1 files changed, 340 insertions, 0 deletions
diff --git a/drivers/clk/visconti/pll.c b/drivers/clk/visconti/pll.c
new file mode 100644
index 000000000..1f3234f22
--- /dev/null
+++ b/drivers/clk/visconti/pll.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Toshiba Visconti PLL driver
+ *
+ * Copyright (c) 2021 TOSHIBA CORPORATION
+ * Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "pll.h"
+
+struct visconti_pll {
+	struct clk_hw	hw;
+	void __iomem	*pll_base;
+	spinlock_t	*lock;
+	unsigned long flags;
+	const struct visconti_pll_rate_table *rate_table;
+	size_t rate_count;
+	struct visconti_pll_provider *ctx;
+};
+
+#define PLL_CONF_REG		0x0000
+#define PLL_CTRL_REG		0x0004
+#define PLL_FRACMODE_REG	0x0010
+#define PLL_INTIN_REG		0x0014
+#define PLL_FRACIN_REG		0x0018
+#define PLL_REFDIV_REG		0x001c
+#define PLL_POSTDIV_REG		0x0020
+
+#define PLL_CONFIG_SEL		BIT(0)
+#define PLL_PLLEN		BIT(4)
+#define PLL_BYPASS		BIT(16)
+#define PLL_INTIN_MASK		GENMASK(11, 0)
+#define PLL_FRACIN_MASK		GENMASK(23, 0)
+#define PLL_REFDIV_MASK		GENMASK(5, 0)
+#define PLL_POSTDIV_MASK	GENMASK(2, 0)
+
+#define PLL0_FRACMODE_DACEN	BIT(4)
+#define PLL0_FRACMODE_DSMEN	BIT(0)
+
+#define PLL_CREATE_FRACMODE(table) (table->dacen << 4 | table->dsmen)
+#define PLL_CREATE_OSTDIV(table) (table->postdiv2 << 4 | table->postdiv1)
+
+static inline struct visconti_pll *to_visconti_pll(struct clk_hw *hw)
+{
+	return container_of(hw, struct visconti_pll, hw);
+}
+
+static void visconti_pll_get_params(struct visconti_pll *pll,
+				    struct visconti_pll_rate_table *rate_table)
+{
+	u32 postdiv, val;
+
+	val = readl(pll->pll_base + PLL_FRACMODE_REG);
+
+	rate_table->dacen = FIELD_GET(PLL0_FRACMODE_DACEN, val);
+	rate_table->dsmen = FIELD_GET(PLL0_FRACMODE_DSMEN, val);
+
+	rate_table->fracin = readl(pll->pll_base + PLL_FRACIN_REG) & PLL_FRACIN_MASK;
+	rate_table->intin = readl(pll->pll_base + PLL_INTIN_REG) & PLL_INTIN_MASK;
+	rate_table->refdiv = readl(pll->pll_base + PLL_REFDIV_REG) & PLL_REFDIV_MASK;
+
+	postdiv = readl(pll->pll_base + PLL_POSTDIV_REG);
+	rate_table->postdiv1 = postdiv & PLL_POSTDIV_MASK;
+	rate_table->postdiv2 = (postdiv >> 4) & PLL_POSTDIV_MASK;
+}
+
+static const struct visconti_pll_rate_table *visconti_get_pll_settings(struct visconti_pll *pll,
+								       unsigned long rate)
+{
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	for (i = 0; i < pll->rate_count; i++)
+		if (rate == rate_table[i].rate)
+			return &rate_table[i];
+
+	return NULL;
+}
+
+static unsigned long visconti_get_pll_rate_from_data(struct visconti_pll *pll,
+						     const struct visconti_pll_rate_table *rate)
+{
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	for (i = 0; i < pll->rate_count; i++)
+		if (memcmp(&rate_table[i].dacen, &rate->dacen,
+			sizeof(*rate) - sizeof(unsigned long)) == 0)
+			return rate_table[i].rate;
+
+	/* set default */
+	return rate_table[0].rate;
+}
+
+static long visconti_pll_round_rate(struct clk_hw *hw,
+				    unsigned long rate, unsigned long *prate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	/* Assumming rate_table is in descending order */
+	for (i = 0; i < pll->rate_count; i++)
+		if (rate >= rate_table[i].rate)
+			return rate_table[i].rate;
+
+	/* return minimum supported value */
+	return rate_table[i - 1].rate;
+}
+
+static unsigned long visconti_pll_recalc_rate(struct clk_hw *hw,
+					      unsigned long parent_rate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	struct visconti_pll_rate_table rate_table;
+
+	memset(&rate_table, 0, sizeof(rate_table));
+	visconti_pll_get_params(pll, &rate_table);
+
+	return visconti_get_pll_rate_from_data(pll, &rate_table);
+}
+
+static int visconti_pll_set_params(struct visconti_pll *pll,
+				   const struct visconti_pll_rate_table *rate_table)
+{
+	writel(PLL_CREATE_FRACMODE(rate_table), pll->pll_base + PLL_FRACMODE_REG);
+	writel(PLL_CREATE_OSTDIV(rate_table), pll->pll_base + PLL_POSTDIV_REG);
+	writel(rate_table->intin, pll->pll_base + PLL_INTIN_REG);
+	writel(rate_table->fracin, pll->pll_base + PLL_FRACIN_REG);
+	writel(rate_table->refdiv, pll->pll_base + PLL_REFDIV_REG);
+
+	return 0;
+}
+
+static int visconti_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table;
+
+	rate_table = visconti_get_pll_settings(pll, rate);
+	if (!rate_table)
+		return -EINVAL;
+
+	return visconti_pll_set_params(pll, rate_table);
+}
+
+static int visconti_pll_is_enabled(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	u32 reg;
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+
+	return (reg & PLL_PLLEN);
+}
+
+static int visconti_pll_enable(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	unsigned long flags;
+	u32 reg;
+
+	if (visconti_pll_is_enabled(hw))
+		return 0;
+
+	spin_lock_irqsave(pll->lock, flags);
+
+	writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	visconti_pll_set_params(pll, &rate_table[0]);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	udelay(1);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	udelay(40);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	spin_unlock_irqrestore(pll->lock, flags);
+
+	return 0;
+}
+
+static void visconti_pll_disable(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	unsigned long flags;
+	u32 reg;
+
+	if (!visconti_pll_is_enabled(hw))
+		return;
+
+	spin_lock_irqsave(pll->lock, flags);
+
+	writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	spin_unlock_irqrestore(pll->lock, flags);
+}
+
+static const struct clk_ops visconti_pll_ops = {
+	.enable = visconti_pll_enable,
+	.disable = visconti_pll_disable,
+	.is_enabled = visconti_pll_is_enabled,
+	.round_rate = visconti_pll_round_rate,
+	.recalc_rate = visconti_pll_recalc_rate,
+	.set_rate = visconti_pll_set_rate,
+};
+
+static struct clk_hw *visconti_register_pll(struct visconti_pll_provider *ctx,
+					    const char *name,
+					    const char *parent_name,
+					    int offset,
+					    const struct visconti_pll_rate_table *rate_table,
+					    spinlock_t *lock)
+{
+	struct clk_init_data init;
+	struct visconti_pll *pll;
+	struct clk_hw *pll_hw_clk;
+	size_t len;
+	int ret;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = CLK_IGNORE_UNUSED;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	for (len = 0; rate_table[len].rate != 0; )
+		len++;
+	pll->rate_count = len;
+	pll->rate_table = kmemdup(rate_table,
+				  pll->rate_count * sizeof(struct visconti_pll_rate_table),
+				  GFP_KERNEL);
+	WARN(!pll->rate_table, "%s: could not allocate rate table for %s\n", __func__, name);
+
+	init.ops = &visconti_pll_ops;
+	pll->hw.init = &init;
+	pll->pll_base = ctx->reg_base + offset;
+	pll->lock = lock;
+	pll->ctx = ctx;
+
+	pll_hw_clk = &pll->hw;
+	ret = clk_hw_register(NULL, &pll->hw);
+	if (ret) {
+		pr_err("failed to register pll clock %s : %d\n", name, ret);
+		kfree(pll->rate_table);
+		kfree(pll);
+		pll_hw_clk = ERR_PTR(ret);
+	}
+
+	return pll_hw_clk;
+}
+
+static void visconti_pll_add_lookup(struct visconti_pll_provider *ctx,
+				    struct clk_hw *hw_clk,
+				    unsigned int id)
+{
+	if (id)
+		ctx->clk_data.hws[id] = hw_clk;
+}
+
+void __init visconti_register_plls(struct visconti_pll_provider *ctx,
+				   const struct visconti_pll_info *list,
+				   unsigned int nr_plls,
+				   spinlock_t *lock)
+{
+	int idx;
+
+	for (idx = 0; idx < nr_plls; idx++, list++) {
+		struct clk_hw *clk;
+
+		clk = visconti_register_pll(ctx,
+					    list->name,
+					    list->parent,
+					    list->base_reg,
+					    list->rate_table,
+					    lock);
+		if (IS_ERR(clk)) {
+			pr_err("failed to register clock %s\n", list->name);
+			continue;
+		}
+
+		visconti_pll_add_lookup(ctx, clk, list->id);
+	}
+}
+
+struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np,
+							void __iomem *base,
+							unsigned long nr_plls)
+{
+	struct visconti_pll_provider *ctx;
+	int i;
+
+	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_plls), GFP_KERNEL);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_plls; ++i)
+		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
+
+	ctx->node = np;
+	ctx->reg_base = base;
+	ctx->clk_data.num = nr_plls;
+
+	return ctx;
+}