mfd: bd71837: Core driver for ROHM BD71837 PMIC

ROHM BD71837 PMIC MFD driver providing interrupts and support
for three subsystems:
- clk
- Regulators
- input/power-key

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/Kconfig

@@ -1817,6 +1817,19 @@ config MFD_STW481X
 	  in various ST Microelectronics and ST-Ericsson embedded
 	  Nomadik series.
 
+config MFD_ROHM_BD718XX
+	tristate "ROHM BD71837 Power Management IC"
+	depends on I2C=y
+	depends on OF
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	select MFD_CORE
+	help
+	  Select this option to get support for the ROHM BD71837
+	  Power Management ICs. BD71837 is designed to power processors like
+	  NXP i.MX8. It contains 8 BUCK outputs and 7 LDOs, voltage monitoring
+	  and emergency shut down as well as 32,768KHz clock output.
+
 config MFD_STM32_LPTIMER
 	tristate "Support for STM32 Low-Power Timer"
 	depends on (ARCH_STM32 && OF) || COMPILE_TEST

drivers/mfd/Makefile

@@ -239,4 +239,5 @@ obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o
 obj-$(CONFIG_MFD_MXS_LRADC)     += mxs-lradc.o
 obj-$(CONFIG_MFD_SC27XX_PMIC)	+= sprd-sc27xx-spi.o
 obj-$(CONFIG_RAVE_SP_CORE)	+= rave-sp.o
+obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 

drivers/mfd/rohm-bd718x7.c

@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Copyright (C) 2018 ROHM Semiconductors
+//
+// ROHM BD71837MWV PMIC driver
+//
+// Datasheet available from
+// https://www.rohm.com/datasheet/BD71837MWV/bd71837mwv-e
+
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/rohm-bd718x7.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+/*
+ * gpio_keys.h requires definiton of bool. It is brought in
+ * by above includes. Keep this as last until gpio_keys.h gets fixed.
+ */
+#include <linux/gpio_keys.h>
+
+static const u8 supported_revisions[] = { 0xA2 /* BD71837 */ };
+
+static struct gpio_keys_button button = {
+	.code = KEY_POWER,
+	.gpio = -1,
+	.type = EV_KEY,
+};
+
+static struct gpio_keys_platform_data bd718xx_powerkey_data = {
+	.buttons = &button,
+	.nbuttons = 1,
+	.name = "bd718xx-pwrkey",
+};
+
+static struct mfd_cell bd71837_mfd_cells[] = {
+	{
+		.name = "gpio-keys",
+		.platform_data = &bd718xx_powerkey_data,
+		.pdata_size = sizeof(bd718xx_powerkey_data),
+	},
+	{ .name = "bd71837-clk", },
+	{ .name = "bd71837-pmic", },
+};
+
+static const struct regmap_irq bd71837_irqs[] = {
+	REGMAP_IRQ_REG(BD71837_INT_SWRST, 0, BD71837_INT_SWRST_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_PWRBTN_S, 0, BD71837_INT_PWRBTN_S_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_PWRBTN_L, 0, BD71837_INT_PWRBTN_L_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_PWRBTN, 0, BD71837_INT_PWRBTN_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_WDOG, 0, BD71837_INT_WDOG_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_ON_REQ, 0, BD71837_INT_ON_REQ_MASK),
+	REGMAP_IRQ_REG(BD71837_INT_STBY_REQ, 0, BD71837_INT_STBY_REQ_MASK),
+};
+
+static struct regmap_irq_chip bd71837_irq_chip = {
+	.name = "bd71837-irq",
+	.irqs = bd71837_irqs,
+	.num_irqs = ARRAY_SIZE(bd71837_irqs),
+	.num_regs = 1,
+	.irq_reg_stride = 1,
+	.status_base = BD71837_REG_IRQ,
+	.mask_base = BD71837_REG_MIRQ,
+	.ack_base = BD71837_REG_IRQ,
+	.init_ack_masked = true,
+	.mask_invert = false,
+};
+
+static const struct regmap_range pmic_status_range = {
+	.range_min = BD71837_REG_IRQ,
+	.range_max = BD71837_REG_POW_STATE,
+};
+
+static const struct regmap_access_table volatile_regs = {
+	.yes_ranges = &pmic_status_range,
+	.n_yes_ranges = 1,
+};
+
+static const struct regmap_config bd71837_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_table = &volatile_regs,
+	.max_register = BD71837_MAX_REGISTER - 1,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int bd71837_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct bd71837 *bd71837;
+	int ret, i;
+	unsigned int val;
+
+	bd71837 = devm_kzalloc(&i2c->dev, sizeof(struct bd71837), GFP_KERNEL);
+
+	if (!bd71837)
+		return -ENOMEM;
+
+	bd71837->chip_irq = i2c->irq;
+
+	if (!bd71837->chip_irq) {
+		dev_err(&i2c->dev, "No IRQ configured\n");
+		return -EINVAL;
+	}
+
+	bd71837->dev = &i2c->dev;
+	dev_set_drvdata(&i2c->dev, bd71837);
+
+	bd71837->regmap = devm_regmap_init_i2c(i2c, &bd71837_regmap_config);
+	if (IS_ERR(bd71837->regmap)) {
+		dev_err(&i2c->dev, "regmap initialization failed\n");
+		return PTR_ERR(bd71837->regmap);
+	}
+
+	ret = regmap_read(bd71837->regmap, BD71837_REG_REV, &val);
+	if (ret) {
+		dev_err(&i2c->dev, "Read BD71837_REG_DEVICE failed\n");
+		return ret;
+	}
+	for (i = 0; i < ARRAY_SIZE(supported_revisions); i++)
+		if (supported_revisions[i] == val)
+			break;
+
+	if (i == ARRAY_SIZE(supported_revisions)) {
+		dev_err(&i2c->dev, "Unsupported chip revision\n");
+		return -ENODEV;
+	}
+
+	ret = devm_regmap_add_irq_chip(&i2c->dev, bd71837->regmap,
+				       bd71837->chip_irq, IRQF_ONESHOT, 0,
+				       &bd71837_irq_chip, &bd71837->irq_data);
+	if (ret) {
+		dev_err(&i2c->dev, "Failed to add irq_chip\n");
+		return ret;
+	}
+
+	/* Configure short press to 10 milliseconds */
+	ret = regmap_update_bits(bd71837->regmap,
+				 BD71837_REG_PWRONCONFIG0,
+				 BD718XX_PWRBTN_PRESS_DURATION_MASK,
+				 BD718XX_PWRBTN_SHORT_PRESS_10MS);
+	if (ret) {
+		dev_err(&i2c->dev,
+			"Failed to configure button short press timeout\n");
+		return ret;
+	}
+
+	/* Configure long press to 10 seconds */
+	ret = regmap_update_bits(bd71837->regmap,
+				 BD71837_REG_PWRONCONFIG1,
+				 BD718XX_PWRBTN_PRESS_DURATION_MASK,
+				 BD718XX_PWRBTN_LONG_PRESS_10S);
+
+	if (ret) {
+		dev_err(&i2c->dev,
+			"Failed to configure button long press timeout\n");
+		return ret;
+	}
+
+	ret = regmap_irq_get_virq(bd71837->irq_data, BD71837_INT_PWRBTN_S);
+
+	if (ret < 0) {
+		dev_err(&i2c->dev, "Failed to get the IRQ\n");
+		return ret;
+	}
+
+	button.irq = ret;
+
+	ret = devm_mfd_add_devices(bd71837->dev, PLATFORM_DEVID_AUTO,
+				   bd71837_mfd_cells,
+				   ARRAY_SIZE(bd71837_mfd_cells), NULL, 0,
+				   regmap_irq_get_domain(bd71837->irq_data));
+	if (ret)
+		dev_err(&i2c->dev, "Failed to create subdevices\n");
+
+	return ret;
+}
+
+static const struct of_device_id bd71837_of_match[] = {
+	{ .compatible = "rohm,bd71837", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bd71837_of_match);
+
+static struct i2c_driver bd71837_i2c_driver = {
+	.driver = {
+		.name = "rohm-bd718x7",
+		.of_match_table = bd71837_of_match,
+	},
+	.probe = bd71837_i2c_probe,
+};
+
+static int __init bd71837_i2c_init(void)
+{
+	return i2c_add_driver(&bd71837_i2c_driver);
+}
+
+/* Initialise early so consumer devices can complete system boot */
+subsys_initcall(bd71837_i2c_init);
+
+static void __exit bd71837_i2c_exit(void)
+{
+	i2c_del_driver(&bd71837_i2c_driver);
+}
+module_exit(bd71837_i2c_exit);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("ROHM BD71837 Power Management IC driver");
+MODULE_LICENSE("GPL");