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linux/drivers/clk/clk-renesas-pcie.c
Catalin Popescu 1758c68c81 clk: rs9: fix wrong default value for clock amplitude 
According to 9FGV0241, 9FGV0441 & 9FGV0841 datasheets, the default
value for the clock amplitude is 0.8V, while the driver assumes 0.7V.

Additionally, define constants for default values for both clock
amplitude and spread spectrum and use them.

Fixes: 892e0ddea1 ("clk: rs9: Add Renesas 9-series PCIe clock generator driver")
Signed-off-by: Catalin Popescu <catalin.popescu@leica-geosystems.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20240415140348.2887619-1-catalin.popescu@leica-geosystems.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2024-04-19 19:09:41 -07:00

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// 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
* - 9FGV0841
*
* 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_DEFAULT RS9_REG_SS_AMP_0V8
#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_DEFAULT RS9_REG_SS_SSC_100
#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_MASK GENMASK(3, 0)
#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
/* Structure to describe features of a particular 9-series model */
struct rs9_chip_info {
unsigned int num_clks;
u8 outshift;
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)
{
/*
* On 9FGV0241, the DIF OE0 is BIT(1) and DIF OE(1) is BIT(2),
* on 9FGV0441 and 9FGV0841 the DIF OE0 is BIT(0) and so on.
* Increment the index in the 9FGV0241 special case here.
*/
return BIT(idx + rs9->chip_info->outshift);
}
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_DEFAULT;
rs9->pll_ssc = RS9_REG_SS_SSC_DEFAULT;
/* Output clock amplitude */
ret = of_property_read_u32(np, "renesas,out-amplitude-microvolt",
&amp);
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_DEFAULT) {
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_DEFAULT) {
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 = i2c_get_match_data(client);
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;
vid &= RS9_REG_VID_MASK;
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 = {
.num_clks = 2,
.outshift = 1,
.did = RS9_REG_DID_TYPE_FGV | 0x02,
};
static const struct rs9_chip_info renesas_9fgv0441_info = {
.num_clks = 4,
.outshift = 0,
.did = RS9_REG_DID_TYPE_FGV | 0x04,
};
static const struct rs9_chip_info renesas_9fgv0841_info = {
.num_clks = 8,
.outshift = 0,
.did = RS9_REG_DID_TYPE_FGV | 0x08,
};
static const struct i2c_device_id rs9_id[] = {
{ "9fgv0241", .driver_data = (kernel_ulong_t)&renesas_9fgv0241_info },
{ "9fgv0441", .driver_data = (kernel_ulong_t)&renesas_9fgv0441_info },
{ "9fgv0841", .driver_data = (kernel_ulong_t)&renesas_9fgv0841_info },
{ }
};
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 },
{ .compatible = "renesas,9fgv0841", .data = &renesas_9fgv0841_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 = 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");
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