ASoC: cs35l56: Revert support for dual-ownership of ASP registers

This patch reverts a series of commits that allowed for the ASP
registers to be owned by either the driver or the firmware. Nothing
currently depends on the functionality that is being reverted, so
it is safe to remove.

The commits being reverted are (last 3 are bugfixes to the first 2):
commit 72a77d7
("ASoC: cs35l56: Fix to ensure ASP1 registers match cache")
commit 07f7d6e
("ASoC: cs35l56: Fix for initializing ASP1 mixer registers")
commit 4703b01
("ASoC: cs35l56: fix reversed if statement in cs35l56_dspwait_asp1tx_put()")
commit c14f09f
("ASoC: cs35l56: Fix deadlock in ASP1 mixer register initialization")
commit dfd2ffb
("ASoC: cs35l56: Prevent overwriting firmware ASP config")

These reverts have been squashed into a single commit because there
would be no reason to revert only some of them (which would just
reintroduce bugs).

The changes introduced by the commits were well-intentioned but
somewhat misguided. ACPI does not provide any information about how
audio hardware is linked together, so that information has to be
hardcoded into drivers. On Windows the firmware is customized to
statically setup appropriate configuration of the audio links,
and the intent of the commits was to re-use this information if the
Linux host drivers aren't taking control of the ASP. This would
avoid having to hardcode the ASP config into the machine driver on
some systems.

However, this added complexity and race conditions into the driver.
It also complicates implementation of new code.

The only case where the ASP is used but the host is not taking
ownership is when CS35L56 is used in SoundWire mode with the ASP
as a reference audio interconnect. But even in that case it's not
necessarily required even if the firmware initialized it. Typically
it is used to avoid the host SDCA drivers having to be capable of
aggregating capture paths from multiple SoundWire peripherals. But
the SOF SoundWire support is capable of doing that aggregation.

Reverting all these commits significantly simplifies the driver.
Let's just use the normal Linux mechanisms of the machine driver and
ALSA controls to set things up instead of trying to use the firmware
to do use-case setup.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20240701104444.172556-2-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: rfvirgil

include/sound/cs35l56.h

@@ -267,13 +267,18 @@ struct cs35l56_base {
 	bool fw_patched;
 	bool secured;
 	bool can_hibernate;
-	bool fw_owns_asp1;
 	bool cal_data_valid;
 	s8 cal_index;
 	struct cirrus_amp_cal_data cal_data;
 	struct gpio_desc *reset_gpio;
 };
 
+/* Temporary to avoid a build break with the HDA driver */
+static inline int cs35l56_force_sync_asp1_registers_from_cache(struct cs35l56_base *cs35l56_base)
+{
+	return 0;
+}
+
 extern struct regmap_config cs35l56_regmap_i2c;
 extern struct regmap_config cs35l56_regmap_spi;
 extern struct regmap_config cs35l56_regmap_sdw;
@@ -284,8 +289,6 @@ extern const char * const cs35l56_tx_input_texts[CS35L56_NUM_INPUT_SRC];
 extern const unsigned int cs35l56_tx_input_values[CS35L56_NUM_INPUT_SRC];
 
 int cs35l56_set_patch(struct cs35l56_base *cs35l56_base);
-int cs35l56_init_asp1_regs_for_driver_control(struct cs35l56_base *cs35l56_base);
-int cs35l56_force_sync_asp1_registers_from_cache(struct cs35l56_base *cs35l56_base);
 int cs35l56_mbox_send(struct cs35l56_base *cs35l56_base, unsigned int command);
 int cs35l56_firmware_shutdown(struct cs35l56_base *cs35l56_base);
 int cs35l56_wait_for_firmware_boot(struct cs35l56_base *cs35l56_base);

sound/soc/codecs/cs35l56-shared.c

@@ -20,6 +20,18 @@ static const struct reg_sequence cs35l56_patch[] = {
 	 * Firmware can change these to non-defaults to satisfy SDCA.
 	 * Ensure that they are at known defaults.
 	 */
+	{ CS35L56_ASP1_ENABLES1,		0x00000000 },
+	{ CS35L56_ASP1_CONTROL1,		0x00000028 },
+	{ CS35L56_ASP1_CONTROL2,		0x18180200 },
+	{ CS35L56_ASP1_CONTROL3,		0x00000002 },
+	{ CS35L56_ASP1_FRAME_CONTROL1,		0x03020100 },
+	{ CS35L56_ASP1_FRAME_CONTROL5,		0x00020100 },
+	{ CS35L56_ASP1_DATA_CONTROL1,		0x00000018 },
+	{ CS35L56_ASP1_DATA_CONTROL5,		0x00000018 },
+	{ CS35L56_ASP1TX1_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX2_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX3_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX4_INPUT,		0x00000000 },
 	{ CS35L56_SWIRE_DP3_CH1_INPUT,		0x00000018 },
 	{ CS35L56_SWIRE_DP3_CH2_INPUT,		0x00000019 },
 	{ CS35L56_SWIRE_DP3_CH3_INPUT,		0x00000029 },
@@ -41,12 +53,18 @@ EXPORT_SYMBOL_NS_GPL(cs35l56_set_patch, SND_SOC_CS35L56_SHARED);
 static const struct reg_default cs35l56_reg_defaults[] = {
 	/* no defaults for OTP_MEM - first read populates cache */
 
-	/*
-	 * No defaults for ASP1 control or ASP1TX mixer. See
-	 * cs35l56_populate_asp1_register_defaults() and
-	 * cs35l56_sync_asp1_mixer_widgets_with_firmware().
-	 */
-
+	{ CS35L56_ASP1_ENABLES1,		0x00000000 },
+	{ CS35L56_ASP1_CONTROL1,		0x00000028 },
+	{ CS35L56_ASP1_CONTROL2,		0x18180200 },
+	{ CS35L56_ASP1_CONTROL3,		0x00000002 },
+	{ CS35L56_ASP1_FRAME_CONTROL1,		0x03020100 },
+	{ CS35L56_ASP1_FRAME_CONTROL5,		0x00020100 },
+	{ CS35L56_ASP1_DATA_CONTROL1,		0x00000018 },
+	{ CS35L56_ASP1_DATA_CONTROL5,		0x00000018 },
+	{ CS35L56_ASP1TX1_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX2_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX3_INPUT,		0x00000000 },
+	{ CS35L56_ASP1TX4_INPUT,		0x00000000 },
 	{ CS35L56_SWIRE_DP3_CH1_INPUT,		0x00000018 },
 	{ CS35L56_SWIRE_DP3_CH2_INPUT,		0x00000019 },
 	{ CS35L56_SWIRE_DP3_CH3_INPUT,		0x00000029 },
@@ -206,77 +224,6 @@ static bool cs35l56_volatile_reg(struct device *dev, unsigned int reg)
 	}
 }
 
-static const struct reg_sequence cs35l56_asp1_defaults[] = {
-	REG_SEQ0(CS35L56_ASP1_ENABLES1,		0x00000000),
-	REG_SEQ0(CS35L56_ASP1_CONTROL1,		0x00000028),
-	REG_SEQ0(CS35L56_ASP1_CONTROL2,		0x18180200),
-	REG_SEQ0(CS35L56_ASP1_CONTROL3,		0x00000002),
-	REG_SEQ0(CS35L56_ASP1_FRAME_CONTROL1,	0x03020100),
-	REG_SEQ0(CS35L56_ASP1_FRAME_CONTROL5,	0x00020100),
-	REG_SEQ0(CS35L56_ASP1_DATA_CONTROL1,	0x00000018),
-	REG_SEQ0(CS35L56_ASP1_DATA_CONTROL5,	0x00000018),
-	REG_SEQ0(CS35L56_ASP1TX1_INPUT,		0x00000000),
-	REG_SEQ0(CS35L56_ASP1TX2_INPUT,		0x00000000),
-	REG_SEQ0(CS35L56_ASP1TX3_INPUT,		0x00000000),
-	REG_SEQ0(CS35L56_ASP1TX4_INPUT,		0x00000000),
-};
-
-/*
- * The firmware can have control of the ASP so we don't provide regmap
- * with defaults for these registers, to prevent a regcache_sync() from
- * overwriting the firmware settings. But if the machine driver hooks up
- * the ASP it means the driver is taking control of the ASP, so then the
- * registers are populated with the defaults.
- */
-int cs35l56_init_asp1_regs_for_driver_control(struct cs35l56_base *cs35l56_base)
-{
-	if (!cs35l56_base->fw_owns_asp1)
-		return 0;
-
-	cs35l56_base->fw_owns_asp1 = false;
-
-	return regmap_multi_reg_write(cs35l56_base->regmap, cs35l56_asp1_defaults,
-				      ARRAY_SIZE(cs35l56_asp1_defaults));
-}
-EXPORT_SYMBOL_NS_GPL(cs35l56_init_asp1_regs_for_driver_control, SND_SOC_CS35L56_SHARED);
-
-/*
- * The firmware boot sequence can overwrite the ASP1 config registers so that
- * they don't match regmap's view of their values. Rewrite the values from the
- * regmap cache into the hardware registers.
- */
-int cs35l56_force_sync_asp1_registers_from_cache(struct cs35l56_base *cs35l56_base)
-{
-	struct reg_sequence asp1_regs[ARRAY_SIZE(cs35l56_asp1_defaults)];
-	int i, ret;
-
-	if (cs35l56_base->fw_owns_asp1)
-		return 0;
-
-	memcpy(asp1_regs, cs35l56_asp1_defaults, sizeof(asp1_regs));
-
-	/* Read current values from regmap cache into the write sequence */
-	for (i = 0; i < ARRAY_SIZE(asp1_regs); ++i) {
-		ret = regmap_read(cs35l56_base->regmap, asp1_regs[i].reg, &asp1_regs[i].def);
-		if (ret)
-			goto err;
-	}
-
-	/* Write the values cache-bypassed so that they will be written to silicon */
-	ret = regmap_multi_reg_write_bypassed(cs35l56_base->regmap, asp1_regs,
-					      ARRAY_SIZE(asp1_regs));
-	if (ret)
-		goto err;
-
-	return 0;
-
-err:
-	dev_err(cs35l56_base->dev, "Failed to sync ASP1 registers: %d\n", ret);
-
-	return ret;
-}
-EXPORT_SYMBOL_NS_GPL(cs35l56_force_sync_asp1_registers_from_cache, SND_SOC_CS35L56_SHARED);
-
 int cs35l56_mbox_send(struct cs35l56_base *cs35l56_base, unsigned int command)
 {
 	unsigned int val;