clk: davinci: New driver for davinci PLL clocks

This adds a new driver for mach-davinci PLL clocks. This is porting the
code from arch/arm/mach-davinci/clock.c to the common clock framework.
Additionally, it adds device tree support for these clocks.

The ifeq ($(CONFIG_COMMON_CLK), y) in the Makefile is needed to prevent
compile errors until the clock code in arch/arm/mach-davinci is removed.

Note: although there are similar clocks for TI Keystone we are not able
to share the code for a few reasons. The keystone clocks are device tree
only and use legacy one-node-per-clock bindings. Also the register
layouts are a bit different, which would add even more if/else mess
to the keystone clocks. And the keystone PLL driver doesn't support
setting clock rates.
Signed-off-by: NDavid Lechner <david@lechnology.com>
Signed-off-by: NStephen Boyd <sboyd@kernel.org>

MAINTAINERS

@@ -13792,6 +13792,13 @@ F:	arch/arm/mach-davinci/
 F:	drivers/i2c/busses/i2c-davinci.c
 F:	arch/arm/boot/dts/da850*
 
+TI DAVINCI SERIES CLOCK DRIVER
+M:	David Lechner <david@lechnology.com>
+R:	Sekhar Nori <nsekhar@ti.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/clock/ti/davinci/
+F:	drivers/clk/davinci/
+
 TI DAVINCI SERIES GPIO DRIVER
 M:	Keerthy <j-keerthy@ti.com>
 L:	linux-gpio@vger.kernel.org

drivers/clk/Makefile

@@ -61,6 +61,7 @@ obj-$(CONFIG_ARCH_ARTPEC)		+= axis/
 obj-$(CONFIG_ARC_PLAT_AXS10X)		+= axs10x/
 obj-y					+= bcm/
 obj-$(CONFIG_ARCH_BERLIN)		+= berlin/
+obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
 obj-$(CONFIG_H8300)			+= h8300/
 obj-$(CONFIG_ARCH_HISI)			+= hisilicon/
 obj-y					+= imgtec/

drivers/clk/davinci/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+ifeq ($(CONFIG_COMMON_CLK), y)
+obj-y += pll.o
+endif

drivers/clk/davinci/pll.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PLL clock driver for TI Davinci SoCs
+ *
+ * Copyright (C) 2018 David Lechner <david@lechnology.com>
+ *
+ * Based on arch/arm/mach-davinci/clock.c
+ * Copyright (C) 2006-2007 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/notifier.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_data/clk-davinci-pll.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "pll.h"
+
+#define MAX_NAME_SIZE	20
+#define OSCIN_CLK_NAME	"oscin"
+
+#define REVID		0x000
+#define PLLCTL		0x100
+#define OCSEL		0x104
+#define PLLSECCTL	0x108
+#define PLLM		0x110
+#define PREDIV		0x114
+#define PLLDIV1		0x118
+#define PLLDIV2		0x11c
+#define PLLDIV3		0x120
+#define OSCDIV		0x124
+#define POSTDIV		0x128
+#define BPDIV		0x12c
+#define PLLCMD		0x138
+#define PLLSTAT		0x13c
+#define ALNCTL		0x140
+#define DCHANGE		0x144
+#define CKEN		0x148
+#define CKSTAT		0x14c
+#define SYSTAT		0x150
+#define PLLDIV4		0x160
+#define PLLDIV5		0x164
+#define PLLDIV6		0x168
+#define PLLDIV7		0x16c
+#define PLLDIV8		0x170
+#define PLLDIV9		0x174
+
+#define PLLCTL_PLLEN		BIT(0)
+#define PLLCTL_PLLPWRDN		BIT(1)
+#define PLLCTL_PLLRST		BIT(3)
+#define PLLCTL_PLLDIS		BIT(4)
+#define PLLCTL_PLLENSRC		BIT(5)
+#define PLLCTL_CLKMODE		BIT(8)
+
+/* shared by most *DIV registers */
+#define DIV_RATIO_SHIFT		0
+#define DIV_RATIO_WIDTH		5
+#define DIV_ENABLE_SHIFT	15
+
+#define PLLCMD_GOSET		BIT(0)
+#define PLLSTAT_GOSTAT		BIT(0)
+
+#define CKEN_OBSCLK_SHIFT	1
+#define CKEN_AUXEN_SHIFT	0
+
+/*
+ * OMAP-L138 system reference guide recommends a wait for 4 OSCIN/CLKIN
+ * cycles to ensure that the PLLC has switched to bypass mode. Delay of 1us
+ * ensures we are good for all > 4MHz OSCIN/CLKIN inputs. Typically the input
+ * is ~25MHz. Units are micro seconds.
+ */
+#define PLL_BYPASS_TIME		1
+
+/* From OMAP-L138 datasheet table 6-4. Units are micro seconds */
+#define PLL_RESET_TIME		1
+
+/*
+ * From OMAP-L138 datasheet table 6-4; assuming prediv = 1, sqrt(pllm) = 4
+ * Units are micro seconds.
+ */
+#define PLL_LOCK_TIME		20
+
+/**
+ * struct davinci_pll_clk - Main PLL clock (aka PLLOUT)
+ * @hw: clk_hw for the pll
+ * @base: Base memory address
+ * @pllm_min: The minimum allowable PLLM[PLLM] value
+ * @pllm_max: The maxiumum allowable PLLM[PLLM] value
+ * @pllm_mask: Bitmask for PLLM[PLLM] value
+ */
+struct davinci_pll_clk {
+	struct clk_hw hw;
+	void __iomem *base;
+	u32 pllm_min;
+	u32 pllm_max;
+	u32 pllm_mask;
+};
+
+#define to_davinci_pll_clk(_hw) \
+	container_of((_hw), struct davinci_pll_clk, hw)
+
+static unsigned long davinci_pll_recalc_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
+	unsigned long rate = parent_rate;
+	u32 mult;
+
+	mult = readl(pll->base + PLLM) & pll->pllm_mask;
+	rate *= mult + 1;
+
+	return rate;
+}
+
+static int davinci_pll_determine_rate(struct clk_hw *hw,
+				      struct clk_rate_request *req)
+{
+	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
+	struct clk_hw *parent = req->best_parent_hw;
+	unsigned long parent_rate = req->best_parent_rate;
+	unsigned long rate = req->rate;
+	unsigned long best_rate, r;
+	u32 mult;
+
+	/* there is a limited range of valid outputs (see datasheet) */
+	if (rate < req->min_rate)
+		return -EINVAL;
+
+	rate = min(rate, req->max_rate);
+	mult = rate / parent_rate;
+	best_rate = parent_rate * mult;
+
+	/* easy case when there is no PREDIV */
+	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+		if (best_rate < req->min_rate)
+			return -EINVAL;
+
+		if (mult < pll->pllm_min || mult > pll->pllm_max)
+			return -EINVAL;
+
+		req->rate = best_rate;
+
+		return 0;
+	}
+
+	/* see if the PREDIV clock can help us */
+	best_rate = 0;
+
+	for (mult = pll->pllm_min; mult <= pll->pllm_max; mult++) {
+		parent_rate = clk_hw_round_rate(parent, rate / mult);
+		r = parent_rate * mult;
+		if (r < req->min_rate)
+			continue;
+		if (r > rate || r > req->max_rate)
+			break;
+		if (r > best_rate) {
+			best_rate = r;
+			req->rate = best_rate;
+			req->best_parent_rate = parent_rate;
+			if (best_rate == rate)
+				break;
+		}
+	}
+
+	return 0;
+}
+
+static int davinci_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
+	u32 mult;
+
+	mult = rate / parent_rate;
+	writel(mult - 1, pll->base + PLLM);
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry);
+#else
+#define davinci_pll_debug_init NULL
+#endif
+
+static const struct clk_ops davinci_pll_ops = {
+	.recalc_rate	= davinci_pll_recalc_rate,
+	.determine_rate	= davinci_pll_determine_rate,
+	.set_rate	= davinci_pll_set_rate,
+	.debug_init	= davinci_pll_debug_init,
+};
+
+/* PLLM works differently on DM365 */
+static unsigned long dm365_pll_recalc_rate(struct clk_hw *hw,
+					   unsigned long parent_rate)
+{
+	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
+	unsigned long rate = parent_rate;
+	u32 mult;
+
+	mult = readl(pll->base + PLLM) & pll->pllm_mask;
+	rate *= mult * 2;
+
+	return rate;
+}
+
+static const struct clk_ops dm365_pll_ops = {
+	.recalc_rate	= dm365_pll_recalc_rate,
+	.debug_init	= davinci_pll_debug_init,
+};
+
+/**
+ * davinci_pll_div_register - common *DIV clock implementation
+ * @name: the clock name
+ * @parent_name: the parent clock name
+ * @reg: the *DIV register
+ * @fixed: if true, the divider is a fixed value
+ * @flags: bitmap of CLK_* flags from clock-provider.h
+ */
+static struct clk *davinci_pll_div_register(struct device *dev,
+					    const char *name,
+					    const char *parent_name,
+					    void __iomem *reg,
+					    bool fixed, u32 flags)
+{
+	const char * const *parent_names = parent_name ? &parent_name : NULL;
+	int num_parents = parent_name ? 1 : 0;
+	const struct clk_ops *divider_ops = &clk_divider_ops;
+	struct clk_gate *gate;
+	struct clk_divider *divider;
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	gate->reg = reg;
+	gate->bit_idx = DIV_ENABLE_SHIFT;
+
+	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
+	if (!divider)
+		return ERR_PTR(-ENOMEM);
+
+	divider->reg = reg;
+	divider->shift = DIV_RATIO_SHIFT;
+	divider->width = DIV_RATIO_WIDTH;
+
+	if (fixed) {
+		divider->flags |= CLK_DIVIDER_READ_ONLY;
+		divider_ops = &clk_divider_ro_ops;
+	}
+
+	return clk_register_composite(dev, name, parent_names, num_parents,
+				      NULL, NULL, &divider->hw, divider_ops,
+				      &gate->hw, &clk_gate_ops, flags);
+}
+
+struct davinci_pllen_clk {
+	struct clk_hw hw;
+	void __iomem *base;
+};
+
+#define to_davinci_pllen_clk(_hw) \
+	container_of((_hw), struct davinci_pllen_clk, hw)
+
+static const struct clk_ops davinci_pllen_ops = {
+	/* this clocks just uses the clock notification feature */
+};
+
+/*
+ * The PLL has to be switched into bypass mode while we are chaning the rate,
+ * so we do that on the PLLEN clock since it is the end of the line. This will
+ * switch to bypass before any of the parent clocks (PREDIV, PLL, POSTDIV) are
+ * changed and will switch back to the PLL after the changes have been made.
+ */
+static int davinci_pllen_rate_change(struct notifier_block *nb,
+				     unsigned long flags, void *data)
+{
+	struct clk_notifier_data *cnd = data;
+	struct clk_hw *hw = __clk_get_hw(cnd->clk);
+	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(pll->base + PLLCTL);
+
+	if (flags == PRE_RATE_CHANGE) {
+		/* Switch the PLL to bypass mode */
+		ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
+		writel(ctrl, pll->base + PLLCTL);
+
+		udelay(PLL_BYPASS_TIME);
+
+		/* Reset and enable PLL */
+		ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS);
+		writel(ctrl, pll->base + PLLCTL);
+	} else {
+		udelay(PLL_RESET_TIME);
+
+		/* Bring PLL out of reset */
+		ctrl |= PLLCTL_PLLRST;
+		writel(ctrl, pll->base + PLLCTL);
+
+		udelay(PLL_LOCK_TIME);
+
+		/* Remove PLL from bypass mode */
+		ctrl |= PLLCTL_PLLEN;
+		writel(ctrl, pll->base + PLLCTL);
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct davinci_pll_platform_data *davinci_pll_get_pdata(struct device *dev)
+{
+	struct davinci_pll_platform_data *pdata = dev_get_platdata(dev);
+
+	/*
+	 * Platform data is optional, so allocate a new struct if one was not
+	 * provided. For device tree, this will always be the case.
+	 */
+	if (!pdata)
+		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	/* for device tree, we need to fill in the struct */
+	if (dev->of_node)
+		pdata->cfgchip =
+			syscon_regmap_lookup_by_compatible("ti,da830-cfgchip");
+
+	return pdata;
+}
+
+static struct notifier_block davinci_pllen_notifier = {
+	.notifier_call = davinci_pllen_rate_change,
+};
+
+/**
+ * davinci_pll_clk_register - Register a PLL clock
+ * @info: The device-specific clock info
+ * @parent_name: The parent clock name
+ * @base: The PLL's memory region
+ *
+ * This creates a series of clocks that represent the PLL.
+ *
+ *     OSCIN > [PREDIV >] PLL > [POSTDIV >] PLLEN
+ *
+ * - OSCIN is the parent clock (on secondary PLL, may come from primary PLL)
+ * - PREDIV and POSTDIV are optional (depends on the PLL controller)
+ * - PLL is the PLL output (aka PLLOUT)
+ * - PLLEN is the bypass multiplexer
+ *
+ * Returns: The PLLOUT clock or a negative error code.
+ */
+struct clk *davinci_pll_clk_register(struct device *dev,
+				     const struct davinci_pll_clk_info *info,
+				     const char *parent_name,
+				     void __iomem *base)
+{
+	struct davinci_pll_platform_data *pdata;
+	char prediv_name[MAX_NAME_SIZE];
+	char pllout_name[MAX_NAME_SIZE];
+	char postdiv_name[MAX_NAME_SIZE];
+	char pllen_name[MAX_NAME_SIZE];
+	struct clk_init_data init;
+	struct davinci_pll_clk *pllout;
+	struct davinci_pllen_clk *pllen;
+	struct clk *pllout_clk, *clk;
+
+	pdata = davinci_pll_get_pdata(dev);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	if (info->flags & PLL_HAS_CLKMODE) {
+		/*
+		 * If a PLL has PLLCTL[CLKMODE], then it is the primary PLL.
+		 * We register a clock named "oscin" that serves as the internal
+		 * "input clock" domain shared by both PLLs (if there are 2)
+		 * and will be the parent clock to the AUXCLK, SYSCLKBP and
+		 * OBSCLK domains. NB: The various TRMs use "OSCIN" to mean
+		 * a number of different things. In this driver we use it to
+		 * mean the signal after the PLLCTL[CLKMODE] switch.
+		 */
+		clk = clk_register_fixed_factor(dev, OSCIN_CLK_NAME,
+						parent_name, 0, 1, 1);
+		if (IS_ERR(clk))
+			return clk;
+
+		parent_name = OSCIN_CLK_NAME;
+	}
+
+	if (info->flags & PLL_HAS_PREDIV) {
+		bool fixed = info->flags & PLL_PREDIV_FIXED_DIV;
+		u32 flags = 0;
+
+		snprintf(prediv_name, MAX_NAME_SIZE, "%s_prediv", info->name);
+
+		if (info->flags & PLL_PREDIV_ALWAYS_ENABLED)
+			flags |= CLK_IS_CRITICAL;
+
+		/* Some? DM355 chips don't correctly report the PREDIV value */
+		if (info->flags & PLL_PREDIV_FIXED8)
+			clk = clk_register_fixed_factor(dev, prediv_name,
+						parent_name, flags, 1, 8);
+		else
+			clk = davinci_pll_div_register(dev, prediv_name,
+				parent_name, base + PREDIV, fixed, flags);
+		if (IS_ERR(clk))
+			return clk;
+
+		parent_name = prediv_name;
+	}
+
+	/* Unlock writing to PLL registers */
+	if (info->unlock_reg) {
+		if (IS_ERR_OR_NULL(pdata->cfgchip))
+			dev_warn(dev, "Failed to get CFGCHIP (%ld)\n",
+				 PTR_ERR(pdata->cfgchip));
+		else
+			regmap_write_bits(pdata->cfgchip, info->unlock_reg,
+					  info->unlock_mask, 0);
+	}
+
+	pllout = devm_kzalloc(dev, sizeof(*pllout), GFP_KERNEL);
+	if (!pllout)
+		return ERR_PTR(-ENOMEM);
+
+	snprintf(pllout_name, MAX_NAME_SIZE, "%s_pllout", info->name);
+
+	init.name = pllout_name;
+	if (info->flags & PLL_PLLM_2X)
+		init.ops = &dm365_pll_ops;
+	else
+		init.ops = &davinci_pll_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	init.flags = 0;
+
+	if (info->flags & PLL_HAS_PREDIV)
+		init.flags |= CLK_SET_RATE_PARENT;
+
+	pllout->hw.init = &init;
+	pllout->base = base;
+	pllout->pllm_mask = info->pllm_mask;
+	pllout->pllm_min = info->pllm_min;
+	pllout->pllm_max = info->pllm_max;
+
+	pllout_clk = devm_clk_register(dev, &pllout->hw);
+	if (IS_ERR(pllout_clk))
+		return pllout_clk;
+
+	clk_hw_set_rate_range(&pllout->hw, info->pllout_min_rate,
+			      info->pllout_max_rate);
+
+	parent_name = pllout_name;
+
+	if (info->flags & PLL_HAS_POSTDIV) {
+		bool fixed = info->flags & PLL_POSTDIV_FIXED_DIV;
+		u32 flags = CLK_SET_RATE_PARENT;
+
+		snprintf(postdiv_name, MAX_NAME_SIZE, "%s_postdiv", info->name);
+
+		if (info->flags & PLL_POSTDIV_ALWAYS_ENABLED)
+			flags |= CLK_IS_CRITICAL;
+
+		clk = davinci_pll_div_register(dev, postdiv_name, parent_name,
+					       base + POSTDIV, fixed, flags);
+		if (IS_ERR(clk))
+			return clk;
+
+		parent_name = postdiv_name;
+	}
+
+	pllen = devm_kzalloc(dev, sizeof(*pllout), GFP_KERNEL);
+	if (!pllen)
+		return ERR_PTR(-ENOMEM);
+
+	snprintf(pllen_name, MAX_NAME_SIZE, "%s_pllen", info->name);
+
+	init.name = pllen_name;
+	init.ops = &davinci_pllen_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
+
+	pllen->hw.init = &init;
+	pllen->base = base;
+
+	clk = devm_clk_register(dev, &pllen->hw);
+	if (IS_ERR(clk))
+		return clk;
+
+	clk_notifier_register(clk, &davinci_pllen_notifier);
+
+	return pllout_clk;
+}
+
+/**
+ * davinci_pll_auxclk_register - Register bypass clock (AUXCLK)
+ * @name: The clock name
+ * @base: The PLL memory region
+ */
+struct clk *davinci_pll_auxclk_register(struct device *dev,
+					const char *name,
+					void __iomem *base)
+{
+	return clk_register_gate(dev, name, OSCIN_CLK_NAME, 0, base + CKEN,
+				 CKEN_AUXEN_SHIFT, 0, NULL);
+}
+
+/**
+ * davinci_pll_sysclkbp_clk_register - Register bypass divider clock (SYSCLKBP)
+ * @name: The clock name
+ * @base: The PLL memory region
+ */
+struct clk *davinci_pll_sysclkbp_clk_register(struct device *dev,
+					      const char *name,
+					      void __iomem *base)
+{
+	return clk_register_divider(dev, name, OSCIN_CLK_NAME, 0, base + BPDIV,
+				    DIV_RATIO_SHIFT, DIV_RATIO_WIDTH,
+				    CLK_DIVIDER_READ_ONLY, NULL);
+}
+
+/**
+ * davinci_pll_obsclk_register - Register oscillator divider clock (OBSCLK)
+ * @info: The clock info
+ * @base: The PLL memory region
+ */
+struct clk *
+davinci_pll_obsclk_register(struct device *dev,
+			    const struct davinci_pll_obsclk_info *info,
+			    void __iomem *base)
+{
+	struct clk_mux *mux;
+	struct clk_gate *gate;
+	struct clk_divider *divider;
+	u32 oscdiv;
+
+	mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return ERR_PTR(-ENOMEM);
+
+	mux->reg = base + OCSEL;
+	mux->table = info->table;
+	mux->mask = info->ocsrc_mask;
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	gate->reg = base + CKEN;
+	gate->bit_idx = CKEN_OBSCLK_SHIFT;
+
+	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
+	if (!divider)
+		return ERR_PTR(-ENOMEM);
+
+	divider->reg = base + OSCDIV;
+	divider->shift = DIV_RATIO_SHIFT;
+	divider->width = DIV_RATIO_WIDTH;
+
+	/* make sure divider is enabled just in case bootloader disabled it */
+	oscdiv = readl(base + OSCDIV);
+	oscdiv |= BIT(DIV_ENABLE_SHIFT);
+	writel(oscdiv, base + OSCDIV);
+
+	return clk_register_composite(dev, info->name, info->parent_names,
+				      info->num_parents,
+				      &mux->hw, &clk_mux_ops,
+				      &divider->hw, &clk_divider_ops,
+				      &gate->hw, &clk_gate_ops, 0);
+}
+
+/* The PLL SYSCLKn clocks have a mechanism for synchronizing rate changes. */
+static int davinci_pll_sysclk_rate_change(struct notifier_block *nb,
+					  unsigned long flags, void *data)
+{
+	struct clk_notifier_data *cnd = data;
+	struct clk_hw *hw = __clk_get_hw(clk_get_parent(cnd->clk));
+	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
+	u32 pllcmd, pllstat;
+
+	switch (flags) {
+	case POST_RATE_CHANGE:
+		/* apply the changes */
+		pllcmd = readl(pll->base + PLLCMD);
+		pllcmd |= PLLCMD_GOSET;
+		writel(pllcmd, pll->base + PLLCMD);
+		/* fallthrough */
+	case PRE_RATE_CHANGE:
+		/* Wait until for outstanding changes to take effect */
+		do {
+			pllstat = readl(pll->base + PLLSTAT);
+		} while (pllstat & PLLSTAT_GOSTAT);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block davinci_pll_sysclk_notifier = {
+	.notifier_call = davinci_pll_sysclk_rate_change,
+};
+
+/**
+ * davinci_pll_sysclk_register - Register divider clocks (SYSCLKn)
+ * @info: The clock info
+ * @base: The PLL memory region
+ */
+struct clk *
+davinci_pll_sysclk_register(struct device *dev,
+			    const struct davinci_pll_sysclk_info *info,
+			    void __iomem *base)
+{
+	const struct clk_ops *divider_ops = &clk_divider_ops;
+	struct clk_gate *gate;
+	struct clk_divider *divider;
+	struct clk *clk;
+	u32 reg;
+	u32 flags = 0;
+
+	/* PLLDIVn registers are not entirely consecutive */
+	if (info->id < 4)
+		reg = PLLDIV1 + 4 * (info->id - 1);
+	else
+		reg = PLLDIV4 + 4 * (info->id - 4);
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	gate->reg = base + reg;
+	gate->bit_idx = DIV_ENABLE_SHIFT;
+
+	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
+	if (!divider)
+		return ERR_PTR(-ENOMEM);
+
+	divider->reg = base + reg;
+	divider->shift = DIV_RATIO_SHIFT;
+	divider->width = info->ratio_width;
+	divider->flags = 0;
+
+	if (info->flags & SYSCLK_FIXED_DIV) {
+		divider->flags |= CLK_DIVIDER_READ_ONLY;
+		divider_ops = &clk_divider_ro_ops;
+	}
+
+	/* Only the ARM clock can change the parent PLL rate */
+	if (info->flags & SYSCLK_ARM_RATE)
+		flags |= CLK_SET_RATE_PARENT;
+
+	if (info->flags & SYSCLK_ALWAYS_ENABLED)
+		flags |= CLK_IS_CRITICAL;
+
+	clk = clk_register_composite(dev, info->name, &info->parent_name, 1,
+				     NULL, NULL, &divider->hw, divider_ops,
+				     &gate->hw, &clk_gate_ops, flags);
+	if (IS_ERR(clk))
+		return clk;
+
+	clk_notifier_register(clk, &davinci_pll_sysclk_notifier);
+
+	return clk;
+}
+
+int of_davinci_pll_init(struct device *dev,
+			const struct davinci_pll_clk_info *info,
+			const struct davinci_pll_obsclk_info *obsclk_info,
+			const struct davinci_pll_sysclk_info **div_info,
+			u8 max_sysclk_id,
+			void __iomem *base)
+{
+	struct device_node *node = dev->of_node;
+	struct device_node *child;
+	const char *parent_name;
+	struct clk *clk;
+
+	if (info->flags & PLL_HAS_CLKMODE)
+		parent_name = of_clk_get_parent_name(node, 0);
+	else
+		parent_name = OSCIN_CLK_NAME;
+
+	clk = davinci_pll_clk_register(dev, info, parent_name, base);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "failed to register %s\n", info->name);
+		return PTR_ERR(clk);
+	}
+
+	child = of_get_child_by_name(node, "pllout");
+	if (of_device_is_available(child))
+		of_clk_add_provider(child, of_clk_src_simple_get, clk);
+	of_node_put(child);
+
+	child = of_get_child_by_name(node, "sysclk");
+	if (of_device_is_available(child)) {
+		struct clk_onecell_data *clk_data;
+		struct clk **clks;
+		int n_clks =  max_sysclk_id + 1;
+		int i;
+
+		clk_data = devm_kzalloc(dev, sizeof(*clk_data), GFP_KERNEL);
+		if (!clk_data)
+			return -ENOMEM;
+
+		clks = devm_kmalloc_array(dev, n_clks, sizeof(*clks), GFP_KERNEL);
+		if (!clks)
+			return -ENOMEM;
+
+		clk_data->clks = clks;
+		clk_data->clk_num = n_clks;
+
+		for (i = 0; i < n_clks; i++)
+			clks[i] = ERR_PTR(-ENOENT);
+
+		for (; *div_info; div_info++) {
+			clk = davinci_pll_sysclk_register(dev, *div_info, base);
+			if (IS_ERR(clk))
+				dev_warn(dev, "failed to register %s (%ld)\n",
+					 (*div_info)->name, PTR_ERR(clk));
+			else
+				clks[(*div_info)->id] = clk;
+		}
+		of_clk_add_provider(child, of_clk_src_onecell_get, clk_data);
+	}
+	of_node_put(child);
+
+	child = of_get_child_by_name(node, "auxclk");
+	if (of_device_is_available(child)) {
+		char child_name[MAX_NAME_SIZE];
+
+		snprintf(child_name, MAX_NAME_SIZE, "%s_auxclk", info->name);
+
+		clk = davinci_pll_auxclk_register(dev, child_name, base);
+		if (IS_ERR(clk))
+			dev_warn(dev, "failed to register %s (%ld)\n",
+				 child_name, PTR_ERR(clk));
+		else
+			of_clk_add_provider(child, of_clk_src_simple_get, clk);
+	}
+	of_node_put(child);
+
+	child = of_get_child_by_name(node, "obsclk");
+	if (of_device_is_available(child)) {
+		if (obsclk_info)
+			clk = davinci_pll_obsclk_register(dev, obsclk_info, base);
+		else
+			clk = ERR_PTR(-EINVAL);
+
+		if (IS_ERR(clk))
+			dev_warn(dev, "failed to register obsclk (%ld)\n",
+				 PTR_ERR(clk));
+		else
+			of_clk_add_provider(child, of_clk_src_simple_get, clk);
+	}
+	of_node_put(child);
+
+	return 0;
+}
+
+static const struct of_device_id davinci_pll_of_match[] = {
+	{ }
+};
+
+static const struct platform_device_id davinci_pll_id_table[] = {
+	{ }
+};
+
+typedef int (*davinci_pll_init)(struct device *dev, void __iomem *base);
+
+static int davinci_pll_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *of_id;
+	davinci_pll_init pll_init = NULL;
+	struct resource *res;
+	void __iomem *base;
+
+	of_id = of_match_device(davinci_pll_of_match, dev);
+	if (of_id)
+		pll_init = of_id->data;
+	else if (pdev->id_entry)
+		pll_init = (void *)pdev->id_entry->driver_data;
+
+	if (!pll_init) {
+		dev_err(dev, "unable to find driver data\n");
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base)) {
+		dev_err(dev, "ioremap failed\n");
+		return PTR_ERR(base);
+	}
+
+	return pll_init(dev, base);
+}
+
+static struct platform_driver davinci_pll_driver = {
+	.probe		= davinci_pll_probe,
+	.driver		= {
+		.name		= "davinci-pll-clk",
+		.of_match_table	= davinci_pll_of_match,
+	},
+	.id_table	= davinci_pll_id_table,
+};
+
+static int __init davinci_pll_driver_init(void)
+{
+	return platform_driver_register(&davinci_pll_driver);
+}
+
+/* has to be postcore_initcall because PSC devices depend on PLL parent clocks */
+postcore_initcall(davinci_pll_driver_init);
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+#define DEBUG_REG(n)	\
+{			\
+	.name	= #n,	\
+	.offset	= n,	\
+}
+
+static const struct debugfs_reg32 davinci_pll_regs[] = {
+	DEBUG_REG(REVID),
+	DEBUG_REG(PLLCTL),
+	DEBUG_REG(OCSEL),
+	DEBUG_REG(PLLSECCTL),
+	DEBUG_REG(PLLM),
+	DEBUG_REG(PREDIV),
+	DEBUG_REG(PLLDIV1),
+	DEBUG_REG(PLLDIV2),
+	DEBUG_REG(PLLDIV3),
+	DEBUG_REG(OSCDIV),
+	DEBUG_REG(POSTDIV),
+	DEBUG_REG(BPDIV),
+	DEBUG_REG(PLLCMD),
+	DEBUG_REG(PLLSTAT),
+	DEBUG_REG(ALNCTL),
+	DEBUG_REG(DCHANGE),
+	DEBUG_REG(CKEN),
+	DEBUG_REG(CKSTAT),
+	DEBUG_REG(SYSTAT),
+	DEBUG_REG(PLLDIV4),
+	DEBUG_REG(PLLDIV5),
+	DEBUG_REG(PLLDIV6),
+	DEBUG_REG(PLLDIV7),
+	DEBUG_REG(PLLDIV8),
+	DEBUG_REG(PLLDIV9),
+};
+
+static int davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry)
+{
+	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
+	struct debugfs_regset32 *regset;
+	struct dentry *d;
+
+	regset = kzalloc(sizeof(*regset), GFP_KERNEL);
+	if (!regset)
+		return -ENOMEM;
+
+	regset->regs = davinci_pll_regs;
+	regset->nregs = ARRAY_SIZE(davinci_pll_regs);
+	regset->base = pll->base;
+
+	d = debugfs_create_regset32("registers", 0400, dentry, regset);
+	if (IS_ERR(d)) {
+		kfree(regset);
+		return PTR_ERR(d);
+	}
+
+	return 0;
+}
+#endif

drivers/clk/davinci/pll.h

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Clock driver for TI Davinci PSC controllers
+ *
+ * Copyright (C) 2018 David Lechner <david@lechnology.com>
+ */
+
+#ifndef __CLK_DAVINCI_PLL_H___
+#define __CLK_DAVINCI_PLL_H___
+
+#include <linux/bitops.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/types.h>
+
+#define PLL_HAS_CLKMODE			BIT(0) /* PLL has PLLCTL[CLKMODE] */
+#define PLL_HAS_PREDIV			BIT(1) /* has prediv before PLL */
+#define PLL_PREDIV_ALWAYS_ENABLED	BIT(2) /* don't clear DEN bit */
+#define PLL_PREDIV_FIXED_DIV		BIT(3) /* fixed divider value */
+#define PLL_HAS_POSTDIV			BIT(4) /* has postdiv after PLL */
+#define PLL_POSTDIV_ALWAYS_ENABLED	BIT(5) /* don't clear DEN bit */
+#define PLL_POSTDIV_FIXED_DIV		BIT(6) /* fixed divider value */
+#define PLL_HAS_EXTCLKSRC		BIT(7) /* has selectable bypass */
+#define PLL_PLLM_2X			BIT(8) /* PLLM value is 2x (DM365) */
+#define PLL_PREDIV_FIXED8		BIT(9) /* DM355 quirk */
+
+/** davinci_pll_clk_info - controller-specific PLL info
+ * @name: The name of the PLL
+ * @unlock_reg: Option CFGCHIP register for unlocking PLL
+ * @unlock_mask: Bitmask used with @unlock_reg
+ * @pllm_mask: Bitmask for PLLM[PLLM] value
+ * @pllm_min: Minimum allowable value for PLLM[PLLM]
+ * @pllm_max: Maximum allowable value for PLLM[PLLM]
+ * @pllout_min_rate: Minimum allowable rate for PLLOUT
+ * @pllout_max_rate: Maximum allowable rate for PLLOUT
+ * @flags: Bitmap of PLL_* flags.
+ */
+struct davinci_pll_clk_info {
+	const char *name;
+	u32 unlock_reg;
+	u32 unlock_mask;
+	u32 pllm_mask;
+	u32 pllm_min;
+	u32 pllm_max;
+	unsigned long pllout_min_rate;
+	unsigned long pllout_max_rate;
+	u32 flags;
+};
+
+#define SYSCLK_ARM_RATE		BIT(0) /* Controls ARM rate */
+#define SYSCLK_ALWAYS_ENABLED	BIT(1) /* Or bad things happen */
+#define SYSCLK_FIXED_DIV	BIT(2) /* Fixed divider */
+
+/** davinci_pll_sysclk_info - SYSCLKn-specific info
+ * @name: The name of the clock
+ * @parent_name: The name of the parent clock
+ * @id: "n" in "SYSCLKn"
+ * @ratio_width: Width (in bits) of RATIO in PLLDIVn register
+ * @flags: Bitmap of SYSCLK_* flags.
+ */
+struct davinci_pll_sysclk_info {
+	const char *name;
+	const char *parent_name;
+	u32 id;
+	u32 ratio_width;
+	u32 flags;
+};
+
+#define SYSCLK(i, n, p, w, f)				\
+static const struct davinci_pll_sysclk_info n = {	\
+	.name		= #n,				\
+	.parent_name	= #p,				\
+	.id		= (i),				\
+	.ratio_width	= (w),				\
+	.flags		= (f),				\
+}
+
+/** davinci_pll_obsclk_info - OBSCLK-specific info
+ * @name: The name of the clock
+ * @parent_names: Array of names of the parent clocks
+ * @num_parents: Length of @parent_names
+ * @table: Array of values to write to OCSEL[OCSRC] cooresponding to
+ *         @parent_names
+ * @ocsrc_mask: Bitmask for OCSEL[OCSRC]
+ */
+struct davinci_pll_obsclk_info {
+	const char *name;
+	const char * const *parent_names;
+	u8 num_parents;
+	u32 *table;
+	u32 ocsrc_mask;
+};
+
+struct clk *davinci_pll_clk_register(struct device *dev,
+				     const struct davinci_pll_clk_info *info,
+				     const char *parent_name,
+				     void __iomem *base);
+struct clk *davinci_pll_auxclk_register(struct device *dev,
+					const char *name,
+					void __iomem *base);
+struct clk *davinci_pll_sysclkbp_clk_register(struct device *dev,
+					      const char *name,
+					      void __iomem *base);
+struct clk *
+davinci_pll_obsclk_register(struct device *dev,
+			    const struct davinci_pll_obsclk_info *info,
+			    void __iomem *base);
+struct clk *
+davinci_pll_sysclk_register(struct device *dev,
+			    const struct davinci_pll_sysclk_info *info,
+			    void __iomem *base);
+
+int of_davinci_pll_init(struct device *dev,
+			const struct davinci_pll_clk_info *info,
+			const struct davinci_pll_obsclk_info *obsclk_info,
+			const struct davinci_pll_sysclk_info **div_info,
+			u8 max_sysclk_id,
+			void __iomem *base);
+
+#endif /* __CLK_DAVINCI_PLL_H___ */

include/linux/platform_data/clk-davinci-pll.h

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PLL clock driver for TI Davinci SoCs
+ *
+ * Copyright (C) 2018 David Lechner <david@lechnology.com>
+ */
+
+#ifndef __LINUX_PLATFORM_DATA_CLK_DAVINCI_PLL_H__
+#define __LINUX_PLATFORM_DATA_CLK_DAVINCI_PLL_H__
+
+#include <linux/regmap.h>
+
+/**
+ * davinci_pll_platform_data
+ * @cfgchip: CFGCHIP syscon regmap
+ */
+struct davinci_pll_platform_data {
+	struct regmap *cfgchip;
+};
+
+#endif /* __LINUX_PLATFORM_DATA_CLK_DAVINCI_PLL_H__ */