Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Fletcher Woodruff <fletcherw@chromium.org>
To:     linux-kernel@vger.kernel.org
Cc:     Ben Zhang <benzh@chromium.org>, Bard Liao <bardliao@realtek.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Oder Chiou <oder_chiou@realtek.com>,
        Takashi Iwai <tiwai@suse.com>,
        Curtis Malainey <cujomalainey@chromium.org>,
        Ross Zwisler <zwisler@google.org>, alsa-devel@alsa-project.org,
        Fletcher Woodruff <fletcherw@chromium.org>
Subject: [PATCH 1/2] ASoC: rt5677: allow multiple interrupt sources
Date:   Mon,  1 Apr 2019 14:55:18 -0600
Message-Id: <20190401205519.34023-1-fletcherw@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Ben Zhang <benzh@chromium.org>

This patch allows headphone plug detect and mic present
detect to be enabled at the same time. This patch implements
an irq_chip with irq_domain directly instead of using
regmap_irq, so that interrupt source line polarities can
be flipped to support irq sharing.

Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Fletcher Woodruff <fletcherw@chromium.org>
---
 sound/soc/codecs/rt5677.c | 261 ++++++++++++++++++++++++++++----------
 sound/soc/codecs/rt5677.h |  14 +-
 2 files changed, 208 insertions(+), 67 deletions(-)

diff --git a/sound/soc/codecs/rt5677.c b/sound/soc/codecs/rt5677.c
index 9b7a1833d3316c..33380f82b7008f 100644
--- a/sound/soc/codecs/rt5677.c
+++ b/sound/soc/codecs/rt5677.c
@@ -23,6 +23,10 @@
 #include <linux/firmware.h>
 #include <linux/of_device.h>
 #include <linux/property.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/workqueue.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
@@ -4620,7 +4624,6 @@ static void rt5677_gpio_config(struct rt5677_priv *rt5677, unsigned offset,
 static int rt5677_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct rt5677_priv *rt5677 = gpiochip_get_data(chip);
-	struct regmap_irq_chip_data *data = rt5677->irq_data;
 	int irq;
 
 	if ((rt5677->pdata.jd1_gpio == 1 && offset == RT5677_GPIO1) ||
@@ -4646,7 +4649,7 @@ static int rt5677_to_irq(struct gpio_chip *chip, unsigned offset)
 		return -ENXIO;
 	}
 
-	return regmap_irq_get_virq(data, irq);
+	return irq_create_mapping(rt5677->domain, irq);
 }
 
 static const struct gpio_chip rt5677_template_chip = {
@@ -4716,37 +4719,13 @@ static int rt5677_probe(struct snd_soc_component *component)
 
 	snd_soc_component_force_bias_level(component, SND_SOC_BIAS_OFF);
 
-	regmap_write(rt5677->regmap, RT5677_DIG_MISC, 0x0020);
+	regmap_update_bits(rt5677->regmap, RT5677_DIG_MISC,
+			~RT5677_IRQ_DEBOUNCE_SEL_MASK, 0x0020);
 	regmap_write(rt5677->regmap, RT5677_PWR_DSP2, 0x0c00);
 
 	for (i = 0; i < RT5677_GPIO_NUM; i++)
 		rt5677_gpio_config(rt5677, i, rt5677->pdata.gpio_config[i]);
 
-	if (rt5677->irq_data) {
-		regmap_update_bits(rt5677->regmap, RT5677_GPIO_CTRL1, 0x8000,
-			0x8000);
-		regmap_update_bits(rt5677->regmap, RT5677_DIG_MISC, 0x0018,
-			0x0008);
-
-		if (rt5677->pdata.jd1_gpio)
-			regmap_update_bits(rt5677->regmap, RT5677_JD_CTRL1,
-				RT5677_SEL_GPIO_JD1_MASK,
-				rt5677->pdata.jd1_gpio <<
-				RT5677_SEL_GPIO_JD1_SFT);
-
-		if (rt5677->pdata.jd2_gpio)
-			regmap_update_bits(rt5677->regmap, RT5677_JD_CTRL1,
-				RT5677_SEL_GPIO_JD2_MASK,
-				rt5677->pdata.jd2_gpio <<
-				RT5677_SEL_GPIO_JD2_SFT);
-
-		if (rt5677->pdata.jd3_gpio)
-			regmap_update_bits(rt5677->regmap, RT5677_JD_CTRL1,
-				RT5677_SEL_GPIO_JD3_MASK,
-				rt5677->pdata.jd3_gpio <<
-				RT5677_SEL_GPIO_JD3_SFT);
-	}
-
 	mutex_init(&rt5677->dsp_cmd_lock);
 	mutex_init(&rt5677->dsp_pri_lock);
 
@@ -5063,65 +5042,215 @@ static void rt5677_read_device_properties(struct rt5677_priv *rt5677,
 			&rt5677->pdata.jd3_gpio);
 }
 
-static struct regmap_irq rt5677_irqs[] = {
+struct rt5677_irq_desc {
+	unsigned int enable_mask;
+	unsigned int status_mask;
+	unsigned int polarity_mask;
+};
+
+static const struct rt5677_irq_desc rt5677_irq_descs[] = {
 	[RT5677_IRQ_JD1] = {
-		.reg_offset = 0,
-		.mask = RT5677_EN_IRQ_GPIO_JD1,
+		.enable_mask = RT5677_EN_IRQ_GPIO_JD1,
+		.status_mask = RT5677_STA_GPIO_JD1,
+		.polarity_mask = RT5677_INV_GPIO_JD1,
 	},
 	[RT5677_IRQ_JD2] = {
-		.reg_offset = 0,
-		.mask = RT5677_EN_IRQ_GPIO_JD2,
+		.enable_mask = RT5677_EN_IRQ_GPIO_JD2,
+		.status_mask = RT5677_STA_GPIO_JD2,
+		.polarity_mask = RT5677_INV_GPIO_JD2,
 	},
 	[RT5677_IRQ_JD3] = {
-		.reg_offset = 0,
-		.mask = RT5677_EN_IRQ_GPIO_JD3,
+		.enable_mask = RT5677_EN_IRQ_GPIO_JD3,
+		.status_mask = RT5677_STA_GPIO_JD3,
+		.polarity_mask = RT5677_INV_GPIO_JD3,
 	},
 };
+static irqreturn_t rt5677_irq(int unused, void *data)
+{
+	struct rt5677_priv *rt5677 = data;
+	int ret = 0, i, loop, reg_irq, virq;
+	bool irq_fired;
+
+	mutex_lock(&rt5677->irq_lock);
+	/*
+	 * Loop to handle interrupts until the last i2c read shows no pending
+	 * irqs. The interrupt line is shared by multiple interrupt sources.
+	 * After the regmap_read() below, a new interrupt source line may
+	 * become high before the regmap_write() finishes, so there isn't a
+	 * rising edge on the shared interrupt line for the new interrupt. Thus,
+	 * the loop is needed to avoid missing irqs.
+	 *
+	 * A safeguard of 20 loops is used to avoid hanging in the irq handler
+	 * if there is something wrong with the interrupt status update. The
+	 * interrupt sources here are audio jack plug/unplug events which
+	 * shouldn't happen at a high frequency for a long period of time.
+	 * Empirically, more than 3 loops have never been seen.
+	 */
+	for (loop = 0; loop < 20; loop++) {
+		/* Read interrupt status */
+		ret = regmap_read(rt5677->regmap, RT5677_IRQ_CTRL1, &reg_irq);
+		if (ret)
+			break;
+		/*
+		 * Clear the interrupt by flipping the polarity of the
+		 * interrupt source lines that just fired
+		 */
+		irq_fired = false;
+		for (i = 0; i < RT5677_IRQ_NUM; i++) {
+			if (reg_irq & rt5677_irq_descs[i].status_mask) {
+				reg_irq ^= rt5677_irq_descs[i].polarity_mask;
+				irq_fired = true;
+			}
+		}
+		if (!irq_fired)
+			break;
 
-static struct regmap_irq_chip rt5677_irq_chip = {
-	.name = "rt5677",
-	.irqs = rt5677_irqs,
-	.num_irqs = ARRAY_SIZE(rt5677_irqs),
+		ret = regmap_write(rt5677->regmap, RT5677_IRQ_CTRL1, reg_irq);
+		if (ret)
+			break;
 
-	.num_regs = 1,
-	.status_base = RT5677_IRQ_CTRL1,
-	.mask_base = RT5677_IRQ_CTRL1,
-	.mask_invert = 1,
-};
+		/* Process interrupts */
+		for (i = 0; i < RT5677_IRQ_NUM; i++) {
+			if ((reg_irq & rt5677_irq_descs[i].enable_mask) &&
+			    (reg_irq & rt5677_irq_descs[i].status_mask)) {
+				virq = irq_find_mapping(rt5677->domain, i);
+				if (virq)
+					handle_nested_irq(virq);
+			}
+		}
+	}
+	mutex_unlock(&rt5677->irq_lock);
+	return IRQ_HANDLED;
+}
+static void rt5677_irq_work(struct work_struct *work)
+{
+	struct rt5677_priv *rt5677 =
+		container_of(work, struct rt5677_priv, irq_work.work);
+
+	rt5677_irq(0, rt5677);
+}
 
-static int rt5677_init_irq(struct i2c_client *i2c)
+static void rt5677_irq_bus_lock(struct irq_data *data)
 {
-	int ret;
-	struct rt5677_priv *rt5677 = i2c_get_clientdata(i2c);
+	struct rt5677_priv *rt5677 = irq_data_get_irq_chip_data(data);
 
-	if (!rt5677->pdata.jd1_gpio &&
-		!rt5677->pdata.jd2_gpio &&
-		!rt5677->pdata.jd3_gpio)
-		return 0;
+	mutex_lock(&rt5677->irq_lock);
+}
 
-	if (!i2c->irq) {
-		dev_err(&i2c->dev, "No interrupt specified\n");
-		return -EINVAL;
-	}
+static void rt5677_irq_bus_sync_unlock(struct irq_data *data)
+{
+	struct rt5677_priv *rt5677 = irq_data_get_irq_chip_data(data);
 
-	ret = regmap_add_irq_chip(rt5677->regmap, i2c->irq,
-		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 0,
-		&rt5677_irq_chip, &rt5677->irq_data);
+	regmap_update_bits(rt5677->regmap, RT5677_IRQ_CTRL1,
+			RT5677_EN_IRQ_GPIO_JD1 | RT5677_EN_IRQ_GPIO_JD2 |
+			RT5677_EN_IRQ_GPIO_JD3, rt5677->irq_en);
+	mutex_unlock(&rt5677->irq_lock);
+}
 
-	if (ret != 0) {
-		dev_err(&i2c->dev, "Failed to register IRQ chip: %d\n", ret);
-		return ret;
-	}
+static void rt5677_irq_enable(struct irq_data *data)
+{
+	struct rt5677_priv *rt5677 = irq_data_get_irq_chip_data(data);
+
+	rt5677->irq_en |= rt5677_irq_descs[data->hwirq].enable_mask;
+}
+
+static void rt5677_irq_disable(struct irq_data *data)
+{
+	struct rt5677_priv *rt5677 = irq_data_get_irq_chip_data(data);
+
+	rt5677->irq_en &= ~rt5677_irq_descs[data->hwirq].enable_mask;
+}
 
+static struct irq_chip rt5677_irq_chip = {
+	.name			= "rt5677_irq_chip",
+	.irq_bus_lock		= rt5677_irq_bus_lock,
+	.irq_bus_sync_unlock	= rt5677_irq_bus_sync_unlock,
+	.irq_disable		= rt5677_irq_disable,
+	.irq_enable		= rt5677_irq_enable,
+};
+
+static int rt5677_irq_map(struct irq_domain *h, unsigned int virq,
+			  irq_hw_number_t hw)
+{
+	struct rt5677_priv *rt5677 = h->host_data;
+
+	irq_set_chip_data(virq, rt5677);
+	irq_set_chip(virq, &rt5677_irq_chip);
+	irq_set_nested_thread(virq, 1);
+	irq_set_noprobe(virq);
 	return 0;
 }
 
-static void rt5677_free_irq(struct i2c_client *i2c)
+
+static const struct irq_domain_ops rt5677_domain_ops = {
+	.map	= rt5677_irq_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+static void rt5677_init_irq(struct i2c_client *i2c)
+{
+	struct rt5677_priv *rt5677 = i2c_get_clientdata(i2c);
+	int ret;
+	unsigned int jd_mask = 0, jd_val = 0;
+
+	/* No irq has been assigned to the codec */
+	if (!i2c->irq)
+		return;
+
+	mutex_init(&rt5677->irq_lock);
+	INIT_DELAYED_WORK(&rt5677->irq_work, rt5677_irq_work);
+
+	/*
+	 * Select RC as the debounce clock so that GPIO works even when
+	 * MCLK is gated which happens when there is no audio stream
+	 * (SND_SOC_BIAS_OFF).
+	 */
+	regmap_update_bits(rt5677->regmap, RT5677_DIG_MISC,
+			RT5677_IRQ_DEBOUNCE_SEL_MASK,
+			RT5677_IRQ_DEBOUNCE_SEL_RC);
+	/* Enable auto power on RC when GPIO states are changed */
+	regmap_update_bits(rt5677->regmap, RT5677_GEN_CTRL1, 0xff, 0xff);
+
+	/* Select and enable jack detection sources per platform data */
+	if (rt5677->pdata.jd1_gpio) {
+		jd_mask	|= RT5677_SEL_GPIO_JD1_MASK;
+		jd_val	|= rt5677->pdata.jd1_gpio << RT5677_SEL_GPIO_JD1_SFT;
+	}
+	if (rt5677->pdata.jd2_gpio) {
+		jd_mask	|= RT5677_SEL_GPIO_JD2_MASK;
+		jd_val	|= rt5677->pdata.jd2_gpio << RT5677_SEL_GPIO_JD2_SFT;
+	}
+	if (rt5677->pdata.jd3_gpio) {
+		jd_mask	|= RT5677_SEL_GPIO_JD3_MASK;
+		jd_val	|= rt5677->pdata.jd3_gpio << RT5677_SEL_GPIO_JD3_SFT;
+	}
+	regmap_update_bits(rt5677->regmap, RT5677_JD_CTRL1, jd_mask, jd_val);
+
+	/* Set GPIO1 pin to be IRQ output */
+	regmap_update_bits(rt5677->regmap, RT5677_GPIO_CTRL1,
+			RT5677_GPIO1_PIN_MASK, RT5677_GPIO1_PIN_IRQ);
+
+	/* Ready to listen for interrupts */
+	rt5677->domain = irq_domain_add_linear(i2c->dev.of_node,
+			RT5677_IRQ_NUM, &rt5677_domain_ops, rt5677);
+	if (!rt5677->domain) {
+		dev_err(&i2c->dev, "Failed to create IRQ domain\n");
+		return;
+	}
+	ret = devm_request_threaded_irq(&i2c->dev, i2c->irq, NULL, rt5677_irq,
+			IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+			"rt5677", rt5677);
+	if (ret) {
+		dev_err(&i2c->dev, "Failed to request IRQ: %d\n", ret);
+		return;
+	}
+}
+
+static void rt5677_irq_exit(struct i2c_client *i2c)
 {
 	struct rt5677_priv *rt5677 = i2c_get_clientdata(i2c);
 
-	if (rt5677->irq_data)
-		regmap_del_irq_chip(i2c->irq, rt5677->irq_data);
+	cancel_delayed_work_sync(&rt5677->irq_work);
 }
 
 static int rt5677_i2c_probe(struct i2c_client *i2c)
@@ -5259,7 +5388,7 @@ static int rt5677_i2c_probe(struct i2c_client *i2c)
 
 static int rt5677_i2c_remove(struct i2c_client *i2c)
 {
-	rt5677_free_irq(i2c);
+	rt5677_irq_exit(i2c);
 	rt5677_free_gpio(i2c);
 
 	return 0;
diff --git a/sound/soc/codecs/rt5677.h b/sound/soc/codecs/rt5677.h
index 183d92b030459f..9c73bea8635508 100644
--- a/sound/soc/codecs/rt5677.h
+++ b/sound/soc/codecs/rt5677.h
@@ -1636,6 +1636,12 @@
 #define RT5677_GPIO6_P_NOR			(0x0 << 0)
 #define RT5677_GPIO6_P_INV			(0x1 << 0)
 
+/* General Control (0xfa) */
+#define RT5677_IRQ_DEBOUNCE_SEL_MASK		(0x3 << 3)
+#define RT5677_IRQ_DEBOUNCE_SEL_MCLK		(0x0 << 3)
+#define RT5677_IRQ_DEBOUNCE_SEL_RC		(0x1 << 3)
+#define RT5677_IRQ_DEBOUNCE_SEL_SLIM		(0x2 << 3)
+
 /* Virtual DSP Mixer Control (0xf7 0xf8 0xf9) */
 #define RT5677_DSP_IB_01_H			(0x1 << 15)
 #define RT5677_DSP_IB_01_H_SFT			15
@@ -1713,6 +1719,7 @@ enum {
 	RT5677_IRQ_JD1,
 	RT5677_IRQ_JD2,
 	RT5677_IRQ_JD3,
+	RT5677_IRQ_NUM,
 };
 
 enum rt5677_type {
@@ -1811,9 +1818,14 @@ struct rt5677_priv {
 	struct gpio_chip gpio_chip;
 #endif
 	bool dsp_vad_en;
-	struct regmap_irq_chip_data *irq_data;
 	bool is_dsp_mode;
 	bool is_vref_slow;
+
+	/* Interrupt handling */
+	struct irq_domain *domain;
+	struct mutex irq_lock;
+	unsigned int irq_en;
+	struct delayed_work irq_work;
 };
 
 int rt5677_sel_asrc_clk_src(struct snd_soc_component *component,
-- 
2.21.0.392.gf8f6787159e-goog