https://github.com/torvalds/linux
Tip revision: 9561de3a55bed6bdd44a12820ba81ec416e705a7 authored by Linus Torvalds on 04 June 2023, 18:04:27 UTC
Linux 6.4-rc5
Linux 6.4-rc5
Tip revision: 9561de3
clk-renesas-pcie.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Renesas 9-series PCIe clock generator driver
*
* The following series can be supported:
* - 9FGV/9DBV/9DMV/9FGL/9DML/9QXL/9SQ
* Currently supported:
* - 9FGV0241
* - 9FGV0441
*
* Copyright (C) 2022 Marek Vasut <marex@denx.de>
*/
#include <linux/clk-provider.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#define RS9_REG_OE 0x0
#define RS9_REG_SS 0x1
#define RS9_REG_SS_AMP_0V6 0x0
#define RS9_REG_SS_AMP_0V7 0x1
#define RS9_REG_SS_AMP_0V8 0x2
#define RS9_REG_SS_AMP_0V9 0x3
#define RS9_REG_SS_AMP_MASK 0x3
#define RS9_REG_SS_SSC_100 0
#define RS9_REG_SS_SSC_M025 (1 << 3)
#define RS9_REG_SS_SSC_M050 (3 << 3)
#define RS9_REG_SS_SSC_MASK (3 << 3)
#define RS9_REG_SS_SSC_LOCK BIT(5)
#define RS9_REG_SR 0x2
#define RS9_REG_REF 0x3
#define RS9_REG_REF_OE BIT(4)
#define RS9_REG_REF_OD BIT(5)
#define RS9_REG_REF_SR_SLOWEST 0
#define RS9_REG_REF_SR_SLOW (1 << 6)
#define RS9_REG_REF_SR_FAST (2 << 6)
#define RS9_REG_REF_SR_FASTER (3 << 6)
#define RS9_REG_VID 0x5
#define RS9_REG_DID 0x6
#define RS9_REG_BCP 0x7
#define RS9_REG_VID_IDT 0x01
#define RS9_REG_DID_TYPE_FGV (0x0 << RS9_REG_DID_TYPE_SHIFT)
#define RS9_REG_DID_TYPE_DBV (0x1 << RS9_REG_DID_TYPE_SHIFT)
#define RS9_REG_DID_TYPE_DMV (0x2 << RS9_REG_DID_TYPE_SHIFT)
#define RS9_REG_DID_TYPE_SHIFT 0x6
/* Supported Renesas 9-series models. */
enum rs9_model {
RENESAS_9FGV0241,
RENESAS_9FGV0441,
};
/* Structure to describe features of a particular 9-series model */
struct rs9_chip_info {
const enum rs9_model model;
unsigned int num_clks;
u8 did;
};
struct rs9_driver_data {
struct i2c_client *client;
struct regmap *regmap;
const struct rs9_chip_info *chip_info;
struct clk_hw *clk_dif[4];
u8 pll_amplitude;
u8 pll_ssc;
u8 clk_dif_sr;
};
/*
* Renesas 9-series i2c regmap
*/
static const struct regmap_range rs9_readable_ranges[] = {
regmap_reg_range(RS9_REG_OE, RS9_REG_REF),
regmap_reg_range(RS9_REG_VID, RS9_REG_BCP),
};
static const struct regmap_access_table rs9_readable_table = {
.yes_ranges = rs9_readable_ranges,
.n_yes_ranges = ARRAY_SIZE(rs9_readable_ranges),
};
static const struct regmap_range rs9_writeable_ranges[] = {
regmap_reg_range(RS9_REG_OE, RS9_REG_REF),
regmap_reg_range(RS9_REG_BCP, RS9_REG_BCP),
};
static const struct regmap_access_table rs9_writeable_table = {
.yes_ranges = rs9_writeable_ranges,
.n_yes_ranges = ARRAY_SIZE(rs9_writeable_ranges),
};
static int rs9_regmap_i2c_write(void *context,
unsigned int reg, unsigned int val)
{
struct i2c_client *i2c = context;
const u8 data[3] = { reg, 1, val };
const int count = ARRAY_SIZE(data);
int ret;
ret = i2c_master_send(i2c, data, count);
if (ret == count)
return 0;
else if (ret < 0)
return ret;
else
return -EIO;
}
static int rs9_regmap_i2c_read(void *context,
unsigned int reg, unsigned int *val)
{
struct i2c_client *i2c = context;
struct i2c_msg xfer[2];
u8 txdata = reg;
u8 rxdata[2];
int ret;
xfer[0].addr = i2c->addr;
xfer[0].flags = 0;
xfer[0].len = 1;
xfer[0].buf = (void *)&txdata;
xfer[1].addr = i2c->addr;
xfer[1].flags = I2C_M_RD;
xfer[1].len = 2;
xfer[1].buf = (void *)rxdata;
ret = i2c_transfer(i2c->adapter, xfer, 2);
if (ret < 0)
return ret;
if (ret != 2)
return -EIO;
/*
* Byte 0 is transfer length, which is always 1 due
* to BCP register programming to 1 in rs9_probe(),
* ignore it and use data from Byte 1.
*/
*val = rxdata[1];
return 0;
}
static const struct regmap_config rs9_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.cache_type = REGCACHE_FLAT,
.max_register = RS9_REG_BCP,
.num_reg_defaults_raw = 0x8,
.rd_table = &rs9_readable_table,
.wr_table = &rs9_writeable_table,
.reg_write = rs9_regmap_i2c_write,
.reg_read = rs9_regmap_i2c_read,
};
static u8 rs9_calc_dif(const struct rs9_driver_data *rs9, int idx)
{
enum rs9_model model = rs9->chip_info->model;
if (model == RENESAS_9FGV0241)
return BIT(idx) + 1;
else if (model == RENESAS_9FGV0441)
return BIT(idx);
return 0;
}
static int rs9_get_output_config(struct rs9_driver_data *rs9, int idx)
{
struct i2c_client *client = rs9->client;
u8 dif = rs9_calc_dif(rs9, idx);
unsigned char name[5] = "DIF0";
struct device_node *np;
int ret;
u32 sr;
/* Set defaults */
rs9->clk_dif_sr |= dif;
snprintf(name, 5, "DIF%d", idx);
np = of_get_child_by_name(client->dev.of_node, name);
if (!np)
return 0;
/* Output clock slew rate */
ret = of_property_read_u32(np, "renesas,slew-rate", &sr);
of_node_put(np);
if (!ret) {
if (sr == 2000000) { /* 2V/ns */
rs9->clk_dif_sr &= ~dif;
} else if (sr == 3000000) { /* 3V/ns (default) */
rs9->clk_dif_sr |= dif;
} else
ret = dev_err_probe(&client->dev, -EINVAL,
"Invalid renesas,slew-rate value\n");
}
return ret;
}
static int rs9_get_common_config(struct rs9_driver_data *rs9)
{
struct i2c_client *client = rs9->client;
struct device_node *np = client->dev.of_node;
unsigned int amp, ssc;
int ret;
/* Set defaults */
rs9->pll_amplitude = RS9_REG_SS_AMP_0V7;
rs9->pll_ssc = RS9_REG_SS_SSC_100;
/* Output clock amplitude */
ret = of_property_read_u32(np, "renesas,out-amplitude-microvolt",
&);
if (!ret) {
if (amp == 600000) /* 0.6V */
rs9->pll_amplitude = RS9_REG_SS_AMP_0V6;
else if (amp == 700000) /* 0.7V (default) */
rs9->pll_amplitude = RS9_REG_SS_AMP_0V7;
else if (amp == 800000) /* 0.8V */
rs9->pll_amplitude = RS9_REG_SS_AMP_0V8;
else if (amp == 900000) /* 0.9V */
rs9->pll_amplitude = RS9_REG_SS_AMP_0V9;
else
return dev_err_probe(&client->dev, -EINVAL,
"Invalid renesas,out-amplitude-microvolt value\n");
}
/* Output clock spread spectrum */
ret = of_property_read_u32(np, "renesas,out-spread-spectrum", &ssc);
if (!ret) {
if (ssc == 100000) /* 100% ... no spread (default) */
rs9->pll_ssc = RS9_REG_SS_SSC_100;
else if (ssc == 99750) /* -0.25% ... down spread */
rs9->pll_ssc = RS9_REG_SS_SSC_M025;
else if (ssc == 99500) /* -0.50% ... down spread */
rs9->pll_ssc = RS9_REG_SS_SSC_M050;
else
return dev_err_probe(&client->dev, -EINVAL,
"Invalid renesas,out-spread-spectrum value\n");
}
return 0;
}
static void rs9_update_config(struct rs9_driver_data *rs9)
{
int i;
/* If amplitude is non-default, update it. */
if (rs9->pll_amplitude != RS9_REG_SS_AMP_0V7) {
regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_AMP_MASK,
rs9->pll_amplitude);
}
/* If SSC is non-default, update it. */
if (rs9->pll_ssc != RS9_REG_SS_SSC_100) {
regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_SSC_MASK,
rs9->pll_ssc);
}
for (i = 0; i < rs9->chip_info->num_clks; i++) {
u8 dif = rs9_calc_dif(rs9, i);
if (rs9->clk_dif_sr & dif)
continue;
regmap_update_bits(rs9->regmap, RS9_REG_SR, dif,
rs9->clk_dif_sr & dif);
}
}
static struct clk_hw *
rs9_of_clk_get(struct of_phandle_args *clkspec, void *data)
{
struct rs9_driver_data *rs9 = data;
unsigned int idx = clkspec->args[0];
return rs9->clk_dif[idx];
}
static int rs9_probe(struct i2c_client *client)
{
unsigned char name[5] = "DIF0";
struct rs9_driver_data *rs9;
unsigned int vid, did;
struct clk_hw *hw;
int i, ret;
rs9 = devm_kzalloc(&client->dev, sizeof(*rs9), GFP_KERNEL);
if (!rs9)
return -ENOMEM;
i2c_set_clientdata(client, rs9);
rs9->client = client;
rs9->chip_info = device_get_match_data(&client->dev);
if (!rs9->chip_info)
return -EINVAL;
/* Fetch common configuration from DT (if specified) */
ret = rs9_get_common_config(rs9);
if (ret)
return ret;
/* Fetch DIFx output configuration from DT (if specified) */
for (i = 0; i < rs9->chip_info->num_clks; i++) {
ret = rs9_get_output_config(rs9, i);
if (ret)
return ret;
}
rs9->regmap = devm_regmap_init(&client->dev, NULL,
client, &rs9_regmap_config);
if (IS_ERR(rs9->regmap))
return dev_err_probe(&client->dev, PTR_ERR(rs9->regmap),
"Failed to allocate register map\n");
/* Always read back 1 Byte via I2C */
ret = regmap_write(rs9->regmap, RS9_REG_BCP, 1);
if (ret < 0)
return ret;
ret = regmap_read(rs9->regmap, RS9_REG_VID, &vid);
if (ret < 0)
return ret;
ret = regmap_read(rs9->regmap, RS9_REG_DID, &did);
if (ret < 0)
return ret;
if (vid != RS9_REG_VID_IDT || did != rs9->chip_info->did)
return dev_err_probe(&client->dev, -ENODEV,
"Incorrect VID/DID: %#02x, %#02x. Expected %#02x, %#02x\n",
vid, did, RS9_REG_VID_IDT,
rs9->chip_info->did);
/* Register clock */
for (i = 0; i < rs9->chip_info->num_clks; i++) {
snprintf(name, 5, "DIF%d", i);
hw = devm_clk_hw_register_fixed_factor_index(&client->dev, name,
0, 0, 4, 1);
if (IS_ERR(hw))
return PTR_ERR(hw);
rs9->clk_dif[i] = hw;
}
ret = devm_of_clk_add_hw_provider(&client->dev, rs9_of_clk_get, rs9);
if (!ret)
rs9_update_config(rs9);
return ret;
}
static int __maybe_unused rs9_suspend(struct device *dev)
{
struct rs9_driver_data *rs9 = dev_get_drvdata(dev);
regcache_cache_only(rs9->regmap, true);
regcache_mark_dirty(rs9->regmap);
return 0;
}
static int __maybe_unused rs9_resume(struct device *dev)
{
struct rs9_driver_data *rs9 = dev_get_drvdata(dev);
int ret;
regcache_cache_only(rs9->regmap, false);
ret = regcache_sync(rs9->regmap);
if (ret)
dev_err(dev, "Failed to restore register map: %d\n", ret);
return ret;
}
static const struct rs9_chip_info renesas_9fgv0241_info = {
.model = RENESAS_9FGV0241,
.num_clks = 2,
.did = RS9_REG_DID_TYPE_FGV | 0x02,
};
static const struct rs9_chip_info renesas_9fgv0441_info = {
.model = RENESAS_9FGV0441,
.num_clks = 4,
.did = RS9_REG_DID_TYPE_FGV | 0x04,
};
static const struct i2c_device_id rs9_id[] = {
{ "9fgv0241", .driver_data = RENESAS_9FGV0241 },
{ "9fgv0441", .driver_data = RENESAS_9FGV0441 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rs9_id);
static const struct of_device_id clk_rs9_of_match[] = {
{ .compatible = "renesas,9fgv0241", .data = &renesas_9fgv0241_info },
{ .compatible = "renesas,9fgv0441", .data = &renesas_9fgv0441_info },
{ }
};
MODULE_DEVICE_TABLE(of, clk_rs9_of_match);
static SIMPLE_DEV_PM_OPS(rs9_pm_ops, rs9_suspend, rs9_resume);
static struct i2c_driver rs9_driver = {
.driver = {
.name = "clk-renesas-pcie-9series",
.pm = &rs9_pm_ops,
.of_match_table = clk_rs9_of_match,
},
.probe_new = rs9_probe,
.id_table = rs9_id,
};
module_i2c_driver(rs9_driver);
MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("Renesas 9-series PCIe clock generator driver");
MODULE_LICENSE("GPL");