Thread (20 messages) 20 messages, 4 authors, 2017-07-26

Re: [PATCH v3 3/9] clk: at91: add audio pll clock drivers

From: Stephen Boyd <hidden>
Date: 2017-07-21 22:20:37
Also in: alsa-devel, linux-arm-kernel, linux-clk, lkml

On 07/13, Quentin Schulz wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/at91/clk-audio-pll-pad.c b/drivers/clk/at91/clk-audio-pll-pad.c
new file mode 100644
index 000000000000..10dd6d625696
--- /dev/null
+++ b/drivers/clk/at91/clk-audio-pll-pad.c
@@ -0,0 +1,206 @@
+/*
+ *  Copyright (C) 2016 Atmel Corporation,
+ *                     Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *  Copyright (C) 2017 Free Electrons,
+ *		       Quentin Schulz <quentin.schulz-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
Used?
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+/*
+ * DOC: PAD output for fractional PLL clock for audio
+ *
+ * Traits of this clock:
+ * enable - clk_enable writes divisors and enables PAD output
+ * rate - rate is adjustable.
+ *        clk->rate = parent->rate / (qdaudio * div))
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define AUDIO_PLL_QDPAD(qd, div)	((AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV(qd) & \
+					  AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MASK) | \
+					 (AT91_PMC_AUDIO_PLL_QDPAD_DIV(div) & \
+					  AT91_PMC_AUDIO_PLL_QDPAD_DIV_MASK))
+
+struct clk_audio_pad {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u8 qdaudio;
+	u8 div;
+};
+
+#define to_clk_audio_pad(hw) container_of(hw, struct clk_audio_pad, hw)
+
+static int clk_audio_pll_pad_enable(struct clk_hw *hw)
+{
+	struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+
+	regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL1,
+			   AT91_PMC_AUDIO_PLL_QDPAD_MASK,
+			   AUDIO_PLL_QDPAD(apad_ck->qdaudio, apad_ck->div));
+	regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PADEN, AT91_PMC_AUDIO_PLL_PADEN);
+
+	return 0;
+}
+
+static void clk_audio_pll_pad_disable(struct clk_hw *hw)
+{
+	struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+
+	regmap_update_bits(apad_ck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PADEN, 0);
+}
+
+static unsigned long clk_audio_pll_pad_recalc_rate(struct clk_hw *hw,
+						   unsigned long parent_rate)
+{
+	struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+	unsigned long apad_rate = 0;
+
+	if (apad_ck->qdaudio && apad_ck->div)
+		apad_rate = parent_rate / (apad_ck->qdaudio * apad_ck->div);
+
+	pr_debug("A PLL/PAD: %s, apad_rate = %lu (div = %u, qdaudio = %u)\n",
+		 __func__, apad_rate, apad_ck->div, apad_ck->qdaudio);
+
+	return apad_rate;
+}
+
+static long clk_audio_pll_pad_round_rate(struct clk_hw *hw, unsigned long rate,
+					 unsigned long *parent_rate)
+{
+	struct clk_hw *pclk = clk_hw_get_parent(hw);
+	long best_rate = -EINVAL;
+	unsigned long best_parent_rate;
+	unsigned long tmp_qd;
+	u32 div;
+	long tmp_rate;
+	int tmp_diff;
+	int best_diff = -1;
+
+	pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+		 rate, *parent_rate);
+
+	/*
+	 * Rate divisor is actually made of two different divisors, multiplied
+	 * between themselves before dividing the rate.
+	 * tmp_qd goes from 1 to 31 and div is either 2 or 3.
+	 * In order to avoid testing twice the rate divisor (e.g. divisor 12 can
+	 * be found with (tmp_qd, div) = (2, 6) or (3, 4)), we remove any loop
+	 * for a rate divisor when div is 2 and tmp_qd is a multiple of 3.
+	 * We cannot inverse it (condition div is 3 and tmp_qd is even) or we
+	 * would miss some rate divisor that aren't reachable with div being 2
+	 * (e.g. rate divisor 90 is made with div = 3 and tmp_qd = 30, thus
+	 * tmp_qd is even so we skip it because we think div 2 could make this
+	 * rate divisor which isn't possible since tmp_qd has to be <= 31).
+	 */
+	for (tmp_qd = 1; tmp_qd < AT91_PMC_AUDIO_PLL_QDPAD_EXTDIV_MAX; tmp_qd++)
+		for (div = 2; div <= 3; div++) {
+			if (div == 2 && tmp_qd % 3 == 0)
+				continue;
+
+			best_parent_rate = clk_hw_round_rate(pclk,
+							rate * tmp_qd * div);
+			tmp_rate = best_parent_rate / (div * tmp_qd);
+			tmp_diff = abs(rate - tmp_rate);
+
+			if (best_diff < 0 || best_diff > tmp_diff) {
+				*parent_rate = best_parent_rate;
+				best_rate = tmp_rate;
+				best_diff = tmp_diff;
+			}
+		}
+
+	pr_debug("A PLL/PAD: %s, best_rate = %ld, best_parent_rate = %lu\n",
+		 __func__, best_rate, best_parent_rate);
+
+	return best_rate;
+}
+
+static int clk_audio_pll_pad_set_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long parent_rate)
+{
+	struct clk_audio_pad *apad_ck = to_clk_audio_pad(hw);
+	u8 tmp_div;
+
+	pr_debug("A PLL/PAD: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+		 rate, parent_rate);
+
+	if (!rate)
+		return -EINVAL;
This happens?
+
+	tmp_div = parent_rate / rate;
+	if (tmp_div % 3 == 0) {
+		apad_ck->qdaudio = tmp_div / 3;
+		apad_ck->div = 3;
+	} else {
+		apad_ck->qdaudio = tmp_div / 2;
+		apad_ck->div = 2;
+	}
+
+	return 0;
+}
+
+static const struct clk_ops audio_pll_pad_ops = {
+	.enable = clk_audio_pll_pad_enable,
+	.disable = clk_audio_pll_pad_disable,
+	.recalc_rate = clk_audio_pll_pad_recalc_rate,
+	.round_rate = clk_audio_pll_pad_round_rate,
+	.set_rate = clk_audio_pll_pad_set_rate,
+};
+
+static void __init of_sama5d2_clk_audio_pll_pad_setup(struct device_node *np)
+{
+	struct clk_audio_pad *apad_ck;
+	struct clk_init_data init;
Best to initialize to { } just in case we add something later.
+	struct regmap *regmap;
+	const char *parent_name;
+	const char *name = np->name;
+	int ret;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+
+	of_property_read_string(np, "clock-output-names", &name);
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap))
+		return;
+
+	apad_ck = kzalloc(sizeof(*apad_ck), GFP_KERNEL);
+	if (!apad_ck)
+		return;
+
+	init.name = name;
+	init.ops = &audio_pll_pad_ops;
+	init.parent_names = (parent_name ? &parent_name : NULL);
Use of_clk_parent_fill()?
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+		CLK_SET_RATE_PARENT;
+
+	apad_ck->hw.init = &init;
+	apad_ck->regmap = regmap;
+
+	ret = clk_hw_register(NULL, &apad_ck->hw);
+	if (ret)
+		kfree(apad_ck);
+	else
+		of_clk_add_hw_provider(np, of_clk_hw_simple_get, &apad_ck->hw);
Maybe we should make this register sequence a helper function.
Seems common.
+}
+
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pad_setup,
+	       "atmel,sama5d2-clk-audio-pll-pad",
+	       of_sama5d2_clk_audio_pll_pad_setup);
We can't have a device driver for this?
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/at91/clk-audio-pll-pmc.c b/drivers/clk/at91/clk-audio-pll-pmc.c
new file mode 100644
index 000000000000..7b0847ed7a4b
--- /dev/null
+++ b/drivers/clk/at91/clk-audio-pll-pmc.c
@@ -0,0 +1,174 @@
+/*
+ *  Copyright (C) 2016 Atmel Corporation,
+ *                     Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *  Copyright (C) 2017 Free Electrons,
+ *		       Quentin Schulz <quentin.schulz-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
Used?
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+/*
+ * DOC: PMC output for fractional PLL clock for audio
+ *
+ * Traits of this clock:
+ * enable - clk_enable writes qdpmc, and enables PMC output
+ * rate - rate is adjustable.
+ *        clk->rate = parent->rate / (qdpmc + 1)
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define AUDIO_PLL_QDPMC_MAX		(AT91_PMC_AUDIO_PLL_QDPMC_MASK >> \
+						AT91_PMC_AUDIO_PLL_QDPMC_OFFSET)
+struct clk_audio_pmc {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u8 qdpmc;
+};
+
+#define to_clk_audio_pmc(hw) container_of(hw, struct clk_audio_pmc, hw)
+
+static int clk_audio_pll_pmc_enable(struct clk_hw *hw)
+{
+	struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+	regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PMCEN |
+			   AT91_PMC_AUDIO_PLL_QDPMC_MASK,
+			   AT91_PMC_AUDIO_PLL_PMCEN |
+			   AT91_PMC_AUDIO_PLL_QDPMC(apmc_ck->qdpmc));
+	return 0;
+}
+
+static void clk_audio_pll_pmc_disable(struct clk_hw *hw)
+{
+	struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+	regmap_update_bits(apmc_ck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PMCEN, 0);
+}
+
+static unsigned long clk_audio_pll_pmc_recalc_rate(struct clk_hw *hw,
+						   unsigned long parent_rate)
+{
+	struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+	unsigned long apmc_rate = 0;
+
+	apmc_rate = parent_rate / (apmc_ck->qdpmc + 1);
+
+	pr_debug("A PLL/PMC: %s, apmc_rate = %lu (qdpmc = %u)\n", __func__,
+		 apmc_rate, apmc_ck->qdpmc);
+
+	return apmc_rate;
+}
+
+static long clk_audio_pll_pmc_round_rate(struct clk_hw *hw, unsigned long rate,
+					 unsigned long *parent_rate)
+{
+	struct clk_hw *pclk = clk_hw_get_parent(hw);
+	long best_rate = -EINVAL;
+	unsigned long best_parent_rate = 0;
+	u32 tmp_qd = 0, div;
+	long tmp_rate;
+	int tmp_diff;
+	int best_diff = -1;
+
+	pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+		 rate, *parent_rate);
+
+	for (div = 1; div <= AUDIO_PLL_QDPMC_MAX; div++) {
+		best_parent_rate = clk_round_rate(pclk->clk, rate * div);
+		tmp_rate = best_parent_rate / div;
+		tmp_diff = abs(rate - tmp_rate);
+
+		if (best_diff < 0 || best_diff > tmp_diff) {
+			*parent_rate = best_parent_rate;
+			best_rate = tmp_rate;
+			best_diff = tmp_diff;
+			tmp_qd = div;
+		}
+	}
+
+	pr_debug("A PLL/PMC: %s, best_rate = %ld, best_parent_rate = %lu (qd = %d)\n",
+		 __func__, best_rate, *parent_rate, tmp_qd - 1);
+
+	return best_rate;
+}
+
+static int clk_audio_pll_pmc_set_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long parent_rate)
+{
+	struct clk_audio_pmc *apmc_ck = to_clk_audio_pmc(hw);
+
+	if (!rate)
+		return -EINVAL;
+
+	pr_debug("A PLL/PMC: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+		 rate, parent_rate);
+
+	apmc_ck->qdpmc = parent_rate / rate - 1;
Hopefully rate isn't 1 or that goes undefined.
+
+	return 0;
+}
+
+static const struct clk_ops audio_pll_pmc_ops = {
+	.enable = clk_audio_pll_pmc_enable,
+	.disable = clk_audio_pll_pmc_disable,
+	.recalc_rate = clk_audio_pll_pmc_recalc_rate,
+	.round_rate = clk_audio_pll_pmc_round_rate,
+	.set_rate = clk_audio_pll_pmc_set_rate,
+};
+
+static void __init of_sama5d2_clk_audio_pll_pmc_setup(struct device_node *np)
+{
+	struct clk_audio_pmc *apmc_ck;
+	struct clk_init_data init;
+	struct regmap *regmap;
+	const char *parent_name;
+	const char *name = np->name;
+	int ret;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+
+	of_property_read_string(np, "clock-output-names", &name);
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap))
+		return;
+
+	apmc_ck = kzalloc(sizeof(*apmc_ck), GFP_KERNEL);
+	if (!apmc_ck)
+		return;
+
+	init.name = name;
+	init.ops = &audio_pll_pmc_ops;
+	init.parent_names = (parent_name ? &parent_name : NULL);
This feels repetitive.
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+		CLK_SET_RATE_PARENT;
+
+	apmc_ck->hw.init = &init;
+	apmc_ck->regmap = regmap;
+
+	ret = clk_hw_register(NULL, &apmc_ck->hw);
+	if (ret)
+		kfree(apmc_ck);
+	else
+		of_clk_add_hw_provider(np, of_clk_hw_simple_get, &apmc_ck->hw);
+}
+
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pmc_setup,
+	       "atmel,sama5d2-clk-audio-pll-pmc",
+	       of_sama5d2_clk_audio_pll_pmc_setup);
Very
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/at91/clk-audio-pll.c b/drivers/clk/at91/clk-audio-pll.c
new file mode 100644
index 000000000000..efc2cb58da85
--- /dev/null
+++ b/drivers/clk/at91/clk-audio-pll.c
@@ -0,0 +1,239 @@
+/*
+ *  Copyright (C) 2016 Atmel Corporation,
+ *		       Songjun Wu <songjun.wu-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>,
+ *                     Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *  Copyright (C) 2017 Free Electrons,
+ *		       Quentin Schulz <quentin.schulz-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
Used?
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+/*
+ * DOC: Fractional PLL clock for audio
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare puts audio PLL in reset state
+ * enable - clk_enable writes nd, fracr parameters and enables PLL
+ * rate - rate is adjustable.
+ *        clk->rate = parent->rate * ((nd + 1) + (fracr / 2^22))
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define AUDIO_PLL_DIV_FRAC	BIT(22)
+#define AUDIO_PLL_ND_MAX	(AT91_PMC_AUDIO_PLL_ND_MASK >> \
+					AT91_PMC_AUDIO_PLL_ND_OFFSET)
+
+#define AUDIO_PLL_FOUT_MIN	620000000
+#define AUDIO_PLL_FOUT_MAX	700000000
+
+struct clk_audio_frac {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u32 fracr;
+	u8 nd;
+};
+
+#define to_clk_audio_frac(hw) container_of(hw, struct clk_audio_frac, hw)
+
+static int clk_audio_pll_enable(struct clk_hw *hw)
+{
+	struct clk_audio_frac *fck = to_clk_audio_frac(hw);
+
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_RESETN, 0);
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_RESETN,
+			   AT91_PMC_AUDIO_PLL_RESETN);
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL1,
+			   AT91_PMC_AUDIO_PLL_FRACR_MASK, fck->fracr);
+
+	/*
+	 * reset and enable have to be done in 2 separated writes
+	 * for AT91_PMC_AUDIO_PLL0
+	 */
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PLLEN |
+			   AT91_PMC_AUDIO_PLL_ND_MASK,
+			   AT91_PMC_AUDIO_PLL_PLLEN |
+			   AT91_PMC_AUDIO_PLL_ND(fck->nd));
+
+	return 0;
+}
+
+static void clk_audio_pll_disable(struct clk_hw *hw)
+{
+	struct clk_audio_frac *fck = to_clk_audio_frac(hw);
+
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_PLLEN, 0);
+	/* do it in 2 separated writes */
+	regmap_update_bits(fck->regmap, AT91_PMC_AUDIO_PLL0,
+			   AT91_PMC_AUDIO_PLL_RESETN, 0);
+}
+
+static unsigned long clk_audio_pll_fout(unsigned long parent_rate,
+					unsigned long nd, unsigned long fracr)
+{
+	unsigned long long fr = (unsigned long long)parent_rate *
+						(unsigned long long)fracr;
We only need one cast here?
+
+	pr_debug("A PLL: %s, fr = %llu\n", __func__, fr);
+
+	fr = DIV_ROUND_CLOSEST_ULL(fr, AUDIO_PLL_DIV_FRAC);
+
+	pr_debug("A PLL: %s, fr = %llu\n", __func__, fr);
+
+	return parent_rate * (nd + 1) + fr;
+}
+
+static unsigned long clk_audio_pll_recalc_rate(struct clk_hw *hw,
+					       unsigned long parent_rate)
+{
+	struct clk_audio_frac *fck = to_clk_audio_frac(hw);
+	unsigned long fout;
+
+	fout = clk_audio_pll_fout(parent_rate, fck->nd, fck->fracr);
+
+	pr_debug("A PLL: %s, fout = %lu (nd = %u, fracr = %lu)\n", __func__,
+		 fout, fck->nd, (unsigned long)fck->fracr);
+
+	return fout;
+}
+
+static int clk_audio_pll_compute_frac(unsigned long rate,
+				      unsigned long parent_rate,
+				      unsigned long *nd, unsigned long *fracr)
+{
+	unsigned long long tmp, rem;
+
+	if (!rate)
+		return -EINVAL;
This happens?
+
+	tmp = rate;
+	rem = do_div(tmp, parent_rate);
+	if (!tmp || tmp >= AUDIO_PLL_ND_MAX)
+		return -EINVAL;
+
+	*nd = tmp - 1;
+
+	tmp = rem * AUDIO_PLL_DIV_FRAC;
+	tmp = DIV_ROUND_CLOSEST_ULL(tmp, parent_rate);
+	if (tmp > AT91_PMC_AUDIO_PLL_FRACR_MASK)
+		return -EINVAL;
+
+	/* we can cast here as we verified the bounds just above */
+	*fracr = (unsigned long)tmp;
+
+	return 0;
+}
+
+static long clk_audio_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long *parent_rate)
+{
+	long best_rate = -EINVAL;
+	unsigned long fracr, nd;
+	int ret;
+
+	pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, rate,
+		 *parent_rate);
+
+	if (rate < AUDIO_PLL_FOUT_MIN)
+		rate = AUDIO_PLL_FOUT_MIN;
+	else if (rate > AUDIO_PLL_FOUT_MAX)
+		rate = AUDIO_PLL_FOUT_MAX;
Use clamp. Also, did you want to use determine_rate callback and
clamp the requested rate range?
+
+	ret = clk_audio_pll_compute_frac(rate, *parent_rate, &nd, &fracr);
+	if (ret)
+		return ret;
+
+	best_rate = clk_audio_pll_fout(*parent_rate, nd, fracr);
+
+	pr_debug("A PLL: %s, best_rate = %lu (nd = %lu, fracr = %lu)\n",
+		 __func__, best_rate, nd, fracr);
+
+	return best_rate;
+}
+
+static int clk_audio_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	struct clk_audio_frac *fck = to_clk_audio_frac(hw);
+	unsigned long fracr, nd;
+	int ret;
+
+	pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__, rate,
+		 parent_rate);
+
+	if (rate < AUDIO_PLL_FOUT_MIN || rate > AUDIO_PLL_FOUT_MAX)
+		return -EINVAL;
+
+	ret = clk_audio_pll_compute_frac(rate, parent_rate, &nd, &fracr);
+	if (ret)
+		return ret;
+
+	fck->nd = nd;
+	fck->fracr = fracr;
+
+	return 0;
+}
+
+static const struct clk_ops audio_pll_ops = {
+	.enable = clk_audio_pll_enable,
+	.disable = clk_audio_pll_disable,
+	.recalc_rate = clk_audio_pll_recalc_rate,
+	.round_rate = clk_audio_pll_round_rate,
+	.set_rate = clk_audio_pll_set_rate,
+};
+
+static void __init of_sama5d2_clk_audio_pll_setup(struct device_node *np)
+{
+	struct clk_audio_frac *fck;
+	struct clk_init_data init;
+	struct regmap *regmap;
+	const char *parent_name;
+	const char *name = np->name;
+	int ret;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+
+	of_property_read_string(np, "clock-output-names", &name);
Any way to not rely on clock-output-names?
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap))
+		return;
+
+	fck = kzalloc(sizeof(*fck), GFP_KERNEL);
This variable name looks like f*ck, perhaps name it something
else. frac?
+	if (!fck)
+		return;
+
+	init.name = name;
+	init.ops = &audio_pll_ops;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_GATE;
+
+	fck->hw.init = &init;
+	fck->regmap = regmap;
+
+	ret = clk_hw_register(NULL, &fck->hw);
+	if (ret)
+		kfree(fck);
+	else
+		of_clk_add_hw_provider(np, of_clk_hw_simple_get, &fck->hw);
+}
+
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_setup,
+	       "atmel,sama5d2-clk-audio-pll-frac",
+	       of_sama5d2_clk_audio_pll_setup);
-- 
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