ASoC: tlv320aic32x4: Model PLL in CCF

Model and manage the on-board PLL as a component in the Core
Clock Framework.  This should allow us to do some more complex
clock management and power control.  Also, some of the
on-board chip clocks can be exposed to the outside, and this
change will make those clocks easier to consume by other
parts of the kernel.

Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 323 insertions, 0 deletions

diff --git a/sound/soc/codecs/tlv320aic32x4-clk.c b/sound/soc/codecs/tlv320aic32x4-clk.c
new file mode 100644
index 000000000000..5e495fc8d931
--- /dev/null
+++ b/sound/soc/codecs/tlv320aic32x4-clk.c
@@ -0,0 +1,323 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Clock Tree for the Texas Instruments TLV320AIC32x4
+ *
+ * Copyright 2019 Annaliese McDermond
+ *
+ * Author: Annaliese McDermond <nh6z@nh6z.net>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/regmap.h>
+#include <linux/device.h>
+
+#include "tlv320aic32x4.h"
+
+#define to_clk_aic32x4(_hw) container_of(_hw, struct clk_aic32x4, hw)
+struct clk_aic32x4 {
+	struct clk_hw hw;
+	struct device *dev;
+	struct regmap *regmap;
+	unsigned int reg;
+};
+
+/*
+ * struct clk_aic32x4_pll_muldiv - Multiplier/divider settings
+ * @p:		Divider
+ * @r:		first multiplier
+ * @j:		integer part of second multiplier
+ * @d:		decimal part of second multiplier
+ */
+struct clk_aic32x4_pll_muldiv {
+	u8 p;
+	u16 r;
+	u8 j;
+	u16 d;
+};
+
+struct aic32x4_clkdesc {
+	const char *name;
+	const char * const *parent_names;
+	unsigned int num_parents;
+	const struct clk_ops *ops;
+	unsigned int reg;
+};
+
+static int clk_aic32x4_pll_prepare(struct clk_hw *hw)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+
+	return regmap_update_bits(pll->regmap, AIC32X4_PLLPR,
+				AIC32X4_PLLEN, AIC32X4_PLLEN);
+}
+
+static void clk_aic32x4_pll_unprepare(struct clk_hw *hw)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+
+	regmap_update_bits(pll->regmap, AIC32X4_PLLPR,
+				AIC32X4_PLLEN, 0);
+}
+
+static int clk_aic32x4_pll_is_prepared(struct clk_hw *hw)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(pll->regmap, AIC32X4_PLLPR, &val);
+	if (ret < 0)
+		return ret;
+
+	return !!(val & AIC32X4_PLLEN);
+}
+
+static int clk_aic32x4_pll_get_muldiv(struct clk_aic32x4 *pll,
+			struct clk_aic32x4_pll_muldiv *settings)
+{
+	/*	Change to use regmap_bulk_read? */
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(pll->regmap, AIC32X4_PLLPR, &val);
+	if (ret)
+		return ret;
+	settings->r = val & AIC32X4_PLL_R_MASK;
+	settings->p = (val & AIC32X4_PLL_P_MASK) >> AIC32X4_PLL_P_SHIFT;
+
+	ret = regmap_read(pll->regmap, AIC32X4_PLLJ, &val);
+	if (ret < 0)
+		return ret;
+	settings->j = val;
+
+	ret = regmap_read(pll->regmap, AIC32X4_PLLDMSB, &val);
+	if (ret < 0)
+		return ret;
+	settings->d = val << 8;
+
+	ret = regmap_read(pll->regmap, AIC32X4_PLLDLSB,	 &val);
+	if (ret < 0)
+		return ret;
+	settings->d |= val;
+
+	return 0;
+}
+
+static int clk_aic32x4_pll_set_muldiv(struct clk_aic32x4 *pll,
+			struct clk_aic32x4_pll_muldiv *settings)
+{
+	int ret;
+	/*	Change to use regmap_bulk_write for some if not all? */
+
+	ret = regmap_update_bits(pll->regmap, AIC32X4_PLLPR,
+				AIC32X4_PLL_R_MASK, settings->r);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(pll->regmap, AIC32X4_PLLPR,
+				AIC32X4_PLL_P_MASK,
+				settings->p << AIC32X4_PLL_P_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(pll->regmap, AIC32X4_PLLJ, settings->j);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(pll->regmap, AIC32X4_PLLDMSB, (settings->d >> 8));
+	if (ret < 0)
+		return ret;
+	ret = regmap_write(pll->regmap, AIC32X4_PLLDLSB, (settings->d & 0xff));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static unsigned long clk_aic32x4_pll_calc_rate(
+			struct clk_aic32x4_pll_muldiv *settings,
+			unsigned long parent_rate)
+{
+	u64 rate;
+	/*
+	 * We scale j by 10000 to account for the decimal part of P and divide
+	 * it back out later.
+	 */
+	rate = (u64) parent_rate * settings->r *
+				((settings->j * 10000) + settings->d);
+
+	return (unsigned long) DIV_ROUND_UP_ULL(rate, settings->p * 10000);
+}
+
+static int clk_aic32x4_pll_calc_muldiv(struct clk_aic32x4_pll_muldiv *settings,
+			unsigned long rate, unsigned long parent_rate)
+{
+	u64 multiplier;
+
+	settings->p = parent_rate / AIC32X4_MAX_PLL_CLKIN + 1;
+	if (settings->p > 8)
+		return -1;
+
+	/*
+	 * We scale this figure by 10000 so that we can get the decimal part
+	 * of the multiplier.	This is because we can't do floating point
+	 * math in the kernel.
+	 */
+	 multiplier = (u64) rate * settings->p * 10000;
+	 do_div(multiplier, parent_rate);
+
+	/*
+	 * J can't be over 64, so R can scale this.
+	 * R can't be greater than 4.
+	 */
+	settings->r = ((u32) multiplier / 640000) + 1;
+	if (settings->r > 4)
+		return -1;
+	do_div(multiplier, settings->r);
+
+	/*
+	 * J can't be < 1.
+	 */
+	if (multiplier < 10000)
+		return -1;
+
+	/* Figure out the integer part, J, and the fractional part, D. */
+	settings->j = (u32) multiplier / 10000;
+	settings->d = (u32) multiplier % 10000;
+
+	return 0;
+}
+
+static unsigned long clk_aic32x4_pll_recalc_rate(struct clk_hw *hw,
+			unsigned long parent_rate)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+	struct clk_aic32x4_pll_muldiv settings;
+	int ret;
+
+	ret =  clk_aic32x4_pll_get_muldiv(pll, &settings);
+	if (ret < 0)
+		return 0;
+
+	return clk_aic32x4_pll_calc_rate(&settings, parent_rate);
+}
+
+static long clk_aic32x4_pll_round_rate(struct clk_hw *hw,
+			unsigned long rate,
+			unsigned long *parent_rate)
+{
+	struct clk_aic32x4_pll_muldiv settings;
+	int ret;
+
+	ret = clk_aic32x4_pll_calc_muldiv(&settings, rate, *parent_rate);
+	if (ret < 0)
+		return 0;
+
+	return clk_aic32x4_pll_calc_rate(&settings, *parent_rate);
+}
+
+static int clk_aic32x4_pll_set_rate(struct clk_hw *hw,
+			unsigned long rate,
+			unsigned long parent_rate)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+	struct clk_aic32x4_pll_muldiv settings;
+	int ret;
+
+	ret = clk_aic32x4_pll_calc_muldiv(&settings, rate, parent_rate);
+	if (ret < 0)
+		return -EINVAL;
+
+	return clk_aic32x4_pll_set_muldiv(pll, &settings);
+}
+
+static int clk_aic32x4_pll_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+
+	return regmap_update_bits(pll->regmap,
+				AIC32X4_CLKMUX,
+				AIC32X4_PLL_CLKIN_MASK,
+				index << AIC32X4_PLL_CLKIN_SHIFT);
+}
+
+static u8 clk_aic32x4_pll_get_parent(struct clk_hw *hw)
+{
+	struct clk_aic32x4 *pll = to_clk_aic32x4(hw);
+	unsigned int val;
+
+	regmap_read(pll->regmap, AIC32X4_PLLPR, &val);
+
+	return (val & AIC32X4_PLL_CLKIN_MASK) >> AIC32X4_PLL_CLKIN_SHIFT;
+}
+
+
+static const struct clk_ops aic32x4_pll_ops = {
+	.prepare = clk_aic32x4_pll_prepare,
+	.unprepare = clk_aic32x4_pll_unprepare,
+	.is_prepared = clk_aic32x4_pll_is_prepared,
+	.recalc_rate = clk_aic32x4_pll_recalc_rate,
+	.round_rate = clk_aic32x4_pll_round_rate,
+	.set_rate = clk_aic32x4_pll_set_rate,
+	.set_parent = clk_aic32x4_pll_set_parent,
+	.get_parent = clk_aic32x4_pll_get_parent,
+};
+
+static struct aic32x4_clkdesc aic32x4_clkdesc_array[] = {
+	{
+		.name = "pll",
+		.parent_names =
+			(const char* []) { "mclk", "bclk", "gpio", "din" },
+		.num_parents = 4,
+		.ops = &aic32x4_pll_ops,
+		.reg = 0,
+	},
+};
+
+static struct clk *aic32x4_register_clk(struct device *dev,
+			struct aic32x4_clkdesc *desc)
+{
+	struct clk_init_data init;
+	struct clk_aic32x4 *priv;
+	const char *devname = dev_name(dev);
+
+	init.ops = desc->ops;
+	init.name = desc->name;
+	init.parent_names = desc->parent_names;
+	init.num_parents = desc->num_parents;
+	init.flags = 0;
+
+	priv = devm_kzalloc(dev, sizeof(struct clk_aic32x4), GFP_KERNEL);
+	if (priv == NULL)
+		return (struct clk *) -ENOMEM;
+
+	priv->dev = dev;
+	priv->hw.init = &init;
+	priv->regmap = dev_get_regmap(dev, NULL);
+	priv->reg = desc->reg;
+
+	clk_hw_register_clkdev(&priv->hw, desc->name, devname);
+	return devm_clk_register(dev, &priv->hw);
+}
+
+int aic32x4_register_clocks(struct device *dev, const char *mclk_name)
+{
+	int i;
+
+	/*
+	 * These lines are here to preserve the current functionality of
+	 * the driver with regard to the DT.  These should eventually be set
+	 * by DT nodes so that the connections can be set up in configuration
+	 * rather than code.
+	 */
+	aic32x4_clkdesc_array[0].parent_names =
+			(const char* []) { mclk_name, "bclk", "gpio", "din" };
+
+	for (i = 0; i < ARRAY_SIZE(aic32x4_clkdesc_array); ++i)
+		aic32x4_register_clk(dev, &aic32x4_clkdesc_array[i]);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(aic32x4_register_clocks);