linux/drivers/phy/phy-rockchip-emmc.c

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/*
* Rockchip emmc PHY driver
*
* Copyright (C) 2016 Shawn Lin <shawn.lin@rock-chips.com>
* Copyright (C) 2016 ROCKCHIP, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*
* 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/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
/*
* The higher 16-bit of this register is used for write protection
* only if BIT(x + 16) set to 1 the BIT(x) can be written.
*/
#define HIWORD_UPDATE(val, mask, shift) \
((val) << (shift) | (mask) << ((shift) + 16))
/* Register definition */
#define GRF_EMMCPHY_CON0 0x0
#define GRF_EMMCPHY_CON1 0x4
#define GRF_EMMCPHY_CON2 0x8
#define GRF_EMMCPHY_CON3 0xc
#define GRF_EMMCPHY_CON4 0x10
#define GRF_EMMCPHY_CON5 0x14
#define GRF_EMMCPHY_CON6 0x18
#define GRF_EMMCPHY_STATUS 0x20
#define PHYCTRL_PDB_MASK 0x1
#define PHYCTRL_PDB_SHIFT 0x0
#define PHYCTRL_PDB_PWR_ON 0x1
#define PHYCTRL_PDB_PWR_OFF 0x0
#define PHYCTRL_ENDLL_MASK 0x1
#define PHYCTRL_ENDLL_SHIFT 0x1
#define PHYCTRL_ENDLL_ENABLE 0x1
#define PHYCTRL_ENDLL_DISABLE 0x0
#define PHYCTRL_CALDONE_MASK 0x1
#define PHYCTRL_CALDONE_SHIFT 0x6
#define PHYCTRL_CALDONE_DONE 0x1
#define PHYCTRL_CALDONE_GOING 0x0
#define PHYCTRL_DLLRDY_MASK 0x1
#define PHYCTRL_DLLRDY_SHIFT 0x5
#define PHYCTRL_DLLRDY_DONE 0x1
#define PHYCTRL_DLLRDY_GOING 0x0
struct rockchip_emmc_phy {
unsigned int reg_offset;
struct regmap *reg_base;
};
static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy,
bool on_off)
{
unsigned int caldone;
unsigned int dllrdy;
/*
* Keep phyctrl_pdb and phyctrl_endll low to allow
* initialization of CALIO state M/C DFFs
*/
regmap_write(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_CON6,
HIWORD_UPDATE(PHYCTRL_PDB_PWR_OFF,
PHYCTRL_PDB_MASK,
PHYCTRL_PDB_SHIFT));
regmap_write(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_CON6,
HIWORD_UPDATE(PHYCTRL_ENDLL_DISABLE,
PHYCTRL_ENDLL_MASK,
PHYCTRL_ENDLL_SHIFT));
/* Already finish power_off above */
if (on_off == PHYCTRL_PDB_PWR_OFF)
return 0;
/*
* According to the user manual, calpad calibration
* cycle takes more than 2us without the minimal recommended
* value, so we may need a little margin here
*/
udelay(3);
regmap_write(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_CON6,
HIWORD_UPDATE(PHYCTRL_PDB_PWR_ON,
PHYCTRL_PDB_MASK,
PHYCTRL_PDB_SHIFT));
/*
* According to the user manual, it asks driver to
* wait 5us for calpad busy trimming
*/
udelay(5);
regmap_read(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
&caldone);
caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
if (caldone != PHYCTRL_CALDONE_DONE) {
pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
return -ETIMEDOUT;
}
regmap_write(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_CON6,
HIWORD_UPDATE(PHYCTRL_ENDLL_ENABLE,
PHYCTRL_ENDLL_MASK,
PHYCTRL_ENDLL_SHIFT));
/*
* After enable analog DLL circuits, we need extra 10.2us
* for dll to be ready for work.
*/
udelay(11);
regmap_read(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
&dllrdy);
dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK;
if (dllrdy != PHYCTRL_DLLRDY_DONE) {
pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n");
return -ETIMEDOUT;
}
return 0;
}
static int rockchip_emmc_phy_power_off(struct phy *phy)
{
struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
int ret = 0;
/* Power down emmc phy analog blocks */
ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_OFF);
if (ret)
return ret;
return 0;
}
static int rockchip_emmc_phy_power_on(struct phy *phy)
{
struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
int ret = 0;
/* Power up emmc phy analog blocks */
ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON);
if (ret)
return ret;
return 0;
}
static const struct phy_ops ops = {
.power_on = rockchip_emmc_phy_power_on,
.power_off = rockchip_emmc_phy_power_off,
.owner = THIS_MODULE,
};
static int rockchip_emmc_phy_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rockchip_emmc_phy *rk_phy;
struct phy *generic_phy;
struct phy_provider *phy_provider;
struct regmap *grf;
unsigned int reg_offset;
grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
if (IS_ERR(grf)) {
dev_err(dev, "Missing rockchip,grf property\n");
return PTR_ERR(grf);
}
rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL);
if (!rk_phy)
return -ENOMEM;
if (of_property_read_u32(dev->of_node, "reg", &reg_offset)) {
dev_err(dev, "missing reg property in node %s\n",
dev->of_node->name);
return -EINVAL;
}
rk_phy->reg_offset = reg_offset;
rk_phy->reg_base = grf;
generic_phy = devm_phy_create(dev, dev->of_node, &ops);
if (IS_ERR(generic_phy)) {
dev_err(dev, "failed to create PHY\n");
return PTR_ERR(generic_phy);
}
phy_set_drvdata(generic_phy, rk_phy);
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 rockchip_emmc_phy_dt_ids[] = {
{ .compatible = "rockchip,rk3399-emmc-phy" },
{}
};
MODULE_DEVICE_TABLE(of, rockchip_emmc_phy_dt_ids);
static struct platform_driver rockchip_emmc_driver = {
.probe = rockchip_emmc_phy_probe,
.driver = {
.name = "rockchip-emmc-phy",
.of_match_table = rockchip_emmc_phy_dt_ids,
},
};
module_platform_driver(rockchip_emmc_driver);
MODULE_AUTHOR("Shawn Lin <shawn.lin@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip EMMC PHY driver");
MODULE_LICENSE("GPL v2");