drivers/clk/clk-vt8500.c - maze/linux - Git at Google

 /*
  * Clock implementation for VIA/Wondermedia SoC's
  * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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.
  *
  */

 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/bitops.h>
 #include <linux/clkdev.h>
 #include <linux/clk-provider.h>

 /* All clocks share the same lock as none can be changed concurrently */
 static DEFINE_SPINLOCK(_lock);

 struct clk_device {
 	struct clk_hw	hw;
 	void __iomem	*div_reg;
 	unsigned int	div_mask;
 	void __iomem	*en_reg;
 	int		en_bit;
 	spinlock_t	*lock;
 };

 /*
  * Add new PLL_TYPE_x definitions here as required. Use the first known model
  * to support the new type as the name.
  * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
  * vtwm_pll_set_rate() to handle the new PLL_TYPE_x
  */

 #define PLL_TYPE_VT8500		0
 #define PLL_TYPE_WM8650		1

 struct clk_pll {
 	struct clk_hw	hw;
 	void __iomem	*reg;
 	spinlock_t	*lock;
 	int		type;
 };

 static void __iomem *pmc_base;

 #define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)

 #define VT8500_PMC_BUSY_MASK		0x18

 static void vt8500_pmc_wait_busy(void)
 {
 	while (readl(pmc_base) & VT8500_PMC_BUSY_MASK)
 		cpu_relax();
 }

 static int vt8500_dclk_enable(struct clk_hw *hw)
 {
 	struct clk_device *cdev = to_clk_device(hw);
 	u32 en_val;
 	unsigned long flags = 0;

 	spin_lock_irqsave(cdev->lock, flags);

 	en_val = readl(cdev->en_reg);
 	en_val |= BIT(cdev->en_bit);
 	writel(en_val, cdev->en_reg);

 	spin_unlock_irqrestore(cdev->lock, flags);
 	return 0;
 }

 static void vt8500_dclk_disable(struct clk_hw *hw)
 {
 	struct clk_device *cdev = to_clk_device(hw);
 	u32 en_val;
 	unsigned long flags = 0;

 	spin_lock_irqsave(cdev->lock, flags);

 	en_val = readl(cdev->en_reg);
 	en_val &= ~BIT(cdev->en_bit);
 	writel(en_val, cdev->en_reg);

 	spin_unlock_irqrestore(cdev->lock, flags);
 }

 static int vt8500_dclk_is_enabled(struct clk_hw *hw)
 {
 	struct clk_device *cdev = to_clk_device(hw);
 	u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit));

 	return en_val ? 1 : 0;
 }

 static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw,
 				unsigned long parent_rate)
 {
 	struct clk_device *cdev = to_clk_device(hw);
 	u32 div = readl(cdev->div_reg) & cdev->div_mask;

 	/* Special case for SDMMC devices */
 	if ((cdev->div_mask == 0x3F) && (div & BIT(5)))
 		div = 64 * (div & 0x1f);

 	/* div == 0 is actually the highest divisor */
 	if (div == 0)
 		div = (cdev->div_mask + 1);

 	return parent_rate / div;
 }

 static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long *prate)
 {
 	u32 divisor = *prate / rate;

 	return *prate / divisor;
 }

 static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long parent_rate)
 {
 	struct clk_device *cdev = to_clk_device(hw);
 	u32 divisor = parent_rate / rate;
 	unsigned long flags = 0;

 	if (divisor == cdev->div_mask + 1)
 		divisor = 0;

 	if (divisor > cdev->div_mask) {
 		pr_err("%s: invalid divisor for clock\n", __func__);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(cdev->lock, flags);

 	vt8500_pmc_wait_busy();
 	writel(divisor, cdev->div_reg);
 	vt8500_pmc_wait_busy();

 	spin_lock_irqsave(cdev->lock, flags);

 	return 0;
 }


 static const struct clk_ops vt8500_gated_clk_ops = {
 	.enable = vt8500_dclk_enable,
 	.disable = vt8500_dclk_disable,
 	.is_enabled = vt8500_dclk_is_enabled,
 };

 static const struct clk_ops vt8500_divisor_clk_ops = {
 	.round_rate = vt8500_dclk_round_rate,
 	.set_rate = vt8500_dclk_set_rate,
 	.recalc_rate = vt8500_dclk_recalc_rate,
 };

 static const struct clk_ops vt8500_gated_divisor_clk_ops = {
 	.enable = vt8500_dclk_enable,
 	.disable = vt8500_dclk_disable,
 	.is_enabled = vt8500_dclk_is_enabled,
 	.round_rate = vt8500_dclk_round_rate,
 	.set_rate = vt8500_dclk_set_rate,
 	.recalc_rate = vt8500_dclk_recalc_rate,
 };

 #define CLK_INIT_GATED			BIT(0)
 #define CLK_INIT_DIVISOR		BIT(1)
 #define CLK_INIT_GATED_DIVISOR		(CLK_INIT_DIVISOR | CLK_INIT_GATED)

 static __init void vtwm_device_clk_init(struct device_node *node)
 {
 	u32 en_reg, div_reg;
 	struct clk *clk;
 	struct clk_device *dev_clk;
 	const char *clk_name = node->name;
 	const char *parent_name;
 	struct clk_init_data init;
 	int rc;
 	int clk_init_flags = 0;

 	dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
 	if (WARN_ON(!dev_clk))
 		return;

 	dev_clk->lock = &_lock;

 	rc = of_property_read_u32(node, "enable-reg", &en_reg);
 	if (!rc) {
 		dev_clk->en_reg = pmc_base + en_reg;
 		rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit);
 		if (rc) {
 			pr_err("%s: enable-bit property required for gated clock\n",
 								__func__);
 			return;
 		}
 		clk_init_flags |= CLK_INIT_GATED;
 	}

 	rc = of_property_read_u32(node, "divisor-reg", &div_reg);
 	if (!rc) {
 		dev_clk->div_reg = pmc_base + div_reg;
 		/*
 		 * use 0x1f as the default mask since it covers
 		 * almost all the clocks and reduces dts properties
 		 */
 		dev_clk->div_mask = 0x1f;

 		of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask);
 		clk_init_flags |= CLK_INIT_DIVISOR;
 	}

 	of_property_read_string(node, "clock-output-names", &clk_name);

 	switch (clk_init_flags) {
 	case CLK_INIT_GATED:
 		init.ops = &vt8500_gated_clk_ops;
 		break;
 	case CLK_INIT_DIVISOR:
 		init.ops = &vt8500_divisor_clk_ops;
 		break;
 	case CLK_INIT_GATED_DIVISOR:
 		init.ops = &vt8500_gated_divisor_clk_ops;
 		break;
 	default:
 		pr_err("%s: Invalid clock description in device tree\n",
 								__func__);
 		kfree(dev_clk);
 		return;
 	}

 	init.name = clk_name;
 	init.flags = 0;
 	parent_name = of_clk_get_parent_name(node, 0);
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	dev_clk->hw.init = &init;

 	clk = clk_register(NULL, &dev_clk->hw);
 	if (WARN_ON(IS_ERR(clk))) {
 		kfree(dev_clk);
 		return;
 	}
 	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 	clk_register_clkdev(clk, clk_name, NULL);
 }


 /* PLL clock related functions */

 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)

 /* Helper macros for PLL_VT8500 */
 #define VT8500_PLL_MUL(x)	((x & 0x1F) << 1)
 #define VT8500_PLL_DIV(x)	((x & 0x100) ? 1 : 2)

 #define VT8500_BITS_TO_FREQ(r, m, d)					\
 				((r / d) * m)

 #define VT8500_BITS_TO_VAL(m, d)					\
 				((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))

 /* Helper macros for PLL_WM8650 */
 #define WM8650_PLL_MUL(x)	(x & 0x3FF)
 #define WM8650_PLL_DIV(x)	(((x >> 10) & 7) * (1 << ((x >> 13) & 3)))

 #define WM8650_BITS_TO_FREQ(r, m, d1, d2)				\
 				(r * m / (d1 * (1 << d2)))

 #define WM8650_BITS_TO_VAL(m, d1, d2)					\
 				((d2 << 13) | (d1 << 10) | (m & 0x3FF))


 static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate,
 				u32 *multiplier, u32 *prediv)
 {
 	unsigned long tclk;

 	/* sanity check */
 	if ((rate < parent_rate * 4) || (rate > parent_rate * 62)) {
 		pr_err("%s: requested rate out of range\n", __func__);
 		*multiplier = 0;
 		*prediv = 1;
 		return;
 	}
 	if (rate <= parent_rate * 31)
 		/* use the prediv to double the resolution */
 		*prediv = 2;
 	else
 		*prediv = 1;

 	*multiplier = rate / (parent_rate / *prediv);
 	tclk = (parent_rate / *prediv) * *multiplier;

 	if (tclk != rate)
 		pr_warn("%s: requested rate %lu, found rate %lu\n", __func__,
 								rate, tclk);
 }

 static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate,
 				u32 *multiplier, u32 *divisor1, u32 *divisor2)
 {
 	u32 mul, div1, div2;
 	u32 best_mul, best_div1, best_div2;
 	unsigned long tclk, rate_err, best_err;

 	best_err = (unsigned long)-1;

 	/* Find the closest match (lower or equal to requested) */
 	for (div1 = 5; div1 >= 3; div1--)
 		for (div2 = 3; div2 >= 0; div2--)
 			for (mul = 3; mul <= 1023; mul++) {
 				tclk = parent_rate * mul / (div1 * (1 << div2));
 				if (tclk > rate)
 					continue;
 				/* error will always be +ve */
 				rate_err = rate - tclk;
 				if (rate_err == 0) {
 					*multiplier = mul;
 					*divisor1 = div1;
 					*divisor2 = div2;
 					return;
 				}

 				if (rate_err < best_err) {
 					best_err = rate_err;
 					best_mul = mul;
 					best_div1 = div1;
 					best_div2 = div2;
 				}
 			}

 	/* if we got here, it wasn't an exact match */
 	pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
 							rate - best_err);
 	*multiplier = mul;
 	*divisor1 = div1;
 	*divisor2 = div2;
 }

 static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long parent_rate)
 {
 	struct clk_pll *pll = to_clk_pll(hw);
 	u32 mul, div1, div2;
 	u32 pll_val;
 	unsigned long flags = 0;

 	/* sanity check */

 	switch (pll->type) {
 	case PLL_TYPE_VT8500:
 		vt8500_find_pll_bits(rate, parent_rate, &mul, &div1);
 		pll_val = VT8500_BITS_TO_VAL(mul, div1);
 		break;
 	case PLL_TYPE_WM8650:
 		wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
 		pll_val = WM8650_BITS_TO_VAL(mul, div1, div2);
 		break;
 	default:
 		pr_err("%s: invalid pll type\n", __func__);
 		return 0;
 	}

 	spin_lock_irqsave(pll->lock, flags);

 	vt8500_pmc_wait_busy();
 	writel(pll_val, pll->reg);
 	vt8500_pmc_wait_busy();

 	spin_unlock_irqrestore(pll->lock, flags);

 	return 0;
 }

 static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long *prate)
 {
 	struct clk_pll *pll = to_clk_pll(hw);
 	u32 mul, div1, div2;
 	long round_rate;

 	switch (pll->type) {
 	case PLL_TYPE_VT8500:
 		vt8500_find_pll_bits(rate, *prate, &mul, &div1);
 		round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1);
 		break;
 	case PLL_TYPE_WM8650:
 		wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2);
 		round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2);
 		break;
 	default:
 		round_rate = 0;
 	}

 	return round_rate;
 }

 static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw,
 				unsigned long parent_rate)
 {
 	struct clk_pll *pll = to_clk_pll(hw);
 	u32 pll_val = readl(pll->reg);
 	unsigned long pll_freq;

 	switch (pll->type) {
 	case PLL_TYPE_VT8500:
 		pll_freq = parent_rate * VT8500_PLL_MUL(pll_val);
 		pll_freq /= VT8500_PLL_DIV(pll_val);
 		break;
 	case PLL_TYPE_WM8650:
 		pll_freq = parent_rate * WM8650_PLL_MUL(pll_val);
 		pll_freq /= WM8650_PLL_DIV(pll_val);
 		break;
 	default:
 		pll_freq = 0;
 	}

 	return pll_freq;
 }

 const struct clk_ops vtwm_pll_ops = {
 	.round_rate = vtwm_pll_round_rate,
 	.set_rate = vtwm_pll_set_rate,
 	.recalc_rate = vtwm_pll_recalc_rate,
 };

 static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type)
 {
 	u32 reg;
 	struct clk *clk;
 	struct clk_pll *pll_clk;
 	const char *clk_name = node->name;
 	const char *parent_name;
 	struct clk_init_data init;
 	int rc;

 	rc = of_property_read_u32(node, "reg", &reg);
 	if (WARN_ON(rc))
 		return;

 	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
 	if (WARN_ON(!pll_clk))
 		return;

 	pll_clk->reg = pmc_base + reg;
 	pll_clk->lock = &_lock;
 	pll_clk->type = pll_type;

 	of_property_read_string(node, "clock-output-names", &clk_name);

 	init.name = clk_name;
 	init.ops = &vtwm_pll_ops;
 	init.flags = 0;
 	parent_name = of_clk_get_parent_name(node, 0);
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	pll_clk->hw.init = &init;

 	clk = clk_register(NULL, &pll_clk->hw);
 	if (WARN_ON(IS_ERR(clk))) {
 		kfree(pll_clk);
 		return;
 	}
 	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 	clk_register_clkdev(clk, clk_name, NULL);
 }


 /* Wrappers for initialization functions */

 static void __init vt8500_pll_init(struct device_node *node)
 {
 	vtwm_pll_clk_init(node, PLL_TYPE_VT8500);
 }

 static void __init wm8650_pll_init(struct device_node *node)
 {
 	vtwm_pll_clk_init(node, PLL_TYPE_WM8650);
 }

 static const __initconst struct of_device_id clk_match[] = {
 	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
 	{ .compatible = "via,vt8500-pll-clock", .data = vt8500_pll_init, },
 	{ .compatible = "wm,wm8650-pll-clock", .data = wm8650_pll_init, },
 	{ .compatible = "via,vt8500-device-clock",
 					.data = vtwm_device_clk_init, },
 	{ /* sentinel */ }
 };

 void __init vtwm_clk_init(void __iomem *base)
 {
 	if (!base)
 		return;

 	pmc_base = base;

 	of_clk_init(clk_match);
 }
	/*
	* Clock implementation for VIA/Wondermedia SoC's
	* Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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.
	*
	*/

	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/slab.h>
	#include <linux/bitops.h>
	#include <linux/clkdev.h>
	#include <linux/clk-provider.h>

	/* All clocks share the same lock as none can be changed concurrently */
	static DEFINE_SPINLOCK(_lock);

	struct clk_device {
	struct clk_hw hw;
	void __iomem *div_reg;
	unsigned int div_mask;
	void __iomem *en_reg;
	int en_bit;
	spinlock_t *lock;
	};

	/*
	* Add new PLL_TYPE_x definitions here as required. Use the first known model
	* to support the new type as the name.
	* Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
	* vtwm_pll_set_rate() to handle the new PLL_TYPE_x
	*/

	#define PLL_TYPE_VT8500 0
	#define PLL_TYPE_WM8650 1

	struct clk_pll {
	struct clk_hw hw;
	void __iomem *reg;
	spinlock_t *lock;
	int type;
	};

	static void __iomem *pmc_base;

	#define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)

	#define VT8500_PMC_BUSY_MASK 0x18

	static void vt8500_pmc_wait_busy(void)
	{
	while (readl(pmc_base) & VT8500_PMC_BUSY_MASK)
	cpu_relax();
	}

	static int vt8500_dclk_enable(struct clk_hw *hw)
	{
	struct clk_device *cdev = to_clk_device(hw);
	u32 en_val;
	unsigned long flags = 0;

	spin_lock_irqsave(cdev->lock, flags);

	en_val = readl(cdev->en_reg);
	en_val \|= BIT(cdev->en_bit);
	writel(en_val, cdev->en_reg);

	spin_unlock_irqrestore(cdev->lock, flags);
	return 0;
	}

	static void vt8500_dclk_disable(struct clk_hw *hw)
	{
	struct clk_device *cdev = to_clk_device(hw);
	u32 en_val;
	unsigned long flags = 0;

	spin_lock_irqsave(cdev->lock, flags);

	en_val = readl(cdev->en_reg);
	en_val &= ~BIT(cdev->en_bit);
	writel(en_val, cdev->en_reg);

	spin_unlock_irqrestore(cdev->lock, flags);
	}

	static int vt8500_dclk_is_enabled(struct clk_hw *hw)
	{
	struct clk_device *cdev = to_clk_device(hw);
	u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit));

	return en_val ? 1 : 0;
	}

	static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct clk_device *cdev = to_clk_device(hw);
	u32 div = readl(cdev->div_reg) & cdev->div_mask;

	/* Special case for SDMMC devices */
	if ((cdev->div_mask == 0x3F) && (div & BIT(5)))
	div = 64 * (div & 0x1f);

	/* div == 0 is actually the highest divisor */
	if (div == 0)
	div = (cdev->div_mask + 1);

	return parent_rate / div;
	}

	static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	u32 divisor = *prate / rate;

	return *prate / divisor;
	}

	static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clk_device *cdev = to_clk_device(hw);
	u32 divisor = parent_rate / rate;
	unsigned long flags = 0;

	if (divisor == cdev->div_mask + 1)
	divisor = 0;

	if (divisor > cdev->div_mask) {
	pr_err("%s: invalid divisor for clock\n", __func__);
	return -EINVAL;
	}

	spin_lock_irqsave(cdev->lock, flags);

	vt8500_pmc_wait_busy();
	writel(divisor, cdev->div_reg);
	vt8500_pmc_wait_busy();

	spin_lock_irqsave(cdev->lock, flags);

	return 0;
	}


	static const struct clk_ops vt8500_gated_clk_ops = {
	.enable = vt8500_dclk_enable,
	.disable = vt8500_dclk_disable,
	.is_enabled = vt8500_dclk_is_enabled,
	};

	static const struct clk_ops vt8500_divisor_clk_ops = {
	.round_rate = vt8500_dclk_round_rate,
	.set_rate = vt8500_dclk_set_rate,
	.recalc_rate = vt8500_dclk_recalc_rate,
	};

	static const struct clk_ops vt8500_gated_divisor_clk_ops = {
	.enable = vt8500_dclk_enable,
	.disable = vt8500_dclk_disable,
	.is_enabled = vt8500_dclk_is_enabled,
	.round_rate = vt8500_dclk_round_rate,
	.set_rate = vt8500_dclk_set_rate,
	.recalc_rate = vt8500_dclk_recalc_rate,
	};

	#define CLK_INIT_GATED BIT(0)
	#define CLK_INIT_DIVISOR BIT(1)
	#define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR \| CLK_INIT_GATED)

	static __init void vtwm_device_clk_init(struct device_node *node)
	{
	u32 en_reg, div_reg;
	struct clk *clk;
	struct clk_device *dev_clk;
	const char *clk_name = node->name;
	const char *parent_name;
	struct clk_init_data init;
	int rc;
	int clk_init_flags = 0;

	dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
	if (WARN_ON(!dev_clk))
	return;

	dev_clk->lock = &_lock;

	rc = of_property_read_u32(node, "enable-reg", &en_reg);
	if (!rc) {
	dev_clk->en_reg = pmc_base + en_reg;
	rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit);
	if (rc) {
	pr_err("%s: enable-bit property required for gated clock\n",
	__func__);
	return;
	}
	clk_init_flags \|= CLK_INIT_GATED;
	}

	rc = of_property_read_u32(node, "divisor-reg", &div_reg);
	if (!rc) {
	dev_clk->div_reg = pmc_base + div_reg;
	/*
	* use 0x1f as the default mask since it covers
	* almost all the clocks and reduces dts properties
	*/
	dev_clk->div_mask = 0x1f;

	of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask);
	clk_init_flags \|= CLK_INIT_DIVISOR;
	}

	of_property_read_string(node, "clock-output-names", &clk_name);

	switch (clk_init_flags) {
	case CLK_INIT_GATED:
	init.ops = &vt8500_gated_clk_ops;
	break;
	case CLK_INIT_DIVISOR:
	init.ops = &vt8500_divisor_clk_ops;
	break;
	case CLK_INIT_GATED_DIVISOR:
	init.ops = &vt8500_gated_divisor_clk_ops;
	break;
	default:
	pr_err("%s: Invalid clock description in device tree\n",
	__func__);
	kfree(dev_clk);
	return;
	}

	init.name = clk_name;
	init.flags = 0;
	parent_name = of_clk_get_parent_name(node, 0);
	init.parent_names = &parent_name;
	init.num_parents = 1;

	dev_clk->hw.init = &init;

	clk = clk_register(NULL, &dev_clk->hw);
	if (WARN_ON(IS_ERR(clk))) {
	kfree(dev_clk);
	return;
	}
	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
	clk_register_clkdev(clk, clk_name, NULL);
	}


	/* PLL clock related functions */

	#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)

	/* Helper macros for PLL_VT8500 */
	#define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
	#define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)

	#define VT8500_BITS_TO_FREQ(r, m, d) \
	((r / d) * m)

	#define VT8500_BITS_TO_VAL(m, d) \
	((d == 2 ? 0 : 0x100) \| ((m >> 1) & 0x1F))

	/* Helper macros for PLL_WM8650 */
	#define WM8650_PLL_MUL(x) (x & 0x3FF)
	#define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))

	#define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
	(r * m / (d1 * (1 << d2)))

	#define WM8650_BITS_TO_VAL(m, d1, d2) \
	((d2 << 13) \| (d1 << 10) \| (m & 0x3FF))


	static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate,
	u32 multiplier, u32 prediv)
	{
	unsigned long tclk;

	/* sanity check */
	if ((rate < parent_rate * 4) \|\| (rate > parent_rate * 62)) {
	pr_err("%s: requested rate out of range\n", __func__);
	*multiplier = 0;
	*prediv = 1;
	return;
	}
	if (rate <= parent_rate * 31)
	/* use the prediv to double the resolution */
	*prediv = 2;
	else
	*prediv = 1;

	multiplier = rate / (parent_rate / prediv);
	tclk = (parent_rate / prediv) *multiplier;

	if (tclk != rate)
	pr_warn("%s: requested rate %lu, found rate %lu\n", __func__,
	rate, tclk);
	}

	static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate,
	u32 multiplier, u32 divisor1, u32 *divisor2)
	{
	u32 mul, div1, div2;
	u32 best_mul, best_div1, best_div2;
	unsigned long tclk, rate_err, best_err;

	best_err = (unsigned long)-1;

	/* Find the closest match (lower or equal to requested) */
	for (div1 = 5; div1 >= 3; div1--)
	for (div2 = 3; div2 >= 0; div2--)
	for (mul = 3; mul <= 1023; mul++) {
	tclk = parent_rate * mul / (div1 * (1 << div2));
	if (tclk > rate)
	continue;
	/* error will always be +ve */
	rate_err = rate - tclk;
	if (rate_err == 0) {
	*multiplier = mul;
	*divisor1 = div1;
	*divisor2 = div2;
	return;
	}

	if (rate_err < best_err) {
	best_err = rate_err;
	best_mul = mul;
	best_div1 = div1;
	best_div2 = div2;
	}
	}

	/* if we got here, it wasn't an exact match */
	pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
	rate - best_err);
	*multiplier = mul;
	*divisor1 = div1;
	*divisor2 = div2;
	}

	static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clk_pll *pll = to_clk_pll(hw);
	u32 mul, div1, div2;
	u32 pll_val;
	unsigned long flags = 0;

	/* sanity check */

	switch (pll->type) {
	case PLL_TYPE_VT8500:
	vt8500_find_pll_bits(rate, parent_rate, &mul, &div1);
	pll_val = VT8500_BITS_TO_VAL(mul, div1);
	break;
	case PLL_TYPE_WM8650:
	wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
	pll_val = WM8650_BITS_TO_VAL(mul, div1, div2);
	break;
	default:
	pr_err("%s: invalid pll type\n", __func__);
	return 0;
	}

	spin_lock_irqsave(pll->lock, flags);

	vt8500_pmc_wait_busy();
	writel(pll_val, pll->reg);
	vt8500_pmc_wait_busy();

	spin_unlock_irqrestore(pll->lock, flags);

	return 0;
	}

	static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	struct clk_pll *pll = to_clk_pll(hw);
	u32 mul, div1, div2;
	long round_rate;

	switch (pll->type) {
	case PLL_TYPE_VT8500:
	vt8500_find_pll_bits(rate, *prate, &mul, &div1);
	round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1);
	break;
	case PLL_TYPE_WM8650:
	wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2);
	round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2);
	break;
	default:
	round_rate = 0;
	}

	return round_rate;
	}

	static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct clk_pll *pll = to_clk_pll(hw);
	u32 pll_val = readl(pll->reg);
	unsigned long pll_freq;

	switch (pll->type) {
	case PLL_TYPE_VT8500:
	pll_freq = parent_rate * VT8500_PLL_MUL(pll_val);
	pll_freq /= VT8500_PLL_DIV(pll_val);
	break;
	case PLL_TYPE_WM8650:
	pll_freq = parent_rate * WM8650_PLL_MUL(pll_val);
	pll_freq /= WM8650_PLL_DIV(pll_val);
	break;
	default:
	pll_freq = 0;
	}

	return pll_freq;
	}

	const struct clk_ops vtwm_pll_ops = {
	.round_rate = vtwm_pll_round_rate,
	.set_rate = vtwm_pll_set_rate,
	.recalc_rate = vtwm_pll_recalc_rate,
	};

	static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type)
	{
	u32 reg;
	struct clk *clk;
	struct clk_pll *pll_clk;
	const char *clk_name = node->name;
	const char *parent_name;
	struct clk_init_data init;
	int rc;

	rc = of_property_read_u32(node, "reg", &reg);
	if (WARN_ON(rc))
	return;

	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
	if (WARN_ON(!pll_clk))
	return;

	pll_clk->reg = pmc_base + reg;
	pll_clk->lock = &_lock;
	pll_clk->type = pll_type;

	of_property_read_string(node, "clock-output-names", &clk_name);

	init.name = clk_name;
	init.ops = &vtwm_pll_ops;
	init.flags = 0;
	parent_name = of_clk_get_parent_name(node, 0);
	init.parent_names = &parent_name;
	init.num_parents = 1;

	pll_clk->hw.init = &init;

	clk = clk_register(NULL, &pll_clk->hw);
	if (WARN_ON(IS_ERR(clk))) {
	kfree(pll_clk);
	return;
	}
	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
	clk_register_clkdev(clk, clk_name, NULL);
	}


	/* Wrappers for initialization functions */

	static void __init vt8500_pll_init(struct device_node *node)
	{
	vtwm_pll_clk_init(node, PLL_TYPE_VT8500);
	}

	static void __init wm8650_pll_init(struct device_node *node)
	{
	vtwm_pll_clk_init(node, PLL_TYPE_WM8650);
	}

	static const __initconst struct of_device_id clk_match[] = {
	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
	{ .compatible = "via,vt8500-pll-clock", .data = vt8500_pll_init, },
	{ .compatible = "wm,wm8650-pll-clock", .data = wm8650_pll_init, },
	{ .compatible = "via,vt8500-device-clock",
	.data = vtwm_device_clk_init, },
	{ /* sentinel */ }
	};

	void __init vtwm_clk_init(void __iomem *base)
	{
	if (!base)
	return;

	pmc_base = base;

	of_clk_init(clk_match);
	}