[PATCHv4 13/26] clk: add support for TI K3 SoC clocks

[Tero Kristo <kristo@kernel.org>]

From: Tero Kristo <t-kristo@ti.com>

Add driver to support TI K3 generation SoC clocks. This driver registers
the clocks provided via platform data, and adds support for controlling
the clocks via DT handles.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tero Kristo <kristo@kernel.org>
---
 drivers/clk/ti/Kconfig  |  12 ++
 drivers/clk/ti/Makefile |   1 +
 drivers/clk/ti/clk-k3.c | 374 ++++++++++++++++++++++++++++++++++++++++
 include/k3-clk.h        | 162 +++++++++++++++++
 4 files changed, 549 insertions(+)
 create mode 100644 drivers/clk/ti/clk-k3.c

diff --git a/drivers/clk/ti/Kconfig b/drivers/clk/ti/Kconfig
index a8ec4f541a..fbcdefd889 100644
--- a/drivers/clk/ti/Kconfig
+++ b/drivers/clk/ti/Kconfig
@@ -53,3 +53,15 @@ config SPL_CLK_K3_PLL
 	depends on CLK && LIB_RATIONAL && SPL
 	help
 	  Enables PLL clock support for K3 SoC family of devices.
+
+config CLK_K3
+	bool "Clock support for K3 SoC family of devices"
+	depends on CLK
+	help
+	  Enables the clock translation layer from DT to device clocks.
+
+config SPL_CLK_K3
+	bool "Clock support for K3 SoC family of devices"
+	depends on CLK && SPL
+	help
+	  Enables the clock translation layer from DT to device clocks.
diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
index 47839213e5..07aa9a53e0 100644
--- a/drivers/clk/ti/Makefile
+++ b/drivers/clk/ti/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_CLK_TI_GATE) += clk-gate.o
 obj-$(CONFIG_CLK_TI_MUX) += clk-mux.o
 obj-$(CONFIG_CLK_TI_SCI) += clk-sci.o
 obj-$(CONFIG_$(SPL_TPL_)CLK_K3_PLL) += clk-k3-pll.o
+obj-$(CONFIG_$(SPL_TPL_)CLK_K3) += clk-k3.o
diff --git a/drivers/clk/ti/clk-k3.c b/drivers/clk/ti/clk-k3.c
new file mode 100644
index 0000000000..ec262d5c21
--- /dev/null
+++ b/drivers/clk/ti/clk-k3.c
@@ -0,0 +1,374 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments K3 clock driver
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+ *	Tero Kristo <t-kristo@ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <soc.h>
+#include <clk-uclass.h>
+#include "k3-clk.h"
+
+#define PLL_MIN_FREQ	800000000
+#define PLL_MAX_FREQ	3200000000UL
+#define PLL_MAX_DIV	127
+
+/**
+ * struct clk_map - mapping from dev/clk id tuples towards physical clocks
+ * @dev_id: device ID for the clock
+ * @clk_id: clock ID for the clock
+ * @clk: pointer to the registered clock entry for the mapping
+ */
+struct clk_map {
+	u16 dev_id;
+	u32 clk_id;
+	struct clk *clk;
+};
+
+/**
+ * struct ti_clk_data - clock controller information structure
+ * @map: mapping from dev/clk id tuples to physical clock entries
+ * @size: number of entries in the map
+ */
+struct ti_clk_data {
+	struct clk_map *map;
+	int size;
+};
+
+static ulong osc_freq;
+
+static void clk_add_map(struct ti_clk_data *data, struct clk *clk,
+			u32 dev_id, u32 clk_id)
+{
+	struct clk_map *map;
+
+	debug("%s: added clk=%p, data=%p, dev=%d, clk=%d\n", __func__,
+	      clk, data, dev_id, clk_id);
+	if (!clk)
+		return;
+
+	map = data->map + data->size++;
+
+	map->dev_id = dev_id;
+	map->clk_id = clk_id;
+	map->clk = clk;
+}
+
+static const struct soc_attr ti_k3_soc_clk_data[] = {
+#ifdef CONFIG_SOC_K3_J721E
+	{
+		.family = "J721E",
+		.data = &j721e_clk_platdata,
+	},
+	{
+		.family = "J7200",
+		.data = &j7200_clk_platdata,
+	},
+#endif
+	{ /* sentinel */ }
+};
+
+static int ti_clk_probe(struct udevice *dev)
+{
+	struct ti_clk_data *data = dev_get_priv(dev);
+	struct clk *clk;
+	const char *name;
+	const struct clk_data *ti_clk_data;
+	int i, j;
+	const struct soc_attr *soc_match_data;
+	const struct ti_k3_clk_platdata *pdata;
+
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	soc_match_data = soc_device_match(ti_k3_soc_clk_data);
+	if (!soc_match_data)
+		return -ENODEV;
+
+	pdata = (const struct ti_k3_clk_platdata *)soc_match_data->data;
+
+	data->map = kcalloc(pdata->soc_dev_clk_data_cnt, sizeof(*data->map),
+			    GFP_KERNEL);
+	data->size = 0;
+
+	for (i = 0; i < pdata->clk_list_cnt; i++) {
+		ti_clk_data = &pdata->clk_list[i];
+
+		switch (ti_clk_data->type) {
+		case CLK_TYPE_FIXED_RATE:
+			name = ti_clk_data->clk.fixed_rate.name;
+			clk = clk_register_fixed_rate(NULL,
+						      name,
+						      ti_clk_data->clk.fixed_rate.rate);
+			break;
+		case CLK_TYPE_DIV:
+			name = ti_clk_data->clk.div.name;
+			clk = clk_register_divider(NULL, name,
+						   ti_clk_data->clk.div.parent,
+						   ti_clk_data->clk.div.flags,
+						   map_physmem(ti_clk_data->clk.div.reg, 0, MAP_NOCACHE),
+						   ti_clk_data->clk.div.shift,
+						   ti_clk_data->clk.div.width,
+						   0);
+			break;
+		case CLK_TYPE_MUX:
+			name = ti_clk_data->clk.mux.name;
+			clk = clk_register_mux(NULL, name,
+					       ti_clk_data->clk.mux.parents,
+					       ti_clk_data->clk.mux.num_parents,
+					       ti_clk_data->clk.mux.flags,
+					       map_physmem(ti_clk_data->clk.mux.reg, 0, MAP_NOCACHE),
+					       ti_clk_data->clk.mux.shift,
+					       ti_clk_data->clk.mux.width,
+					       0);
+			break;
+		case CLK_TYPE_PLL:
+			name = ti_clk_data->clk.pll.name;
+			clk = clk_register_ti_pll(name,
+						  ti_clk_data->clk.pll.parent,
+						  map_physmem(ti_clk_data->clk.pll.reg, 0, MAP_NOCACHE));
+
+			if (!osc_freq)
+				osc_freq = clk_get_rate(clk_get_parent(clk));
+			break;
+		default:
+			name = NULL;
+			clk = NULL;
+			printf("WARNING: %s has encountered unknown clk type %d\n",
+			       __func__, ti_clk_data->type);
+		}
+
+		if (clk && ti_clk_data->default_freq)
+			clk_set_rate(clk, ti_clk_data->default_freq);
+
+		if (clk && name) {
+			for (j = 0; j < pdata->soc_dev_clk_data_cnt; j++) {
+				if (!strcmp(name, pdata->soc_dev_clk_data[j].clk_name)) {
+					clk_add_map(data, clk, pdata->soc_dev_clk_data[j].dev_id,
+						    pdata->soc_dev_clk_data[j].clk_id);
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int _clk_cmp(u32 dev_id, u32 clk_id, const struct clk_map *map)
+{
+	if (map->dev_id == dev_id && map->clk_id == clk_id)
+		return 0;
+	if (map->dev_id > dev_id ||
+	    (map->dev_id == dev_id && map->clk_id > clk_id))
+		return -1;
+	return 1;
+}
+
+static int bsearch(u32 dev_id, u32 clk_id, struct clk_map *map, int num)
+{
+	int result;
+	int idx;
+
+	for (idx = 0; idx < num; idx++) {
+		result = _clk_cmp(dev_id, clk_id, &map[idx]);
+
+		if (result == 0)
+			return idx;
+	}
+
+	return -ENOENT;
+}
+
+static int ti_clk_of_xlate(struct clk *clk,
+			   struct ofnode_phandle_args *args)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	int idx;
+
+	debug("%s(clk=%p, args_count=%d [0]=%d [1]=%d)\n", __func__, clk,
+	      args->args_count, args->args[0], args->args[1]);
+
+	if (args->args_count != 2) {
+		debug("Invalid args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	if (!data->size)
+		return -EPROBE_DEFER;
+
+	idx = bsearch(args->args[0], args->args[1], data->map, data->size);
+	if (idx < 0)
+		return idx;
+
+	clk->id = idx;
+
+	return 0;
+}
+
+static ulong ti_clk_get_rate(struct clk *clk)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	struct clk *clkp = data->map[clk->id].clk;
+
+	return clk_get_rate(clkp);
+}
+
+static ulong ti_clk_set_rate(struct clk *clk, ulong rate)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	struct clk *clkp = data->map[clk->id].clk;
+	int div = 1;
+	ulong child_rate;
+	const struct clk_ops *ops;
+	ulong new_rate, rem;
+	ulong diff, new_diff;
+
+	/*
+	 * We must propagate rate change to parent if current clock type
+	 * does not allow setting it.
+	 */
+	while (clkp) {
+		ops = clkp->dev->driver->ops;
+		if (ops->set_rate)
+			break;
+
+		/*
+		 * Store child rate so we can calculate the clock rate
+		 * that must be passed to parent
+		 */
+		child_rate = clk_get_rate(clkp);
+		clkp = clk_get_parent(clkp);
+		if (clkp) {
+			debug("%s: propagating rate change to parent %s, rate=%u.\n",
+			      __func__, clkp->dev->name, (u32)rate / div);
+			div *= clk_get_rate(clkp) / child_rate;
+		}
+	}
+
+	if (!clkp)
+		return -ENOSYS;
+
+	child_rate = clk_get_rate(clkp);
+
+	new_rate = clk_set_rate(clkp, rate / div);
+
+	diff = abs(new_rate - rate / div);
+
+	debug("%s: clk=%s, div=%d, rate=%u, new_rate=%u, diff=%u\n", __func__,
+	      clkp->dev->name, div, (u32)rate, (u32)new_rate, (u32)diff);
+
+	/*
+	 * If the new rate differs by 50% of the target,
+	 * modify parent. This handles typical cases where we have a hsdiv
+	 * following directly a PLL
+	 */
+
+	if (diff > rate / div / 2) {
+		ulong pll_tgt;
+		int pll_div = 0;
+
+		clk = clkp;
+
+		debug("%s: propagating rate change to parent, rate=%u.\n",
+		      __func__, (u32)rate / div);
+
+		clkp = clk_get_parent(clkp);
+
+		if (rate > osc_freq) {
+			if (rate > PLL_MAX_FREQ / 2 && rate < PLL_MAX_FREQ) {
+				pll_tgt = rate;
+				pll_div = 1;
+			} else {
+				for (pll_div = 2; pll_div < PLL_MAX_DIV; pll_div++) {
+					pll_tgt = rate / div * pll_div;
+					if (pll_tgt >= PLL_MIN_FREQ && pll_tgt <= PLL_MAX_FREQ)
+						break;
+				}
+			}
+		} else {
+			pll_tgt = osc_freq;
+			pll_div = rate / div / osc_freq;
+		}
+
+		debug("%s: pll_tgt=%u, rate=%u, div=%u\n", __func__,
+		      (u32)pll_tgt, (u32)rate, pll_div);
+
+		clk_set_rate(clkp, pll_tgt);
+
+		return clk_set_rate(clk, rate / div) * div;
+	}
+
+	/*
+	 * If the new rate differs by@least 5% of the target,
+	 * we must check for rounding error in a divider, so try
+	 * set rate with rate + (parent_freq % rate).
+	 */
+
+	if (diff > rate / div / 20) {
+		u64 parent_freq = clk_get_parent_rate(clkp);
+
+		rem = parent_freq % rate;
+		new_rate = clk_set_rate(clkp, (rate / div) + rem);
+		new_diff = abs(new_rate - rate / div);
+
+		if (new_diff > diff) {
+			new_rate = clk_set_rate(clkp, rate / div);
+		} else {
+			debug("%s: Using better rate %lu that gives diff %lu\n",
+			      __func__, new_rate, new_diff);
+		}
+	}
+
+	return new_rate;
+}
+
+static int ti_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	struct clk *clkp = data->map[clk->id].clk;
+	struct clk *parentp = data->map[parent->id].clk;
+
+	return clk_set_parent(clkp, parentp);
+}
+
+static int ti_clk_enable(struct clk *clk)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	struct clk *clkp = data->map[clk->id].clk;
+
+	return clk_enable(clkp);
+}
+
+static int ti_clk_disable(struct clk *clk)
+{
+	struct ti_clk_data *data = dev_get_priv(clk->dev);
+	struct clk *clkp = data->map[clk->id].clk;
+
+	return clk_disable(clkp);
+}
+
+static const struct udevice_id ti_clk_of_match[] = {
+	{ .compatible = "ti,k2g-sci-clk" },
+	{ /* sentinel */ },
+};
+
+static const struct clk_ops ti_clk_ops = {
+	.of_xlate = ti_clk_of_xlate,
+	.set_rate = ti_clk_set_rate,
+	.get_rate = ti_clk_get_rate,
+	.enable = ti_clk_enable,
+	.disable = ti_clk_disable,
+	.set_parent = ti_clk_set_parent,
+};
+
+U_BOOT_DRIVER(ti_clk) = {
+	.name = "ti-clk",
+	.id = UCLASS_CLK,
+	.of_match = ti_clk_of_match,
+	.probe = ti_clk_probe,
+	.priv_auto = sizeof(struct ti_clk_data),
+	.ops = &ti_clk_ops,
+};
diff --git a/include/k3-clk.h b/include/k3-clk.h
index fc84378d03..36f0ddf7cc 100644
--- a/include/k3-clk.h
+++ b/include/k3-clk.h
@@ -7,7 +7,169 @@
 #ifndef __K3_CLK_H__
 #define __K3_CLK_H__
 
+#include <common.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
 #include <linux/clk-provider.h>
+#include <linux/types.h>
+#include <stdint.h>
+
+struct dev_clk {
+	int dev_id;
+	int clk_id;
+	const char *clk_name;
+};
+
+#define DEV_CLK(_dev_id, _clk_id, _clk_name) { .dev_id = _dev_id,		\
+					.clk_id = _clk_id, .clk_name = _clk_name, }
+
+#define CLK_TYPE_MUX		0x01
+#define CLK_TYPE_DIV		0x02
+#define CLK_TYPE_PLL		0x03
+#define CLK_TYPE_HFOSC		0x04
+#define CLK_TYPE_POSTDIV	0x05
+#define CLK_TYPE_MUX_PLLCTRL	0x06
+#define CLK_TYPE_FIXED_RATE	0x07
+
+struct pll_data {
+	u32 reg;
+	const char *name;
+	const char *parent;
+	u32 flags;
+};
+
+struct mux_data {
+	u32 reg;
+	const char *name;
+	const char * const *parents;
+	int num_parents;
+	u32 flags;
+	int shift;
+	int width;
+};
+
+struct div_data {
+	u32 reg;
+	const char *name;
+	const char *parent;
+	u32 flags;
+	int shift;
+	int width;
+};
+
+struct hfosc_data {
+	const char *name;
+	u32 flags;
+};
+
+struct fixed_rate_data {
+	const char *name;
+	u64 rate;
+	u32 flags;
+};
+
+struct postdiv_data {
+	const char *name;
+	const char *parent;
+	int width;
+	u32 flags;
+};
+
+struct mux_pllctrl_data {
+	u32 reg;
+	const char *name;
+	const char * const *parents;
+	int num_parents;
+	u32 flags;
+};
+
+struct clk_data {
+	int type;
+	u32 default_freq;
+	union {
+		struct pll_data pll;
+		struct mux_data mux;
+		struct div_data div;
+		struct hfosc_data hfosc;
+		struct postdiv_data postdiv;
+		struct mux_pllctrl_data mux_pllctrl;
+		struct fixed_rate_data fixed_rate;
+	} clk;
+};
+
+#define CLK_MUX(_name, _parents, _num_parents, _reg, _shift, _width, _flags) \
+	{								\
+		.type = CLK_TYPE_MUX,					\
+		.clk.mux = { .name = _name, .parents = _parents,	\
+		.reg = _reg,						\
+		.num_parents = _num_parents, .shift = _shift,		\
+		.width = _width, .flags = _flags }			\
+	}
+
+#define CLK_DIV(_name, _parent, _reg, _shift, _width, _flags)	\
+	{							\
+		.type = CLK_TYPE_DIV,				\
+		.clk.div = {.name = _name, .parent = _parent, .reg = _reg, .shift = _shift, .width = _width, .flags = _flags } \
+	}
+
+#define CLK_DIV_DEFFREQ(_name, _parent, _reg, _shift, _width, _flags, _freq) \
+	{							\
+		.type = CLK_TYPE_DIV,				\
+		.default_freq = _freq,				\
+		.clk.div = {					\
+			.name = _name, .parent = _parent,	\
+			.reg = _reg, .shift = _shift,		\
+			.width = _width, .flags = _flags }	\
+	}
+
+#define CLK_PLL(_name, _parent, _reg,  _flags)	\
+	{					\
+		.type = CLK_TYPE_PLL,		\
+		.clk.pll = {.name = _name, .parent = _parent, .reg = _reg, .flags = _flags } \
+	}
+
+#define CLK_PLL_DEFFREQ(_name, _parent, _reg, _flags, _freq)	\
+	{							\
+		.type = CLK_TYPE_PLL,				\
+		.default_freq = _freq,				\
+		.clk.pll = { .name = _name, .parent = _parent,	\
+				.reg = _reg, .flags = _flags }	\
+	}
+
+#define CLK_HFOSC(_name, _flags)		\
+	{					\
+		.type = CLK_TYPE_HFOSC,		\
+		.clk.hfosc = { .name = _name, .flags = _flags } \
+	}
+
+#define CLK_FIXED_RATE(_name, _rate, _flags)		\
+	{						\
+		.type = CLK_TYPE_FIXED_RATE,		\
+		.clk.fixed_rate = { .name = _name, .rate = _rate, .flags = _flags } \
+	}
+
+#define CLK_POSTDIV(_name, _parent, _width, _flags)	\
+	{						\
+		.type = CLK_TYPE_POSTDIV,		\
+		.clk.postdiv = {.name = _name, .parent = _parent, .width = _width, .flags = _flags } \
+	}
+
+#define CLK_MUX_PLLCTRL(_name, _parents, _num_parents, _reg, _flags)	\
+	{								\
+		.type = CLK_TYPE_MUX,					\
+		.clk.mux_pllctrl = { .name = _name, .parents = _parents,\
+		.num_parents = _num_parents, .flags = _flags }		\
+	}
+
+struct ti_k3_clk_platdata {
+	const struct clk_data *clk_list;
+	int clk_list_cnt;
+	const struct dev_clk *soc_dev_clk_data;
+	int soc_dev_clk_data_cnt;
+};
+
+extern const struct ti_k3_clk_platdata j721e_clk_platdata;
+extern const struct ti_k3_clk_platdata j7200_clk_platdata;
 
 struct clk *clk_register_ti_pll(const char *name, const char *parent_name,
 				void __iomem *reg);
-- 
2.17.1