clk: imx: Rename the SCCG to SSCG

According to the manual the acronym stands for
Spread Sprectum Clock Generator.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

1 files changed, 549 insertions, 0 deletions

diff --git a/drivers/clk/imx/clk-sscg-pll.c b/drivers/clk/imx/clk-sscg-pll.c
new file mode 100644
index 000000000000..0669e172d46f
--- /dev/null
+++ b/drivers/clk/imx/clk-sscg-pll.c
@@ -0,0 +1,549 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Copyright 2018 NXP.
+ *
+ * This driver supports the SCCG plls found in the imx8m SOCs
+ *
+ * Documentation for this SCCG pll can be found at:
+ *   https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/slab.h>
+#include <linux/bitfield.h>
+
+#include "clk.h"
+
+/* PLL CFGs */
+#define PLL_CFG0		0x0
+#define PLL_CFG1		0x4
+#define PLL_CFG2		0x8
+
+#define PLL_DIVF1_MASK		GENMASK(18, 13)
+#define PLL_DIVF2_MASK		GENMASK(12, 7)
+#define PLL_DIVR1_MASK		GENMASK(27, 25)
+#define PLL_DIVR2_MASK		GENMASK(24, 19)
+#define PLL_DIVQ_MASK           GENMASK(6, 1)
+#define PLL_REF_MASK		GENMASK(2, 0)
+
+#define PLL_LOCK_MASK		BIT(31)
+#define PLL_PD_MASK		BIT(7)
+
+/* These are the specification limits for the SSCG PLL */
+#define PLL_REF_MIN_FREQ		25000000UL
+#define PLL_REF_MAX_FREQ		235000000UL
+
+#define PLL_STAGE1_MIN_FREQ		1600000000UL
+#define PLL_STAGE1_MAX_FREQ		2400000000UL
+
+#define PLL_STAGE1_REF_MIN_FREQ		25000000UL
+#define PLL_STAGE1_REF_MAX_FREQ		54000000UL
+
+#define PLL_STAGE2_MIN_FREQ		1200000000UL
+#define PLL_STAGE2_MAX_FREQ		2400000000UL
+
+#define PLL_STAGE2_REF_MIN_FREQ		54000000UL
+#define PLL_STAGE2_REF_MAX_FREQ		75000000UL
+
+#define PLL_OUT_MIN_FREQ		20000000UL
+#define PLL_OUT_MAX_FREQ		1200000000UL
+
+#define PLL_DIVR1_MAX			7
+#define PLL_DIVR2_MAX			63
+#define PLL_DIVF1_MAX			63
+#define PLL_DIVF2_MAX			63
+#define PLL_DIVQ_MAX			63
+
+#define PLL_BYPASS_NONE			0x0
+#define PLL_BYPASS1			0x2
+#define PLL_BYPASS2			0x1
+
+#define SSCG_PLL_BYPASS1_MASK           BIT(5)
+#define SSCG_PLL_BYPASS2_MASK           BIT(4)
+#define SSCG_PLL_BYPASS_MASK		GENMASK(5, 4)
+
+#define PLL_SCCG_LOCK_TIMEOUT		70
+
+struct clk_sscg_pll_setup {
+	int divr1, divf1;
+	int divr2, divf2;
+	int divq;
+	int bypass;
+
+	uint64_t vco1;
+	uint64_t vco2;
+	uint64_t fout;
+	uint64_t ref;
+	uint64_t ref_div1;
+	uint64_t ref_div2;
+	uint64_t fout_request;
+	int fout_error;
+};
+
+struct clk_sscg_pll {
+	struct clk_hw	hw;
+	const struct clk_ops  ops;
+
+	void __iomem *base;
+
+	struct clk_sscg_pll_setup setup;
+
+	u8 parent;
+	u8 bypass1;
+	u8 bypass2;
+};
+
+#define to_clk_sscg_pll(_hw) container_of(_hw, struct clk_sscg_pll, hw)
+
+static int clk_sscg_pll_wait_lock(struct clk_sscg_pll *pll)
+{
+	u32 val;
+
+	val = readl_relaxed(pll->base + PLL_CFG0);
+
+	/* don't wait for lock if all plls are bypassed */
+	if (!(val & SSCG_PLL_BYPASS2_MASK))
+		return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK,
+						0, PLL_SCCG_LOCK_TIMEOUT);
+
+	return 0;
+}
+
+static int clk_sscg_pll2_check_match(struct clk_sscg_pll_setup *setup,
+					struct clk_sscg_pll_setup *temp_setup)
+{
+	int new_diff = temp_setup->fout - temp_setup->fout_request;
+	int diff = temp_setup->fout_error;
+
+	if (abs(diff) > abs(new_diff)) {
+		temp_setup->fout_error = new_diff;
+		memcpy(setup, temp_setup, sizeof(struct clk_sscg_pll_setup));
+
+		if (temp_setup->fout_request == temp_setup->fout)
+			return 0;
+	}
+	return -1;
+}
+
+static int clk_sscg_divq_lookup(struct clk_sscg_pll_setup *setup,
+				struct clk_sscg_pll_setup *temp_setup)
+{
+	int ret = -EINVAL;
+
+	for (temp_setup->divq = 0; temp_setup->divq <= PLL_DIVQ_MAX;
+	     temp_setup->divq++) {
+		temp_setup->vco2 = temp_setup->vco1;
+		do_div(temp_setup->vco2, temp_setup->divr2 + 1);
+		temp_setup->vco2 *= 2;
+		temp_setup->vco2 *= temp_setup->divf2 + 1;
+		if (temp_setup->vco2 >= PLL_STAGE2_MIN_FREQ &&
+				temp_setup->vco2 <= PLL_STAGE2_MAX_FREQ) {
+			temp_setup->fout = temp_setup->vco2;
+			do_div(temp_setup->fout, 2 * (temp_setup->divq + 1));
+
+			ret = clk_sscg_pll2_check_match(setup, temp_setup);
+			if (!ret) {
+				temp_setup->bypass = PLL_BYPASS1;
+				return ret;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static int clk_sscg_divf2_lookup(struct clk_sscg_pll_setup *setup,
+					struct clk_sscg_pll_setup *temp_setup)
+{
+	int ret = -EINVAL;
+
+	for (temp_setup->divf2 = 0; temp_setup->divf2 <= PLL_DIVF2_MAX;
+	     temp_setup->divf2++) {
+		ret = clk_sscg_divq_lookup(setup, temp_setup);
+		if (!ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int clk_sscg_divr2_lookup(struct clk_sscg_pll_setup *setup,
+				struct clk_sscg_pll_setup *temp_setup)
+{
+	int ret = -EINVAL;
+
+	for (temp_setup->divr2 = 0; temp_setup->divr2 <= PLL_DIVR2_MAX;
+	     temp_setup->divr2++) {
+		temp_setup->ref_div2 = temp_setup->vco1;
+		do_div(temp_setup->ref_div2, temp_setup->divr2 + 1);
+		if (temp_setup->ref_div2 >= PLL_STAGE2_REF_MIN_FREQ &&
+		    temp_setup->ref_div2 <= PLL_STAGE2_REF_MAX_FREQ) {
+			ret = clk_sscg_divf2_lookup(setup, temp_setup);
+			if (!ret)
+				return ret;
+		}
+	}
+
+	return ret;
+}
+
+static int clk_sscg_pll2_find_setup(struct clk_sscg_pll_setup *setup,
+					struct clk_sscg_pll_setup *temp_setup,
+					uint64_t ref)
+{
+
+	int ret = -EINVAL;
+
+	if (ref < PLL_STAGE1_MIN_FREQ || ref > PLL_STAGE1_MAX_FREQ)
+		return ret;
+
+	temp_setup->vco1 = ref;
+
+	ret = clk_sscg_divr2_lookup(setup, temp_setup);
+	return ret;
+}
+
+static int clk_sscg_divf1_lookup(struct clk_sscg_pll_setup *setup,
+				struct clk_sscg_pll_setup *temp_setup)
+{
+	int ret = -EINVAL;
+
+	for (temp_setup->divf1 = 0; temp_setup->divf1 <= PLL_DIVF1_MAX;
+	     temp_setup->divf1++) {
+		uint64_t vco1 = temp_setup->ref;
+
+		do_div(vco1, temp_setup->divr1 + 1);
+		vco1 *= 2;
+		vco1 *= temp_setup->divf1 + 1;
+
+		ret = clk_sscg_pll2_find_setup(setup, temp_setup, vco1);
+		if (!ret) {
+			temp_setup->bypass = PLL_BYPASS_NONE;
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+static int clk_sscg_divr1_lookup(struct clk_sscg_pll_setup *setup,
+				struct clk_sscg_pll_setup *temp_setup)
+{
+	int ret = -EINVAL;
+
+	for (temp_setup->divr1 = 0; temp_setup->divr1 <= PLL_DIVR1_MAX;
+	     temp_setup->divr1++) {
+		temp_setup->ref_div1 = temp_setup->ref;
+		do_div(temp_setup->ref_div1, temp_setup->divr1 + 1);
+		if (temp_setup->ref_div1 >= PLL_STAGE1_REF_MIN_FREQ &&
+		    temp_setup->ref_div1 <= PLL_STAGE1_REF_MAX_FREQ) {
+			ret = clk_sscg_divf1_lookup(setup, temp_setup);
+			if (!ret)
+				return ret;
+		}
+	}
+
+	return ret;
+}
+
+static int clk_sscg_pll1_find_setup(struct clk_sscg_pll_setup *setup,
+					struct clk_sscg_pll_setup *temp_setup,
+					uint64_t ref)
+{
+
+	int ret = -EINVAL;
+
+	if (ref < PLL_REF_MIN_FREQ || ref > PLL_REF_MAX_FREQ)
+		return ret;
+
+	temp_setup->ref = ref;
+
+	ret = clk_sscg_divr1_lookup(setup, temp_setup);
+
+	return ret;
+}
+
+static int clk_sscg_pll_find_setup(struct clk_sscg_pll_setup *setup,
+					uint64_t prate,
+					uint64_t rate, int try_bypass)
+{
+	struct clk_sscg_pll_setup temp_setup;
+	int ret = -EINVAL;
+
+	memset(&temp_setup, 0, sizeof(struct clk_sscg_pll_setup));
+	memset(setup, 0, sizeof(struct clk_sscg_pll_setup));
+
+	temp_setup.fout_error = PLL_OUT_MAX_FREQ;
+	temp_setup.fout_request = rate;
+
+	switch (try_bypass) {
+
+	case PLL_BYPASS2:
+		if (prate == rate) {
+			setup->bypass = PLL_BYPASS2;
+			setup->fout = rate;
+			ret = 0;
+		}
+		break;
+
+	case PLL_BYPASS1:
+		ret = clk_sscg_pll2_find_setup(setup, &temp_setup, prate);
+		break;
+
+	case PLL_BYPASS_NONE:
+		ret = clk_sscg_pll1_find_setup(setup, &temp_setup, prate);
+		break;
+	}
+
+	return ret;
+}
+
+
+static int clk_sscg_pll_is_prepared(struct clk_hw *hw)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+
+	u32 val = readl_relaxed(pll->base + PLL_CFG0);
+
+	return (val & PLL_PD_MASK) ? 0 : 1;
+}
+
+static int clk_sscg_pll_prepare(struct clk_hw *hw)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	u32 val;
+
+	val = readl_relaxed(pll->base + PLL_CFG0);
+	val &= ~PLL_PD_MASK;
+	writel_relaxed(val, pll->base + PLL_CFG0);
+
+	return clk_sscg_pll_wait_lock(pll);
+}
+
+static void clk_sscg_pll_unprepare(struct clk_hw *hw)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	u32 val;
+
+	val = readl_relaxed(pll->base + PLL_CFG0);
+	val |= PLL_PD_MASK;
+	writel_relaxed(val, pll->base + PLL_CFG0);
+}
+
+static unsigned long clk_sscg_pll_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	u32 val, divr1, divf1, divr2, divf2, divq;
+	u64 temp64;
+
+	val = readl_relaxed(pll->base + PLL_CFG2);
+	divr1 = FIELD_GET(PLL_DIVR1_MASK, val);
+	divr2 = FIELD_GET(PLL_DIVR2_MASK, val);
+	divf1 = FIELD_GET(PLL_DIVF1_MASK, val);
+	divf2 = FIELD_GET(PLL_DIVF2_MASK, val);
+	divq = FIELD_GET(PLL_DIVQ_MASK, val);
+
+	temp64 = parent_rate;
+
+	val = readl(pll->base + PLL_CFG0);
+	if (val & SSCG_PLL_BYPASS2_MASK) {
+		temp64 = parent_rate;
+	} else if (val & SSCG_PLL_BYPASS1_MASK) {
+		temp64 *= divf2;
+		do_div(temp64, (divr2 + 1) * (divq + 1));
+	} else {
+		temp64 *= 2;
+		temp64 *= (divf1 + 1) * (divf2 + 1);
+		do_div(temp64, (divr1 + 1) * (divr2 + 1) * (divq + 1));
+	}
+
+	return temp64;
+}
+
+static int clk_sscg_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	struct clk_sscg_pll_setup *setup = &pll->setup;
+	u32 val;
+
+	/* set bypass here too since the parent might be the same */
+	val = readl(pll->base + PLL_CFG0);
+	val &= ~SSCG_PLL_BYPASS_MASK;
+	val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, setup->bypass);
+	writel(val, pll->base + PLL_CFG0);
+
+	val = readl_relaxed(pll->base + PLL_CFG2);
+	val &= ~(PLL_DIVF1_MASK | PLL_DIVF2_MASK);
+	val &= ~(PLL_DIVR1_MASK | PLL_DIVR2_MASK | PLL_DIVQ_MASK);
+	val |= FIELD_PREP(PLL_DIVF1_MASK, setup->divf1);
+	val |= FIELD_PREP(PLL_DIVF2_MASK, setup->divf2);
+	val |= FIELD_PREP(PLL_DIVR1_MASK, setup->divr1);
+	val |= FIELD_PREP(PLL_DIVR2_MASK, setup->divr2);
+	val |= FIELD_PREP(PLL_DIVQ_MASK, setup->divq);
+	writel_relaxed(val, pll->base + PLL_CFG2);
+
+	return clk_sscg_pll_wait_lock(pll);
+}
+
+static u8 clk_sscg_pll_get_parent(struct clk_hw *hw)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	u32 val;
+	u8 ret = pll->parent;
+
+	val = readl(pll->base + PLL_CFG0);
+	if (val & SSCG_PLL_BYPASS2_MASK)
+		ret = pll->bypass2;
+	else if (val & SSCG_PLL_BYPASS1_MASK)
+		ret = pll->bypass1;
+	return ret;
+}
+
+static int clk_sscg_pll_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	u32 val;
+
+	val = readl(pll->base + PLL_CFG0);
+	val &= ~SSCG_PLL_BYPASS_MASK;
+	val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, pll->setup.bypass);
+	writel(val, pll->base + PLL_CFG0);
+
+	return clk_sscg_pll_wait_lock(pll);
+}
+
+static int __clk_sscg_pll_determine_rate(struct clk_hw *hw,
+					struct clk_rate_request *req,
+					uint64_t min,
+					uint64_t max,
+					uint64_t rate,
+					int bypass)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	struct clk_sscg_pll_setup *setup = &pll->setup;
+	struct clk_hw *parent_hw = NULL;
+	int bypass_parent_index;
+	int ret = -EINVAL;
+
+	req->max_rate = max;
+	req->min_rate = min;
+
+	switch (bypass) {
+	case PLL_BYPASS2:
+		bypass_parent_index = pll->bypass2;
+		break;
+	case PLL_BYPASS1:
+		bypass_parent_index = pll->bypass1;
+		break;
+	default:
+		bypass_parent_index = pll->parent;
+		break;
+	}
+
+	parent_hw = clk_hw_get_parent_by_index(hw, bypass_parent_index);
+	ret = __clk_determine_rate(parent_hw, req);
+	if (!ret) {
+		ret = clk_sscg_pll_find_setup(setup, req->rate,
+						rate, bypass);
+	}
+
+	req->best_parent_hw = parent_hw;
+	req->best_parent_rate = req->rate;
+	req->rate = setup->fout;
+
+	return ret;
+}
+
+static int clk_sscg_pll_determine_rate(struct clk_hw *hw,
+				       struct clk_rate_request *req)
+{
+	struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+	struct clk_sscg_pll_setup *setup = &pll->setup;
+	uint64_t rate = req->rate;
+	uint64_t min = req->min_rate;
+	uint64_t max = req->max_rate;
+	int ret = -EINVAL;
+
+	if (rate < PLL_OUT_MIN_FREQ || rate > PLL_OUT_MAX_FREQ)
+		return ret;
+
+	ret = __clk_sscg_pll_determine_rate(hw, req, req->rate, req->rate,
+						rate, PLL_BYPASS2);
+	if (!ret)
+		return ret;
+
+	ret = __clk_sscg_pll_determine_rate(hw, req, PLL_STAGE1_REF_MIN_FREQ,
+						PLL_STAGE1_REF_MAX_FREQ, rate,
+						PLL_BYPASS1);
+	if (!ret)
+		return ret;
+
+	ret = __clk_sscg_pll_determine_rate(hw, req, PLL_REF_MIN_FREQ,
+						PLL_REF_MAX_FREQ, rate,
+						PLL_BYPASS_NONE);
+	if (!ret)
+		return ret;
+
+	if (setup->fout >= min && setup->fout <= max)
+		ret = 0;
+
+	return ret;
+}
+
+static const struct clk_ops clk_sscg_pll_ops = {
+	.prepare	= clk_sscg_pll_prepare,
+	.unprepare	= clk_sscg_pll_unprepare,
+	.is_prepared	= clk_sscg_pll_is_prepared,
+	.recalc_rate	= clk_sscg_pll_recalc_rate,
+	.set_rate	= clk_sscg_pll_set_rate,
+	.set_parent	= clk_sscg_pll_set_parent,
+	.get_parent	= clk_sscg_pll_get_parent,
+	.determine_rate	= clk_sscg_pll_determine_rate,
+};
+
+struct clk *imx_clk_sscg_pll(const char *name,
+				const char * const *parent_names,
+				u8 num_parents,
+				u8 parent, u8 bypass1, u8 bypass2,
+				void __iomem *base,
+				unsigned long flags)
+{
+	struct clk_sscg_pll *pll;
+	struct clk_init_data init;
+	struct clk_hw *hw;
+	int ret;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	pll->parent = parent;
+	pll->bypass1 = bypass1;
+	pll->bypass2 = bypass2;
+
+	pll->base = base;
+	init.name = name;
+	init.ops = &clk_sscg_pll_ops;
+
+	init.flags = flags;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	pll->base = base;
+	pll->hw.init = &init;
+
+	hw = &pll->hw;
+
+	ret = clk_hw_register(NULL, hw);
+	if (ret) {
+		kfree(pll);
+		return ERR_PTR(ret);
+	}
+
+	return hw->clk;
+}