diff mbox

[v6,02/14] clk: qcom: Add rcg ops to return floor value closest to the requested rate

Message ID 1478517877-23733-3-git-send-email-riteshh@codeaurora.org (mailing list archive)
State Not Applicable, archived
Delegated to: Andy Gross
Headers show

Commit Message

Ritesh Harjani Nov. 7, 2016, 11:24 a.m. UTC 
From: Rajendra Nayak <rnayak@codeaurora.org>

The default behaviour with clk_rcg2_ops is for the
clk_round_rate()/clk_set_rate() to return/set a ceil clock
rate closest to the requested rate by looking up the corresponding
frequency table.
However, we do have some instances (mainly sdcc on various platforms)
of clients expecting a clk_set_rate() to set a floor value instead.
Add a new clk_rcg2_floor_ops to handle this for such specific
rcg instances

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 drivers/clk/qcom/clk-rcg.h  |  1 +
 drivers/clk/qcom/clk-rcg2.c | 75 +++++++++++++++++++++++++++++++++++++++------
 drivers/clk/qcom/common.c   | 26 ++++++++++++++++
 drivers/clk/qcom/common.h   |  2 ++
 4 files changed, 95 insertions(+), 9 deletions(-)

Comments

kernel test robot Nov. 7, 2016, 1:51 p.m. UTC | #1 
Hi Rajendra,

[auto build test WARNING on ulf.hansson-mmc/next]
[also build test WARNING on v4.9-rc4 next-20161028]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Ritesh-Harjani/mmc-sdhci-msm-Add-clk-rates-DDR-HS400-support/20161107-203031
base:   https://git.linaro.org/people/ulf.hansson/mmc next
config: i386-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

   drivers/clk/qcom/clk-rcg2.c: In function '_freq_tbl_determine_rate':
>> drivers/clk/qcom/clk-rcg2.c:192:2: warning: switch condition has boolean value [-Wswitch-bool]
     switch (match) {
     ^~~~~~
   drivers/clk/qcom/clk-rcg2.c: In function '__clk_rcg2_set_rate':
   drivers/clk/qcom/clk-rcg2.c:297:2: warning: switch condition has boolean value [-Wswitch-bool]
     switch (match) {
     ^~~~~~

coccinelle warnings: (new ones prefixed by >>)

>> drivers/clk/qcom/clk-rcg2.c:306:2-3: Unneeded semicolon
   drivers/clk/qcom/clk-rcg2.c:201:2-3: Unneeded semicolon

Please review and possibly fold the followup patch.

vim +192 drivers/clk/qcom/clk-rcg2.c

   186	{
   187		unsigned long clk_flags, rate = req->rate;
   188		struct clk_hw *p;
   189		struct clk_rcg2 *rcg = to_clk_rcg2(hw);
   190		int index;
   191	
 > 192		switch (match) {
   193		case FLOOR:
   194			f = qcom_find_freq_floor(f, rate);
   195			break;
   196		case CEIL:
   197			f = qcom_find_freq(f, rate);
   198			break;
   199		default:
   200			return -EINVAL;
   201		};
   202	
   203		if (!f)
   204			return -EINVAL;
   205	
   206		index = qcom_find_src_index(hw, rcg->parent_map, f->src);
   207		if (index < 0)
   208			return index;
   209	
   210		clk_flags = clk_hw_get_flags(hw);
   211		p = clk_hw_get_parent_by_index(hw, index);
   212		if (clk_flags & CLK_SET_RATE_PARENT) {
   213			if (f->pre_div) {
   214				rate /= 2;
   215				rate *= f->pre_div + 1;
   216			}
   217	
   218			if (f->n) {
   219				u64 tmp = rate;
   220				tmp = tmp * f->n;
   221				do_div(tmp, f->m);
   222				rate = tmp;
   223			}
   224		} else {
   225			rate =  clk_hw_get_rate(p);
   226		}
   227		req->best_parent_hw = p;
   228		req->best_parent_rate = rate;
   229		req->rate = f->freq;
   230	
   231		return 0;
   232	}
   233	
   234	static int clk_rcg2_determine_rate(struct clk_hw *hw,
   235					   struct clk_rate_request *req)
   236	{
   237		struct clk_rcg2 *rcg = to_clk_rcg2(hw);
   238	
   239		return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, CEIL);
   240	}
   241	
   242	static int clk_rcg2_determine_floor_rate(struct clk_hw *hw,
   243						 struct clk_rate_request *req)
   244	{
   245		struct clk_rcg2 *rcg = to_clk_rcg2(hw);
   246	
   247		return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, FLOOR);
   248	}
   249	
   250	static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
   251	{
   252		u32 cfg, mask;
   253		struct clk_hw *hw = &rcg->clkr.hw;
   254		int ret, index = qcom_find_src_index(hw, rcg->parent_map, f->src);
   255	
   256		if (index < 0)
   257			return index;
   258	
   259		if (rcg->mnd_width && f->n) {
   260			mask = BIT(rcg->mnd_width) - 1;
   261			ret = regmap_update_bits(rcg->clkr.regmap,
   262					rcg->cmd_rcgr + M_REG, mask, f->m);
   263			if (ret)
   264				return ret;
   265	
   266			ret = regmap_update_bits(rcg->clkr.regmap,
   267					rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
   268			if (ret)
   269				return ret;
   270	
   271			ret = regmap_update_bits(rcg->clkr.regmap,
   272					rcg->cmd_rcgr + D_REG, mask, ~f->n);
   273			if (ret)
   274				return ret;
   275		}
   276	
   277		mask = BIT(rcg->hid_width) - 1;
   278		mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
   279		cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
   280		cfg |= rcg->parent_map[index].cfg << CFG_SRC_SEL_SHIFT;
   281		if (rcg->mnd_width && f->n && (f->m != f->n))
   282			cfg |= CFG_MODE_DUAL_EDGE;
   283		ret = regmap_update_bits(rcg->clkr.regmap,
   284				rcg->cmd_rcgr + CFG_REG, mask, cfg);
   285		if (ret)
   286			return ret;
   287	
   288		return update_config(rcg);
   289	}
   290	
   291	static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
   292				       bool match)
   293	{
   294		struct clk_rcg2 *rcg = to_clk_rcg2(hw);
   295		const struct freq_tbl *f;
   296	
   297		switch (match) {
   298		case FLOOR:
   299			f = qcom_find_freq_floor(rcg->freq_tbl, rate);
   300			break;
   301		case CEIL:
   302			f = qcom_find_freq(rcg->freq_tbl, rate);
   303			break;
   304		default:
   305			return -EINVAL;
 > 306		};
   307	
   308		if (!f)
   309			return -EINVAL;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Stephen Boyd Nov. 8, 2016, 11:02 p.m. UTC | #2 
On 11/07, Ritesh Harjani wrote:
> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
> index b904c33..1b3e8d2 100644
> --- a/drivers/clk/qcom/clk-rcg.h
> +++ b/drivers/clk/qcom/clk-rcg.h
> @@ -173,6 +173,7 @@ struct clk_rcg2 {
>  #define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
>  
>  extern const struct clk_ops clk_rcg2_ops;
> +extern const struct clk_ops clk_rcg2_floor_ops;
>  extern const struct clk_ops clk_rcg2_shared_ops;
>  extern const struct clk_ops clk_edp_pixel_ops;
>  extern const struct clk_ops clk_byte_ops;
> diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
> index a071bba..04433a6 100644
> --- a/drivers/clk/qcom/clk-rcg2.c
> +++ b/drivers/clk/qcom/clk-rcg2.c
> @@ -47,6 +47,11 @@
>  #define N_REG			0xc
>  #define D_REG			0x10
>  
> +enum {
> +	FLOOR,
> +	CEIL,
> +};

Give it a name.

> +
>  static int clk_rcg2_is_enabled(struct clk_hw *hw)
>  {
>  	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
> @@ -176,15 +181,25 @@ static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
>  	return calc_rate(parent_rate, m, n, mode, hid_div);
>  }
>  
> -static int _freq_tbl_determine_rate(struct clk_hw *hw,
> -		const struct freq_tbl *f, struct clk_rate_request *req)
> +static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
> +				    struct clk_rate_request *req, bool match)

Use the enum please. Also name it something besides match.
policy?

>  {
>  	unsigned long clk_flags, rate = req->rate;
>  	struct clk_hw *p;
>  	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
>  	int index;
>  
> -	f = qcom_find_freq(f, rate);
> +	switch (match) {
> +	case FLOOR:
> +		f = qcom_find_freq_floor(f, rate);
> +		break;
> +	case CEIL:
> +		f = qcom_find_freq(f, rate);
> +		break;
> +	default:
> +		return -EINVAL;
> +	};
> +
>  	if (!f)
>  		return -EINVAL;
>  
> diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
> index fffcbaf..cf6b87f 100644
> --- a/drivers/clk/qcom/common.c
> +++ b/drivers/clk/qcom/common.c
> @@ -46,6 +46,32 @@ struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
>  }
>  EXPORT_SYMBOL_GPL(qcom_find_freq);
>  
> +const
> +struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,

We can't put const and struct on the same line?

> +				      unsigned long rate)
> +{
> +	int size = 0;
> +
> +	if (!f)
> +		return NULL;
> +
> +	/*
> +	 * The freq table has entries in the ascending order of frequencies
> +	 * To find the floor for a given frequency, we need to do a reverse
> +	 * lookup of the table
> +	 */
> +	for (; f->freq; f++, size++)
> +		;
> +
> +	for (f--; size; f--, size--)
> +		if (rate >= f->freq)
> +			return f;

I don't understand why we can't do this while iterating through
the table. We shouldn't need to size up the frequency table first.

	const struct freq_tbl *best = NULL;

	for ( ; f->freq; f++) {
		if (rate >= f->freq)
			best = f->freq;
		else
			break;
	}
	
	return best;

> +
> +	/* could not find any rates lower than *rate* */

> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(qcom_find_freq_floor);
Ritesh Harjani Nov. 9, 2016, 11:53 a.m. UTC | #3 
Hi Stephen,

Thanks for the review.

On 11/9/2016 4:32 AM, Stephen Boyd wrote:
> On 11/07, Ritesh Harjani wrote:
>> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
>> index b904c33..1b3e8d2 100644
>> --- a/drivers/clk/qcom/clk-rcg.h
>> +++ b/drivers/clk/qcom/clk-rcg.h
>> @@ -173,6 +173,7 @@ struct clk_rcg2 {
>>  #define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
>>
>>  extern const struct clk_ops clk_rcg2_ops;
>> +extern const struct clk_ops clk_rcg2_floor_ops;
>>  extern const struct clk_ops clk_rcg2_shared_ops;
>>  extern const struct clk_ops clk_edp_pixel_ops;
>>  extern const struct clk_ops clk_byte_ops;
>> diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
>> index a071bba..04433a6 100644
>> --- a/drivers/clk/qcom/clk-rcg2.c
>> +++ b/drivers/clk/qcom/clk-rcg2.c
>> @@ -47,6 +47,11 @@
>>  #define N_REG			0xc
>>  #define D_REG			0x10
>>
>> +enum {
>> +	FLOOR,
>> +	CEIL,
>> +};
>
> Give it a name.
Yes, sure. I will keep it as freq_policy.

>
>> +
>>  static int clk_rcg2_is_enabled(struct clk_hw *hw)
>>  {
>>  	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
>> @@ -176,15 +181,25 @@ static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
>>  	return calc_rate(parent_rate, m, n, mode, hid_div);
>>  }
>>
>> -static int _freq_tbl_determine_rate(struct clk_hw *hw,
>> -		const struct freq_tbl *f, struct clk_rate_request *req)
>> +static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
>> +				    struct clk_rate_request *req, bool match)
>
> Use the enum please. Also name it something besides match.
> policy?
Sure. (freq_policy)

>
>>  {
>>  	unsigned long clk_flags, rate = req->rate;
>>  	struct clk_hw *p;
>>  	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
>>  	int index;
>>
>> -	f = qcom_find_freq(f, rate);
>> +	switch (match) {
>> +	case FLOOR:
>> +		f = qcom_find_freq_floor(f, rate);
>> +		break;
>> +	case CEIL:
>> +		f = qcom_find_freq(f, rate);
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	};
>> +
>>  	if (!f)
>>  		return -EINVAL;
>>
>> diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
>> index fffcbaf..cf6b87f 100644
>> --- a/drivers/clk/qcom/common.c
>> +++ b/drivers/clk/qcom/common.c
>> @@ -46,6 +46,32 @@ struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
>>  }
>>  EXPORT_SYMBOL_GPL(qcom_find_freq);
>>
>> +const
>> +struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,
>
> We can't put const and struct on the same line?
Ok sure.

>
>> +				      unsigned long rate)
>> +{
>> +	int size = 0;
>> +
>> +	if (!f)
>> +		return NULL;
>> +
>> +	/*
>> +	 * The freq table has entries in the ascending order of frequencies
>> +	 * To find the floor for a given frequency, we need to do a reverse
>> +	 * lookup of the table
>> +	 */
>> +	for (; f->freq; f++, size++)
>> +		;
>> +
>> +	for (f--; size; f--, size--)
>> +		if (rate >= f->freq)
>> +			return f;
>
> I don't understand why we can't do this while iterating through
> the table. We shouldn't need to size up the frequency table first.
>
> 	const struct freq_tbl *best = NULL;
>
> 	for ( ; f->freq; f++) {
> 		if (rate >= f->freq)
> 			best = f->freq;
> 		else
> 			break;
> 	}
> 	
> 	return best;
>
Yes, will do above change.

>> +
>> +	/* could not find any rates lower than *rate* */
>
>> +	return NULL;
>> +}
>> +EXPORT_SYMBOL_GPL(qcom_find_freq_floor);
>
diff mbox

Patch

diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index b904c33..1b3e8d2 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/drivers/clk/qcom/clk-rcg.h
@@ -173,6 +173,7 @@  struct clk_rcg2 {
 #define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
 
 extern const struct clk_ops clk_rcg2_ops;
+extern const struct clk_ops clk_rcg2_floor_ops;
 extern const struct clk_ops clk_rcg2_shared_ops;
 extern const struct clk_ops clk_edp_pixel_ops;
 extern const struct clk_ops clk_byte_ops;
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index a071bba..04433a6 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -47,6 +47,11 @@ 
 #define N_REG			0xc
 #define D_REG			0x10
 
+enum {
+	FLOOR,
+	CEIL,
+};
+
 static int clk_rcg2_is_enabled(struct clk_hw *hw)
 {
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
@@ -176,15 +181,25 @@  static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
 	return calc_rate(parent_rate, m, n, mode, hid_div);
 }
 
-static int _freq_tbl_determine_rate(struct clk_hw *hw,
-		const struct freq_tbl *f, struct clk_rate_request *req)
+static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
+				    struct clk_rate_request *req, bool match)
 {
 	unsigned long clk_flags, rate = req->rate;
 	struct clk_hw *p;
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
 	int index;
 
-	f = qcom_find_freq(f, rate);
+	switch (match) {
+	case FLOOR:
+		f = qcom_find_freq_floor(f, rate);
+		break;
+	case CEIL:
+		f = qcom_find_freq(f, rate);
+		break;
+	default:
+		return -EINVAL;
+	};
+
 	if (!f)
 		return -EINVAL;
 
@@ -221,7 +236,15 @@  static int clk_rcg2_determine_rate(struct clk_hw *hw,
 {
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
 
-	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req);
+	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, CEIL);
+}
+
+static int clk_rcg2_determine_floor_rate(struct clk_hw *hw,
+					 struct clk_rate_request *req)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+
+	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, FLOOR);
 }
 
 static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
@@ -265,12 +288,23 @@  static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
 	return update_config(rcg);
 }
 
-static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
+static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
+			       bool match)
 {
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
 	const struct freq_tbl *f;
 
-	f = qcom_find_freq(rcg->freq_tbl, rate);
+	switch (match) {
+	case FLOOR:
+		f = qcom_find_freq_floor(rcg->freq_tbl, rate);
+		break;
+	case CEIL:
+		f = qcom_find_freq(rcg->freq_tbl, rate);
+		break;
+	default:
+		return -EINVAL;
+	};
+
 	if (!f)
 		return -EINVAL;
 
@@ -280,13 +314,25 @@  static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
 static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
 			    unsigned long parent_rate)
 {
-	return __clk_rcg2_set_rate(hw, rate);
+	return __clk_rcg2_set_rate(hw, rate, CEIL);
+}
+
+static int clk_rcg2_set_floor_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	return __clk_rcg2_set_rate(hw, rate, FLOOR);
 }
 
 static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
 		unsigned long rate, unsigned long parent_rate, u8 index)
 {
-	return __clk_rcg2_set_rate(hw, rate);
+	return __clk_rcg2_set_rate(hw, rate, CEIL);
+}
+
+static int clk_rcg2_set_floor_rate_and_parent(struct clk_hw *hw,
+		unsigned long rate, unsigned long parent_rate, u8 index)
+{
+	return __clk_rcg2_set_rate(hw, rate, FLOOR);
 }
 
 const struct clk_ops clk_rcg2_ops = {
@@ -300,6 +346,17 @@  static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
 };
 EXPORT_SYMBOL_GPL(clk_rcg2_ops);
 
+const struct clk_ops clk_rcg2_floor_ops = {
+	.is_enabled = clk_rcg2_is_enabled,
+	.get_parent = clk_rcg2_get_parent,
+	.set_parent = clk_rcg2_set_parent,
+	.recalc_rate = clk_rcg2_recalc_rate,
+	.determine_rate = clk_rcg2_determine_floor_rate,
+	.set_rate = clk_rcg2_set_floor_rate,
+	.set_rate_and_parent = clk_rcg2_set_floor_rate_and_parent,
+};
+EXPORT_SYMBOL_GPL(clk_rcg2_floor_ops);
+
 static int clk_rcg2_shared_force_enable(struct clk_hw *hw, unsigned long rate)
 {
 	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
@@ -323,7 +380,7 @@  static int clk_rcg2_shared_force_enable(struct clk_hw *hw, unsigned long rate)
 		pr_err("%s: RCG did not turn on\n", name);
 
 	/* set clock rate */
-	ret = __clk_rcg2_set_rate(hw, rate);
+	ret = __clk_rcg2_set_rate(hw, rate, CEIL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index fffcbaf..cf6b87f 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -46,6 +46,32 @@  struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
 }
 EXPORT_SYMBOL_GPL(qcom_find_freq);
 
+const
+struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,
+				      unsigned long rate)
+{
+	int size = 0;
+
+	if (!f)
+		return NULL;
+
+	/*
+	 * The freq table has entries in the ascending order of frequencies
+	 * To find the floor for a given frequency, we need to do a reverse
+	 * lookup of the table
+	 */
+	for (; f->freq; f++, size++)
+		;
+
+	for (f--; size; f--, size--)
+		if (rate >= f->freq)
+			return f;
+
+	/* could not find any rates lower than *rate* */
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(qcom_find_freq_floor);
+
 int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map, u8 src)
 {
 	int i, num_parents = clk_hw_get_num_parents(hw);
diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h
index ae9bdeb..76886a1 100644
--- a/drivers/clk/qcom/common.h
+++ b/drivers/clk/qcom/common.h
@@ -34,6 +34,8 @@  struct qcom_cc_desc {
 
 extern const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f,
 					     unsigned long rate);
+extern const struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,
+						   unsigned long rate);
 extern int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map,
 			       u8 src);