CLK: Pistachio: Add PLL driver

Add a driver for the integer (GF40LP_LAINT) and fractional (GF40LP_FRAC)
PLLs present on Pistachio.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: James Hartley <james.hartley@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Patchwork: https://patchwork.linux-mips.org/patch/9316/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

drivers/clk/pistachio/Makefile

 obj-y	+= clk.o
+obj-y	+= clk-pll.o

drivers/clk/pistachio/clk-pll.c

+/*
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+#define PLL_STATUS			0x0
+#define PLL_STATUS_LOCK			BIT(0)
+
+#define PLL_CTRL1			0x4
+#define PLL_CTRL1_REFDIV_SHIFT		0
+#define PLL_CTRL1_REFDIV_MASK		0x3f
+#define PLL_CTRL1_FBDIV_SHIFT		6
+#define PLL_CTRL1_FBDIV_MASK		0xfff
+#define PLL_INT_CTRL1_POSTDIV1_SHIFT	18
+#define PLL_INT_CTRL1_POSTDIV1_MASK	0x7
+#define PLL_INT_CTRL1_POSTDIV2_SHIFT	21
+#define PLL_INT_CTRL1_POSTDIV2_MASK	0x7
+#define PLL_INT_CTRL1_PD		BIT(24)
+#define PLL_INT_CTRL1_DSMPD		BIT(25)
+#define PLL_INT_CTRL1_FOUTPOSTDIVPD	BIT(26)
+#define PLL_INT_CTRL1_FOUTVCOPD		BIT(27)
+
+#define PLL_CTRL2			0x8
+#define PLL_FRAC_CTRL2_FRAC_SHIFT	0
+#define PLL_FRAC_CTRL2_FRAC_MASK	0xffffff
+#define PLL_FRAC_CTRL2_POSTDIV1_SHIFT	24
+#define PLL_FRAC_CTRL2_POSTDIV1_MASK	0x7
+#define PLL_FRAC_CTRL2_POSTDIV2_SHIFT	27
+#define PLL_FRAC_CTRL2_POSTDIV2_MASK	0x7
+#define PLL_INT_CTRL2_BYPASS		BIT(28)
+
+#define PLL_CTRL3			0xc
+#define PLL_FRAC_CTRL3_PD		BIT(0)
+#define PLL_FRAC_CTRL3_DACPD		BIT(1)
+#define PLL_FRAC_CTRL3_DSMPD		BIT(2)
+#define PLL_FRAC_CTRL3_FOUTPOSTDIVPD	BIT(3)
+#define PLL_FRAC_CTRL3_FOUT4PHASEPD	BIT(4)
+#define PLL_FRAC_CTRL3_FOUTVCOPD	BIT(5)
+
+#define PLL_CTRL4			0x10
+#define PLL_FRAC_CTRL4_BYPASS		BIT(28)
+
+struct pistachio_clk_pll {
+	struct clk_hw hw;
+	void __iomem *base;
+	struct pistachio_pll_rate_table *rates;
+	unsigned int nr_rates;
+};
+
+static inline u32 pll_readl(struct pistachio_clk_pll *pll, u32 reg)
+{
+	return readl(pll->base + reg);
+}
+
+static inline void pll_writel(struct pistachio_clk_pll *pll, u32 val, u32 reg)
+{
+	writel(val, pll->base + reg);
+}
+
+static inline u32 do_div_round_closest(u64 dividend, u32 divisor)
+{
+	dividend += divisor / 2;
+	do_div(dividend, divisor);
+
+	return dividend;
+}
+
+static inline struct pistachio_clk_pll *to_pistachio_pll(struct clk_hw *hw)
+{
+	return container_of(hw, struct pistachio_clk_pll, hw);
+}
+
+static struct pistachio_pll_rate_table *
+pll_get_params(struct pistachio_clk_pll *pll, unsigned long fref,
+	       unsigned long fout)
+{
+	unsigned int i;
+
+	for (i = 0; i < pll->nr_rates; i++) {
+		if (pll->rates[i].fref == fref && pll->rates[i].fout == fout)
+			return &pll->rates[i];
+	}
+
+	return NULL;
+}
+
+static long pll_round_rate(struct clk_hw *hw, unsigned long rate,
+			   unsigned long *parent_rate)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	unsigned int i;
+
+	for (i = 0; i < pll->nr_rates; i++) {
+		if (i > 0 && pll->rates[i].fref == *parent_rate &&
+		    pll->rates[i].fout <= rate)
+			return pll->rates[i - 1].fout;
+	}
+
+	return pll->rates[0].fout;
+}
+
+static int pll_gf40lp_frac_enable(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val;
+
+	val = pll_readl(pll, PLL_CTRL3);
+	val &= ~(PLL_FRAC_CTRL3_PD | PLL_FRAC_CTRL3_DACPD |
+		 PLL_FRAC_CTRL3_DSMPD | PLL_FRAC_CTRL3_FOUTPOSTDIVPD |
+		 PLL_FRAC_CTRL3_FOUT4PHASEPD | PLL_FRAC_CTRL3_FOUTVCOPD);
+	pll_writel(pll, val, PLL_CTRL3);
+
+	val = pll_readl(pll, PLL_CTRL4);
+	val &= ~PLL_FRAC_CTRL4_BYPASS;
+	pll_writel(pll, val, PLL_CTRL4);
+
+	return 0;
+}
+
+static void pll_gf40lp_frac_disable(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val;
+
+	val = pll_readl(pll, PLL_CTRL3);
+	val |= PLL_FRAC_CTRL3_PD;
+	pll_writel(pll, val, PLL_CTRL3);
+}
+
+static int pll_gf40lp_frac_is_enabled(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+
+	return !(pll_readl(pll, PLL_CTRL3) & PLL_FRAC_CTRL3_PD);
+}
+
+static int pll_gf40lp_frac_set_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long parent_rate)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	struct pistachio_pll_rate_table *params;
+	bool was_enabled;
+	u32 val;
+
+	params = pll_get_params(pll, parent_rate, rate);
+	if (!params)
+		return -EINVAL;
+
+	was_enabled = pll_gf40lp_frac_is_enabled(hw);
+	if (!was_enabled)
+		pll_gf40lp_frac_enable(hw);
+
+	val = pll_readl(pll, PLL_CTRL1);
+	val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
+		 (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT));
+	val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) |
+		(params->fbdiv << PLL_CTRL1_FBDIV_SHIFT);
+	pll_writel(pll, val, PLL_CTRL1);
+
+	val = pll_readl(pll, PLL_CTRL2);
+	val &= ~((PLL_FRAC_CTRL2_FRAC_MASK << PLL_FRAC_CTRL2_FRAC_SHIFT) |
+		 (PLL_FRAC_CTRL2_POSTDIV1_MASK <<
+		  PLL_FRAC_CTRL2_POSTDIV1_SHIFT) |
+		 (PLL_FRAC_CTRL2_POSTDIV2_MASK <<
+		  PLL_FRAC_CTRL2_POSTDIV2_SHIFT));
+	val |= (params->frac << PLL_FRAC_CTRL2_FRAC_SHIFT) |
+		(params->postdiv1 << PLL_FRAC_CTRL2_POSTDIV1_SHIFT) |
+		(params->postdiv2 << PLL_FRAC_CTRL2_POSTDIV2_SHIFT);
+	pll_writel(pll, val, PLL_CTRL2);
+
+	while (!(pll_readl(pll, PLL_STATUS) & PLL_STATUS_LOCK))
+		cpu_relax();
+
+	if (!was_enabled)
+		pll_gf40lp_frac_disable(hw);
+
+	return 0;
+}
+
+static unsigned long pll_gf40lp_frac_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val, prediv, fbdiv, frac, postdiv1, postdiv2;
+	u64 rate = parent_rate;
+
+	val = pll_readl(pll, PLL_CTRL1);
+	prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK;
+	fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK;
+
+	val = pll_readl(pll, PLL_CTRL2);
+	postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) &
+		PLL_FRAC_CTRL2_POSTDIV1_MASK;
+	postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) &
+		PLL_FRAC_CTRL2_POSTDIV2_MASK;
+	frac = (val >> PLL_FRAC_CTRL2_FRAC_SHIFT) & PLL_FRAC_CTRL2_FRAC_MASK;
+
+	rate *= (fbdiv << 24) + frac;
+	rate = do_div_round_closest(rate, (prediv * postdiv1 * postdiv2) << 24);
+
+	return rate;
+}
+
+static struct clk_ops pll_gf40lp_frac_ops = {
+	.enable = pll_gf40lp_frac_enable,
+	.disable = pll_gf40lp_frac_disable,
+	.is_enabled = pll_gf40lp_frac_is_enabled,
+	.recalc_rate = pll_gf40lp_frac_recalc_rate,
+	.round_rate = pll_round_rate,
+	.set_rate = pll_gf40lp_frac_set_rate,
+};
+
+static struct clk_ops pll_gf40lp_frac_fixed_ops = {
+	.enable = pll_gf40lp_frac_enable,
+	.disable = pll_gf40lp_frac_disable,
+	.is_enabled = pll_gf40lp_frac_is_enabled,
+	.recalc_rate = pll_gf40lp_frac_recalc_rate,
+};
+
+static int pll_gf40lp_laint_enable(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val;
+
+	val = pll_readl(pll, PLL_CTRL1);
+	val &= ~(PLL_INT_CTRL1_PD | PLL_INT_CTRL1_DSMPD |
+		 PLL_INT_CTRL1_FOUTPOSTDIVPD | PLL_INT_CTRL1_FOUTVCOPD);
+	pll_writel(pll, val, PLL_CTRL1);
+
+	val = pll_readl(pll, PLL_CTRL2);
+	val &= ~PLL_INT_CTRL2_BYPASS;
+	pll_writel(pll, val, PLL_CTRL2);
+
+	return 0;
+}
+
+static void pll_gf40lp_laint_disable(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val;
+
+	val = pll_readl(pll, PLL_CTRL1);
+	val |= PLL_INT_CTRL1_PD;
+	pll_writel(pll, val, PLL_CTRL1);
+}
+
+static int pll_gf40lp_laint_is_enabled(struct clk_hw *hw)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+
+	return !(pll_readl(pll, PLL_CTRL1) & PLL_INT_CTRL1_PD);
+}
+
+static int pll_gf40lp_laint_set_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long parent_rate)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	struct pistachio_pll_rate_table *params;
+	bool was_enabled;
+	u32 val;
+
+	params = pll_get_params(pll, parent_rate, rate);
+	if (!params)
+		return -EINVAL;
+
+	was_enabled = pll_gf40lp_laint_is_enabled(hw);
+	if (!was_enabled)
+		pll_gf40lp_laint_enable(hw);
+
+	val = pll_readl(pll, PLL_CTRL1);
+	val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) |
+		 (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT) |
+		 (PLL_INT_CTRL1_POSTDIV1_MASK << PLL_INT_CTRL1_POSTDIV1_SHIFT) |
+		 (PLL_INT_CTRL1_POSTDIV2_MASK << PLL_INT_CTRL1_POSTDIV2_SHIFT));
+	val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) |
+		(params->fbdiv << PLL_CTRL1_FBDIV_SHIFT) |
+		(params->postdiv1 << PLL_INT_CTRL1_POSTDIV1_SHIFT) |
+		(params->postdiv2 << PLL_INT_CTRL1_POSTDIV2_SHIFT);
+	pll_writel(pll, val, PLL_CTRL1);
+
+	while (!(pll_readl(pll, PLL_STATUS) & PLL_STATUS_LOCK))
+		cpu_relax();
+
+	if (!was_enabled)
+		pll_gf40lp_laint_disable(hw);
+
+	return 0;
+}
+
+static unsigned long pll_gf40lp_laint_recalc_rate(struct clk_hw *hw,
+						  unsigned long parent_rate)
+{
+	struct pistachio_clk_pll *pll = to_pistachio_pll(hw);
+	u32 val, prediv, fbdiv, postdiv1, postdiv2;
+	u64 rate = parent_rate;
+
+	val = pll_readl(pll, PLL_CTRL1);
+	prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK;
+	fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK;
+	postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) &
+		PLL_INT_CTRL1_POSTDIV1_MASK;
+	postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) &
+		PLL_INT_CTRL1_POSTDIV2_MASK;
+
+	rate *= fbdiv;
+	rate = do_div_round_closest(rate, prediv * postdiv1 * postdiv2);
+
+	return rate;
+}
+
+static struct clk_ops pll_gf40lp_laint_ops = {
+	.enable = pll_gf40lp_laint_enable,
+	.disable = pll_gf40lp_laint_disable,
+	.is_enabled = pll_gf40lp_laint_is_enabled,
+	.recalc_rate = pll_gf40lp_laint_recalc_rate,
+	.round_rate = pll_round_rate,
+	.set_rate = pll_gf40lp_laint_set_rate,
+};
+
+static struct clk_ops pll_gf40lp_laint_fixed_ops = {
+	.enable = pll_gf40lp_laint_enable,
+	.disable = pll_gf40lp_laint_disable,
+	.is_enabled = pll_gf40lp_laint_is_enabled,
+	.recalc_rate = pll_gf40lp_laint_recalc_rate,
+};
+
+static struct clk *pll_register(const char *name, const char *parent_name,
+				unsigned long flags, void __iomem *base,
+				enum pistachio_pll_type type,
+				struct pistachio_pll_rate_table *rates,
+				unsigned int nr_rates)
+{
+	struct pistachio_clk_pll *pll;
+	struct clk_init_data init;
+	struct clk *clk;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = flags | CLK_GET_RATE_NOCACHE;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	switch (type) {
+	case PLL_GF40LP_FRAC:
+		if (rates)
+			init.ops = &pll_gf40lp_frac_ops;
+		else
+			init.ops = &pll_gf40lp_frac_fixed_ops;
+		break;
+	case PLL_GF40LP_LAINT:
+		if (rates)
+			init.ops = &pll_gf40lp_laint_ops;
+		else
+			init.ops = &pll_gf40lp_laint_fixed_ops;
+		break;
+	default:
+		pr_err("Unrecognized PLL type %u\n", type);
+		kfree(pll);
+		return ERR_PTR(-EINVAL);
+	}
+
+	pll->hw.init = &init;
+	pll->base = base;
+	pll->rates = rates;
+	pll->nr_rates = nr_rates;
+
+	clk = clk_register(NULL, &pll->hw);
+	if (IS_ERR(clk))
+		kfree(pll);
+
+	return clk;
+}
+
+void pistachio_clk_register_pll(struct pistachio_clk_provider *p,
+				struct pistachio_pll *pll,
+				unsigned int num)
+{
+	struct clk *clk;
+	unsigned int i;
+
+	for (i = 0; i < num; i++) {
+		clk = pll_register(pll[i].name, pll[i].parent,
+				   0, p->base + pll[i].reg_base,
+				   pll[i].type, pll[i].rates,
+				   pll[i].nr_rates);
+		p->clk_data.clks[pll[i].id] = clk;
+	}
+}

drivers/clk/pistachio/clk.h

@@ -94,6 +94,53 @@ struct pistachio_fixed_factor {
 		.parent		= _pname,			\
 	}
 
+struct pistachio_pll_rate_table {
+	unsigned long fref;
+	unsigned long fout;
+	unsigned int refdiv;
+	unsigned int fbdiv;
+	unsigned int postdiv1;
+	unsigned int postdiv2;
+	unsigned int frac;
+};
+
+enum pistachio_pll_type {
+	PLL_GF40LP_LAINT,
+	PLL_GF40LP_FRAC,
+};
+
+struct pistachio_pll {
+	unsigned int id;
+	unsigned long reg_base;
+	enum pistachio_pll_type type;
+	struct pistachio_pll_rate_table *rates;
+	unsigned int nr_rates;
+	const char *name;
+	const char *parent;
+};
+
+#define PLL(_id, _name, _pname, _type, _reg, _rates)		\
+	{							\
+		.id		= _id,				\
+		.reg_base	= _reg,				\
+		.type		= _type,			\
+		.rates		= _rates,			\
+		.nr_rates	= ARRAY_SIZE(_rates),		\
+		.name		= _name,			\
+		.parent		= _pname,			\
+	}
+
+#define PLL_FIXED(_id, _name, _pname, _type, _reg)		\
+	{							\
+		.id		= _id,				\
+		.reg_base	= _reg,				\
+		.type		= _type,			\
+		.rates		= NULL,				\
+		.nr_rates	= 0,				\
+		.name		= _name,			\
+		.parent		= _pname,			\
+	}
+
 struct pistachio_clk_provider {
 	struct device_node *node;
 	void __iomem *base;
@@ -117,6 +164,9 @@ extern void
 pistachio_clk_register_fixed_factor(struct pistachio_clk_provider *p,
 				    struct pistachio_fixed_factor *ff,
 				    unsigned int num);
+extern void pistachio_clk_register_pll(struct pistachio_clk_provider *p,
+				       struct pistachio_pll *pll,
+				       unsigned int num);
 
 extern void pistachio_clk_force_enable(struct pistachio_clk_provider *p,
 				       unsigned int *clk_ids, unsigned int num);