mfd: pm8xxx: add support to pm8821

This patch adds support to PM8821 PMIC and interrupt support.
PM8821 is companion device that supplements primary PMIC PM8921 IC.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/mfd/qcom-pm8xxx.txt

@@ -10,6 +10,7 @@ voltages and other various functionality to Qualcomm SoCs.
 	Value type: <string>
 	Definition: must be one of:
 		    "qcom,pm8058"
+		    "qcom,pm8821"
 		    "qcom,pm8921"
 
 - #address-cells:

drivers/mfd/qcom-pm8xxx.c

@@ -39,6 +39,20 @@
 #define	SSBI_REG_ADDR_IRQ_CONFIG	(SSBI_REG_ADDR_IRQ_BASE + 7)
 #define	SSBI_REG_ADDR_IRQ_RT_STATUS	(SSBI_REG_ADDR_IRQ_BASE + 8)
 
+#define	PM8821_SSBI_REG_ADDR_IRQ_BASE	0x100
+#define	PM8821_SSBI_REG_ADDR_IRQ_MASTER0 (PM8821_SSBI_REG_ADDR_IRQ_BASE + 0x30)
+#define	PM8821_SSBI_REG_ADDR_IRQ_MASTER1 (PM8821_SSBI_REG_ADDR_IRQ_BASE + 0xb0)
+#define	PM8821_SSBI_REG(m, b, offset) \
+			((m == 0) ? \
+			(PM8821_SSBI_REG_ADDR_IRQ_MASTER0 + b + offset) : \
+			(PM8821_SSBI_REG_ADDR_IRQ_MASTER1 + b + offset))
+#define	PM8821_SSBI_ADDR_IRQ_ROOT(m, b)		PM8821_SSBI_REG(m, b, 0x0)
+#define	PM8821_SSBI_ADDR_IRQ_CLEAR(m, b)	PM8821_SSBI_REG(m, b, 0x01)
+#define	PM8821_SSBI_ADDR_IRQ_MASK(m, b)		PM8821_SSBI_REG(m, b, 0x08)
+#define	PM8821_SSBI_ADDR_IRQ_RT_STATUS(m, b)	PM8821_SSBI_REG(m, b, 0x0f)
+
+#define	PM8821_BLOCKS_PER_MASTER	7
+
 #define	PM_IRQF_LVL_SEL			0x01	/* level select */
 #define	PM_IRQF_MASK_FE			0x02	/* mask falling edge */
 #define	PM_IRQF_MASK_RE			0x04	/* mask rising edge */
@@ -54,6 +68,7 @@
 #define REG_HWREV_2		0x0E8  /* PMIC4 revision 2 */
 
 #define PM8XXX_NR_IRQS		256
+#define PM8821_NR_IRQS		112
 
 struct pm_irq_chip {
 	struct regmap		*regmap;
@@ -65,6 +80,12 @@ struct pm_irq_chip {
 	u8			config[0];
 };
 
+struct pm_irq_data {
+	int num_irqs;
+	const struct irq_domain_ops  *irq_domain_ops;
+	void (*irq_handler)(struct irq_desc *desc);
+};
+
 static int pm8xxx_read_block_irq(struct pm_irq_chip *chip, unsigned int bp,
 				 unsigned int *ip)
 {
@@ -182,6 +203,78 @@ static void pm8xxx_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(irq_chip, desc);
 }
 
+static void pm8821_irq_block_handler(struct pm_irq_chip *chip,
+				     int master, int block)
+{
+	int pmirq, irq, i, ret;
+	unsigned int bits;
+
+	ret = regmap_read(chip->regmap,
+			  PM8821_SSBI_ADDR_IRQ_ROOT(master, block), &bits);
+	if (ret) {
+		pr_err("Reading block %d failed ret=%d", block, ret);
+		return;
+	}
+
+	/* Convert block offset to global block number */
+	block += (master * PM8821_BLOCKS_PER_MASTER) - 1;
+
+	/* Check IRQ bits */
+	for (i = 0; i < 8; i++) {
+		if (bits & BIT(i)) {
+			pmirq = block * 8 + i;
+			irq = irq_find_mapping(chip->irqdomain, pmirq);
+			generic_handle_irq(irq);
+		}
+	}
+}
+
+static inline void pm8821_irq_master_handler(struct pm_irq_chip *chip,
+					     int master, u8 master_val)
+{
+	int block;
+
+	for (block = 1; block < 8; block++)
+		if (master_val & BIT(block))
+			pm8821_irq_block_handler(chip, master, block);
+}
+
+static void pm8821_irq_handler(struct irq_desc *desc)
+{
+	struct pm_irq_chip *chip = irq_desc_get_handler_data(desc);
+	struct irq_chip *irq_chip = irq_desc_get_chip(desc);
+	unsigned int master;
+	int ret;
+
+	chained_irq_enter(irq_chip, desc);
+	ret = regmap_read(chip->regmap,
+			  PM8821_SSBI_REG_ADDR_IRQ_MASTER0, &master);
+	if (ret) {
+		pr_err("Failed to read master 0 ret=%d\n", ret);
+		goto done;
+	}
+
+	/* bits 1 through 7 marks the first 7 blocks in master 0 */
+	if (master & GENMASK(7, 1))
+		pm8821_irq_master_handler(chip, 0, master);
+
+	/* bit 0 marks if master 1 contains any bits */
+	if (!(master & BIT(0)))
+		goto done;
+
+	ret = regmap_read(chip->regmap,
+			  PM8821_SSBI_REG_ADDR_IRQ_MASTER1, &master);
+	if (ret) {
+		pr_err("Failed to read master 1 ret=%d\n", ret);
+		goto done;
+	}
+
+	pm8821_irq_master_handler(chip, 1, master);
+
+done:
+	chained_irq_exit(irq_chip, desc);
+}
+
 static void pm8xxx_irq_mask_ack(struct irq_data *d)
 {
 	struct pm_irq_chip *chip = irq_data_get_irq_chip_data(d);
@@ -299,6 +392,104 @@ static const struct irq_domain_ops pm8xxx_irq_domain_ops = {
 	.map = pm8xxx_irq_domain_map,
 };
 
+static void pm8821_irq_mask_ack(struct irq_data *d)
+{
+	struct pm_irq_chip *chip = irq_data_get_irq_chip_data(d);
+	unsigned int pmirq = irqd_to_hwirq(d);
+	u8 block, master;
+	int irq_bit, rc;
+
+	block = pmirq / 8;
+	master = block / PM8821_BLOCKS_PER_MASTER;
+	irq_bit = pmirq % 8;
+	block %= PM8821_BLOCKS_PER_MASTER;
+
+	rc = regmap_update_bits(chip->regmap,
+				PM8821_SSBI_ADDR_IRQ_MASK(master, block),
+				BIT(irq_bit), BIT(irq_bit));
+	if (rc) {
+		pr_err("Failed to mask IRQ:%d rc=%d\n", pmirq, rc);
+		return;
+	}
+
+	rc = regmap_update_bits(chip->regmap,
+				PM8821_SSBI_ADDR_IRQ_CLEAR(master, block),
+				BIT(irq_bit), BIT(irq_bit));
+	if (rc)
+		pr_err("Failed to CLEAR IRQ:%d rc=%d\n", pmirq, rc);
+}
+
+static void pm8821_irq_unmask(struct irq_data *d)
+{
+	struct pm_irq_chip *chip = irq_data_get_irq_chip_data(d);
+	unsigned int pmirq = irqd_to_hwirq(d);
+	int irq_bit, rc;
+	u8 block, master;
+
+	block = pmirq / 8;
+	master = block / PM8821_BLOCKS_PER_MASTER;
+	irq_bit = pmirq % 8;
+	block %= PM8821_BLOCKS_PER_MASTER;
+
+	rc = regmap_update_bits(chip->regmap,
+				PM8821_SSBI_ADDR_IRQ_MASK(master, block),
+				BIT(irq_bit), ~BIT(irq_bit));
+	if (rc)
+		pr_err("Failed to read/write unmask IRQ:%d rc=%d\n", pmirq, rc);
+
+}
+
+static int pm8821_irq_get_irqchip_state(struct irq_data *d,
+					enum irqchip_irq_state which,
+					bool *state)
+{
+	struct pm_irq_chip *chip = irq_data_get_irq_chip_data(d);
+	int rc, pmirq = irqd_to_hwirq(d);
+	u8 block, irq_bit, master;
+	unsigned int bits;
+
+	block = pmirq / 8;
+	master = block / PM8821_BLOCKS_PER_MASTER;
+	irq_bit = pmirq % 8;
+	block %= PM8821_BLOCKS_PER_MASTER;
+
+	rc = regmap_read(chip->regmap,
+		PM8821_SSBI_ADDR_IRQ_RT_STATUS(master, block), &bits);
+	if (rc) {
+		pr_err("Reading Status of IRQ %d failed rc=%d\n", pmirq, rc);
+		return rc;
+	}
+
+	*state = !!(bits & BIT(irq_bit));
+
+	return rc;
+}
+
+static struct irq_chip pm8821_irq_chip = {
+	.name		= "pm8821",
+	.irq_mask_ack	= pm8821_irq_mask_ack,
+	.irq_unmask	= pm8821_irq_unmask,
+	.irq_get_irqchip_state = pm8821_irq_get_irqchip_state,
+	.flags		= IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE,
+};
+
+static int pm8821_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				   irq_hw_number_t hwirq)
+{
+	struct pm_irq_chip *chip = d->host_data;
+
+	irq_set_chip_and_handler(irq, &pm8821_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, chip);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops pm8821_irq_domain_ops = {
+	.xlate = irq_domain_xlate_twocell,
+	.map = pm8821_irq_domain_map,
+};
+
 static const struct regmap_config ssbi_regmap_config = {
 	.reg_bits = 16,
 	.val_bits = 8,
@@ -308,22 +499,41 @@ static const struct regmap_config ssbi_regmap_config = {
 	.reg_write = ssbi_reg_write
 };
 
+static const struct pm_irq_data pm8xxx_data = {
+	.num_irqs = PM8XXX_NR_IRQS,
+	.irq_domain_ops = &pm8xxx_irq_domain_ops,
+	.irq_handler = pm8xxx_irq_handler,
+};
+
+static const struct pm_irq_data pm8821_data = {
+	.num_irqs = PM8821_NR_IRQS,
+	.irq_domain_ops = &pm8821_irq_domain_ops,
+	.irq_handler = pm8821_irq_handler,
+};
+
 static const struct of_device_id pm8xxx_id_table[] = {
-	{ .compatible = "qcom,pm8018", },
-	{ .compatible = "qcom,pm8058", },
-	{ .compatible = "qcom,pm8921", },
+	{ .compatible = "qcom,pm8018", .data = &pm8xxx_data},
+	{ .compatible = "qcom,pm8058", .data = &pm8xxx_data},
+	{ .compatible = "qcom,pm8821", .data = &pm8821_data},
+	{ .compatible = "qcom,pm8921", .data = &pm8xxx_data},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
 
 static int pm8xxx_probe(struct platform_device *pdev)
 {
+	const struct pm_irq_data *data;
 	struct regmap *regmap;
 	int irq, rc;
 	unsigned int val;
 	u32 rev;
 	struct pm_irq_chip *chip;
-	unsigned int nirqs = PM8XXX_NR_IRQS;
+
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data) {
+		dev_err(&pdev->dev, "No matching driver data found\n");
+		return -EINVAL;
+	}
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
@@ -354,25 +564,26 @@ static int pm8xxx_probe(struct platform_device *pdev)
 	rev |= val << BITS_PER_BYTE;
 
 	chip = devm_kzalloc(&pdev->dev, sizeof(*chip) +
-					sizeof(chip->config[0]) * nirqs,
-					GFP_KERNEL);
+			    sizeof(chip->config[0]) * data->num_irqs,
+			    GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
 	platform_set_drvdata(pdev, chip);
 	chip->regmap = regmap;
-	chip->num_irqs = nirqs;
+	chip->num_irqs = data->num_irqs;
 	chip->num_blocks = DIV_ROUND_UP(chip->num_irqs, 8);
 	chip->num_masters = DIV_ROUND_UP(chip->num_blocks, 8);
 	spin_lock_init(&chip->pm_irq_lock);
 
-	chip->irqdomain = irq_domain_add_linear(pdev->dev.of_node, nirqs,
-						&pm8xxx_irq_domain_ops,
+	chip->irqdomain = irq_domain_add_linear(pdev->dev.of_node,
+						data->num_irqs,
+						data->irq_domain_ops,
 						chip);
 	if (!chip->irqdomain)
 		return -ENODEV;
 
-	irq_set_chained_handler_and_data(irq, pm8xxx_irq_handler, chip);
+	irq_set_chained_handler_and_data(irq, data->irq_handler, chip);
 	irq_set_irq_wake(irq, 1);
 
 	rc = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);