clk: amlogic: get regmap with clk_regmap_init

Add clk_regmap_init() and use it with all clock types which derive from
clk_regmap. This helps initialise clk_regmap clocks without requiring
tables to keep track of the clock using this type.

The way it is done couples clk_regmap with the controllers, which is not
ideal. This is a temporary solution to get rid of the tables. The situation
will eventually be improved.

Link: https://lore.kernel.org/r/20250623-amlogic-clk-drop-clk-regmap-tables-v4-1-ff04918211cc@baylibre.com
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

drivers/clk/meson/Kconfig

@@ -5,6 +5,7 @@ menu "Clock support for Amlogic platforms"
 config COMMON_CLK_MESON_REGMAP
 	tristate
 	select REGMAP
+	select MFD_SYSCON
 
 config COMMON_CLK_MESON_DUALDIV
 	tristate

drivers/clk/meson/clk-cpu-dyndiv.c

@@ -61,6 +61,7 @@ static int meson_clk_cpu_dyndiv_set_rate(struct clk_hw *hw, unsigned long rate,
 };
 
 const struct clk_ops meson_clk_cpu_dyndiv_ops = {
+	.init = clk_regmap_init,
 	.recalc_rate = meson_clk_cpu_dyndiv_recalc_rate,
 	.determine_rate = meson_clk_cpu_dyndiv_determine_rate,
 	.set_rate = meson_clk_cpu_dyndiv_set_rate,

drivers/clk/meson/clk-dualdiv.c

@@ -126,6 +126,7 @@ static int meson_clk_dualdiv_set_rate(struct clk_hw *hw, unsigned long rate,
 }
 
 const struct clk_ops meson_clk_dualdiv_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= meson_clk_dualdiv_recalc_rate,
 	.determine_rate	= meson_clk_dualdiv_determine_rate,
 	.set_rate	= meson_clk_dualdiv_set_rate,
@@ -133,6 +134,7 @@ const struct clk_ops meson_clk_dualdiv_ops = {
 EXPORT_SYMBOL_NS_GPL(meson_clk_dualdiv_ops, "CLK_MESON");
 
 const struct clk_ops meson_clk_dualdiv_ro_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= meson_clk_dualdiv_recalc_rate,
 };
 EXPORT_SYMBOL_NS_GPL(meson_clk_dualdiv_ro_ops, "CLK_MESON");

drivers/clk/meson/clk-mpll.c

@@ -128,6 +128,11 @@ static int mpll_init(struct clk_hw *hw)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
+	int ret;
+
+	ret = clk_regmap_init(hw);
+	if (ret)
+		return ret;
 
 	if (mpll->init_count)
 		regmap_multi_reg_write(clk->map, mpll->init_regs,
@@ -151,6 +156,7 @@ static int mpll_init(struct clk_hw *hw)
 }
 
 const struct clk_ops meson_clk_mpll_ro_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= mpll_recalc_rate,
 	.determine_rate	= mpll_determine_rate,
 };

drivers/clk/meson/clk-phase.c

@@ -58,6 +58,7 @@ static int meson_clk_phase_set_phase(struct clk_hw *hw, int degrees)
 }
 
 const struct clk_ops meson_clk_phase_ops = {
+	.init		= clk_regmap_init,
 	.get_phase	= meson_clk_phase_get_phase,
 	.set_phase	= meson_clk_phase_set_phase,
 };
@@ -83,6 +84,11 @@ static int meson_clk_triphase_sync(struct clk_hw *hw)
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
 	unsigned int val;
+	int ret;
+
+	ret = clk_regmap_init(hw);
+	if (ret)
+		return ret;
 
 	/* Get phase 0 and sync it to phase 1 and 2 */
 	val = meson_parm_read(clk->map, &tph->ph0);
@@ -142,6 +148,11 @@ static int meson_sclk_ws_inv_sync(struct clk_hw *hw)
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_sclk_ws_inv_data *tph = meson_sclk_ws_inv_data(clk);
 	unsigned int val;
+	int ret;
+
+	ret = clk_regmap_init(hw);
+	if (ret)
+		return ret;
 
 	/* Get phase and sync the inverted value to ws */
 	val = meson_parm_read(clk->map, &tph->ph);

drivers/clk/meson/clk-pll.c

@@ -311,6 +311,11 @@ static int meson_clk_pll_init(struct clk_hw *hw)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
+	int ret;
+
+	ret = clk_regmap_init(hw);
+	if (ret)
+		return ret;
 
 	/*
 	 * Keep the clock running, which was already initialized and enabled
@@ -468,6 +473,7 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
  * the other ops except set_rate since the rate is fixed.
  */
 const struct clk_ops meson_clk_pcie_pll_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= meson_clk_pll_recalc_rate,
 	.determine_rate	= meson_clk_pll_determine_rate,
 	.is_enabled	= meson_clk_pll_is_enabled,
@@ -488,6 +494,7 @@ const struct clk_ops meson_clk_pll_ops = {
 EXPORT_SYMBOL_NS_GPL(meson_clk_pll_ops, "CLK_MESON");
 
 const struct clk_ops meson_clk_pll_ro_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= meson_clk_pll_recalc_rate,
 	.is_enabled	= meson_clk_pll_is_enabled,
 };

drivers/clk/meson/clk-regmap.c

@@ -4,9 +4,52 @@
  * Author: Jerome Brunet <jbrunet@baylibre.com>
  */
 
+#include <linux/device.h>
 #include <linux/module.h>
+#include <linux/mfd/syscon.h>
 #include "clk-regmap.h"
 
+int clk_regmap_init(struct clk_hw *hw)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct device_node *np, *parent_np;
+	struct device *dev;
+
+	/* Allow regmap to be preset as it was historically done */
+	if (clk->map)
+		return 0;
+
+	/*
+	 * FIXME: what follows couples the controller implementation
+	 * and clk_regmap clock type. This situation is not desirable
+	 * but temporary, until the controller is able to register
+	 * a hook to initialize a clock type
+	 */
+
+	/* Check the usual dev enabled controller with an basic IO regmap */
+	dev = clk_hw_get_dev(hw);
+	if (dev) {
+		clk->map = dev_get_regmap(dev, NULL);
+		if (clk->map)
+			return 0;
+	}
+
+	/* Move on to early and syscon based controllers */
+	np = clk_hw_get_of_node(hw);
+	if (np) {
+		parent_np = of_get_parent(np);
+		clk->map = syscon_node_to_regmap(parent_np);
+		of_node_put(parent_np);
+
+		if (!IS_ERR_OR_NULL(clk->map))
+			return 0;
+	}
+
+	/* Bail out if regmap can't be found */
+	return -EINVAL;
+}
+EXPORT_SYMBOL_NS_GPL(clk_regmap_init, "CLK_MESON");
+
 static int clk_regmap_gate_endisable(struct clk_hw *hw, int enable)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
@@ -45,6 +88,7 @@ static int clk_regmap_gate_is_enabled(struct clk_hw *hw)
 }
 
 const struct clk_ops clk_regmap_gate_ops = {
+	.init		= clk_regmap_init,
 	.enable = clk_regmap_gate_enable,
 	.disable = clk_regmap_gate_disable,
 	.is_enabled = clk_regmap_gate_is_enabled,
@@ -52,6 +96,7 @@ const struct clk_ops clk_regmap_gate_ops = {
 EXPORT_SYMBOL_NS_GPL(clk_regmap_gate_ops, "CLK_MESON");
 
 const struct clk_ops clk_regmap_gate_ro_ops = {
+	.init		= clk_regmap_init,
 	.is_enabled = clk_regmap_gate_is_enabled,
 };
 EXPORT_SYMBOL_NS_GPL(clk_regmap_gate_ro_ops, "CLK_MESON");
@@ -121,6 +166,7 @@ static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
 /* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
 
 const struct clk_ops clk_regmap_divider_ops = {
+	.init = clk_regmap_init,
 	.recalc_rate = clk_regmap_div_recalc_rate,
 	.determine_rate = clk_regmap_div_determine_rate,
 	.set_rate = clk_regmap_div_set_rate,
@@ -128,6 +174,7 @@ const struct clk_ops clk_regmap_divider_ops = {
 EXPORT_SYMBOL_NS_GPL(clk_regmap_divider_ops, "CLK_MESON");
 
 const struct clk_ops clk_regmap_divider_ro_ops = {
+	.init = clk_regmap_init,
 	.recalc_rate = clk_regmap_div_recalc_rate,
 	.determine_rate = clk_regmap_div_determine_rate,
 };
@@ -170,6 +217,7 @@ static int clk_regmap_mux_determine_rate(struct clk_hw *hw,
 }
 
 const struct clk_ops clk_regmap_mux_ops = {
+	.init		= clk_regmap_init,
 	.get_parent = clk_regmap_mux_get_parent,
 	.set_parent = clk_regmap_mux_set_parent,
 	.determine_rate = clk_regmap_mux_determine_rate,
@@ -177,6 +225,7 @@ const struct clk_ops clk_regmap_mux_ops = {
 EXPORT_SYMBOL_NS_GPL(clk_regmap_mux_ops, "CLK_MESON");
 
 const struct clk_ops clk_regmap_mux_ro_ops = {
+	.init		= clk_regmap_init,
 	.get_parent = clk_regmap_mux_get_parent,
 };
 EXPORT_SYMBOL_NS_GPL(clk_regmap_mux_ro_ops, "CLK_MESON");

drivers/clk/meson/clk-regmap.h

@@ -7,6 +7,7 @@
 #ifndef __CLK_REGMAP_H
 #define __CLK_REGMAP_H
 
+#include <linux/device.h>
 #include <linux/clk-provider.h>
 #include <linux/regmap.h>
 
@@ -31,6 +32,9 @@ static inline struct clk_regmap *to_clk_regmap(struct clk_hw *hw)
 	return container_of(hw, struct clk_regmap, hw);
 }
 
+/* clk_regmap init op to get and cache regmap from the controllers */
+int clk_regmap_init(struct clk_hw *hw);
+
 /**
  * struct clk_regmap_gate_data - regmap backed gate specific data
  *

drivers/clk/meson/sclk-div.c

@@ -222,6 +222,11 @@ static int sclk_div_init(struct clk_hw *hw)
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk);
 	unsigned int val;
+	int ret;
+
+	ret = clk_regmap_init(hw);
+	if (ret)
+		return ret;
 
 	val = meson_parm_read(clk->map, &sclk->div);
 

drivers/clk/meson/vclk.c

@@ -45,6 +45,7 @@ static int meson_vclk_gate_is_enabled(struct clk_hw *hw)
 }
 
 const struct clk_ops meson_vclk_gate_ops = {
+	.init = clk_regmap_init,
 	.enable = meson_vclk_gate_enable,
 	.disable = meson_vclk_gate_disable,
 	.is_enabled = meson_vclk_gate_is_enabled,
@@ -127,6 +128,7 @@ static int meson_vclk_div_is_enabled(struct clk_hw *hw)
 }
 
 const struct clk_ops meson_vclk_div_ops = {
+	.init = clk_regmap_init,
 	.recalc_rate = meson_vclk_div_recalc_rate,
 	.determine_rate = meson_vclk_div_determine_rate,
 	.set_rate = meson_vclk_div_set_rate,

drivers/clk/meson/vid-pll-div.c

@@ -90,6 +90,7 @@ static unsigned long meson_vid_pll_div_recalc_rate(struct clk_hw *hw,
 }
 
 const struct clk_ops meson_vid_pll_div_ro_ops = {
+	.init		= clk_regmap_init,
 	.recalc_rate	= meson_vid_pll_div_recalc_rate,
 };
 EXPORT_SYMBOL_NS_GPL(meson_vid_pll_div_ro_ops, "CLK_MESON");