2_clrbits(qphy->base, QUSB2PHY_PORT_POWERDOWN, POWER_DOWN);
/* Required to get phy pll lock successfully */
usleep_range(150, 160);
/* Default is single-ended clock on msm8996 */
qphy->has_se_clk_scheme = true;
/*
* read TCSR_PHY_CLK_SCHEME register to check if single-ended
* clock scheme is selected. If yes, then disable differential
* ref_clk and use single-ended clock, otherwise use differential
* ref_clk only.
*/
if (qphy->tcsr) {
ret = regmap_read(qphy->tcsr, qphy->cfg->clk_scheme_offset,
&clk_scheme);
if (ret) {
dev_err(&phy->dev, "failed to read clk scheme reg\n");
goto assert_phy_reset;
}
/* is it a differential clock scheme ? */
if (!(clk_scheme & PHY_CLK_SCHEME_SEL)) {
dev_vdbg(&phy->dev, "%s(): select differential clk\n",
__func__);
qphy->has_se_clk_scheme = false;
} else {
dev_vdbg(&phy->dev, "%s(): select single-ended clk\n",
__func__);
}
}
if (!qphy->has_se_clk_scheme) {
val &= ~CLK_REF_SEL;
ret = clk_prepare_enable(qphy->ref_clk);
if (ret) {
dev_err(&phy->dev, "failed to enable ref clk, %d\n",
ret);
goto assert_phy_reset;
}
} else {
val |= CLK_REF_SEL;
}
writel(val, qphy->base + QUSB2PHY_PLL_TEST);
/* ensure above write is through */
readl(qphy->base + QUSB2PHY_PLL_TEST);
/* Required to get phy pll lock successfully */
usleep_range(100, 110);
val = readb(qphy->base + QUSB2PHY_PLL_STATUS);
if (!(val & PLL_LOCKED)) {
dev_err(&phy->dev,
"QUSB2PHY pll lock failed: status reg = %x\n", val);
ret = -EBUSY;
goto disable_ref_clk;
}
return 0;
disable_ref_clk:
if (!qphy->has_se_clk_scheme)
clk_disable_unprepare(qphy->ref_clk);
assert_phy_reset:
reset_control_assert(qphy->phy_reset);
disable_ahb_clk:
clk_disable_unprepare(qphy->cfg_ahb_clk);
return ret;
}
static int qusb2_phy_exit(struct phy *phy)
{
struct qusb2_phy *qphy = phy_get_drvdata(phy);
/* Disable the PHY */
qusb2_setbits(qphy->base, QUSB2PHY_PORT_POWERDOWN,
CLAMP_N_EN | FREEZIO_N | POWER_DOWN);
if (!qphy->has_se_clk_scheme)
clk_disable_unprepare(qphy->ref_clk);
reset_control_assert(qphy->phy_reset);
clk_disable_unprepare(qphy->cfg_ahb_clk);
return 0;
}
static const struct phy_ops qusb2_phy_gen_ops = {
.init = qusb2_phy_init,
.exit = qusb2_phy_exit,
.power_on = qusb2_phy_poweron,
.power_off = qusb2_phy_poweroff,
.owner = THIS_MODULE,
};
static const struct of_device_id qusb2_phy_of_match_table[] = {
{
.compatible = "qcom,msm8996-qusb2-phy",
.data = &msm8996_phy_cfg,
},
{ },
};
MODULE_DEVICE_TABLE(of, qusb2_phy_of_match_table);
static int qusb2_phy_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct qusb2_phy *qphy;
struct phy_provider *phy_provider;
struct phy *generic_phy;
struct resource *res;
int ret, i;
int num;
qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
if (!qphy)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
qphy->base = devm_ioremap_resource(dev, res);
if (IS_ERR(qphy->base))
return PTR_ERR(qphy->base);
qphy->cfg_ahb_clk = devm_clk_get(dev, "cfg_ahb");
if (IS_ERR(qphy->cfg_ahb_clk)) {
ret = PTR_ERR(qphy->cfg_ahb_clk);
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to get cfg ahb clk, %d\n", ret);
return ret;
}
qphy->ref_clk = devm_clk_get(dev, "ref");
if (IS_ERR(qphy->ref_clk)) {
ret = PTR_ERR(qphy->ref_clk);
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to get ref clk, %d\n", ret);
return ret;
}
qphy->iface_clk = devm_clk_get(dev, "iface");
if (IS_ERR(qphy->iface_clk)) {
ret = PTR_ERR(qphy->iface_clk);
if (ret == -EPROBE_DEFER)
return ret;
qphy->iface_clk = NULL;
dev_dbg(dev, "failed to get iface clk, %d\n", ret);
}
qphy->phy_reset = devm_reset_control_get_by_index(&pdev->dev, 0);
if (IS_ERR(qphy->phy_reset)) {
dev_err(dev, "failed to get phy core reset\n");
return PTR_ERR(qphy->phy_reset);
}
num = ARRAY_SIZE(qphy->vregs);
for (i = 0; i < num; i++)
qphy->vregs[i].supply = qusb2_phy_vreg_names[i];
ret = devm_regulator_bulk_get(dev, num, qphy->vregs);
if (ret) {
dev_err(dev, "failed to get regulator supplies\n");
return ret;
}
/* Get the specific init parameters of QMP phy */
qphy->cfg = of_device_get_match_data(dev);
qphy->tcsr = syscon_regmap_lookup_by_phandle(dev->of_node,
"qcom,tcsr-syscon");
if (IS_ERR(qphy->tcsr)) {
dev_dbg(dev, "failed to lookup TCSR regmap\n");
qphy->tcsr = NULL;
}
qphy->cell = devm_nvmem_cell_get(dev, NULL);
if (IS_ERR(qphy->cell)) {
if (PTR_ERR(qphy->cell) == -EPROBE_DEFER)
return -EPROBE_DEFER;
qphy->cell = NULL;
dev_dbg(dev, "failed to lookup tune2 hstx trim value\n");
}
generic_phy = devm_phy_create(dev, NULL, &qusb2_phy_gen_ops);
if (IS_ERR(generic_phy)) {
ret = PTR_ERR(generic_phy);
dev_err(dev, "failed to create phy, %d\n", ret);
return ret;
}
qphy->phy = generic_phy;
dev_set_drvdata(dev, qphy);
phy_set_drvdata(generic_phy, qphy);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (!IS_ERR(phy_provider))
dev_info(dev, "Registered Qcom-QUSB2 phy\n");
return PTR_ERR_OR_ZERO(phy_provider);
}
static struct platform_driver qusb2_phy_driver = {
.probe = qusb2_phy_probe,
.driver = {
.name = "qcom-qusb2-phy",
.of_match_table = qusb2_phy_of_match_table,
},
};
module_platform_driver(qusb2_phy_driver);
MODULE_AUTHOR("Vivek Gautam <vivek.gautam@codeaurora.org>");
MODULE_DESCRIPTION("Qualcomm QUSB2 PHY driver");
MODULE_LICENSE("GPL v2");