diff --git a/MAINTAINERS b/MAINTAINERS
index 162d904d5cc3..890fc9e3c191 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6113,6 +6113,11 @@ S:	Maintained
 F:	drivers/mfd/lpc_ich.c
 F:	drivers/gpio/gpio-ich.c
 
+IDT VersaClock 5 CLOCK DRIVER
+M:	Marek Vasut <marek.vasut@gmail.com>
+S:	Maintained
+F:	drivers/clk/clk-versaclock5.c
+
 IDE SUBSYSTEM
 M:	"David S. Miller" <davem@davemloft.net>
 L:	linux-ide@vger.kernel.org
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 6a8ac04bedeb..9160e6712067 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -198,6 +198,16 @@ config COMMON_CLK_OXNAS
 	---help---
 	  Support for the OXNAS SoC Family clocks.
 
+config COMMON_CLK_VC5
+	tristate "Clock driver for IDT VersaClock5 devices"
+	depends on I2C
+	depends on OF
+	select REGMAP_I2C
+	help
+	---help---
+	  This driver supports the IDT VersaClock5 programmable clock
+	  generator.
+
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
 source "drivers/clk/mediatek/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 925081ec14c0..e0754d9fc2df 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_ARCH_TANGO)		+= clk-tango4.o
 obj-$(CONFIG_CLK_TWL6040)		+= clk-twl6040.o
 obj-$(CONFIG_ARCH_U300)			+= clk-u300.o
 obj-$(CONFIG_ARCH_VT8500)		+= clk-vt8500.o
+obj-$(CONFIG_COMMON_CLK_VC5)		+= clk-versaclock5.o
 obj-$(CONFIG_COMMON_CLK_WM831X)		+= clk-wm831x.o
 obj-$(CONFIG_COMMON_CLK_XGENE)		+= clk-xgene.o
 
diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
new file mode 100644
index 000000000000..8ace7c13a1d8
--- /dev/null
+++ b/drivers/clk/clk-versaclock5.c
@@ -0,0 +1,795 @@
+/*
+ * Driver for IDT Versaclock 5
+ *
+ * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+/*
+ * Possible optimizations:
+ * - Use spread spectrum
+ * - Use integer divider in FOD if applicable
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/rational.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* VersaClock5 registers */
+#define VC5_OTP_CONTROL				0x00
+
+/* Factory-reserved register block */
+#define VC5_RSVD_DEVICE_ID			0x01
+#define VC5_RSVD_ADC_GAIN_7_0			0x02
+#define VC5_RSVD_ADC_GAIN_15_8			0x03
+#define VC5_RSVD_ADC_OFFSET_7_0			0x04
+#define VC5_RSVD_ADC_OFFSET_15_8		0x05
+#define VC5_RSVD_TEMPY				0x06
+#define VC5_RSVD_OFFSET_TBIN			0x07
+#define VC5_RSVD_GAIN				0x08
+#define VC5_RSVD_TEST_NP			0x09
+#define VC5_RSVD_UNUSED				0x0a
+#define VC5_RSVD_BANDGAP_TRIM_UP		0x0b
+#define VC5_RSVD_BANDGAP_TRIM_DN		0x0c
+#define VC5_RSVD_CLK_R_12_CLK_AMP_4		0x0d
+#define VC5_RSVD_CLK_R_34_CLK_AMP_4		0x0e
+#define VC5_RSVD_CLK_AMP_123			0x0f
+
+/* Configuration register block */
+#define VC5_PRIM_SRC_SHDN			0x10
+#define VC5_PRIM_SRC_SHDN_EN_XTAL		BIT(7)
+#define VC5_PRIM_SRC_SHDN_EN_CLKIN		BIT(6)
+#define VC5_PRIM_SRC_SHDN_SP			BIT(1)
+#define VC5_PRIM_SRC_SHDN_EN_GBL_SHDN		BIT(0)
+
+#define VC5_VCO_BAND				0x11
+#define VC5_XTAL_X1_LOAD_CAP			0x12
+#define VC5_XTAL_X2_LOAD_CAP			0x13
+#define VC5_REF_DIVIDER				0x15
+#define VC5_REF_DIVIDER_SEL_PREDIV2		BIT(7)
+#define VC5_REF_DIVIDER_REF_DIV(n)		((n) & 0x3f)
+
+#define VC5_VCO_CTRL_AND_PREDIV			0x16
+#define VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV	BIT(7)
+
+#define VC5_FEEDBACK_INT_DIV			0x17
+#define VC5_FEEDBACK_INT_DIV_BITS		0x18
+#define VC5_FEEDBACK_FRAC_DIV(n)		(0x19 + (n))
+#define VC5_RC_CONTROL0				0x1e
+#define VC5_RC_CONTROL1				0x1f
+/* Register 0x20 is factory reserved */
+
+/* Output divider control for divider 1,2,3,4 */
+#define VC5_OUT_DIV_CONTROL(idx)	(0x21 + ((idx) * 0x10))
+#define VC5_OUT_DIV_CONTROL_RESET	BIT(7)
+#define VC5_OUT_DIV_CONTROL_SELB_NORM	BIT(3)
+#define VC5_OUT_DIV_CONTROL_SEL_EXT	BIT(2)
+#define VC5_OUT_DIV_CONTROL_INT_MODE	BIT(1)
+#define VC5_OUT_DIV_CONTROL_EN_FOD	BIT(0)
+
+#define VC5_OUT_DIV_FRAC(idx, n)	(0x22 + ((idx) * 0x10) + (n))
+#define VC5_OUT_DIV_FRAC4_OD_SCEE	BIT(1)
+
+#define VC5_OUT_DIV_STEP_SPREAD(idx, n)	(0x26 + ((idx) * 0x10) + (n))
+#define VC5_OUT_DIV_SPREAD_MOD(idx, n)	(0x29 + ((idx) * 0x10) + (n))
+#define VC5_OUT_DIV_SKEW_INT(idx, n)	(0x2b + ((idx) * 0x10) + (n))
+#define VC5_OUT_DIV_INT(idx, n)		(0x2d + ((idx) * 0x10) + (n))
+#define VC5_OUT_DIV_SKEW_FRAC(idx)	(0x2f + ((idx) * 0x10))
+/* Registers 0x30, 0x40, 0x50 are factory reserved */
+
+/* Clock control register for clock 1,2 */
+#define VC5_CLK_OUTPUT_CFG(idx, n)	(0x60 + ((idx) * 0x2) + (n))
+#define VC5_CLK_OUTPUT_CFG1_EN_CLKBUF	BIT(0)
+
+#define VC5_CLK_OE_SHDN				0x68
+#define VC5_CLK_OS_SHDN				0x69
+
+#define VC5_GLOBAL_REGISTER			0x76
+#define VC5_GLOBAL_REGISTER_GLOBAL_RESET	BIT(5)
+
+/* PLL/VCO runs between 2.5 GHz and 3.0 GHz */
+#define VC5_PLL_VCO_MIN				2500000000UL
+#define VC5_PLL_VCO_MAX				3000000000UL
+
+/* VC5 Input mux settings */
+#define VC5_MUX_IN_XIN		BIT(0)
+#define VC5_MUX_IN_CLKIN	BIT(1)
+
+/* Supported IDT VC5 models. */
+enum vc5_model {
+	IDT_VC5_5P49V5923,
+	IDT_VC5_5P49V5933,
+};
+
+struct vc5_driver_data;
+
+struct vc5_hw_data {
+	struct clk_hw		hw;
+	struct vc5_driver_data	*vc5;
+	u32			div_int;
+	u32			div_frc;
+	unsigned int		num;
+};
+
+struct vc5_driver_data {
+	struct i2c_client	*client;
+	struct regmap		*regmap;
+	enum vc5_model		model;
+
+	struct clk		*pin_xin;
+	struct clk		*pin_clkin;
+	unsigned char		clk_mux_ins;
+	struct clk_hw		clk_mux;
+	struct vc5_hw_data	clk_pll;
+	struct vc5_hw_data	clk_fod[2];
+	struct vc5_hw_data	clk_out[3];
+};
+
+static const char * const vc5_mux_names[] = {
+	"mux"
+};
+
+static const char * const vc5_pll_names[] = {
+	"pll"
+};
+
+static const char * const vc5_fod_names[] = {
+	"fod0", "fod1", "fod2", "fod3",
+};
+
+static const char * const vc5_clk_out_names[] = {
+	"out0_sel_i2cb", "out1", "out2", "out3", "out4",
+};
+
+/*
+ * VersaClock5 i2c regmap
+ */
+static bool vc5_regmap_is_writeable(struct device *dev, unsigned int reg)
+{
+	/* Factory reserved regs, make them read-only */
+	if (reg <= 0xf)
+		return false;
+
+	/* Factory reserved regs, make them read-only */
+	if (reg == 0x14 || reg == 0x1c || reg == 0x1d)
+		return false;
+
+	return true;
+}
+
+static const struct regmap_config vc5_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+	.max_register = 0x76,
+	.writeable_reg = vc5_regmap_is_writeable,
+};
+
+/*
+ * VersaClock5 input multiplexer between XTAL and CLKIN divider
+ */
+static unsigned char vc5_mux_get_parent(struct clk_hw *hw)
+{
+	struct vc5_driver_data *vc5 =
+		container_of(hw, struct vc5_driver_data, clk_mux);
+	const u8 mask = VC5_PRIM_SRC_SHDN_EN_XTAL | VC5_PRIM_SRC_SHDN_EN_CLKIN;
+	unsigned int src;
+
+	regmap_read(vc5->regmap, VC5_PRIM_SRC_SHDN, &src);
+	src &= mask;
+
+	if (src == VC5_PRIM_SRC_SHDN_EN_XTAL)
+		return 0;
+
+	if (src == VC5_PRIM_SRC_SHDN_EN_CLKIN)
+		return 1;
+
+	dev_warn(&vc5->client->dev,
+		 "Invalid clock input configuration (%02x)\n", src);
+	return 0;
+}
+
+static int vc5_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct vc5_driver_data *vc5 =
+		container_of(hw, struct vc5_driver_data, clk_mux);
+	const u8 mask = VC5_PRIM_SRC_SHDN_EN_XTAL | VC5_PRIM_SRC_SHDN_EN_CLKIN;
+	u8 src;
+
+	if ((index > 1) || !vc5->clk_mux_ins)
+		return -EINVAL;
+
+	if (vc5->clk_mux_ins == (VC5_MUX_IN_CLKIN | VC5_MUX_IN_XIN)) {
+		if (index == 0)
+			src = VC5_PRIM_SRC_SHDN_EN_XTAL;
+		if (index == 1)
+			src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
+	} else {
+		if (index != 0)
+			return -EINVAL;
+
+		if (vc5->clk_mux_ins == VC5_MUX_IN_XIN)
+			src = VC5_PRIM_SRC_SHDN_EN_XTAL;
+		if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
+			src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
+	}
+
+	return regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, mask, src);
+}
+
+static unsigned long vc5_mux_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct vc5_driver_data *vc5 =
+		container_of(hw, struct vc5_driver_data, clk_mux);
+	unsigned int prediv, div;
+
+	regmap_read(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV, &prediv);
+
+	/* The bypass_prediv is set, PLL fed from Ref_in directly. */
+	if (prediv & VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV)
+		return parent_rate;
+
+	regmap_read(vc5->regmap, VC5_REF_DIVIDER, &div);
+
+	/* The Sel_prediv2 is set, PLL fed from prediv2 (Ref_in / 2) */
+	if (div & VC5_REF_DIVIDER_SEL_PREDIV2)
+		return parent_rate / 2;
+	else
+		return parent_rate / VC5_REF_DIVIDER_REF_DIV(div);
+}
+
+static long vc5_mux_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *parent_rate)
+{
+	unsigned long idiv;
+
+	/* PLL cannot operate with input clock above 50 MHz. */
+	if (rate > 50000000)
+		return -EINVAL;
+
+	/* CLKIN within range of PLL input, feed directly to PLL. */
+	if (*parent_rate <= 50000000)
+		return *parent_rate;
+
+	idiv = DIV_ROUND_UP(*parent_rate, rate);
+	if (idiv > 127)
+		return -EINVAL;
+
+	return *parent_rate / idiv;
+}
+
+static int vc5_mux_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct vc5_driver_data *vc5 =
+		container_of(hw, struct vc5_driver_data, clk_mux);
+	unsigned long idiv;
+	u8 div;
+
+	/* CLKIN within range of PLL input, feed directly to PLL. */
+	if (parent_rate <= 50000000) {
+		regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
+				   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV,
+				   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV);
+		regmap_update_bits(vc5->regmap, VC5_REF_DIVIDER, 0xff, 0x00);
+		return 0;
+	}
+
+	idiv = DIV_ROUND_UP(parent_rate, rate);
+
+	/* We have dedicated div-2 predivider. */
+	if (idiv == 2)
+		div = VC5_REF_DIVIDER_SEL_PREDIV2;
+	else
+		div = VC5_REF_DIVIDER_REF_DIV(idiv);
+
+	regmap_update_bits(vc5->regmap, VC5_REF_DIVIDER, 0xff, div);
+	regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
+			   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV, 0);
+
+	return 0;
+}
+
+static const struct clk_ops vc5_mux_ops = {
+	.set_parent	= vc5_mux_set_parent,
+	.get_parent	= vc5_mux_get_parent,
+	.recalc_rate	= vc5_mux_recalc_rate,
+	.round_rate	= vc5_mux_round_rate,
+	.set_rate	= vc5_mux_set_rate,
+};
+
+/*
+ * VersaClock5 PLL/VCO
+ */
+static unsigned long vc5_pll_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	u32 div_int, div_frc;
+	u8 fb[5];
+
+	regmap_bulk_read(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
+
+	div_int = (fb[0] << 4) | (fb[1] >> 4);
+	div_frc = (fb[2] << 16) | (fb[3] << 8) | fb[4];
+
+	/* The PLL divider has 12 integer bits and 24 fractional bits */
+	return (parent_rate * div_int) + ((parent_rate * div_frc) >> 24);
+}
+
+static long vc5_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	u32 div_int;
+	u64 div_frc;
+
+	if (rate < VC5_PLL_VCO_MIN)
+		rate = VC5_PLL_VCO_MIN;
+	if (rate > VC5_PLL_VCO_MAX)
+		rate = VC5_PLL_VCO_MAX;
+
+	/* Determine integer part, which is 12 bit wide */
+	div_int = rate / *parent_rate;
+	if (div_int > 0xfff)
+		rate = *parent_rate * 0xfff;
+
+	/* Determine best fractional part, which is 24 bit wide */
+	div_frc = rate % *parent_rate;
+	div_frc *= BIT(24) - 1;
+	do_div(div_frc, *parent_rate);
+
+	hwdata->div_int = div_int;
+	hwdata->div_frc = (u32)div_frc;
+
+	return (*parent_rate * div_int) + ((*parent_rate * div_frc) >> 24);
+}
+
+static int vc5_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	u8 fb[5];
+
+	fb[0] = hwdata->div_int >> 4;
+	fb[1] = hwdata->div_int << 4;
+	fb[2] = hwdata->div_frc >> 16;
+	fb[3] = hwdata->div_frc >> 8;
+	fb[4] = hwdata->div_frc;
+
+	return regmap_bulk_write(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
+}
+
+static const struct clk_ops vc5_pll_ops = {
+	.recalc_rate	= vc5_pll_recalc_rate,
+	.round_rate	= vc5_pll_round_rate,
+	.set_rate	= vc5_pll_set_rate,
+};
+
+static unsigned long vc5_fod_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	/* VCO frequency is divided by two before entering FOD */
+	u32 f_in = parent_rate / 2;
+	u32 div_int, div_frc;
+	u8 od_int[2];
+	u8 od_frc[4];
+
+	regmap_bulk_read(vc5->regmap, VC5_OUT_DIV_INT(hwdata->num, 0),
+			 od_int, 2);
+	regmap_bulk_read(vc5->regmap, VC5_OUT_DIV_FRAC(hwdata->num, 0),
+			 od_frc, 4);
+
+	div_int = (od_int[0] << 4) | (od_int[1] >> 4);
+	div_frc = (od_frc[0] << 22) | (od_frc[1] << 14) |
+		  (od_frc[2] << 6) | (od_frc[3] >> 2);
+
+	/* The PLL divider has 12 integer bits and 30 fractional bits */
+	return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
+}
+
+static long vc5_fod_round_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	/* VCO frequency is divided by two before entering FOD */
+	u32 f_in = *parent_rate / 2;
+	u32 div_int;
+	u64 div_frc;
+
+	/* Determine integer part, which is 12 bit wide */
+	div_int = f_in / rate;
+	/*
+	 * WARNING: The clock chip does not output signal if the integer part
+	 *          of the divider is 0xfff and fractional part is non-zero.
+	 *          Clamp the divider at 0xffe to keep the code simple.
+	 */
+	if (div_int > 0xffe) {
+		div_int = 0xffe;
+		rate = f_in / div_int;
+	}
+
+	/* Determine best fractional part, which is 30 bit wide */
+	div_frc = f_in % rate;
+	div_frc <<= 24;
+	do_div(div_frc, rate);
+
+	hwdata->div_int = div_int;
+	hwdata->div_frc = (u32)div_frc;
+
+	return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
+}
+
+static int vc5_fod_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	u8 data[14] = {
+		hwdata->div_frc >> 22, hwdata->div_frc >> 14,
+		hwdata->div_frc >> 6, hwdata->div_frc << 2,
+		0, 0, 0, 0, 0,
+		0, 0,
+		hwdata->div_int >> 4, hwdata->div_int << 4,
+		0
+	};
+
+	regmap_bulk_write(vc5->regmap, VC5_OUT_DIV_FRAC(hwdata->num, 0),
+			  data, 14);
+
+	/*
+	 * Toggle magic bit in undocumented register for unknown reason.
+	 * This is what the IDT timing commander tool does and the chip
+	 * datasheet somewhat implies this is needed, but the register
+	 * and the bit is not documented.
+	 */
+	regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
+			   VC5_GLOBAL_REGISTER_GLOBAL_RESET, 0);
+	regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
+			   VC5_GLOBAL_REGISTER_GLOBAL_RESET,
+			   VC5_GLOBAL_REGISTER_GLOBAL_RESET);
+	return 0;
+}
+
+static const struct clk_ops vc5_fod_ops = {
+	.recalc_rate	= vc5_fod_recalc_rate,
+	.round_rate	= vc5_fod_round_rate,
+	.set_rate	= vc5_fod_set_rate,
+};
+
+static int vc5_clk_out_prepare(struct clk_hw *hw)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+
+	/* Enable the clock buffer */
+	regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
+			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF,
+			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF);
+	return 0;
+}
+
+static void vc5_clk_out_unprepare(struct clk_hw *hw)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+
+	/* Enable the clock buffer */
+	regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
+			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF, 0);
+}
+
+static unsigned char vc5_clk_out_get_parent(struct clk_hw *hw)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	const u8 mask = VC5_OUT_DIV_CONTROL_SELB_NORM |
+			VC5_OUT_DIV_CONTROL_SEL_EXT |
+			VC5_OUT_DIV_CONTROL_EN_FOD;
+	const u8 fodclkmask = VC5_OUT_DIV_CONTROL_SELB_NORM |
+			      VC5_OUT_DIV_CONTROL_EN_FOD;
+	const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
+			  VC5_OUT_DIV_CONTROL_SEL_EXT;
+	unsigned int src;
+
+	regmap_read(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num), &src);
+	src &= mask;
+
+	if ((src & fodclkmask) == VC5_OUT_DIV_CONTROL_EN_FOD)
+		return 0;
+
+	if (src == extclk)
+		return 1;
+
+	dev_warn(&vc5->client->dev,
+		 "Invalid clock output configuration (%02x)\n", src);
+	return 0;
+}
+
+static int vc5_clk_out_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
+	struct vc5_driver_data *vc5 = hwdata->vc5;
+	const u8 mask = VC5_OUT_DIV_CONTROL_RESET |
+			VC5_OUT_DIV_CONTROL_SELB_NORM |
+			VC5_OUT_DIV_CONTROL_SEL_EXT |
+			VC5_OUT_DIV_CONTROL_EN_FOD;
+	const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
+			  VC5_OUT_DIV_CONTROL_SEL_EXT;
+	u8 src = VC5_OUT_DIV_CONTROL_RESET;
+
+	if (index == 0)
+		src |= VC5_OUT_DIV_CONTROL_EN_FOD;
+	else
+		src |= extclk;
+
+	return regmap_update_bits(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num),
+				  mask, src);
+}
+
+static const struct clk_ops vc5_clk_out_ops = {
+	.prepare	= vc5_clk_out_prepare,
+	.unprepare	= vc5_clk_out_unprepare,
+	.set_parent	= vc5_clk_out_set_parent,
+	.get_parent	= vc5_clk_out_get_parent,
+};
+
+static struct clk_hw *
+vc5_of_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct vc5_driver_data *vc5 = data;
+	unsigned int idx = clkspec->args[0];
+
+	if (idx > 2) {
+		pr_err("%s: invalid index %u\n", __func__, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return &vc5->clk_out[idx].hw;
+}
+
+static int vc5_map_index_to_output(const enum vc5_model model,
+				   const unsigned int n)
+{
+	switch (model) {
+	case IDT_VC5_5P49V5933:
+		return (n == 0) ? 0 : 3;
+	case IDT_VC5_5P49V5923:
+	default:
+		return n;
+	}
+}
+
+static const struct of_device_id clk_vc5_of_match[];
+
+static int vc5_probe(struct i2c_client *client,
+		     const struct i2c_device_id *id)
+{
+	const struct of_device_id *of_id =
+		of_match_device(clk_vc5_of_match, &client->dev);
+	struct vc5_driver_data *vc5;
+	struct clk_init_data init;
+	const char *parent_names[2];
+	unsigned int n, idx;
+	int ret;
+
+	vc5 = devm_kzalloc(&client->dev, sizeof(*vc5), GFP_KERNEL);
+	if (vc5 == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, vc5);
+	vc5->client = client;
+	vc5->model = (enum vc5_model)of_id->data;
+
+	vc5->pin_xin = devm_clk_get(&client->dev, "xin");
+	if (PTR_ERR(vc5->pin_xin) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	vc5->pin_clkin = devm_clk_get(&client->dev, "clkin");
+	if (PTR_ERR(vc5->pin_clkin) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	vc5->regmap = devm_regmap_init_i2c(client, &vc5_regmap_config);
+	if (IS_ERR(vc5->regmap)) {
+		dev_err(&client->dev, "failed to allocate register map\n");
+		return PTR_ERR(vc5->regmap);
+	}
+
+	/* Register clock input mux */
+	memset(&init, 0, sizeof(init));
+
+	if (!IS_ERR(vc5->pin_xin)) {
+		vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
+		parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
+	} else if (vc5->model == IDT_VC5_5P49V5933) {
+		/* IDT VC5 5P49V5933 has built-in oscilator. */
+		vc5->pin_xin = clk_register_fixed_rate(&client->dev,
+						       "internal-xtal", NULL,
+						       0, 25000000);
+		if (IS_ERR(vc5->pin_xin))
+			return PTR_ERR(vc5->pin_xin);
+		vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
+		parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
+	}
+
+	if (!IS_ERR(vc5->pin_clkin)) {
+		vc5->clk_mux_ins |= VC5_MUX_IN_CLKIN;
+		parent_names[init.num_parents++] =
+			__clk_get_name(vc5->pin_clkin);
+	}
+
+	if (!init.num_parents) {
+		dev_err(&client->dev, "no input clock specified!\n");
+		return -EINVAL;
+	}
+
+	init.name = vc5_mux_names[0];
+	init.ops = &vc5_mux_ops;
+	init.flags = 0;
+	init.parent_names = parent_names;
+	vc5->clk_mux.init = &init;
+	ret = devm_clk_hw_register(&client->dev, &vc5->clk_mux);
+	if (ret) {
+		dev_err(&client->dev, "unable to register %s\n", init.name);
+		goto err_clk;
+	}
+
+	/* Register PLL */
+	memset(&init, 0, sizeof(init));
+	init.name = vc5_pll_names[0];
+	init.ops = &vc5_pll_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+	init.parent_names = vc5_mux_names;
+	init.num_parents = 1;
+	vc5->clk_pll.num = 0;
+	vc5->clk_pll.vc5 = vc5;
+	vc5->clk_pll.hw.init = &init;
+	ret = devm_clk_hw_register(&client->dev, &vc5->clk_pll.hw);
+	if (ret) {
+		dev_err(&client->dev, "unable to register %s\n", init.name);
+		goto err_clk;
+	}
+
+	/* Register FODs */
+	for (n = 0; n < 2; n++) {
+		idx = vc5_map_index_to_output(vc5->model, n);
+		memset(&init, 0, sizeof(init));
+		init.name = vc5_fod_names[idx];
+		init.ops = &vc5_fod_ops;
+		init.flags = CLK_SET_RATE_PARENT;
+		init.parent_names = vc5_pll_names;
+		init.num_parents = 1;
+		vc5->clk_fod[n].num = idx;
+		vc5->clk_fod[n].vc5 = vc5;
+		vc5->clk_fod[n].hw.init = &init;
+		ret = devm_clk_hw_register(&client->dev, &vc5->clk_fod[n].hw);
+		if (ret) {
+			dev_err(&client->dev, "unable to register %s\n",
+				init.name);
+			goto err_clk;
+		}
+	}
+
+	/* Register MUX-connected OUT0_I2C_SELB output */
+	memset(&init, 0, sizeof(init));
+	init.name = vc5_clk_out_names[0];
+	init.ops = &vc5_clk_out_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+	init.parent_names = vc5_mux_names;
+	init.num_parents = 1;
+	vc5->clk_out[0].num = idx;
+	vc5->clk_out[0].vc5 = vc5;
+	vc5->clk_out[0].hw.init = &init;
+	ret = devm_clk_hw_register(&client->dev, &vc5->clk_out[0].hw);
+	if (ret) {
+		dev_err(&client->dev, "unable to register %s\n",
+			init.name);
+		goto err_clk;
+	}
+
+	/* Register FOD-connected OUTx outputs */
+	for (n = 1; n < 3; n++) {
+		idx = vc5_map_index_to_output(vc5->model, n - 1);
+		parent_names[0] = vc5_fod_names[idx];
+		if (n == 1)
+			parent_names[1] = vc5_mux_names[0];
+		else
+			parent_names[1] = vc5_clk_out_names[n - 1];
+
+		memset(&init, 0, sizeof(init));
+		init.name = vc5_clk_out_names[idx + 1];
+		init.ops = &vc5_clk_out_ops;
+		init.flags = CLK_SET_RATE_PARENT;
+		init.parent_names = parent_names;
+		init.num_parents = 2;
+		vc5->clk_out[n].num = idx;
+		vc5->clk_out[n].vc5 = vc5;
+		vc5->clk_out[n].hw.init = &init;
+		ret = devm_clk_hw_register(&client->dev,
+					   &vc5->clk_out[n].hw);
+		if (ret) {
+			dev_err(&client->dev, "unable to register %s\n",
+				init.name);
+			goto err_clk;
+		}
+	}
+
+	ret = of_clk_add_hw_provider(client->dev.of_node, vc5_of_clk_get, vc5);
+	if (ret) {
+		dev_err(&client->dev, "unable to add clk provider\n");
+		goto err_clk;
+	}
+
+	return 0;
+
+err_clk:
+	if (vc5->model == IDT_VC5_5P49V5933)
+		clk_unregister_fixed_rate(vc5->pin_xin);
+	return ret;
+}
+
+static int vc5_remove(struct i2c_client *client)
+{
+	struct vc5_driver_data *vc5 = i2c_get_clientdata(client);
+
+	of_clk_del_provider(client->dev.of_node);
+
+	if (vc5->model == IDT_VC5_5P49V5933)
+		clk_unregister_fixed_rate(vc5->pin_xin);
+
+	return 0;
+}
+
+static const struct i2c_device_id vc5_id[] = {
+	{ "5p49v5923", .driver_data = IDT_VC5_5P49V5923 },
+	{ "5p49v5933", .driver_data = IDT_VC5_5P49V5933 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, vc5_id);
+
+static const struct of_device_id clk_vc5_of_match[] = {
+	{ .compatible = "idt,5p49v5923", .data = (void *)IDT_VC5_5P49V5923 },
+	{ .compatible = "idt,5p49v5933", .data = (void *)IDT_VC5_5P49V5933 },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, clk_vc5_of_match);
+
+static struct i2c_driver vc5_driver = {
+	.driver = {
+		.name = "vc5",
+		.of_match_table = clk_vc5_of_match,
+	},
+	.probe		= vc5_probe,
+	.remove		= vc5_remove,
+	.id_table	= vc5_id,
+};
+
+module_i2c_driver(vc5_driver);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("IDT VersaClock 5 driver");
+MODULE_LICENSE("GPL");
