mfd: Add support for the MediaTek MT6358 PMIC

This adds support for the MediaTek MT6358 PMIC. This is a
multifunction device with the following sub modules:

- Regulator
- RTC
- Codec
- Interrupt

It is interfaced to the host controller using SPI interface
by a proprietary hardware called PMIC wrapper or pwrap.
MT6358 MFD is a child device of the pwrap.

Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@mediatek.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 235 insertions, 0 deletions

diff --git a/drivers/mfd/mt6358-irq.c b/drivers/mfd/mt6358-irq.c
new file mode 100644
index 000000000000..db734f2831ff
--- /dev/null
+++ b/drivers/mfd/mt6358-irq.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2020 MediaTek Inc.
+
+#include <linux/interrupt.h>
+#include <linux/mfd/mt6358/core.h>
+#include <linux/mfd/mt6358/registers.h>
+#include <linux/mfd/mt6397/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static struct irq_top_t mt6358_ints[] = {
+	MT6358_TOP_GEN(BUCK),
+	MT6358_TOP_GEN(LDO),
+	MT6358_TOP_GEN(PSC),
+	MT6358_TOP_GEN(SCK),
+	MT6358_TOP_GEN(BM),
+	MT6358_TOP_GEN(HK),
+	MT6358_TOP_GEN(AUD),
+	MT6358_TOP_GEN(MISC),
+};
+
+static void pmic_irq_enable(struct irq_data *data)
+{
+	unsigned int hwirq = irqd_to_hwirq(data);
+	struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
+	struct pmic_irq_data *irqd = chip->irq_data;
+
+	irqd->enable_hwirq[hwirq] = true;
+}
+
+static void pmic_irq_disable(struct irq_data *data)
+{
+	unsigned int hwirq = irqd_to_hwirq(data);
+	struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
+	struct pmic_irq_data *irqd = chip->irq_data;
+
+	irqd->enable_hwirq[hwirq] = false;
+}
+
+static void pmic_irq_lock(struct irq_data *data)
+{
+	struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&chip->irqlock);
+}
+
+static void pmic_irq_sync_unlock(struct irq_data *data)
+{
+	unsigned int i, top_gp, gp_offset, en_reg, int_regs, shift;
+	struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
+	struct pmic_irq_data *irqd = chip->irq_data;
+
+	for (i = 0; i < irqd->num_pmic_irqs; i++) {
+		if (irqd->enable_hwirq[i] == irqd->cache_hwirq[i])
+			continue;
+
+		/* Find out the IRQ group */
+		top_gp = 0;
+		while ((top_gp + 1) < irqd->num_top &&
+		       i >= mt6358_ints[top_gp + 1].hwirq_base)
+			top_gp++;
+
+		/* Find the IRQ registers */
+		gp_offset = i - mt6358_ints[top_gp].hwirq_base;
+		int_regs = gp_offset / MT6358_REG_WIDTH;
+		shift = gp_offset % MT6358_REG_WIDTH;
+		en_reg = mt6358_ints[top_gp].en_reg +
+			 (mt6358_ints[top_gp].en_reg_shift * int_regs);
+
+		regmap_update_bits(chip->regmap, en_reg, BIT(shift),
+				   irqd->enable_hwirq[i] << shift);
+
+		irqd->cache_hwirq[i] = irqd->enable_hwirq[i];
+	}
+	mutex_unlock(&chip->irqlock);
+}
+
+static struct irq_chip mt6358_irq_chip = {
+	.name = "mt6358-irq",
+	.flags = IRQCHIP_SKIP_SET_WAKE,
+	.irq_enable = pmic_irq_enable,
+	.irq_disable = pmic_irq_disable,
+	.irq_bus_lock = pmic_irq_lock,
+	.irq_bus_sync_unlock = pmic_irq_sync_unlock,
+};
+
+static void mt6358_irq_sp_handler(struct mt6397_chip *chip,
+				  unsigned int top_gp)
+{
+	unsigned int irq_status, sta_reg, status;
+	unsigned int hwirq, virq;
+	int i, j, ret;
+
+	for (i = 0; i < mt6358_ints[top_gp].num_int_regs; i++) {
+		sta_reg = mt6358_ints[top_gp].sta_reg +
+			mt6358_ints[top_gp].sta_reg_shift * i;
+
+		ret = regmap_read(chip->regmap, sta_reg, &irq_status);
+		if (ret) {
+			dev_err(chip->dev,
+				"Failed to read IRQ status, ret=%d\n", ret);
+			return;
+		}
+
+		if (!irq_status)
+			continue;
+
+		status = irq_status;
+		do {
+			j = __ffs(status);
+
+			hwirq = mt6358_ints[top_gp].hwirq_base +
+				MT6358_REG_WIDTH * i + j;
+
+			virq = irq_find_mapping(chip->irq_domain, hwirq);
+			if (virq)
+				handle_nested_irq(virq);
+
+			status &= ~BIT(j);
+		} while (status);
+
+		regmap_write(chip->regmap, sta_reg, irq_status);
+	}
+}
+
+static irqreturn_t mt6358_irq_handler(int irq, void *data)
+{
+	struct mt6397_chip *chip = data;
+	struct pmic_irq_data *mt6358_irq_data = chip->irq_data;
+	unsigned int bit, i, top_irq_status = 0;
+	int ret;
+
+	ret = regmap_read(chip->regmap,
+			  mt6358_irq_data->top_int_status_reg,
+			  &top_irq_status);
+	if (ret) {
+		dev_err(chip->dev,
+			"Failed to read status from the device, ret=%d\n", ret);
+		return IRQ_NONE;
+	}
+
+	for (i = 0; i < mt6358_irq_data->num_top; i++) {
+		bit = BIT(mt6358_ints[i].top_offset);
+		if (top_irq_status & bit) {
+			mt6358_irq_sp_handler(chip, i);
+			top_irq_status &= ~bit;
+			if (!top_irq_status)
+				break;
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int pmic_irq_domain_map(struct irq_domain *d, unsigned int irq,
+			       irq_hw_number_t hw)
+{
+	struct mt6397_chip *mt6397 = d->host_data;
+
+	irq_set_chip_data(irq, mt6397);
+	irq_set_chip_and_handler(irq, &mt6358_irq_chip, handle_level_irq);
+	irq_set_nested_thread(irq, 1);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops mt6358_irq_domain_ops = {
+	.map = pmic_irq_domain_map,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+int mt6358_irq_init(struct mt6397_chip *chip)
+{
+	int i, j, ret;
+	struct pmic_irq_data *irqd;
+
+	irqd = devm_kzalloc(chip->dev, sizeof(*irqd), GFP_KERNEL);
+	if (!irqd)
+		return -ENOMEM;
+
+	chip->irq_data = irqd;
+
+	mutex_init(&chip->irqlock);
+	irqd->top_int_status_reg = MT6358_TOP_INT_STATUS0;
+	irqd->num_pmic_irqs = MT6358_IRQ_NR;
+	irqd->num_top = ARRAY_SIZE(mt6358_ints);
+
+	irqd->enable_hwirq = devm_kcalloc(chip->dev,
+					  irqd->num_pmic_irqs,
+					  sizeof(*irqd->enable_hwirq),
+					  GFP_KERNEL);
+	if (!irqd->enable_hwirq)
+		return -ENOMEM;
+
+	irqd->cache_hwirq = devm_kcalloc(chip->dev,
+					 irqd->num_pmic_irqs,
+					 sizeof(*irqd->cache_hwirq),
+					 GFP_KERNEL);
+	if (!irqd->cache_hwirq)
+		return -ENOMEM;
+
+	/* Disable all interrupts for initializing */
+	for (i = 0; i < irqd->num_top; i++) {
+		for (j = 0; j < mt6358_ints[i].num_int_regs; j++)
+			regmap_write(chip->regmap,
+				     mt6358_ints[i].en_reg +
+				     mt6358_ints[i].en_reg_shift * j, 0);
+	}
+
+	chip->irq_domain = irq_domain_add_linear(chip->dev->of_node,
+						 irqd->num_pmic_irqs,
+						 &mt6358_irq_domain_ops, chip);
+	if (!chip->irq_domain) {
+		dev_err(chip->dev, "Could not create IRQ domain\n");
+		return -ENODEV;
+	}
+
+	ret = devm_request_threaded_irq(chip->dev, chip->irq, NULL,
+					mt6358_irq_handler, IRQF_ONESHOT,
+					mt6358_irq_chip.name, chip);
+	if (ret) {
+		dev_err(chip->dev, "Failed to register IRQ=%d, ret=%d\n",
+			chip->irq, ret);
+		return ret;
+	}
+
+	enable_irq_wake(chip->irq);
+	return ret;
+}