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From:   Maciej Strozek <mstrozek@opensource.cirrus.com>
To:     Mark Brown <broonie@kernel.org>
CC:     James Schulman <james.schulman@cirrus.com>,
        David Rhodes <david.rhodes@cirrus.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        <alsa-devel@alsa-project.org>, <patches@opensource.cirrus.com>,
        <linux-sound@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Maciej Strozek <mstrozek@opensource.cirrus.com>
Subject: [PATCH v3] ASoC: cs43130: Allow driver to work without IRQ connection
Date:   Mon, 20 Nov 2023 14:17:34 +0000
Message-ID: <20231120141734.76679-1-mstrozek@opensource.cirrus.com>
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Precedence: bulk

Add a polling mechanism that will keep the driver operational even in
absence of physical IRQ connection. If IRQ line is detected, the driver
will continue working as usual, in case of missing IRQ line it will
fallback to the polling mechanism introduced in this change.
This will support users which choose not to connect an IRQ line as it
is not critical to part's operation.

Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
---
V2 -> V3: Amended changelog message and subject line
V1 -> V2: Add changelog message

 sound/soc/codecs/cs43130.c | 56 +++++++++++++++++++++++++++++++-------
 sound/soc/codecs/cs43130.h |  1 +
 2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/cs43130.c b/sound/soc/codecs/cs43130.c
index fd39328579fb..1e7c32eedc7b 100644
--- a/sound/soc/codecs/cs43130.c
+++ b/sound/soc/codecs/cs43130.c
@@ -326,6 +326,43 @@ static int cs43130_set_pll(struct snd_soc_component *component, int pll_id, int
 	return ret;
 }

+static int cs43130_wait_for_completion(struct cs43130_private *cs43130, struct completion *to_poll,
+					int time)
+{
+	int stickies, offset, flag;
+	int ret = 0;
+
+	if (cs43130->has_irq_line) {
+		ret = wait_for_completion_timeout(to_poll, msecs_to_jiffies(time));
+	} else {
+		if (to_poll == &cs43130->xtal_rdy) {
+			offset = 0;
+			flag = CS43130_XTAL_RDY_INT;
+		} else if (to_poll == &cs43130->pll_rdy) {
+			offset = 0;
+			flag = CS43130_PLL_RDY_INT;
+		} else if (to_poll == &cs43130->hpload_evt) {
+			offset = 3;
+			flag = CS43130_HPLOAD_NO_DC_INT | CS43130_HPLOAD_UNPLUG_INT |
+				CS43130_HPLOAD_OOR_INT | CS43130_HPLOAD_AC_INT |
+				CS43130_HPLOAD_DC_INT | CS43130_HPLOAD_ON_INT |
+				CS43130_HPLOAD_OFF_INT;
+		} else {
+			return 0;
+		}
+
+		ret = regmap_read_poll_timeout(cs43130->regmap, CS43130_INT_STATUS_1 + offset,
+					       stickies, (stickies & flag),
+					       1000, time * 1000);
+
+		/*
+		 * Return 0 for an timeout/error to be consistent with wait_for_completion_timeout
+		 */
+		ret = !ret;
+	}
+	return ret;
+}
+
 static int cs43130_change_clksrc(struct snd_soc_component *component,
 				 enum cs43130_mclk_src_sel src)
 {
@@ -364,8 +401,7 @@ static int cs43130_change_clksrc(struct snd_soc_component *component,
 					   CS43130_XTAL_RDY_INT_MASK, 0);
 			regmap_update_bits(cs43130->regmap, CS43130_PWDN_CTL,
 					   CS43130_PDN_XTAL_MASK, 0);
-			ret = wait_for_completion_timeout(&cs43130->xtal_rdy,
-							  msecs_to_jiffies(100));
+			ret = cs43130_wait_for_completion(cs43130, &cs43130->xtal_rdy, 100);
 			regmap_update_bits(cs43130->regmap, CS43130_INT_MASK_1,
 					   CS43130_XTAL_RDY_INT_MASK,
 					   1 << CS43130_XTAL_RDY_INT_SHIFT);
@@ -400,8 +436,7 @@ static int cs43130_change_clksrc(struct snd_soc_component *component,
 					   CS43130_XTAL_RDY_INT_MASK, 0);
 			regmap_update_bits(cs43130->regmap, CS43130_PWDN_CTL,
 					   CS43130_PDN_XTAL_MASK, 0);
-			ret = wait_for_completion_timeout(&cs43130->xtal_rdy,
-							  msecs_to_jiffies(100));
+			ret = cs43130_wait_for_completion(cs43130, &cs43130->xtal_rdy, 100);
 			regmap_update_bits(cs43130->regmap, CS43130_INT_MASK_1,
 					   CS43130_XTAL_RDY_INT_MASK,
 					   1 << CS43130_XTAL_RDY_INT_SHIFT);
@@ -416,8 +451,7 @@ static int cs43130_change_clksrc(struct snd_soc_component *component,
 				   CS43130_PLL_RDY_INT_MASK, 0);
 		regmap_update_bits(cs43130->regmap, CS43130_PWDN_CTL,
 				   CS43130_PDN_PLL_MASK, 0);
-		ret = wait_for_completion_timeout(&cs43130->pll_rdy,
-						  msecs_to_jiffies(100));
+		ret = cs43130_wait_for_completion(cs43130, &cs43130->pll_rdy, 100);
 		regmap_update_bits(cs43130->regmap, CS43130_INT_MASK_1,
 				   CS43130_PLL_RDY_INT_MASK,
 				   1 << CS43130_PLL_RDY_INT_SHIFT);
@@ -2040,8 +2074,8 @@ static int cs43130_hpload_proc(struct cs43130_private *cs43130,
 	regmap_multi_reg_write(cs43130->regmap, seq,
 			       seq_size);

-	ret = wait_for_completion_timeout(&cs43130->hpload_evt,
-					  msecs_to_jiffies(1000));
+	ret = cs43130_wait_for_completion(cs43130, &cs43130->hpload_evt, 1000);
+
 	regmap_read(cs43130->regmap, CS43130_INT_MASK_4, &msk);
 	if (!ret) {
 		dev_err(cs43130->dev, "Timeout waiting for HPLOAD interrupt\n");
@@ -2545,8 +2579,10 @@ static int cs43130_i2c_probe(struct i2c_client *client)
 					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
 					"cs43130", cs43130);
 	if (ret != 0) {
-		dev_err(cs43130->dev, "Failed to request IRQ: %d\n", ret);
-		goto err;
+		dev_dbg(cs43130->dev, "Failed to request IRQ: %d, will poll instead\n", ret);
+		cs43130->has_irq_line = 0;
+	} else {
+		cs43130->has_irq_line = 1;
 	}

 	cs43130->mclk_int_src = CS43130_MCLK_SRC_RCO;
diff --git a/sound/soc/codecs/cs43130.h b/sound/soc/codecs/cs43130.h
index d3f595bbd3ba..dbdb5b262f1b 100644
--- a/sound/soc/codecs/cs43130.h
+++ b/sound/soc/codecs/cs43130.h
@@ -508,6 +508,7 @@ struct	cs43130_private {
 	struct gpio_desc		*reset_gpio;
 	unsigned int			dev_id; /* codec device ID */
 	int				xtal_ibias;
+	bool				has_irq_line;

 	/* shared by both DAIs */
 	struct mutex			clk_mutex;
--
2.34.1