1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c
new file mode 100644
index 000000000..249d6a53c
--- /dev/null
+++ b/drivers/clk/at91/clk-pll.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+#define PLL_STATUS_MASK(id)	(1 << (1 + (id)))
+#define PLL_REG(id)		(AT91_CKGR_PLLAR + ((id) * 4))
+#define PLL_DIV_MASK		0xff
+#define PLL_DIV_MAX		PLL_DIV_MASK
+#define PLL_DIV(reg)		((reg) & PLL_DIV_MASK)
+#define PLL_MUL(reg, layout)	(((reg) >> (layout)->mul_shift) & \
+				 (layout)->mul_mask)
+#define PLL_MUL_MIN		2
+#define PLL_MUL_MASK(layout)	((layout)->mul_mask)
+#define PLL_MUL_MAX(layout)	(PLL_MUL_MASK(layout) + 1)
+#define PLL_ICPR_SHIFT(id)	((id) * 16)
+#define PLL_ICPR_MASK(id)	(0xffff << PLL_ICPR_SHIFT(id))
+#define PLL_MAX_COUNT		0x3f
+#define PLL_COUNT_SHIFT		8
+#define PLL_OUT_SHIFT		14
+#define PLL_MAX_ID		1
+
+#define to_clk_pll(hw) container_of(hw, struct clk_pll, hw)
+
+struct clk_pll {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u8 id;
+	u8 div;
+	u8 range;
+	u16 mul;
+	const struct clk_pll_layout *layout;
+	const struct clk_pll_characteristics *characteristics;
+	struct at91_clk_pms pms;
+};
+
+static inline bool clk_pll_ready(struct regmap *regmap, int id)
+{
+	unsigned int status;
+
+	regmap_read(regmap, AT91_PMC_SR, &status);
+
+	return status & PLL_STATUS_MASK(id) ? 1 : 0;
+}
+
+static int clk_pll_prepare(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	struct regmap *regmap = pll->regmap;
+	const struct clk_pll_layout *layout = pll->layout;
+	const struct clk_pll_characteristics *characteristics =
+							pll->characteristics;
+	u8 id = pll->id;
+	u32 mask = PLL_STATUS_MASK(id);
+	int offset = PLL_REG(id);
+	u8 out = 0;
+	unsigned int pllr;
+	unsigned int status;
+	u8 div;
+	u16 mul;
+
+	regmap_read(regmap, offset, &pllr);
+	div = PLL_DIV(pllr);
+	mul = PLL_MUL(pllr, layout);
+
+	regmap_read(regmap, AT91_PMC_SR, &status);
+	if ((status & mask) &&
+	    (div == pll->div && mul == pll->mul))
+		return 0;
+
+	if (characteristics->out)
+		out = characteristics->out[pll->range];
+
+	if (characteristics->icpll)
+		regmap_update_bits(regmap, AT91_PMC_PLLICPR, PLL_ICPR_MASK(id),
+			characteristics->icpll[pll->range] << PLL_ICPR_SHIFT(id));
+
+	regmap_update_bits(regmap, offset, layout->pllr_mask,
+			pll->div | (PLL_MAX_COUNT << PLL_COUNT_SHIFT) |
+			(out << PLL_OUT_SHIFT) |
+			((pll->mul & layout->mul_mask) << layout->mul_shift));
+
+	while (!clk_pll_ready(regmap, pll->id))
+		cpu_relax();
+
+	return 0;
+}
+
+static int clk_pll_is_prepared(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+
+	return clk_pll_ready(pll->regmap, pll->id);
+}
+
+static void clk_pll_unprepare(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	unsigned int mask = pll->layout->pllr_mask;
+
+	regmap_update_bits(pll->regmap, PLL_REG(pll->id), mask, ~mask);
+}
+
+static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+
+	if (!pll->div || !pll->mul)
+		return 0;
+
+	return (parent_rate / pll->div) * (pll->mul + 1);
+}
+
+static long clk_pll_get_best_div_mul(struct clk_pll *pll, unsigned long rate,
+				     unsigned long parent_rate,
+				     u32 *div, u32 *mul,
+				     u32 *index) {
+	const struct clk_pll_layout *layout = pll->layout;
+	const struct clk_pll_characteristics *characteristics =
+							pll->characteristics;
+	unsigned long bestremainder = ULONG_MAX;
+	unsigned long maxdiv, mindiv, tmpdiv;
+	long bestrate = -ERANGE;
+	unsigned long bestdiv;
+	unsigned long bestmul;
+	int i = 0;
+
+	/* Check if parent_rate is a valid input rate */
+	if (parent_rate < characteristics->input.min)
+		return -ERANGE;
+
+	/*
+	 * Calculate minimum divider based on the minimum multiplier, the
+	 * parent_rate and the requested rate.
+	 * Should always be 2 according to the input and output characteristics
+	 * of the PLL blocks.
+	 */
+	mindiv = (parent_rate * PLL_MUL_MIN) / rate;
+	if (!mindiv)
+		mindiv = 1;
+
+	if (parent_rate > characteristics->input.max) {
+		tmpdiv = DIV_ROUND_UP(parent_rate, characteristics->input.max);
+		if (tmpdiv > PLL_DIV_MAX)
+			return -ERANGE;
+
+		if (tmpdiv > mindiv)
+			mindiv = tmpdiv;
+	}
+
+	/*
+	 * Calculate the maximum divider which is limited by PLL register
+	 * layout (limited by the MUL or DIV field size).
+	 */
+	maxdiv = DIV_ROUND_UP(parent_rate * PLL_MUL_MAX(layout), rate);
+	if (maxdiv > PLL_DIV_MAX)
+		maxdiv = PLL_DIV_MAX;
+
+	/*
+	 * Iterate over the acceptable divider values to find the best
+	 * divider/multiplier pair (the one that generates the closest
+	 * rate to the requested one).
+	 */
+	for (tmpdiv = mindiv; tmpdiv <= maxdiv; tmpdiv++) {
+		unsigned long remainder;
+		unsigned long tmprate;
+		unsigned long tmpmul;
+
+		/*
+		 * Calculate the multiplier associated with the current
+		 * divider that provide the closest rate to the requested one.
+		 */
+		tmpmul = DIV_ROUND_CLOSEST(rate, parent_rate / tmpdiv);
+		tmprate = (parent_rate / tmpdiv) * tmpmul;
+		if (tmprate > rate)
+			remainder = tmprate - rate;
+		else
+			remainder = rate - tmprate;
+
+		/*
+		 * Compare the remainder with the best remainder found until
+		 * now and elect a new best multiplier/divider pair if the
+		 * current remainder is smaller than the best one.
+		 */
+		if (remainder < bestremainder) {
+			bestremainder = remainder;
+			bestdiv = tmpdiv;
+			bestmul = tmpmul;
+			bestrate = tmprate;
+		}
+
+		/*
+		 * We've found a perfect match!
+		 * Stop searching now and use this multiplier/divider pair.
+		 */
+		if (!remainder)
+			break;
+	}
+
+	/* We haven't found any multiplier/divider pair => return -ERANGE */
+	if (bestrate < 0)
+		return bestrate;
+
+	/* Check if bestrate is a valid output rate  */
+	for (i = 0; i < characteristics->num_output; i++) {
+		if (bestrate >= characteristics->output[i].min &&
+		    bestrate <= characteristics->output[i].max)
+			break;
+	}
+
+	if (i >= characteristics->num_output)
+		return -ERANGE;
+
+	if (div)
+		*div = bestdiv;
+	if (mul)
+		*mul = bestmul - 1;
+	if (index)
+		*index = i;
+
+	return bestrate;
+}
+
+static long clk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+					unsigned long *parent_rate)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+
+	return clk_pll_get_best_div_mul(pll, rate, *parent_rate,
+					NULL, NULL, NULL);
+}
+
+static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	long ret;
+	u32 div;
+	u32 mul;
+	u32 index;
+
+	ret = clk_pll_get_best_div_mul(pll, rate, parent_rate,
+				       &div, &mul, &index);
+	if (ret < 0)
+		return ret;
+
+	pll->range = index;
+	pll->div = div;
+	pll->mul = mul;
+
+	return 0;
+}
+
+static int clk_pll_save_context(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	struct clk_hw *parent_hw = clk_hw_get_parent(hw);
+
+	pll->pms.parent_rate = clk_hw_get_rate(parent_hw);
+	pll->pms.rate = clk_pll_recalc_rate(&pll->hw, pll->pms.parent_rate);
+	pll->pms.status = clk_pll_ready(pll->regmap, PLL_REG(pll->id));
+
+	return 0;
+}
+
+static void clk_pll_restore_context(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	unsigned long calc_rate;
+	unsigned int pllr, pllr_out, pllr_count;
+	u8 out = 0;
+
+	if (pll->characteristics->out)
+		out = pll->characteristics->out[pll->range];
+
+	regmap_read(pll->regmap, PLL_REG(pll->id), &pllr);
+
+	calc_rate = (pll->pms.parent_rate / PLL_DIV(pllr)) *
+		     (PLL_MUL(pllr, pll->layout) + 1);
+	pllr_count = (pllr >> PLL_COUNT_SHIFT) & PLL_MAX_COUNT;
+	pllr_out = (pllr >> PLL_OUT_SHIFT) & out;
+
+	if (pll->pms.rate != calc_rate ||
+	    pll->pms.status != clk_pll_ready(pll->regmap, PLL_REG(pll->id)) ||
+	    pllr_count != PLL_MAX_COUNT ||
+	    (out && pllr_out != out))
+		pr_warn("PLLAR was not configured properly by firmware\n");
+}
+
+static const struct clk_ops pll_ops = {
+	.prepare = clk_pll_prepare,
+	.unprepare = clk_pll_unprepare,
+	.is_prepared = clk_pll_is_prepared,
+	.recalc_rate = clk_pll_recalc_rate,
+	.round_rate = clk_pll_round_rate,
+	.set_rate = clk_pll_set_rate,
+	.save_context = clk_pll_save_context,
+	.restore_context = clk_pll_restore_context,
+};
+
+struct clk_hw * __init
+at91_clk_register_pll(struct regmap *regmap, const char *name,
+		      const char *parent_name, u8 id,
+		      const struct clk_pll_layout *layout,
+		      const struct clk_pll_characteristics *characteristics)
+{
+	struct clk_pll *pll;
+	struct clk_hw *hw;
+	struct clk_init_data init;
+	int offset = PLL_REG(id);
+	unsigned int pllr;
+	int ret;
+
+	if (id > PLL_MAX_ID)
+		return ERR_PTR(-EINVAL);
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &pll_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_GATE;
+
+	pll->id = id;
+	pll->hw.init = &init;
+	pll->layout = layout;
+	pll->characteristics = characteristics;
+	pll->regmap = regmap;
+	regmap_read(regmap, offset, &pllr);
+	pll->div = PLL_DIV(pllr);
+	pll->mul = PLL_MUL(pllr, layout);
+
+	hw = &pll->hw;
+	ret = clk_hw_register(NULL, &pll->hw);
+	if (ret) {
+		kfree(pll);
+		hw = ERR_PTR(ret);
+	}
+
+	return hw;
+}
+
+
+const struct clk_pll_layout at91rm9200_pll_layout = {
+	.pllr_mask = 0x7FFFFFF,
+	.mul_shift = 16,
+	.mul_mask = 0x7FF,
+};
+
+const struct clk_pll_layout at91sam9g45_pll_layout = {
+	.pllr_mask = 0xFFFFFF,
+	.mul_shift = 16,
+	.mul_mask = 0xFF,
+};
+
+const struct clk_pll_layout at91sam9g20_pllb_layout = {
+	.pllr_mask = 0x3FFFFF,
+	.mul_shift = 16,
+	.mul_mask = 0x3F,
+};
+
+const struct clk_pll_layout sama5d3_pll_layout = {
+	.pllr_mask = 0x1FFFFFF,
+	.mul_shift = 18,
+	.mul_mask = 0x7F,
+};