clk: amlogic: axg-audio: revert reset implementation

The audio subsystem of axg based platform is not probing anymore.
This is due to the introduction of RESET_MESON_AUX and the config
not being enabled with the default arm64 defconfig.

This brought another discussion around proper decoupling between
the clock and reset part. While this discussion gets sorted out,
revert back to the initial implementation.

This reverts
 * commit 681ed49 ("clk: amlogic: axg-audio: fix Kconfig dependency on RESET_MESON_AUX")
 * commit 664988e ("clk: amlogic: axg-audio: use the auxiliary reset driver")

Both are reverted with single change to avoid creating more compilation
problems.

Fixes: 681ed49 ("clk: amlogic: axg-audio: fix Kconfig dependency on RESET_MESON_AUX")
Cc: Arnd Bergmann <arnd@arndb.de>
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20241128-clk-audio-fix-rst-missing-v2-1-cf437d1a73da@baylibre.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/meson/Kconfig

@@ -106,7 +106,7 @@ config COMMON_CLK_AXG_AUDIO
 	select COMMON_CLK_MESON_SCLK_DIV
 	select COMMON_CLK_MESON_CLKC_UTILS
 	select REGMAP_MMIO
-	depends on RESET_MESON_AUX
+	select RESET_CONTROLLER
 	help
 	  Support for the audio clock controller on AmLogic A113D devices,
 	  aka axg, Say Y if you want audio subsystem to work.

drivers/clk/meson/axg-audio.c

@@ -15,8 +15,6 @@
 #include <linux/reset-controller.h>
 #include <linux/slab.h>
 
-#include <soc/amlogic/reset-meson-aux.h>
-
 #include "meson-clkc-utils.h"
 #include "axg-audio.h"
 #include "clk-regmap.h"
@@ -1680,6 +1678,84 @@ static struct clk_regmap *const sm1_clk_regmaps[] = {
 	&sm1_earcrx_dmac_clk,
 };
 
+struct axg_audio_reset_data {
+	struct reset_controller_dev rstc;
+	struct regmap *map;
+	unsigned int offset;
+};
+
+static void axg_audio_reset_reg_and_bit(struct axg_audio_reset_data *rst,
+					unsigned long id,
+					unsigned int *reg,
+					unsigned int *bit)
+{
+	unsigned int stride = regmap_get_reg_stride(rst->map);
+
+	*reg = (id / (stride * BITS_PER_BYTE)) * stride;
+	*reg += rst->offset;
+	*bit = id % (stride * BITS_PER_BYTE);
+}
+
+static int axg_audio_reset_update(struct reset_controller_dev *rcdev,
+				unsigned long id, bool assert)
+{
+	struct axg_audio_reset_data *rst =
+		container_of(rcdev, struct axg_audio_reset_data, rstc);
+	unsigned int offset, bit;
+
+	axg_audio_reset_reg_and_bit(rst, id, &offset, &bit);
+
+	regmap_update_bits(rst->map, offset, BIT(bit),
+			assert ? BIT(bit) : 0);
+
+	return 0;
+}
+
+static int axg_audio_reset_status(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct axg_audio_reset_data *rst =
+		container_of(rcdev, struct axg_audio_reset_data, rstc);
+	unsigned int val, offset, bit;
+
+	axg_audio_reset_reg_and_bit(rst, id, &offset, &bit);
+
+	regmap_read(rst->map, offset, &val);
+
+	return !!(val & BIT(bit));
+}
+
+static int axg_audio_reset_assert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return axg_audio_reset_update(rcdev, id, true);
+}
+
+static int axg_audio_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return axg_audio_reset_update(rcdev, id, false);
+}
+
+static int axg_audio_reset_toggle(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	int ret;
+
+	ret = axg_audio_reset_assert(rcdev, id);
+	if (ret)
+		return ret;
+
+	return axg_audio_reset_deassert(rcdev, id);
+}
+
+static const struct reset_control_ops axg_audio_rstc_ops = {
+	.assert = axg_audio_reset_assert,
+	.deassert = axg_audio_reset_deassert,
+	.reset = axg_audio_reset_toggle,
+	.status = axg_audio_reset_status,
+};
+
 static struct regmap_config axg_audio_regmap_cfg = {
 	.reg_bits	= 32,
 	.val_bits	= 32,
@@ -1690,14 +1766,16 @@ struct audioclk_data {
 	struct clk_regmap *const *regmap_clks;
 	unsigned int regmap_clk_num;
 	struct meson_clk_hw_data hw_clks;
+	unsigned int reset_offset;
+	unsigned int reset_num;
 	unsigned int max_register;
-	const char *rst_drvname;
 };
 
 static int axg_audio_clkc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct audioclk_data *data;
+	struct axg_audio_reset_data *rst;
 	struct regmap *map;
 	void __iomem *regs;
 	struct clk_hw *hw;
@@ -1756,11 +1834,22 @@ static int axg_audio_clkc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	/* Register auxiliary reset driver when applicable */
-	if (data->rst_drvname)
-		ret = devm_meson_rst_aux_register(dev, map, data->rst_drvname);
+	/* Stop here if there is no reset */
+	if (!data->reset_num)
+		return 0;
+
+	rst = devm_kzalloc(dev, sizeof(*rst), GFP_KERNEL);
+	if (!rst)
+		return -ENOMEM;
+
+	rst->map = map;
+	rst->offset = data->reset_offset;
+	rst->rstc.nr_resets = data->reset_num;
+	rst->rstc.ops = &axg_audio_rstc_ops;
+	rst->rstc.of_node = dev->of_node;
+	rst->rstc.owner = THIS_MODULE;
 
-	return ret;
+	return devm_reset_controller_register(dev, &rst->rstc);
 }
 
 static const struct audioclk_data axg_audioclk_data = {
@@ -1780,8 +1869,9 @@ static const struct audioclk_data g12a_audioclk_data = {
 		.hws = g12a_audio_hw_clks,
 		.num = ARRAY_SIZE(g12a_audio_hw_clks),
 	},
+	.reset_offset = AUDIO_SW_RESET,
+	.reset_num = 26,
 	.max_register = AUDIO_CLK_SPDIFOUT_B_CTRL,
-	.rst_drvname = "rst-g12a",
 };
 
 static const struct audioclk_data sm1_audioclk_data = {
@@ -1791,8 +1881,9 @@ static const struct audioclk_data sm1_audioclk_data = {
 		.hws = sm1_audio_hw_clks,
 		.num = ARRAY_SIZE(sm1_audio_hw_clks),
 	},
+	.reset_offset = AUDIO_SM1_SW_RESET0,
+	.reset_num = 39,
 	.max_register = AUDIO_EARCRX_DMAC_CLK_CTRL,
-	.rst_drvname = "rst-sm1",
 };
 
 static const struct of_device_id clkc_match_table[] = {