drivers/clk/clk-si521xx.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Driver for Skyworks Si521xx PCIe clock generator driver
  *
  * The following series can be supported:
  *   - Si52144 - 4x DIFF
  *   - Si52146 - 6x DIFF
  *   - Si52147 - 9x DIFF
  * Currently tested:
  *   - Si52144
  *
  * Copyright (C) 2022 Marek Vasut <marex@denx.de>
  */

 #include <linux/bitfield.h>
 #include <linux/bitrev.h>
 #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>

 /* OE1 and OE2 register */
 #define SI521XX_REG_OE(n)			(((n) & 0x1) + 1)
 #define SI521XX_REG_ID				0x3
 #define SI521XX_REG_ID_PROG			GENMASK(7, 4)
 #define SI521XX_REG_ID_VENDOR			GENMASK(3, 0)
 #define SI521XX_REG_BC				0x4
 #define SI521XX_REG_DA				0x5
 #define SI521XX_REG_DA_AMP_SEL			BIT(7)
 #define SI521XX_REG_DA_AMP_MASK			GENMASK(6, 4)
 #define SI521XX_REG_DA_AMP_MIN			300000
 #define SI521XX_REG_DA_AMP_DEFAULT		800000
 #define SI521XX_REG_DA_AMP_MAX			1000000
 #define SI521XX_REG_DA_AMP_STEP			100000
 #define SI521XX_REG_DA_AMP(UV)			\
 	FIELD_PREP(SI521XX_REG_DA_AMP_MASK,	\
 		   ((UV) - SI521XX_REG_DA_AMP_MIN) / SI521XX_REG_DA_AMP_STEP)
 #define SI521XX_REG_DA_UNKNOWN			BIT(3)	/* Always set */

 /* Count of populated OE bits in control register ref, 1 and 2 */
 #define SI521XX_OE_MAP(cr1, cr2)	(((cr2) << 8) | (cr1))
 #define SI521XX_OE_MAP_GET_OE(oe, map)	(((map) >> (((oe) - 1) * 8)) & 0xff)

 #define SI521XX_DIFF_MULT	4
 #define SI521XX_DIFF_DIV	1

 /* Supported Skyworks Si521xx models. */
 enum si521xx_model {
 	SI52144 = 0x44,
 	SI52146 = 0x46,
 	SI52147 = 0x47,
 };

 struct si521xx;

 struct si_clk {
 	struct clk_hw		hw;
 	struct si521xx		*si;
 	u8			reg;
 	u8			bit;
 };

 struct si521xx {
 	struct i2c_client	*client;
 	struct regmap		*regmap;
 	struct si_clk		clk_dif[9];
 	u16			chip_info;
 	u8			pll_amplitude;
 };

 /*
  * Si521xx i2c regmap
  */
 static const struct regmap_range si521xx_readable_ranges[] = {
 	regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_DA),
 };

 static const struct regmap_access_table si521xx_readable_table = {
 	.yes_ranges = si521xx_readable_ranges,
 	.n_yes_ranges = ARRAY_SIZE(si521xx_readable_ranges),
 };

 static const struct regmap_range si521xx_writeable_ranges[] = {
 	regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_OE(1)),
 	regmap_reg_range(SI521XX_REG_BC, SI521XX_REG_DA),
 };

 static const struct regmap_access_table si521xx_writeable_table = {
 	.yes_ranges = si521xx_writeable_ranges,
 	.n_yes_ranges = ARRAY_SIZE(si521xx_writeable_ranges),
 };

 static int si521xx_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 si521xx_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 si521xx_probe(),
 	 * ignore it and use data from Byte 1.
 	 */
 	*val = rxdata[1];
 	return 0;
 }

 static const struct regmap_config si521xx_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.cache_type = REGCACHE_NONE,
 	.max_register = SI521XX_REG_DA,
 	.rd_table = &si521xx_readable_table,
 	.wr_table = &si521xx_writeable_table,
 	.reg_write = si521xx_regmap_i2c_write,
 	.reg_read = si521xx_regmap_i2c_read,
 };

 static unsigned long si521xx_diff_recalc_rate(struct clk_hw *hw,
 					      unsigned long parent_rate)
 {
 	unsigned long long rate;

 	rate = (unsigned long long)parent_rate * SI521XX_DIFF_MULT;
 	do_div(rate, SI521XX_DIFF_DIV);
 	return (unsigned long)rate;
 }

 static long si521xx_diff_round_rate(struct clk_hw *hw, unsigned long rate,
 				    unsigned long *prate)
 {
 	unsigned long best_parent;

 	best_parent = (rate / SI521XX_DIFF_MULT) * SI521XX_DIFF_DIV;
 	*prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);

 	return (*prate / SI521XX_DIFF_DIV) * SI521XX_DIFF_MULT;
 }

 static int si521xx_diff_set_rate(struct clk_hw *hw, unsigned long rate,
 				 unsigned long parent_rate)
 {
 	/*
 	 * We must report success but we can do so unconditionally because
 	 * si521xx_diff_round_rate returns values that ensure this call is a
 	 * nop.
 	 */

 	return 0;
 }

 #define to_si521xx_clk(_hw) container_of(_hw, struct si_clk, hw)

 static int si521xx_diff_prepare(struct clk_hw *hw)
 {
 	struct si_clk *si_clk = to_si521xx_clk(hw);
 	struct si521xx *si = si_clk->si;

 	regmap_set_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit);

 	return 0;
 }

 static void si521xx_diff_unprepare(struct clk_hw *hw)
 {
 	struct si_clk *si_clk = to_si521xx_clk(hw);
 	struct si521xx *si = si_clk->si;

 	regmap_clear_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit);
 }

 static const struct clk_ops si521xx_diff_clk_ops = {
 	.round_rate	= si521xx_diff_round_rate,
 	.set_rate	= si521xx_diff_set_rate,
 	.recalc_rate	= si521xx_diff_recalc_rate,
 	.prepare	= si521xx_diff_prepare,
 	.unprepare	= si521xx_diff_unprepare,
 };

 static int si521xx_get_common_config(struct si521xx *si)
 {
 	struct i2c_client *client = si->client;
 	struct device_node *np = client->dev.of_node;
 	unsigned int amp;
 	int ret;

 	/* Set defaults */
 	si->pll_amplitude = SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT);

 	/* Output clock amplitude */
 	ret = of_property_read_u32(np, "skyworks,out-amplitude-microvolt",
 				   &amp);
 	if (!ret) {
 		if (amp < SI521XX_REG_DA_AMP_MIN || amp > SI521XX_REG_DA_AMP_MAX ||
 		    amp % SI521XX_REG_DA_AMP_STEP) {
 			return dev_err_probe(&client->dev, -EINVAL,
 					     "Invalid skyworks,out-amplitude-microvolt value\n");
 		}
 		si->pll_amplitude = SI521XX_REG_DA_AMP(amp);
 	}

 	return 0;
 }

 static void si521xx_update_config(struct si521xx *si)
 {
 	/* If amplitude is non-default, update it. */
 	if (si->pll_amplitude == SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT))
 		return;

 	regmap_update_bits(si->regmap, SI521XX_REG_DA,
 			   SI521XX_REG_DA_AMP_MASK, si->pll_amplitude);
 }

 static void si521xx_diff_idx_to_reg_bit(const u16 chip_info, const int idx,
 					struct si_clk *clk)
 {
 	unsigned long mask;
 	int oe, b, ctr = 0;

 	for (oe = 1; oe <= 2; oe++) {
 		mask = bitrev8(SI521XX_OE_MAP_GET_OE(oe, chip_info));
 		for_each_set_bit(b, &mask, 8) {
 			if (ctr++ != idx)
 				continue;
 			clk->reg = SI521XX_REG_OE(oe);
 			clk->bit = 7 - b;
 			return;
 		}
 	}
 }

 static struct clk_hw *
 si521xx_of_clk_get(struct of_phandle_args *clkspec, void *data)
 {
 	struct si521xx *si = data;
 	unsigned int idx = clkspec->args[0];

 	return &si->clk_dif[idx].hw;
 }

 static int si521xx_probe(struct i2c_client *client)
 {
 	const u16 chip_info = (u16)(uintptr_t)device_get_match_data(&client->dev);
 	const struct clk_parent_data clk_parent_data = { .index = 0 };
 	struct si521xx *si;
 	unsigned char name[6] = "DIFF0";
 	struct clk_init_data init = {};
 	int i, ret;

 	if (!chip_info)
 		return -EINVAL;

 	si = devm_kzalloc(&client->dev, sizeof(*si), GFP_KERNEL);
 	if (!si)
 		return -ENOMEM;

 	i2c_set_clientdata(client, si);
 	si->client = client;

 	/* Fetch common configuration from DT (if specified) */
 	ret = si521xx_get_common_config(si);
 	if (ret)
 		return ret;

 	si->regmap = devm_regmap_init(&client->dev, NULL, client,
 				      &si521xx_regmap_config);
 	if (IS_ERR(si->regmap))
 		return dev_err_probe(&client->dev, PTR_ERR(si->regmap),
 				     "Failed to allocate register map\n");

 	/* Always read back 1 Byte via I2C */
 	ret = regmap_write(si->regmap, SI521XX_REG_BC, 1);
 	if (ret < 0)
 		return ret;

 	/* Register clock */
 	for (i = 0; i < hweight16(chip_info); i++) {
 		memset(&init, 0, sizeof(init));
 		snprintf(name, 6, "DIFF%d", i);
 		init.name = name;
 		init.ops = &si521xx_diff_clk_ops;
 		init.parent_data = &clk_parent_data;
 		init.num_parents = 1;
 		init.flags = CLK_SET_RATE_PARENT;

 		si->clk_dif[i].hw.init = &init;
 		si->clk_dif[i].si = si;

 		si521xx_diff_idx_to_reg_bit(chip_info, i, &si->clk_dif[i]);

 		ret = devm_clk_hw_register(&client->dev, &si->clk_dif[i].hw);
 		if (ret)
 			return ret;
 	}

 	ret = devm_of_clk_add_hw_provider(&client->dev, si521xx_of_clk_get, si);
 	if (!ret)
 		si521xx_update_config(si);

 	return ret;
 }

 static int __maybe_unused si521xx_suspend(struct device *dev)
 {
 	struct si521xx *si = dev_get_drvdata(dev);

 	regcache_cache_only(si->regmap, true);
 	regcache_mark_dirty(si->regmap);

 	return 0;
 }

 static int __maybe_unused si521xx_resume(struct device *dev)
 {
 	struct si521xx *si = dev_get_drvdata(dev);
 	int ret;

 	regcache_cache_only(si->regmap, false);
 	ret = regcache_sync(si->regmap);
 	if (ret)
 		dev_err(dev, "Failed to restore register map: %d\n", ret);
 	return ret;
 }

 static const struct i2c_device_id si521xx_id[] = {
 	{ "si52144", .driver_data = SI521XX_OE_MAP(0x5, 0xc0) },
 	{ "si52146", .driver_data = SI521XX_OE_MAP(0x15, 0xe0) },
 	{ "si52147", .driver_data = SI521XX_OE_MAP(0x17, 0xf8) },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, si521xx_id);

 static const struct of_device_id clk_si521xx_of_match[] = {
 	{ .compatible = "skyworks,si52144", .data = (void *)SI521XX_OE_MAP(0x5, 0xc0) },
 	{ .compatible = "skyworks,si52146", .data = (void *)SI521XX_OE_MAP(0x15, 0xe0) },
 	{ .compatible = "skyworks,si52147", .data = (void *)SI521XX_OE_MAP(0x15, 0xf8) },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, clk_si521xx_of_match);

 static SIMPLE_DEV_PM_OPS(si521xx_pm_ops, si521xx_suspend, si521xx_resume);

 static struct i2c_driver si521xx_driver = {
 	.driver = {
 		.name = "clk-si521xx",
 		.pm	= &si521xx_pm_ops,
 		.of_match_table = clk_si521xx_of_match,
 	},
 	.probe_new	= si521xx_probe,
 	.id_table	= si521xx_id,
 };
 module_i2c_driver(si521xx_driver);

 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
 MODULE_DESCRIPTION("Skyworks Si521xx PCIe clock generator driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Driver for Skyworks Si521xx PCIe clock generator driver
	*
	* The following series can be supported:
	* - Si52144 - 4x DIFF
	* - Si52146 - 6x DIFF
	* - Si52147 - 9x DIFF
	* Currently tested:
	* - Si52144
	*
	* Copyright (C) 2022 Marek Vasut <marex@denx.de>
	*/

	#include <linux/bitfield.h>
	#include <linux/bitrev.h>
	#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>

	/* OE1 and OE2 register */
	#define SI521XX_REG_OE(n) (((n) & 0x1) + 1)
	#define SI521XX_REG_ID 0x3
	#define SI521XX_REG_ID_PROG GENMASK(7, 4)
	#define SI521XX_REG_ID_VENDOR GENMASK(3, 0)
	#define SI521XX_REG_BC 0x4
	#define SI521XX_REG_DA 0x5
	#define SI521XX_REG_DA_AMP_SEL BIT(7)
	#define SI521XX_REG_DA_AMP_MASK GENMASK(6, 4)
	#define SI521XX_REG_DA_AMP_MIN 300000
	#define SI521XX_REG_DA_AMP_DEFAULT 800000
	#define SI521XX_REG_DA_AMP_MAX 1000000
	#define SI521XX_REG_DA_AMP_STEP 100000
	#define SI521XX_REG_DA_AMP(UV) \
	FIELD_PREP(SI521XX_REG_DA_AMP_MASK, \
	((UV) - SI521XX_REG_DA_AMP_MIN) / SI521XX_REG_DA_AMP_STEP)
	#define SI521XX_REG_DA_UNKNOWN BIT(3) /* Always set */

	/* Count of populated OE bits in control register ref, 1 and 2 */
	#define SI521XX_OE_MAP(cr1, cr2) (((cr2) << 8) \| (cr1))
	#define SI521XX_OE_MAP_GET_OE(oe, map) (((map) >> (((oe) - 1) * 8)) & 0xff)

	#define SI521XX_DIFF_MULT 4
	#define SI521XX_DIFF_DIV 1

	/* Supported Skyworks Si521xx models. */
	enum si521xx_model {
	SI52144 = 0x44,
	SI52146 = 0x46,
	SI52147 = 0x47,
	};

	struct si521xx;

	struct si_clk {
	struct clk_hw hw;
	struct si521xx *si;
	u8 reg;
	u8 bit;
	};

	struct si521xx {
	struct i2c_client *client;
	struct regmap *regmap;
	struct si_clk clk_dif[9];
	u16 chip_info;
	u8 pll_amplitude;
	};

	/*
	* Si521xx i2c regmap
	*/
	static const struct regmap_range si521xx_readable_ranges[] = {
	regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_DA),
	};

	static const struct regmap_access_table si521xx_readable_table = {
	.yes_ranges = si521xx_readable_ranges,
	.n_yes_ranges = ARRAY_SIZE(si521xx_readable_ranges),
	};

	static const struct regmap_range si521xx_writeable_ranges[] = {
	regmap_reg_range(SI521XX_REG_OE(0), SI521XX_REG_OE(1)),
	regmap_reg_range(SI521XX_REG_BC, SI521XX_REG_DA),
	};

	static const struct regmap_access_table si521xx_writeable_table = {
	.yes_ranges = si521xx_writeable_ranges,
	.n_yes_ranges = ARRAY_SIZE(si521xx_writeable_ranges),
	};

	static int si521xx_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 si521xx_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 si521xx_probe(),
	* ignore it and use data from Byte 1.
	*/
	*val = rxdata[1];
	return 0;
	}

	static const struct regmap_config si521xx_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.cache_type = REGCACHE_NONE,
	.max_register = SI521XX_REG_DA,
	.rd_table = &si521xx_readable_table,
	.wr_table = &si521xx_writeable_table,
	.reg_write = si521xx_regmap_i2c_write,
	.reg_read = si521xx_regmap_i2c_read,
	};

	static unsigned long si521xx_diff_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	unsigned long long rate;

	rate = (unsigned long long)parent_rate * SI521XX_DIFF_MULT;
	do_div(rate, SI521XX_DIFF_DIV);
	return (unsigned long)rate;
	}

	static long si521xx_diff_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	unsigned long best_parent;

	best_parent = (rate / SI521XX_DIFF_MULT) * SI521XX_DIFF_DIV;
	*prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);

	return (prate / SI521XX_DIFF_DIV) SI521XX_DIFF_MULT;
	}

	static int si521xx_diff_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	/*
	* We must report success but we can do so unconditionally because
	* si521xx_diff_round_rate returns values that ensure this call is a
	* nop.
	*/

	return 0;
	}

	#define to_si521xx_clk(_hw) container_of(_hw, struct si_clk, hw)

	static int si521xx_diff_prepare(struct clk_hw *hw)
	{
	struct si_clk *si_clk = to_si521xx_clk(hw);
	struct si521xx *si = si_clk->si;

	regmap_set_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit);

	return 0;
	}

	static void si521xx_diff_unprepare(struct clk_hw *hw)
	{
	struct si_clk *si_clk = to_si521xx_clk(hw);
	struct si521xx *si = si_clk->si;

	regmap_clear_bits(si->regmap, SI521XX_REG_OE(si_clk->reg), si_clk->bit);
	}

	static const struct clk_ops si521xx_diff_clk_ops = {
	.round_rate = si521xx_diff_round_rate,
	.set_rate = si521xx_diff_set_rate,
	.recalc_rate = si521xx_diff_recalc_rate,
	.prepare = si521xx_diff_prepare,
	.unprepare = si521xx_diff_unprepare,
	};

	static int si521xx_get_common_config(struct si521xx *si)
	{
	struct i2c_client *client = si->client;
	struct device_node *np = client->dev.of_node;
	unsigned int amp;
	int ret;

	/* Set defaults */
	si->pll_amplitude = SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT);

	/* Output clock amplitude */
	ret = of_property_read_u32(np, "skyworks,out-amplitude-microvolt",
	&amp);
	if (!ret) {
	if (amp < SI521XX_REG_DA_AMP_MIN \|\| amp > SI521XX_REG_DA_AMP_MAX \|\|
	amp % SI521XX_REG_DA_AMP_STEP) {
	return dev_err_probe(&client->dev, -EINVAL,
	"Invalid skyworks,out-amplitude-microvolt value\n");
	}
	si->pll_amplitude = SI521XX_REG_DA_AMP(amp);
	}

	return 0;
	}

	static void si521xx_update_config(struct si521xx *si)
	{
	/* If amplitude is non-default, update it. */
	if (si->pll_amplitude == SI521XX_REG_DA_AMP(SI521XX_REG_DA_AMP_DEFAULT))
	return;

	regmap_update_bits(si->regmap, SI521XX_REG_DA,
	SI521XX_REG_DA_AMP_MASK, si->pll_amplitude);
	}

	static void si521xx_diff_idx_to_reg_bit(const u16 chip_info, const int idx,
	struct si_clk *clk)
	{
	unsigned long mask;
	int oe, b, ctr = 0;

	for (oe = 1; oe <= 2; oe++) {
	mask = bitrev8(SI521XX_OE_MAP_GET_OE(oe, chip_info));
	for_each_set_bit(b, &mask, 8) {
	if (ctr++ != idx)
	continue;
	clk->reg = SI521XX_REG_OE(oe);
	clk->bit = 7 - b;
	return;
	}
	}
	}

	static struct clk_hw *
	si521xx_of_clk_get(struct of_phandle_args clkspec, void data)
	{
	struct si521xx *si = data;
	unsigned int idx = clkspec->args[0];

	return &si->clk_dif[idx].hw;
	}

	static int si521xx_probe(struct i2c_client *client)
	{
	const u16 chip_info = (u16)(uintptr_t)device_get_match_data(&client->dev);
	const struct clk_parent_data clk_parent_data = { .index = 0 };
	struct si521xx *si;
	unsigned char name[6] = "DIFF0";
	struct clk_init_data init = {};
	int i, ret;

	if (!chip_info)
	return -EINVAL;

	si = devm_kzalloc(&client->dev, sizeof(*si), GFP_KERNEL);
	if (!si)
	return -ENOMEM;

	i2c_set_clientdata(client, si);
	si->client = client;

	/* Fetch common configuration from DT (if specified) */
	ret = si521xx_get_common_config(si);
	if (ret)
	return ret;

	si->regmap = devm_regmap_init(&client->dev, NULL, client,
	&si521xx_regmap_config);
	if (IS_ERR(si->regmap))
	return dev_err_probe(&client->dev, PTR_ERR(si->regmap),
	"Failed to allocate register map\n");

	/* Always read back 1 Byte via I2C */
	ret = regmap_write(si->regmap, SI521XX_REG_BC, 1);
	if (ret < 0)
	return ret;

	/* Register clock */
	for (i = 0; i < hweight16(chip_info); i++) {
	memset(&init, 0, sizeof(init));
	snprintf(name, 6, "DIFF%d", i);
	init.name = name;
	init.ops = &si521xx_diff_clk_ops;
	init.parent_data = &clk_parent_data;
	init.num_parents = 1;
	init.flags = CLK_SET_RATE_PARENT;

	si->clk_dif[i].hw.init = &init;
	si->clk_dif[i].si = si;

	si521xx_diff_idx_to_reg_bit(chip_info, i, &si->clk_dif[i]);

	ret = devm_clk_hw_register(&client->dev, &si->clk_dif[i].hw);
	if (ret)
	return ret;
	}

	ret = devm_of_clk_add_hw_provider(&client->dev, si521xx_of_clk_get, si);
	if (!ret)
	si521xx_update_config(si);

	return ret;
	}

	static int __maybe_unused si521xx_suspend(struct device *dev)
	{
	struct si521xx *si = dev_get_drvdata(dev);

	regcache_cache_only(si->regmap, true);
	regcache_mark_dirty(si->regmap);

	return 0;
	}

	static int __maybe_unused si521xx_resume(struct device *dev)
	{
	struct si521xx *si = dev_get_drvdata(dev);
	int ret;

	regcache_cache_only(si->regmap, false);
	ret = regcache_sync(si->regmap);
	if (ret)
	dev_err(dev, "Failed to restore register map: %d\n", ret);
	return ret;
	}

	static const struct i2c_device_id si521xx_id[] = {
	{ "si52144", .driver_data = SI521XX_OE_MAP(0x5, 0xc0) },
	{ "si52146", .driver_data = SI521XX_OE_MAP(0x15, 0xe0) },
	{ "si52147", .driver_data = SI521XX_OE_MAP(0x17, 0xf8) },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, si521xx_id);

	static const struct of_device_id clk_si521xx_of_match[] = {
	{ .compatible = "skyworks,si52144", .data = (void *)SI521XX_OE_MAP(0x5, 0xc0) },
	{ .compatible = "skyworks,si52146", .data = (void *)SI521XX_OE_MAP(0x15, 0xe0) },
	{ .compatible = "skyworks,si52147", .data = (void *)SI521XX_OE_MAP(0x15, 0xf8) },
	{ }
	};
	MODULE_DEVICE_TABLE(of, clk_si521xx_of_match);

	static SIMPLE_DEV_PM_OPS(si521xx_pm_ops, si521xx_suspend, si521xx_resume);

	static struct i2c_driver si521xx_driver = {
	.driver = {
	.name = "clk-si521xx",
	.pm = &si521xx_pm_ops,
	.of_match_table = clk_si521xx_of_match,
	},
	.probe_new = si521xx_probe,
	.id_table = si521xx_id,
	};
	module_i2c_driver(si521xx_driver);

	MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
	MODULE_DESCRIPTION("Skyworks Si521xx PCIe clock generator driver");
	MODULE_LICENSE("GPL");