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path: root/drivers/clk/at91/clk-audio-pll.c
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-rw-r--r--drivers/clk/at91/clk-audio-pll.c536
1 files changed, 536 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-audio-pll.c b/drivers/clk/at91/clk-audio-pll.c
new file mode 100644
index 000000000000..da7bafcfbe70
--- /dev/null
+++ b/drivers/clk/at91/clk-audio-pll.c
@@ -0,0 +1,536 @@
+/*
+ * Copyright (C) 2016 Atmel Corporation,
+ * Songjun Wu <songjun.wu@atmel.com>,
+ * Nicolas Ferre <nicolas.ferre@atmel.com>
+ * Copyright (C) 2017 Free Electrons,
+ * Quentin Schulz <quentin.schulz@free-electrons.com>
+ *
+ * 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.
+ *
+ * The Sama5d2 SoC has two audio PLLs (PMC and PAD) that shares the same parent
+ * (FRAC). FRAC can output between 620 and 700MHz and only multiply the rate of
+ * its own parent. PMC and PAD can then divide the FRAC rate to best match the
+ * asked rate.
+ *
+ * Traits of FRAC clock:
+ * 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
+ *
+ * Traits of PMC 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
+ *
+ * Traits of PAD 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
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#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_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))
+
+#define AUDIO_PLL_QDPMC_MAX (AT91_PMC_AUDIO_PLL_QDPMC_MASK >> \
+ AT91_PMC_AUDIO_PLL_QDPMC_OFFSET)
+
+#define AUDIO_PLL_FOUT_MIN 620000000UL
+#define AUDIO_PLL_FOUT_MAX 700000000UL
+
+struct clk_audio_frac {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u32 fracr;
+ u8 nd;
+};
+
+struct clk_audio_pad {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u8 qdaudio;
+ u8 div;
+};
+
+struct clk_audio_pmc {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u8 qdpmc;
+};
+
+#define to_clk_audio_frac(hw) container_of(hw, struct clk_audio_frac, hw)
+#define to_clk_audio_pad(hw) container_of(hw, struct clk_audio_pad, hw)
+#define to_clk_audio_pmc(hw) container_of(hw, struct clk_audio_pmc, hw)
+
+static int clk_audio_pll_frac_enable(struct clk_hw *hw)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN, 0);
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN,
+ AT91_PMC_AUDIO_PLL_RESETN);
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL1,
+ AT91_PMC_AUDIO_PLL_FRACR_MASK, frac->fracr);
+
+ /*
+ * reset and enable have to be done in 2 separated writes
+ * for AT91_PMC_AUDIO_PLL0
+ */
+ regmap_update_bits(frac->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(frac->nd));
+
+ return 0;
+}
+
+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 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_frac_disable(struct clk_hw *hw)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_PLLEN, 0);
+ /* do it in 2 separated writes */
+ regmap_update_bits(frac->regmap, AT91_PMC_AUDIO_PLL0,
+ AT91_PMC_AUDIO_PLL_RESETN, 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 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_fout(unsigned long parent_rate,
+ unsigned long nd, unsigned long fracr)
+{
+ unsigned long long fr = (unsigned long long)parent_rate * fracr;
+
+ 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_frac_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_audio_frac *frac = to_clk_audio_frac(hw);
+ unsigned long fout;
+
+ fout = clk_audio_pll_fout(parent_rate, frac->nd, frac->fracr);
+
+ pr_debug("A PLL: %s, fout = %lu (nd = %u, fracr = %lu)\n", __func__,
+ fout, frac->nd, (unsigned long)frac->fracr);
+
+ return fout;
+}
+
+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 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 int clk_audio_pll_frac_compute_frac(unsigned long rate,
+ unsigned long parent_rate,
+ unsigned long *nd,
+ unsigned long *fracr)
+{
+ unsigned long long tmp, rem;
+
+ if (!rate)
+ return -EINVAL;
+
+ 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 int clk_audio_pll_frac_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ unsigned long fracr, nd;
+ int ret;
+
+ pr_debug("A PLL: %s, rate = %lu (parent_rate = %lu)\n", __func__,
+ req->rate, req->best_parent_rate);
+
+ req->rate = clamp(req->rate, AUDIO_PLL_FOUT_MIN, AUDIO_PLL_FOUT_MAX);
+
+ req->min_rate = max(req->min_rate, AUDIO_PLL_FOUT_MIN);
+ req->max_rate = min(req->max_rate, AUDIO_PLL_FOUT_MAX);
+
+ ret = clk_audio_pll_frac_compute_frac(req->rate, req->best_parent_rate,
+ &nd, &fracr);
+ if (ret)
+ return ret;
+
+ req->rate = clk_audio_pll_fout(req->best_parent_rate, nd, fracr);
+
+ req->best_parent_hw = clk_hw_get_parent(hw);
+
+ pr_debug("A PLL: %s, best_rate = %lu (nd = %lu, fracr = %lu)\n",
+ __func__, req->rate, nd, fracr);
+
+ return 0;
+}
+
+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 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_frac_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_audio_frac *frac = 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_frac_compute_frac(rate, parent_rate, &nd, &fracr);
+ if (ret)
+ return ret;
+
+ frac->nd = nd;
+ frac->fracr = fracr;
+
+ return 0;
+}
+
+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;
+
+ 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 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;
+
+ return 0;
+}
+
+static const struct clk_ops audio_pll_frac_ops = {
+ .enable = clk_audio_pll_frac_enable,
+ .disable = clk_audio_pll_frac_disable,
+ .recalc_rate = clk_audio_pll_frac_recalc_rate,
+ .determine_rate = clk_audio_pll_frac_determine_rate,
+ .set_rate = clk_audio_pll_frac_set_rate,
+};
+
+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 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 int of_sama5d2_clk_audio_pll_setup(struct device_node *np,
+ struct clk_init_data *init,
+ struct clk_hw *hw,
+ struct regmap **clk_audio_regmap)
+{
+ struct regmap *regmap;
+ const char *parent_names[1];
+ int ret;
+
+ regmap = syscon_node_to_regmap(of_get_parent(np));
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ init->name = np->name;
+ of_clk_parent_fill(np, parent_names, 1);
+ init->parent_names = parent_names;
+ init->num_parents = 1;
+
+ hw->init = init;
+ *clk_audio_regmap = regmap;
+
+ ret = clk_hw_register(NULL, hw);
+ if (ret)
+ return ret;
+
+ return of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+
+static void __init of_sama5d2_clk_audio_pll_frac_setup(struct device_node *np)
+{
+ struct clk_audio_frac *frac_ck;
+ struct clk_init_data init = {};
+
+ frac_ck = kzalloc(sizeof(*frac_ck), GFP_KERNEL);
+ if (!frac_ck)
+ return;
+
+ init.ops = &audio_pll_frac_ops;
+ init.flags = CLK_SET_RATE_GATE;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &frac_ck->hw,
+ &frac_ck->regmap))
+ kfree(frac_ck);
+}
+
+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 = {};
+
+ apad_ck = kzalloc(sizeof(*apad_ck), GFP_KERNEL);
+ if (!apad_ck)
+ return;
+
+ init.ops = &audio_pll_pad_ops;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &apad_ck->hw,
+ &apad_ck->regmap))
+ kfree(apad_ck);
+}
+
+static void __init of_sama5d2_clk_audio_pll_pmc_setup(struct device_node *np)
+{
+ struct clk_audio_pad *apmc_ck;
+ struct clk_init_data init = {};
+
+ apmc_ck = kzalloc(sizeof(*apmc_ck), GFP_KERNEL);
+ if (!apmc_ck)
+ return;
+
+ init.ops = &audio_pll_pmc_ops;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
+
+ if (of_sama5d2_clk_audio_pll_setup(np, &init, &apmc_ck->hw,
+ &apmc_ck->regmap))
+ kfree(apmc_ck);
+}
+
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_frac_setup,
+ "atmel,sama5d2-clk-audio-pll-frac",
+ of_sama5d2_clk_audio_pll_frac_setup);
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pad_setup,
+ "atmel,sama5d2-clk-audio-pll-pad",
+ of_sama5d2_clk_audio_pll_pad_setup);
+CLK_OF_DECLARE(of_sama5d2_clk_audio_pll_pmc_setup,
+ "atmel,sama5d2-clk-audio-pll-pmc",
+ of_sama5d2_clk_audio_pll_pmc_setup);
generated by cgit (git 2.34.1) at 2024-05-09 15:55:01 +0000