drivers/clk/clk-renesas-pcie.c - linux - Git at Google

 // 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_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_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_0V7;
 	rs9->pll_ssc = RS9_REG_SS_SSC_100;

 	/* 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_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 = 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");
	// 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_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_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_0V7;
	rs9->pll_ssc = RS9_REG_SS_SSC_100;

	/* 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_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 = 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");