Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 749 insertions, 0 deletions

diff --git a/drivers/clk/ti/clkctrl.c b/drivers/clk/ti/clkctrl.c
new file mode 100644
index 000000000..87e562478
--- /dev/null
+++ b/drivers/clk/ti/clkctrl.c
@@ -0,0 +1,749 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMAP clkctrl clock support
+ *
+ * Copyright (C) 2017 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/ti.h>
+#include <linux/delay.h>
+#include <linux/timekeeping.h>
+#include "clock.h"
+
+#define NO_IDLEST			0
+
+#define OMAP4_MODULEMODE_MASK		0x3
+
+#define MODULEMODE_HWCTRL		0x1
+#define MODULEMODE_SWCTRL		0x2
+
+#define OMAP4_IDLEST_MASK		(0x3 << 16)
+#define OMAP4_IDLEST_SHIFT		16
+
+#define OMAP4_STBYST_MASK		BIT(18)
+#define OMAP4_STBYST_SHIFT		18
+
+#define CLKCTRL_IDLEST_FUNCTIONAL	0x0
+#define CLKCTRL_IDLEST_INTERFACE_IDLE	0x2
+#define CLKCTRL_IDLEST_DISABLED		0x3
+
+/* These timeouts are in us */
+#define OMAP4_MAX_MODULE_READY_TIME	2000
+#define OMAP4_MAX_MODULE_DISABLE_TIME	5000
+
+static bool _early_timeout = true;
+
+struct omap_clkctrl_provider {
+	void __iomem *base;
+	struct list_head clocks;
+	char *clkdm_name;
+};
+
+struct omap_clkctrl_clk {
+	struct clk_hw *clk;
+	u16 reg_offset;
+	int bit_offset;
+	struct list_head node;
+};
+
+union omap4_timeout {
+	u32 cycles;
+	ktime_t start;
+};
+
+static const struct omap_clkctrl_data default_clkctrl_data[] __initconst = {
+	{ 0 },
+};
+
+static u32 _omap4_idlest(u32 val)
+{
+	val &= OMAP4_IDLEST_MASK;
+	val >>= OMAP4_IDLEST_SHIFT;
+
+	return val;
+}
+
+static bool _omap4_is_idle(u32 val)
+{
+	val = _omap4_idlest(val);
+
+	return val == CLKCTRL_IDLEST_DISABLED;
+}
+
+static bool _omap4_is_ready(u32 val)
+{
+	val = _omap4_idlest(val);
+
+	return val == CLKCTRL_IDLEST_FUNCTIONAL ||
+	       val == CLKCTRL_IDLEST_INTERFACE_IDLE;
+}
+
+static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
+{
+	/*
+	 * There are two special cases where ktime_to_ns() can't be
+	 * used to track the timeouts. First one is during early boot
+	 * when the timers haven't been initialized yet. The second
+	 * one is during suspend-resume cycle while timekeeping is
+	 * being suspended / resumed. Clocksource for the system
+	 * can be from a timer that requires pm_runtime access, which
+	 * will eventually bring us here with timekeeping_suspended,
+	 * during both suspend entry and resume paths. This happens
+	 * at least on am43xx platform. Account for flakeyness
+	 * with udelay() by multiplying the timeout value by 2.
+	 */
+	if (unlikely(_early_timeout || timekeeping_suspended)) {
+		if (time->cycles++ < timeout) {
+			udelay(1 * 2);
+			return false;
+		}
+	} else {
+		if (!ktime_to_ns(time->start)) {
+			time->start = ktime_get();
+			return false;
+		}
+
+		if (ktime_us_delta(ktime_get(), time->start) < timeout) {
+			cpu_relax();
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int __init _omap4_disable_early_timeout(void)
+{
+	_early_timeout = false;
+
+	return 0;
+}
+arch_initcall(_omap4_disable_early_timeout);
+
+static int _omap4_clkctrl_clk_enable(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	u32 val;
+	int ret;
+	union omap4_timeout timeout = { 0 };
+
+	if (clk->clkdm) {
+		ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
+		if (ret) {
+			WARN(1,
+			     "%s: could not enable %s's clockdomain %s: %d\n",
+			     __func__, clk_hw_get_name(hw),
+			     clk->clkdm_name, ret);
+			return ret;
+		}
+	}
+
+	if (!clk->enable_bit)
+		return 0;
+
+	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
+
+	val &= ~OMAP4_MODULEMODE_MASK;
+	val |= clk->enable_bit;
+
+	ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
+
+	if (test_bit(NO_IDLEST, &clk->flags))
+		return 0;
+
+	/* Wait until module is enabled */
+	while (!_omap4_is_ready(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
+		if (_omap4_is_timeout(&timeout, OMAP4_MAX_MODULE_READY_TIME)) {
+			pr_err("%s: failed to enable\n", clk_hw_get_name(hw));
+			return -EBUSY;
+		}
+	}
+
+	return 0;
+}
+
+static void _omap4_clkctrl_clk_disable(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	u32 val;
+	union omap4_timeout timeout = { 0 };
+
+	if (!clk->enable_bit)
+		goto exit;
+
+	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
+
+	val &= ~OMAP4_MODULEMODE_MASK;
+
+	ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
+
+	if (test_bit(NO_IDLEST, &clk->flags))
+		goto exit;
+
+	/* Wait until module is disabled */
+	while (!_omap4_is_idle(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
+		if (_omap4_is_timeout(&timeout,
+				      OMAP4_MAX_MODULE_DISABLE_TIME)) {
+			pr_err("%s: failed to disable\n", clk_hw_get_name(hw));
+			break;
+		}
+	}
+
+exit:
+	if (clk->clkdm)
+		ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
+}
+
+static int _omap4_clkctrl_clk_is_enabled(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	u32 val;
+
+	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
+
+	if (val & clk->enable_bit)
+		return 1;
+
+	return 0;
+}
+
+static const struct clk_ops omap4_clkctrl_clk_ops = {
+	.enable		= _omap4_clkctrl_clk_enable,
+	.disable	= _omap4_clkctrl_clk_disable,
+	.is_enabled	= _omap4_clkctrl_clk_is_enabled,
+	.init		= omap2_init_clk_clkdm,
+};
+
+static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
+					      void *data)
+{
+	struct omap_clkctrl_provider *provider = data;
+	struct omap_clkctrl_clk *entry = NULL, *iter;
+
+	if (clkspec->args_count != 2)
+		return ERR_PTR(-EINVAL);
+
+	pr_debug("%s: looking for %x:%x\n", __func__,
+		 clkspec->args[0], clkspec->args[1]);
+
+	list_for_each_entry(iter, &provider->clocks, node) {
+		if (iter->reg_offset == clkspec->args[0] &&
+		    iter->bit_offset == clkspec->args[1]) {
+			entry = iter;
+			break;
+		}
+	}
+
+	if (!entry)
+		return ERR_PTR(-EINVAL);
+
+	return entry->clk;
+}
+
+/* Get clkctrl clock base name based on clkctrl_name or dts node */
+static const char * __init clkctrl_get_clock_name(struct device_node *np,
+						  const char *clkctrl_name,
+						  int offset, int index,
+						  bool legacy_naming)
+{
+	char *clock_name;
+
+	/* l4per-clkctrl:1234:0 style naming based on clkctrl_name */
+	if (clkctrl_name && !legacy_naming) {
+		clock_name = kasprintf(GFP_KERNEL, "%s-clkctrl:%04x:%d",
+				       clkctrl_name, offset, index);
+		if (!clock_name)
+			return NULL;
+
+		strreplace(clock_name, '_', '-');
+
+		return clock_name;
+	}
+
+	/* l4per:1234:0 old style naming based on clkctrl_name */
+	if (clkctrl_name)
+		return kasprintf(GFP_KERNEL, "%s_cm:clk:%04x:%d",
+				 clkctrl_name, offset, index);
+
+	/* l4per_cm:1234:0 old style naming based on parent node name */
+	if (legacy_naming)
+		return kasprintf(GFP_KERNEL, "%pOFn:clk:%04x:%d",
+				 np->parent, offset, index);
+
+	/* l4per-clkctrl:1234:0 style naming based on node name */
+	return kasprintf(GFP_KERNEL, "%pOFn:%04x:%d", np, offset, index);
+}
+
+static int __init
+_ti_clkctrl_clk_register(struct omap_clkctrl_provider *provider,
+			 struct device_node *node, struct clk_hw *clk_hw,
+			 u16 offset, u8 bit, const char * const *parents,
+			 int num_parents, const struct clk_ops *ops,
+			 const char *clkctrl_name)
+{
+	struct clk_init_data init = { NULL };
+	struct clk *clk;
+	struct omap_clkctrl_clk *clkctrl_clk;
+	int ret = 0;
+
+	init.name = clkctrl_get_clock_name(node, clkctrl_name, offset, bit,
+					   ti_clk_get_features()->flags &
+					   TI_CLK_CLKCTRL_COMPAT);
+
+	clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
+	if (!init.name || !clkctrl_clk) {
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
+	clk_hw->init = &init;
+	init.parent_names = parents;
+	init.num_parents = num_parents;
+	init.ops = ops;
+	init.flags = 0;
+
+	clk = of_ti_clk_register(node, clk_hw, init.name);
+	if (IS_ERR_OR_NULL(clk)) {
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	clkctrl_clk->reg_offset = offset;
+	clkctrl_clk->bit_offset = bit;
+	clkctrl_clk->clk = clk_hw;
+
+	list_add(&clkctrl_clk->node, &provider->clocks);
+
+	return 0;
+
+cleanup:
+	kfree(init.name);
+	kfree(clkctrl_clk);
+	return ret;
+}
+
+static void __init
+_ti_clkctrl_setup_gate(struct omap_clkctrl_provider *provider,
+		       struct device_node *node, u16 offset,
+		       const struct omap_clkctrl_bit_data *data,
+		       void __iomem *reg, const char *clkctrl_name)
+{
+	struct clk_hw_omap *clk_hw;
+
+	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
+	if (!clk_hw)
+		return;
+
+	clk_hw->enable_bit = data->bit;
+	clk_hw->enable_reg.ptr = reg;
+
+	if (_ti_clkctrl_clk_register(provider, node, &clk_hw->hw, offset,
+				     data->bit, data->parents, 1,
+				     &omap_gate_clk_ops, clkctrl_name))
+		kfree(clk_hw);
+}
+
+static void __init
+_ti_clkctrl_setup_mux(struct omap_clkctrl_provider *provider,
+		      struct device_node *node, u16 offset,
+		      const struct omap_clkctrl_bit_data *data,
+		      void __iomem *reg, const char *clkctrl_name)
+{
+	struct clk_omap_mux *mux;
+	int num_parents = 0;
+	const char * const *pname;
+
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return;
+
+	pname = data->parents;
+	while (*pname) {
+		num_parents++;
+		pname++;
+	}
+
+	mux->mask = num_parents;
+	if (!(mux->flags & CLK_MUX_INDEX_ONE))
+		mux->mask--;
+
+	mux->mask = (1 << fls(mux->mask)) - 1;
+
+	mux->shift = data->bit;
+	mux->reg.ptr = reg;
+
+	if (_ti_clkctrl_clk_register(provider, node, &mux->hw, offset,
+				     data->bit, data->parents, num_parents,
+				     &ti_clk_mux_ops, clkctrl_name))
+		kfree(mux);
+}
+
+static void __init
+_ti_clkctrl_setup_div(struct omap_clkctrl_provider *provider,
+		      struct device_node *node, u16 offset,
+		      const struct omap_clkctrl_bit_data *data,
+		      void __iomem *reg, const char *clkctrl_name)
+{
+	struct clk_omap_divider *div;
+	const struct omap_clkctrl_div_data *div_data = data->data;
+	u8 div_flags = 0;
+
+	div = kzalloc(sizeof(*div), GFP_KERNEL);
+	if (!div)
+		return;
+
+	div->reg.ptr = reg;
+	div->shift = data->bit;
+	div->flags = div_data->flags;
+
+	if (div->flags & CLK_DIVIDER_POWER_OF_TWO)
+		div_flags |= CLKF_INDEX_POWER_OF_TWO;
+
+	if (ti_clk_parse_divider_data((int *)div_data->dividers, 0,
+				      div_data->max_div, div_flags,
+				      div)) {
+		pr_err("%s: Data parsing for %pOF:%04x:%d failed\n", __func__,
+		       node, offset, data->bit);
+		kfree(div);
+		return;
+	}
+
+	if (_ti_clkctrl_clk_register(provider, node, &div->hw, offset,
+				     data->bit, data->parents, 1,
+				     &ti_clk_divider_ops, clkctrl_name))
+		kfree(div);
+}
+
+static void __init
+_ti_clkctrl_setup_subclks(struct omap_clkctrl_provider *provider,
+			  struct device_node *node,
+			  const struct omap_clkctrl_reg_data *data,
+			  void __iomem *reg, const char *clkctrl_name)
+{
+	const struct omap_clkctrl_bit_data *bits = data->bit_data;
+
+	if (!bits)
+		return;
+
+	while (bits->bit) {
+		switch (bits->type) {
+		case TI_CLK_GATE:
+			_ti_clkctrl_setup_gate(provider, node, data->offset,
+					       bits, reg, clkctrl_name);
+			break;
+
+		case TI_CLK_DIVIDER:
+			_ti_clkctrl_setup_div(provider, node, data->offset,
+					      bits, reg, clkctrl_name);
+			break;
+
+		case TI_CLK_MUX:
+			_ti_clkctrl_setup_mux(provider, node, data->offset,
+					      bits, reg, clkctrl_name);
+			break;
+
+		default:
+			pr_err("%s: bad subclk type: %d\n", __func__,
+			       bits->type);
+			return;
+		}
+		bits++;
+	}
+}
+
+static void __init _clkctrl_add_provider(void *data,
+					 struct device_node *np)
+{
+	of_clk_add_hw_provider(np, _ti_omap4_clkctrl_xlate, data);
+}
+
+/*
+ * Get clock name based on "clock-output-names" property or the
+ * compatible property for clkctrl.
+ */
+static const char * __init clkctrl_get_name(struct device_node *np)
+{
+	struct property *prop;
+	const int prefix_len = 11;
+	const char *compat;
+	const char *output;
+	char *name;
+
+	if (!of_property_read_string_index(np, "clock-output-names", 0,
+					   &output)) {
+		const char *end;
+		int len;
+
+		len = strlen(output);
+		end = strstr(output, "_clkctrl");
+		if (end)
+			len -= strlen(end);
+		name = kstrndup(output, len, GFP_KERNEL);
+
+		return name;
+	}
+
+	of_property_for_each_string(np, "compatible", prop, compat) {
+		if (!strncmp("ti,clkctrl-", compat, prefix_len)) {
+			/* Two letter minimum name length for l3, l4 etc */
+			if (strnlen(compat + prefix_len, 16) < 2)
+				continue;
+			name = kasprintf(GFP_KERNEL, "%s", compat + prefix_len);
+			if (!name)
+				continue;
+			strreplace(name, '-', '_');
+
+			return name;
+		}
+	}
+
+	return NULL;
+}
+
+static void __init _ti_omap4_clkctrl_setup(struct device_node *node)
+{
+	struct omap_clkctrl_provider *provider;
+	const struct omap_clkctrl_data *data = default_clkctrl_data;
+	const struct omap_clkctrl_reg_data *reg_data;
+	struct clk_init_data init = { NULL };
+	struct clk_hw_omap *hw;
+	struct clk *clk;
+	struct omap_clkctrl_clk *clkctrl_clk = NULL;
+	const __be32 *addrp;
+	bool legacy_naming;
+	const char *clkctrl_name;
+	u32 addr;
+	int ret;
+	char *c;
+	u16 soc_mask = 0;
+
+	addrp = of_get_address(node, 0, NULL, NULL);
+	addr = (u32)of_translate_address(node, addrp);
+
+#ifdef CONFIG_ARCH_OMAP4
+	if (of_machine_is_compatible("ti,omap4"))
+		data = omap4_clkctrl_data;
+#endif
+#ifdef CONFIG_SOC_OMAP5
+	if (of_machine_is_compatible("ti,omap5"))
+		data = omap5_clkctrl_data;
+#endif
+#ifdef CONFIG_SOC_DRA7XX
+	if (of_machine_is_compatible("ti,dra7"))
+		data = dra7_clkctrl_data;
+	if (of_machine_is_compatible("ti,dra72"))
+		soc_mask = CLKF_SOC_DRA72;
+	if (of_machine_is_compatible("ti,dra74"))
+		soc_mask = CLKF_SOC_DRA74;
+	if (of_machine_is_compatible("ti,dra76"))
+		soc_mask = CLKF_SOC_DRA76;
+#endif
+#ifdef CONFIG_SOC_AM33XX
+	if (of_machine_is_compatible("ti,am33xx"))
+		data = am3_clkctrl_data;
+#endif
+#ifdef CONFIG_SOC_AM43XX
+	if (of_machine_is_compatible("ti,am4372"))
+		data = am4_clkctrl_data;
+
+	if (of_machine_is_compatible("ti,am438x"))
+		data = am438x_clkctrl_data;
+#endif
+#ifdef CONFIG_SOC_TI81XX
+	if (of_machine_is_compatible("ti,dm814"))
+		data = dm814_clkctrl_data;
+
+	if (of_machine_is_compatible("ti,dm816"))
+		data = dm816_clkctrl_data;
+#endif
+
+	if (ti_clk_get_features()->flags & TI_CLK_DEVICE_TYPE_GP)
+		soc_mask |= CLKF_SOC_NONSEC;
+
+	while (data->addr) {
+		if (addr == data->addr)
+			break;
+
+		data++;
+	}
+
+	if (!data->addr) {
+		pr_err("%pOF not found from clkctrl data.\n", node);
+		return;
+	}
+
+	provider = kzalloc(sizeof(*provider), GFP_KERNEL);
+	if (!provider)
+		return;
+
+	provider->base = of_iomap(node, 0);
+
+	legacy_naming = ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT;
+	clkctrl_name = clkctrl_get_name(node);
+	if (clkctrl_name) {
+		provider->clkdm_name = kasprintf(GFP_KERNEL,
+						 "%s_clkdm", clkctrl_name);
+		if (!provider->clkdm_name) {
+			kfree(provider);
+			return;
+		}
+		goto clkdm_found;
+	}
+
+	/*
+	 * The code below can be removed when all clkctrl nodes use domain
+	 * specific compatible property and standard clock node naming
+	 */
+	if (legacy_naming) {
+		provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFnxxx", node->parent);
+		if (!provider->clkdm_name) {
+			kfree(provider);
+			return;
+		}
+
+		/*
+		 * Create default clkdm name, replace _cm from end of parent
+		 * node name with _clkdm
+		 */
+		provider->clkdm_name[strlen(provider->clkdm_name) - 2] = 0;
+	} else {
+		provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFn", node);
+		if (!provider->clkdm_name) {
+			kfree(provider);
+			return;
+		}
+
+		/*
+		 * Create default clkdm name, replace _clkctrl from end of
+		 * node name with _clkdm
+		 */
+		provider->clkdm_name[strlen(provider->clkdm_name) - 7] = 0;
+	}
+
+	strcat(provider->clkdm_name, "clkdm");
+
+	/* Replace any dash from the clkdm name with underscore */
+	c = provider->clkdm_name;
+
+	while (*c) {
+		if (*c == '-')
+			*c = '_';
+		c++;
+	}
+clkdm_found:
+	INIT_LIST_HEAD(&provider->clocks);
+
+	/* Generate clocks */
+	reg_data = data->regs;
+
+	while (reg_data->parent) {
+		if ((reg_data->flags & CLKF_SOC_MASK) &&
+		    (reg_data->flags & soc_mask) == 0) {
+			reg_data++;
+			continue;
+		}
+
+		hw = kzalloc(sizeof(*hw), GFP_KERNEL);
+		if (!hw)
+			return;
+
+		hw->enable_reg.ptr = provider->base + reg_data->offset;
+
+		_ti_clkctrl_setup_subclks(provider, node, reg_data,
+					  hw->enable_reg.ptr, clkctrl_name);
+
+		if (reg_data->flags & CLKF_SW_SUP)
+			hw->enable_bit = MODULEMODE_SWCTRL;
+		if (reg_data->flags & CLKF_HW_SUP)
+			hw->enable_bit = MODULEMODE_HWCTRL;
+		if (reg_data->flags & CLKF_NO_IDLEST)
+			set_bit(NO_IDLEST, &hw->flags);
+
+		if (reg_data->clkdm_name)
+			hw->clkdm_name = reg_data->clkdm_name;
+		else
+			hw->clkdm_name = provider->clkdm_name;
+
+		init.parent_names = &reg_data->parent;
+		init.num_parents = 1;
+		init.flags = 0;
+		if (reg_data->flags & CLKF_SET_RATE_PARENT)
+			init.flags |= CLK_SET_RATE_PARENT;
+
+		init.name = clkctrl_get_clock_name(node, clkctrl_name,
+						   reg_data->offset, 0,
+						   legacy_naming);
+		if (!init.name)
+			goto cleanup;
+
+		clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
+		if (!clkctrl_clk)
+			goto cleanup;
+
+		init.ops = &omap4_clkctrl_clk_ops;
+		hw->hw.init = &init;
+
+		clk = of_ti_clk_register_omap_hw(node, &hw->hw, init.name);
+		if (IS_ERR_OR_NULL(clk))
+			goto cleanup;
+
+		clkctrl_clk->reg_offset = reg_data->offset;
+		clkctrl_clk->clk = &hw->hw;
+
+		list_add(&clkctrl_clk->node, &provider->clocks);
+
+		reg_data++;
+	}
+
+	ret = of_clk_add_hw_provider(node, _ti_omap4_clkctrl_xlate, provider);
+	if (ret == -EPROBE_DEFER)
+		ti_clk_retry_init(node, provider, _clkctrl_add_provider);
+
+	kfree(clkctrl_name);
+
+	return;
+
+cleanup:
+	kfree(hw);
+	kfree(init.name);
+	kfree(clkctrl_name);
+	kfree(clkctrl_clk);
+}
+CLK_OF_DECLARE(ti_omap4_clkctrl_clock, "ti,clkctrl",
+	       _ti_omap4_clkctrl_setup);
+
+/**
+ * ti_clk_is_in_standby - Check if clkctrl clock is in standby or not
+ * @clk: clock to check standby status for
+ *
+ * Finds whether the provided clock is in standby mode or not. Returns
+ * true if the provided clock is a clkctrl type clock and it is in standby,
+ * false otherwise.
+ */
+bool ti_clk_is_in_standby(struct clk *clk)
+{
+	struct clk_hw *hw;
+	struct clk_hw_omap *hwclk;
+	u32 val;
+
+	hw = __clk_get_hw(clk);
+
+	if (!omap2_clk_is_hw_omap(hw))
+		return false;
+
+	hwclk = to_clk_hw_omap(hw);
+
+	val = ti_clk_ll_ops->clk_readl(&hwclk->enable_reg);
+
+	if (val & OMAP4_STBYST_MASK)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(ti_clk_is_in_standby);