irqchip: Add driver for Cirrus Logic Madera codecs

The Cirrus Logic Madera codecs (Cirrus Logic CS47L35/85/90/91 and WM1840)
are highly complex devices containing up to 7 programmable DSPs and many
other internal sources of interrupts plus a number of GPIOs that can be
used as interrupt inputs. The large number (>150) of internal interrupt
sources are managed by an on-board interrupt controller.

This driver provides the handling for the interrupt controller. As the
codec is accessed via regmap, we can make use of the generic IRQ
functionality from regmap to do most of the work. Only around half of
the possible interrupt source are currently of interest from the driver
so only this subset is defined. Others can be added in future if needed.

The KConfig options are not user-configurable because this driver is
mandatory so is automatically included when the parent MFD driver is
selected.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

3 files changed, 260 insertions, 0 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 9d54645870ad..bab0b97b5b1f 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -150,6 +150,9 @@ config IMGPDC_IRQ
 	select GENERIC_IRQ_CHIP
 	select IRQ_DOMAIN
 
+config MADERA_IRQ
+	tristate
+
 config IRQ_MIPS_CPU
 	bool
 	select GENERIC_IRQ_CHIP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 417108027e40..bc53a58bd403 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -92,3 +92,4 @@ obj-$(CONFIG_QCOM_PDC)			+= qcom-pdc.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
+obj-$(CONFIG_MADERA_IRQ)		+= irq-madera.o
diff --git a/drivers/irqchip/irq-madera.c b/drivers/irqchip/irq-madera.c
new file mode 100644
index 000000000000..e9256dee1a45
--- /dev/null
+++ b/drivers/irqchip/irq-madera.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Interrupt support for Cirrus Logic Madera codecs
+ *
+ * Copyright (C) 2015-2018 Cirrus Logic, Inc. and
+ *                         Cirrus Logic International Semiconductor Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_irq.h>
+#include <linux/irqchip/irq-madera.h>
+#include <linux/mfd/madera/core.h>
+#include <linux/mfd/madera/pdata.h>
+#include <linux/mfd/madera/registers.h>
+
+#define MADERA_IRQ(_irq, _reg)					\
+	[MADERA_IRQ_ ## _irq] = {				\
+		.reg_offset = (_reg) - MADERA_IRQ1_STATUS_2,	\
+		.mask = MADERA_ ## _irq ## _EINT1		\
+	}
+
+/* Mappings are the same for all Madera codecs */
+static const struct regmap_irq madera_irqs[MADERA_NUM_IRQ] = {
+	MADERA_IRQ(FLL1_LOCK,		MADERA_IRQ1_STATUS_2),
+	MADERA_IRQ(FLL2_LOCK,		MADERA_IRQ1_STATUS_2),
+	MADERA_IRQ(FLL3_LOCK,		MADERA_IRQ1_STATUS_2),
+	MADERA_IRQ(FLLAO_LOCK,		MADERA_IRQ1_STATUS_2),
+
+	MADERA_IRQ(MICDET1,		MADERA_IRQ1_STATUS_6),
+	MADERA_IRQ(MICDET2,		MADERA_IRQ1_STATUS_6),
+	MADERA_IRQ(HPDET,		MADERA_IRQ1_STATUS_6),
+
+	MADERA_IRQ(MICD_CLAMP_RISE,	MADERA_IRQ1_STATUS_7),
+	MADERA_IRQ(MICD_CLAMP_FALL,	MADERA_IRQ1_STATUS_7),
+	MADERA_IRQ(JD1_RISE,		MADERA_IRQ1_STATUS_7),
+	MADERA_IRQ(JD1_FALL,		MADERA_IRQ1_STATUS_7),
+
+	MADERA_IRQ(ASRC2_IN1_LOCK,	MADERA_IRQ1_STATUS_9),
+	MADERA_IRQ(ASRC2_IN2_LOCK,	MADERA_IRQ1_STATUS_9),
+	MADERA_IRQ(ASRC1_IN1_LOCK,	MADERA_IRQ1_STATUS_9),
+	MADERA_IRQ(ASRC1_IN2_LOCK,	MADERA_IRQ1_STATUS_9),
+	MADERA_IRQ(DRC2_SIG_DET,	MADERA_IRQ1_STATUS_9),
+	MADERA_IRQ(DRC1_SIG_DET,	MADERA_IRQ1_STATUS_9),
+
+	MADERA_IRQ(DSP_IRQ1,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ2,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ3,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ4,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ5,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ6,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ7,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ8,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ9,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ10,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ11,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ12,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ13,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ14,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ15,		MADERA_IRQ1_STATUS_11),
+	MADERA_IRQ(DSP_IRQ16,		MADERA_IRQ1_STATUS_11),
+
+	MADERA_IRQ(HP3R_SC,		MADERA_IRQ1_STATUS_12),
+	MADERA_IRQ(HP3L_SC,		MADERA_IRQ1_STATUS_12),
+	MADERA_IRQ(HP2R_SC,		MADERA_IRQ1_STATUS_12),
+	MADERA_IRQ(HP2L_SC,		MADERA_IRQ1_STATUS_12),
+	MADERA_IRQ(HP1R_SC,		MADERA_IRQ1_STATUS_12),
+	MADERA_IRQ(HP1L_SC,		MADERA_IRQ1_STATUS_12),
+
+	MADERA_IRQ(SPK_OVERHEAT_WARN,	MADERA_IRQ1_STATUS_15),
+	MADERA_IRQ(SPK_OVERHEAT,	MADERA_IRQ1_STATUS_15),
+
+	MADERA_IRQ(DSP1_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP2_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP3_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP4_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP5_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP6_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+	MADERA_IRQ(DSP7_BUS_ERR,	MADERA_IRQ1_STATUS_33),
+};
+
+static const struct regmap_irq_chip madera_irq_chip = {
+	.name		= "madera IRQ",
+	.status_base	= MADERA_IRQ1_STATUS_2,
+	.mask_base	= MADERA_IRQ1_MASK_2,
+	.ack_base	= MADERA_IRQ1_STATUS_2,
+	.runtime_pm	= true,
+	.num_regs	= 32,
+	.irqs		= madera_irqs,
+	.num_irqs	= ARRAY_SIZE(madera_irqs),
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int madera_suspend(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev->parent);
+
+	dev_dbg(madera->irq_dev, "Suspend, disabling IRQ\n");
+
+	/*
+	 * A runtime resume would be needed to access the chip interrupt
+	 * controller but runtime pm doesn't function during suspend.
+	 * Temporarily disable interrupts until we reach suspend_noirq state.
+	 */
+	disable_irq(madera->irq);
+
+	return 0;
+}
+
+static int madera_suspend_noirq(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev->parent);
+
+	dev_dbg(madera->irq_dev, "No IRQ suspend, reenabling IRQ\n");
+
+	/* Re-enable interrupts to service wakeup interrupts from the chip */
+	enable_irq(madera->irq);
+
+	return 0;
+}
+
+static int madera_resume_noirq(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev->parent);
+
+	dev_dbg(madera->irq_dev, "No IRQ resume, disabling IRQ\n");
+
+	/*
+	 * We can't handle interrupts until runtime pm is available again.
+	 * Disable them temporarily.
+	 */
+	disable_irq(madera->irq);
+
+	return 0;
+}
+
+static int madera_resume(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev->parent);
+
+	dev_dbg(madera->irq_dev, "Resume, reenabling IRQ\n");
+
+	/* Interrupts can now be handled */
+	enable_irq(madera->irq);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops madera_irq_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(madera_suspend, madera_resume)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(madera_suspend_noirq,
+				      madera_resume_noirq)
+};
+
+static int madera_irq_probe(struct platform_device *pdev)
+{
+	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
+	struct irq_data *irq_data;
+	unsigned int irq_flags = 0;
+	int ret;
+
+	dev_dbg(&pdev->dev, "probe\n");
+
+	/*
+	 * Read the flags from the interrupt controller if not specified
+	 * by pdata
+	 */
+	irq_flags = madera->pdata.irq_flags;
+	if (!irq_flags) {
+		irq_data = irq_get_irq_data(madera->irq);
+		if (!irq_data) {
+			dev_err(&pdev->dev, "Invalid IRQ: %d\n", madera->irq);
+			return -EINVAL;
+		}
+
+		irq_flags = irqd_get_trigger_type(irq_data);
+
+		/* Codec defaults to trigger low, use this if no flags given */
+		if (irq_flags == IRQ_TYPE_NONE)
+			irq_flags = IRQF_TRIGGER_LOW;
+	}
+
+	if (irq_flags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) {
+		dev_err(&pdev->dev, "Host interrupt not level-triggered\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * The silicon always starts at active-low, check if we need to
+	 * switch to active-high.
+	 */
+	if (irq_flags & IRQF_TRIGGER_HIGH) {
+		ret = regmap_update_bits(madera->regmap, MADERA_IRQ1_CTRL,
+					 MADERA_IRQ_POL_MASK, 0);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Failed to set IRQ polarity: %d\n", ret);
+			return ret;
+		}
+	}
+
+	/*
+	 * NOTE: regmap registers this against the OF node of the parent of
+	 * the regmap - that is, against the mfd driver
+	 */
+	ret = regmap_add_irq_chip(madera->regmap, madera->irq, IRQF_ONESHOT, 0,
+				  &madera_irq_chip, &madera->irq_data);
+	if (ret) {
+		dev_err(&pdev->dev, "add_irq_chip failed: %d\n", ret);
+		return ret;
+	}
+
+	/* Save dev in parent MFD struct so it is accessible to siblings */
+	madera->irq_dev = &pdev->dev;
+
+	return 0;
+}
+
+static int madera_irq_remove(struct platform_device *pdev)
+{
+	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
+
+	/*
+	 * The IRQ is disabled by the parent MFD driver before
+	 * it starts cleaning up all child drivers
+	 */
+	madera->irq_dev = NULL;
+	regmap_del_irq_chip(madera->irq, madera->irq_data);
+
+	return 0;
+}
+
+static struct platform_driver madera_irq_driver = {
+	.probe	= &madera_irq_probe,
+	.remove = &madera_irq_remove,
+	.driver = {
+		.name	= "madera-irq",
+		.pm	= &madera_irq_pm_ops,
+	}
+};
+module_platform_driver(madera_irq_driver);
+
+MODULE_SOFTDEP("pre: madera");
+MODULE_DESCRIPTION("Madera IRQ driver");
+MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
+MODULE_LICENSE("GPL v2");