Introduce QTI I2C PMIC controller

The Qualcomm Technologies, Inc. I2C PMIC Controller is used by multi-function PMIC devices which communicate over the I2C bus. The controller enumerates all child nodes as platform devices, and instantiates a regmap interface for them to communicate over the I2C bus.

The controller also controls interrupts for all of the children platform devices. The controller handles the summary interrupt by deciphering which peripheral triggered the interrupt, and which of the peripheral interrupts were triggered. Finally, it calls the interrupt handlers for each of the virtual interrupts that were registered.

Signed-off-by Guru Das Srinagesh <[email protected]>

---
 .../devicetree/bindings/mfd/qcom,i2c-pmic.yaml     | 89 ++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/qcom,i2c-pmic.yaml

The Qualcomm Technologies, Inc. I2C PMIC Controller is used by multi-function PMIC devices which communicate over the I2C bus. The controller enumerates all child nodes as platform devices, and instantiates a regmap interface for them to communicate over the I2C bus.

The controller also controls interrupts for all of the children platform devices. The controller handles the summary interrupt by deciphering which peripheral triggered the interrupt, and which of the peripheral interrupts were triggered. Finally, it calls the interrupt handlers for each of the virtual interrupts that were registered.

Nicholas Troast is the original author of this driver.

Signed-off-by Guru Das Srinagesh <[email protected]>

---
 drivers/mfd/Kconfig         |  11 +
 drivers/mfd/Makefile        |   1 +
 drivers/mfd/qcom-i2c-pmic.c | 737 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 749 insertions(+)
 create mode 100644 drivers/mfd/qcom-i2c-pmic.c

drivers/mfd/Kconfig +0 -0

index 54b6aa4..bf112eb 100644

drivers/mfd/Kconfig +9 -0

+	depends on I2C && OF
+	select IRQ_DOMAIN
+	select REGMAP_I2C
+	help
+	  This enables support for controlling Qualcomm Technologies, Inc.
+	  PMICs over I2C. The driver controls interrupts, and provides register
+	  access for all of the device's peripherals.  Some QTI PMIC chips
+	  support communication over both I2C and SPMI.
+
 config MFD_QCOM_RPM
 	tristate "Qualcomm Resource Power Manager (RPM)"
 	depends on ARCH_QCOM && OF

drivers/mfd/Makefile +1 -0

index 7761f84..26f0b80 100644
@@ -199,6 +199,7 @@ obj-$(CONFIG_MFD_SI476X_CORE)	+= si476x-core.o
 obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o omap-usb-tll.o
 obj-$(CONFIG_MFD_PM8XXX) 	+= qcom-pm8xxx.o ssbi.o
+obj-$(CONFIG_MFD_I2C_PMIC)     += qcom-i2c-pmic.o
 obj-$(CONFIG_MFD_QCOM_RPM)	+= qcom_rpm.o
 obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o

drivers/mfd/qcom-i2c-pmic.c new file +0 -0

new file mode 100644
index 0000000..d0f600a

drivers/mfd/qcom-i2c-pmic.c new file +401 -0

+#define I2C_INTR_STATUS_BASE	0x0550
+#define INT_RT_STS_OFFSET	0x10
+#define INT_SET_TYPE_OFFSET	0x11
+#define INT_POL_HIGH_OFFSET	0x12
+#define INT_POL_LOW_OFFSET	0x13
+#define INT_LATCHED_CLR_OFFSET	0x14
+#define INT_EN_SET_OFFSET	0x15
+#define INT_EN_CLR_OFFSET	0x16
+#define INT_LATCHED_STS_OFFSET	0x18
+#define INT_PENDING_STS_OFFSET	0x19
+#define INT_MID_SEL_OFFSET	0x1A
+#define INT_MID_SEL_MASK	GENMASK(1, 0)
+#define INT_PRIORITY_OFFSET	0x1B
+#define INT_PRIORITY_BIT	BIT(0)
+
+enum {
+	IRQ_SET_TYPE = 0,
+	IRQ_POL_HIGH,
+	IRQ_POL_LOW,
+	IRQ_LATCHED_CLR, /* not needed but makes life easy */
+	IRQ_EN_SET,
+	IRQ_MAX_REGS,
+};
+
+struct i2c_pmic_periph {
+	void		*data;
+	u16		addr;
+	u8		cached[IRQ_MAX_REGS];
+	u8		synced[IRQ_MAX_REGS];
+	u8		wake;
+	struct mutex	lock;
+};
+
+struct i2c_pmic {
+	struct device		*dev;
+	struct regmap		*regmap;
+	struct irq_domain	*domain;
+	struct i2c_pmic_periph	*periph;
+	struct pinctrl		*pinctrl;
+	struct mutex		irq_complete;
+	const char		*pinctrl_name;
+	int			num_periphs;
+	int			summary_irq;
+	bool			resume_completed;
+	bool			irq_waiting;
+};
+
+static void i2c_pmic_irq_bus_lock(struct irq_data *d)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+
+	mutex_lock(&periph->lock);
+}
+
+static void i2c_pmic_sync_type_polarity(struct i2c_pmic *chip,
+			       struct i2c_pmic_periph *periph)
+{
+	int rc;
+
+	/* did any irq type change? */
+	if (periph->cached[IRQ_SET_TYPE] ^ periph->synced[IRQ_SET_TYPE]) {
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_SET_TYPE_OFFSET,
+				  periph->cached[IRQ_SET_TYPE]);
+		if (rc < 0) {
+			pr_err("Couldn't set periph 0x%04x irqs 0x%02x type rc=%d\n",
+				periph->addr, periph->cached[IRQ_SET_TYPE], rc);
+			return;
+		}
+
+		periph->synced[IRQ_SET_TYPE] = periph->cached[IRQ_SET_TYPE];
+	}
+
+	/* did any polarity high change? */
+	if (periph->cached[IRQ_POL_HIGH] ^ periph->synced[IRQ_POL_HIGH]) {
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_POL_HIGH_OFFSET,
+				  periph->cached[IRQ_POL_HIGH]);
+		if (rc < 0) {
+			pr_err("Couldn't set periph 0x%04x irqs 0x%02x polarity high rc=%d\n",
+				periph->addr, periph->cached[IRQ_POL_HIGH], rc);
+			return;
+		}
+
+		periph->synced[IRQ_POL_HIGH] = periph->cached[IRQ_POL_HIGH];
+	}
+
+	/* did any polarity low change? */
+	if (periph->cached[IRQ_POL_LOW] ^ periph->synced[IRQ_POL_LOW]) {
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_POL_LOW_OFFSET,
+				  periph->cached[IRQ_POL_LOW]);
+		if (rc < 0) {
+			pr_err("Couldn't set periph 0x%04x irqs 0x%02x polarity low rc=%d\n",
+				periph->addr, periph->cached[IRQ_POL_LOW], rc);
+			return;
+		}
+
+		periph->synced[IRQ_POL_LOW] = periph->cached[IRQ_POL_LOW];
+	}
+}
+
+static void i2c_pmic_sync_enable(struct i2c_pmic *chip,
+				 struct i2c_pmic_periph *periph)
+{
+	u8 en_set, en_clr;
+	int rc;
+
+	/* determine which irqs were enabled and which were disabled */
+	en_clr = periph->synced[IRQ_EN_SET] & ~periph->cached[IRQ_EN_SET];
+	en_set = ~periph->synced[IRQ_EN_SET] & periph->cached[IRQ_EN_SET];
+
+	/* were any irqs disabled? */
+	if (en_clr) {
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_EN_CLR_OFFSET, en_clr);
+		if (rc < 0) {
+			pr_err("Couldn't disable periph 0x%04x irqs 0x%02x rc=%d\n",
+				periph->addr, en_clr, rc);
+			return;
+		}
+	}
+
+	/* were any irqs enabled? */
+	if (en_set) {
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_EN_SET_OFFSET, en_set);
+		if (rc < 0) {
+			pr_err("Couldn't enable periph 0x%04x irqs 0x%02x rc=%d\n",
+				periph->addr, en_set, rc);
+			return;
+		}
+	}
+
+	/* irq enabled status was written to hardware */
+	periph->synced[IRQ_EN_SET] = periph->cached[IRQ_EN_SET];
+}
+
+static void i2c_pmic_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+	struct i2c_pmic *chip = periph->data;
+
+	i2c_pmic_sync_type_polarity(chip, periph);
+	i2c_pmic_sync_enable(chip, periph);
+	mutex_unlock(&periph->lock);
+}
+
+static void i2c_pmic_irq_disable(struct irq_data *d)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+
+	periph->cached[IRQ_EN_SET] &= ~d->hwirq & 0xFF;
+}
+
+static void i2c_pmic_irq_enable(struct irq_data *d)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+
+	periph->cached[IRQ_EN_SET] |= d->hwirq & 0xFF;
+}
+
+static int i2c_pmic_irq_set_type(struct irq_data *d, unsigned int irq_type)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+
+	switch (irq_type) {
+	case IRQ_TYPE_EDGE_RISING:
+		periph->cached[IRQ_SET_TYPE] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_HIGH] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_LOW] &= ~d->hwirq & 0xFF;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		periph->cached[IRQ_SET_TYPE] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_HIGH] &= ~d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_LOW] |= d->hwirq & 0xFF;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		periph->cached[IRQ_SET_TYPE] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_HIGH] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_LOW] |= d->hwirq & 0xFF;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		periph->cached[IRQ_SET_TYPE] &= ~d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_HIGH] |= d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_LOW] &= ~d->hwirq & 0xFF;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		periph->cached[IRQ_SET_TYPE] &= ~d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_HIGH] &= ~d->hwirq & 0xFF;
+		periph->cached[IRQ_POL_LOW] |= d->hwirq & 0xFF;
+		break;
+	default:
+		pr_err("irq type 0x%04x is not supported\n", irq_type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int i2c_pmic_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+	struct i2c_pmic_periph *periph = irq_data_get_irq_chip_data(d);
+
+	if (on)
+		periph->wake |= d->hwirq & 0xFF;
+	else
+		periph->wake &= ~d->hwirq & 0xFF;
+
+	return 0;
+}
+#else
+#define i2c_pmic_irq_set_wake NULL
+#endif
+
+static struct irq_chip i2c_pmic_irq_chip = {
+	.name			= "i2c_pmic_irq_chip",
+	.irq_bus_lock		= i2c_pmic_irq_bus_lock,
+	.irq_bus_sync_unlock	= i2c_pmic_irq_bus_sync_unlock,
+	.irq_disable		= i2c_pmic_irq_disable,
+	.irq_enable		= i2c_pmic_irq_enable,
+	.irq_set_type		= i2c_pmic_irq_set_type,
+	.irq_set_wake		= i2c_pmic_irq_set_wake,
+};
+
+static struct i2c_pmic_periph *i2c_pmic_find_periph(struct i2c_pmic *chip,
+						    irq_hw_number_t hwirq)
+{
+	int i;
+
+	for (i = 0; i < chip->num_periphs; i++)
+		if (chip->periph[i].addr == (hwirq & 0xFF00))
+			return &chip->periph[i];
+
+	pr_err_ratelimited("Couldn't find periph struct for hwirq 0x%04lx\n",
+			   hwirq);
+	return NULL;
+}
+
+static int i2c_pmic_domain_map(struct irq_domain *d, unsigned int virq,
+			irq_hw_number_t hwirq)
+{
+	struct i2c_pmic *chip = d->host_data;
+	struct i2c_pmic_periph *periph = i2c_pmic_find_periph(chip, hwirq);
+
+	if (!periph)
+		return -ENODEV;
+
+	irq_set_chip_data(virq, periph);
+	irq_set_chip_and_handler(virq, &i2c_pmic_irq_chip, handle_level_irq);
+	irq_set_nested_thread(virq, 1);
+	irq_set_noprobe(virq);
+	return 0;
+}
+
+static int i2c_pmic_domain_xlate(struct irq_domain *d,
+				 struct device_node *ctrlr, const u32 *intspec,
+				 unsigned int intsize, unsigned long *out_hwirq,
+				 unsigned int *out_type)
+{
+	if (intsize != 3)
+		return -EINVAL;
+
+	if (intspec[0] > 0xFF || intspec[1] > 0x7 ||
+					intspec[2] > IRQ_TYPE_SENSE_MASK)
+		return -EINVAL;
+
+	/*
+	 * Interrupt specifiers are triplets
+	 * <peripheral-address, irq-number, IRQ_TYPE_*>
+	 *
+	 * peripheral-address - The base address of the peripheral
+	 * irq-number	      - The zero based bit position of the peripheral's
+	 *			interrupt registers corresponding to the irq
+	 *			where the LSB is 0 and the MSB is 7
+	 * IRQ_TYPE_*	      - Please refer to linux/irq.h
+	 */
+	*out_hwirq = intspec[0] << 8 | BIT(intspec[1]);
+	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static const struct irq_domain_ops i2c_pmic_domain_ops = {
+	.map	= i2c_pmic_domain_map,
+	.xlate	= i2c_pmic_domain_xlate,
+};
+
+static void i2c_pmic_irq_ack_now(struct i2c_pmic *chip, u16 hwirq)
+{
+	int rc;
+
+	rc = regmap_write(chip->regmap,
+			  (hwirq & 0xFF00) | INT_LATCHED_CLR_OFFSET,
+			  hwirq & 0xFF);
+	if (rc < 0)
+		pr_err_ratelimited("Couldn't ack 0x%04x rc=%d\n", hwirq, rc);
+}
+
+static void i2c_pmic_irq_disable_now(struct i2c_pmic *chip, u16 hwirq)
+{
+	struct i2c_pmic_periph *periph = i2c_pmic_find_periph(chip, hwirq);
+	int rc;
+
+	if (!periph)
+		return;
+
+	mutex_lock(&periph->lock);
+	periph->cached[IRQ_EN_SET] &= ~hwirq & 0xFF;
+
+	rc = regmap_write(chip->regmap,
+			  (hwirq & 0xFF00) | INT_EN_CLR_OFFSET,
+			  hwirq & 0xFF);
+	if (rc < 0) {
+		pr_err_ratelimited("Couldn't disable irq 0x%04x rc=%d\n",
+				   hwirq, rc);
+		goto unlock;
+	}
+
+	periph->synced[IRQ_EN_SET] = periph->cached[IRQ_EN_SET];
+
+unlock:
+	mutex_unlock(&periph->lock);
+}
+
+static void i2c_pmic_periph_status_handler(struct i2c_pmic *chip,
+					   u16 periph_address, u8 periph_status)
+{
+	unsigned int hwirq, virq;
+	int i;
+
+	while (periph_status) {
+		i = ffs(periph_status) - 1;
+		periph_status &= ~BIT(i);
+		hwirq = periph_address | BIT(i);
+		virq = irq_find_mapping(chip->domain, hwirq);
+		if (virq == 0) {
+			pr_err_ratelimited("Couldn't find mapping; disabling 0x%04x\n",
+					   hwirq);
+			i2c_pmic_irq_disable_now(chip, hwirq);
+			continue;
+		}
+
+		handle_nested_irq(virq);
+		i2c_pmic_irq_ack_now(chip, hwirq);
+	}
+}
+
+static void i2c_pmic_summary_status_handler(struct i2c_pmic *chip,
+					    struct i2c_pmic_periph *periph,
+					    u8 summary_status)
+{
+	unsigned int periph_status;
+	int rc, i;
+
+	while (summary_status) {
+		i = ffs(summary_status) - 1;
+		summary_status &= ~BIT(i);
+
+		rc = regmap_read(chip->regmap,
+				 periph[i].addr | INT_LATCHED_STS_OFFSET,
+				 &periph_status);
+		if (rc < 0) {
+			pr_err_ratelimited("Couldn't read 0x%04x | INT_LATCHED_STS rc=%d\n",
+					   periph[i].addr, rc);
+			continue;
+		}
+
+		i2c_pmic_periph_status_handler(chip, periph[i].addr,
+					       periph_status);
+	}
+}
+
+static irqreturn_t i2c_pmic_irq_handler(int irq, void *dev_id)
+{
+	struct i2c_pmic *chip = dev_id;
+	struct i2c_pmic_periph *periph;
+	unsigned int summary_status;
+	int rc, i;
+
+	mutex_lock(&chip->irq_complete);
+	chip->irq_waiting = true;
+	if (!chip->resume_completed) {
+		pr_debug("IRQ triggered before device-resume\n");
+		disable_irq_nosync(irq);
+		mutex_unlock(&chip->irq_complete);
+		return IRQ_HANDLED;
+	}
+	chip->irq_waiting = false;
+
+	for (i = 0; i < DIV_ROUND_UP(chip->num_periphs, BITS_PER_BYTE); i++) {
+		rc = regmap_read(chip->regmap, I2C_INTR_STATUS_BASE + i,
+				&summary_status);
+		if (rc < 0) {
+			pr_err_ratelimited("Couldn't read I2C_INTR_STATUS%d rc=%d\n",
+					   i, rc);
+			continue;
+		}
+
+		if (summary_status == 0)

drivers/mfd/qcom-i2c-pmic.c new file +13 -0

+		return -EINVAL;
+	}
+
+	chip->periph = devm_kcalloc(chip->dev, chip->num_periphs,
+				     sizeof(*chip->periph), GFP_KERNEL);
+	if (!chip->periph)
+		return -ENOMEM;
+
+	for (i = 0; i < chip->num_periphs; i++) {
+		rc = of_property_read_u32_index(node, "qcom,periph-map",
+						i, &temp);
+		if (rc < 0) {
+			pr_err("Couldn't read qcom,periph-map[%d]

rc=%d\n",

drivers/mfd/qcom-i2c-pmic.c new file +10 -0

+			return rc;
+		}
+
+		memcpy(chip->periph[i].synced, chip->periph[i].cached,
+		       IRQ_MAX_REGS * sizeof(*chip->periph[i].synced));
+	}
+
+	return 0;
+}
+

drivers/mfd/qcom-i2c-pmic.c new file +6 -0

+	return 0;
+}
+
+static int i2c_pmic_suspend(struct device *dev)
+{
+	struct i2c_pmic *chip = dev_get_drvdata(dev);

drivers/mfd/qcom-i2c-pmic.c new file +26 -0

+	if (!rc) {
+		mutex_lock(&chip->irq_complete);
+		chip->resume_completed = false;
+		mutex_unlock(&chip->irq_complete);
+	}
+
+	return rc;
+}
+
+static int i2c_pmic_resume(struct device *dev)
+{
+	struct i2c_pmic *chip = dev_get_drvdata(dev);
+	struct i2c_pmic_periph *periph;
+	int rc = 0, i;
+
+	for (i = 0; i < chip->num_periphs; i++) {
+		periph = &chip->periph[i];
+
+		rc = regmap_write(chip->regmap,
+				  periph->addr | INT_EN_CLR_OFFSET, 0xFF);
+		if (rc < 0) {
+			pr_err("Couldn't clear 0x%04x irqs rc=%d\n",
+				periph->addr, rc);
+			continue;
+		}
+

drivers/mfd/qcom-i2c-pmic.c new file +18 -0

+		/* irq was pending, call the handler */
+		i2c_pmic_irq_handler(chip->summary_irq, chip);
+		enable_irq(chip->summary_irq);
+	} else {
+		mutex_unlock(&chip->irq_complete);
+	}
+
+	return rc;
+}
+#else
+static int i2c_pmic_suspend(struct device *dev)
+{
+	return 0;
+}
+static int i2c_pmic_resume(struct device *dev)
+{
+	return 0;
+}

drivers/mfd/qcom-i2c-pmic.c new file +4 -0

+module_i2c_driver(i2c_pmic_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("i2c:i2c_pmic");