mfd: max77620: Add core driver for MAX77620/MAX20024

MAX77620/MAX20024 are Power Management IC from the MAXIM.
It supports RTC, multiple GPIOs, multiple DCDC and LDOs,
watchdog, clock etc.

Add MFD drier to provides common support for accessing the
device; additional drivers is developed on respected subsystem
in order to use the functionality of the device.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mallikarjun Kasoju <mkasoju@nvidia.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 590 insertions, 0 deletions

diff --git a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c
new file mode 100644
index 000000000000..199d261990be
--- /dev/null
+++ b/drivers/mfd/max77620.c
@@ -0,0 +1,590 @@
+/*
+ * Maxim MAX77620 MFD Driver
+ *
+ * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author:
+ *	Laxman Dewangan <ldewangan@nvidia.com>
+ *	Chaitanya Bandi <bandik@nvidia.com>
+ *	Mallikarjun Kasoju <mkasoju@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/****************** Teminology used in driver ********************
+ * Here are some terminology used from datasheet for quick reference:
+ * Flexible Power Sequence (FPS):
+ * The Flexible Power Sequencer (FPS) allows each regulator to power up under
+ * hardware or software control. Additionally, each regulator can power on
+ * independently or among a group of other regulators with an adjustable
+ * power-up and power-down delays (sequencing). GPIO1, GPIO2, and GPIO3 can
+ * be programmed to be part of a sequence allowing external regulators to be
+ * sequenced along with internal regulators. 32KHz clock can be programmed to
+ * be part of a sequence.
+ * There is 3 FPS confguration registers and all resources are configured to
+ * any of these FPS or no FPS.
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max77620.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+static struct resource gpio_resources[] = {
+	DEFINE_RES_IRQ(MAX77620_IRQ_TOP_GPIO),
+};
+
+static struct resource power_resources[] = {
+	DEFINE_RES_IRQ(MAX77620_IRQ_LBT_MBATLOW),
+};
+
+static struct resource rtc_resources[] = {
+	DEFINE_RES_IRQ(MAX77620_IRQ_TOP_RTC),
+};
+
+static struct resource thermal_resources[] = {
+	DEFINE_RES_IRQ(MAX77620_IRQ_LBT_TJALRM1),
+	DEFINE_RES_IRQ(MAX77620_IRQ_LBT_TJALRM2),
+};
+
+static const struct regmap_irq max77620_top_irqs[] = {
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_GLBL, 0, MAX77620_IRQ_TOP_GLBL_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_SD, 0, MAX77620_IRQ_TOP_SD_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_LDO, 0, MAX77620_IRQ_TOP_LDO_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_GPIO, 0, MAX77620_IRQ_TOP_GPIO_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_RTC, 0, MAX77620_IRQ_TOP_RTC_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_32K, 0, MAX77620_IRQ_TOP_32K_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_TOP_ONOFF, 0, MAX77620_IRQ_TOP_ONOFF_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_LBT_MBATLOW, 1, MAX77620_IRQ_LBM_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_LBT_TJALRM1, 1, MAX77620_IRQ_TJALRM1_MASK),
+	REGMAP_IRQ_REG(MAX77620_IRQ_LBT_TJALRM2, 1, MAX77620_IRQ_TJALRM2_MASK),
+};
+
+static const struct mfd_cell max77620_children[] = {
+	{ .name = "max77620-pinctrl", },
+	{ .name = "max77620-clock", },
+	{ .name = "max77620-pmic", },
+	{ .name = "max77620-watchdog", },
+	{
+		.name = "max77620-gpio",
+		.resources = gpio_resources,
+		.num_resources = ARRAY_SIZE(gpio_resources),
+	}, {
+		.name = "max77620-rtc",
+		.resources = rtc_resources,
+		.num_resources = ARRAY_SIZE(rtc_resources),
+	}, {
+		.name = "max77620-power",
+		.resources = power_resources,
+		.num_resources = ARRAY_SIZE(power_resources),
+	}, {
+		.name = "max77620-thermal",
+		.resources = thermal_resources,
+		.num_resources = ARRAY_SIZE(thermal_resources),
+	},
+};
+
+static const struct mfd_cell max20024_children[] = {
+	{ .name = "max20024-pinctrl", },
+	{ .name = "max77620-clock", },
+	{ .name = "max20024-pmic", },
+	{ .name = "max77620-watchdog", },
+	{
+		.name = "max77620-gpio",
+		.resources = gpio_resources,
+		.num_resources = ARRAY_SIZE(gpio_resources),
+	}, {
+		.name = "max77620-rtc",
+		.resources = rtc_resources,
+		.num_resources = ARRAY_SIZE(rtc_resources),
+	}, {
+		.name = "max20024-power",
+		.resources = power_resources,
+		.num_resources = ARRAY_SIZE(power_resources),
+	},
+};
+
+static struct regmap_irq_chip max77620_top_irq_chip = {
+	.name = "max77620-top",
+	.irqs = max77620_top_irqs,
+	.num_irqs = ARRAY_SIZE(max77620_top_irqs),
+	.num_regs = 2,
+	.status_base = MAX77620_REG_IRQTOP,
+	.mask_base = MAX77620_REG_IRQTOPM,
+};
+
+static const struct regmap_range max77620_readable_ranges[] = {
+	regmap_reg_range(MAX77620_REG_CNFGGLBL1, MAX77620_REG_DVSSD4),
+};
+
+static const struct regmap_access_table max77620_readable_table = {
+	.yes_ranges = max77620_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max77620_readable_ranges),
+};
+
+static const struct regmap_range max20024_readable_ranges[] = {
+	regmap_reg_range(MAX77620_REG_CNFGGLBL1, MAX77620_REG_DVSSD4),
+	regmap_reg_range(MAX20024_REG_MAX_ADD, MAX20024_REG_MAX_ADD),
+};
+
+static const struct regmap_access_table max20024_readable_table = {
+	.yes_ranges = max20024_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max20024_readable_ranges),
+};
+
+static const struct regmap_range max77620_writable_ranges[] = {
+	regmap_reg_range(MAX77620_REG_CNFGGLBL1, MAX77620_REG_DVSSD4),
+};
+
+static const struct regmap_access_table max77620_writable_table = {
+	.yes_ranges = max77620_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max77620_writable_ranges),
+};
+
+static const struct regmap_range max77620_cacheable_ranges[] = {
+	regmap_reg_range(MAX77620_REG_SD0_CFG, MAX77620_REG_LDO_CFG3),
+	regmap_reg_range(MAX77620_REG_FPS_CFG0, MAX77620_REG_FPS_SD3),
+};
+
+static const struct regmap_access_table max77620_volatile_table = {
+	.no_ranges = max77620_cacheable_ranges,
+	.n_no_ranges = ARRAY_SIZE(max77620_cacheable_ranges),
+};
+
+static const struct regmap_config max77620_regmap_config = {
+	.name = "power-slave",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX77620_REG_DVSSD4 + 1,
+	.cache_type = REGCACHE_RBTREE,
+	.rd_table = &max77620_readable_table,
+	.wr_table = &max77620_writable_table,
+	.volatile_table = &max77620_volatile_table,
+};
+
+static const struct regmap_config max20024_regmap_config = {
+	.name = "power-slave",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX20024_REG_MAX_ADD + 1,
+	.cache_type = REGCACHE_RBTREE,
+	.rd_table = &max20024_readable_table,
+	.wr_table = &max77620_writable_table,
+	.volatile_table = &max77620_volatile_table,
+};
+
+/* max77620_get_fps_period_reg_value:  Get FPS bit field value from
+ *				       requested periods.
+ * MAX77620 supports the FPS period of 40, 80, 160, 320, 540, 1280, 2560
+ * and 5120 microseconds. MAX20024 supports the FPS period of 20, 40, 80,
+ * 160, 320, 540, 1280 and 2560 microseconds.
+ * The FPS register has 3 bits field to set the FPS period as
+ * bits		max77620		max20024
+ * 000		40			20
+ * 001		80			40
+ * :::
+*/
+static int max77620_get_fps_period_reg_value(struct max77620_chip *chip,
+					     int tperiod)
+{
+	int fps_min_period;
+	int i;
+
+	switch (chip->chip_id) {
+	case MAX20024:
+		fps_min_period = MAX20024_FPS_PERIOD_MIN_US;
+		break;
+	case MAX77620:
+		fps_min_period = MAX77620_FPS_PERIOD_MIN_US;
+	default:
+		return -EINVAL;
+	}
+
+	for (i = 0; i < 7; i++) {
+		if (fps_min_period >= tperiod)
+			return i;
+		fps_min_period *= 2;
+	}
+
+	return i;
+}
+
+/* max77620_config_fps: Configure FPS configuration registers
+ *			based on platform specific information.
+ */
+static int max77620_config_fps(struct max77620_chip *chip,
+			       struct device_node *fps_np)
+{
+	struct device *dev = chip->dev;
+	unsigned int mask = 0, config = 0;
+	u32 fps_max_period;
+	u32 param_val;
+	int tperiod, fps_id;
+	int ret;
+	char fps_name[10];
+
+	switch (chip->chip_id) {
+	case MAX20024:
+		fps_max_period = MAX20024_FPS_PERIOD_MAX_US;
+		break;
+	case MAX77620:
+		fps_max_period = MAX77620_FPS_PERIOD_MAX_US;
+	default:
+		return -EINVAL;
+	}
+
+	for (fps_id = 0; fps_id < MAX77620_FPS_COUNT; fps_id++) {
+		sprintf(fps_name, "fps%d", fps_id);
+		if (!strcmp(fps_np->name, fps_name))
+			break;
+	}
+
+	if (fps_id == MAX77620_FPS_COUNT) {
+		dev_err(dev, "FPS node name %s is not valid\n", fps_np->name);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32(fps_np, "maxim,shutdown-fps-time-period-us",
+				   &param_val);
+	if (!ret) {
+		mask |= MAX77620_FPS_TIME_PERIOD_MASK;
+		chip->shutdown_fps_period[fps_id] = min(param_val,
+							fps_max_period);
+		tperiod = max77620_get_fps_period_reg_value(chip,
+				chip->shutdown_fps_period[fps_id]);
+		config |= tperiod << MAX77620_FPS_TIME_PERIOD_SHIFT;
+	}
+
+	ret = of_property_read_u32(fps_np, "maxim,suspend-fps-time-period-us",
+				   &param_val);
+	if (!ret)
+		chip->suspend_fps_period[fps_id] = min(param_val,
+						       fps_max_period);
+
+	ret = of_property_read_u32(fps_np, "maxim,fps-event-source",
+				   &param_val);
+	if (!ret) {
+		if (param_val > 2) {
+			dev_err(dev, "FPS%d event-source invalid\n", fps_id);
+			return -EINVAL;
+		}
+		mask |= MAX77620_FPS_EN_SRC_MASK;
+		config |= param_val << MAX77620_FPS_EN_SRC_SHIFT;
+		if (param_val == 2) {
+			mask |= MAX77620_FPS_ENFPS_SW_MASK;
+			config |= MAX77620_FPS_ENFPS_SW;
+		}
+	}
+
+	if (!chip->sleep_enable && !chip->enable_global_lpm) {
+		ret = of_property_read_u32(fps_np,
+				"maxim,device-state-on-disabled-event",
+				&param_val);
+		if (!ret) {
+			if (param_val == 0)
+				chip->sleep_enable = true;
+			else if (param_val == 1)
+				chip->enable_global_lpm = true;
+		}
+	}
+
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_FPS_CFG0 + fps_id,
+				 mask, config);
+	if (ret < 0) {
+		dev_err(dev, "Failed to update FPS CFG: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int max77620_initialise_fps(struct max77620_chip *chip)
+{
+	struct device *dev = chip->dev;
+	struct device_node *fps_np, *fps_child;
+	u8 config;
+	int fps_id;
+	int ret;
+
+	for (fps_id = 0; fps_id < MAX77620_FPS_COUNT; fps_id++) {
+		chip->shutdown_fps_period[fps_id] = -1;
+		chip->suspend_fps_period[fps_id] = -1;
+	}
+
+	fps_np = of_get_child_by_name(dev->of_node, "fps");
+	if (!fps_np)
+		goto skip_fps;
+
+	for_each_child_of_node(fps_np, fps_child) {
+		ret = max77620_config_fps(chip, fps_child);
+		if (ret < 0)
+			return ret;
+	}
+
+	config = chip->enable_global_lpm ? MAX77620_ONOFFCNFG2_SLP_LPM_MSK : 0;
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG2,
+				 MAX77620_ONOFFCNFG2_SLP_LPM_MSK, config);
+	if (ret < 0) {
+		dev_err(dev, "Failed to update SLP_LPM: %d\n", ret);
+		return ret;
+	}
+
+skip_fps:
+	/* Enable wake on EN0 pin */
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG2,
+				 MAX77620_ONOFFCNFG2_WK_EN0,
+				 MAX77620_ONOFFCNFG2_WK_EN0);
+	if (ret < 0) {
+		dev_err(dev, "Failed to update WK_EN0: %d\n", ret);
+		return ret;
+	}
+
+	/* For MAX20024, SLPEN will be POR reset if CLRSE is b11 */
+	if ((chip->chip_id == MAX20024) && chip->sleep_enable) {
+		config = MAX77620_ONOFFCNFG1_SLPEN | MAX20024_ONOFFCNFG1_CLRSE;
+		ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG1,
+					 config, config);
+		if (ret < 0) {
+			dev_err(dev, "Failed to update SLPEN: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int max77620_read_es_version(struct max77620_chip *chip)
+{
+	unsigned int val;
+	u8 cid_val[6];
+	int i;
+	int ret;
+
+	for (i = MAX77620_REG_CID0; i <= MAX77620_REG_CID5; i++) {
+		ret = regmap_read(chip->rmap, i, &val);
+		if (ret < 0) {
+			dev_err(chip->dev, "Failed to read CID: %d\n", ret);
+			return ret;
+		}
+		dev_dbg(chip->dev, "CID%d: 0x%02x\n",
+			i - MAX77620_REG_CID0, val);
+		cid_val[i - MAX77620_REG_CID0] = val;
+	}
+
+	/* CID4 is OTP Version  and CID5 is ES version */
+	dev_info(chip->dev, "PMIC Version OTP:0x%02X and ES:0x%X\n",
+		 cid_val[4], MAX77620_CID5_DIDM(cid_val[5]));
+
+	return ret;
+}
+
+static int max77620_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	const struct regmap_config *rmap_config;
+	struct max77620_chip *chip;
+	const struct mfd_cell *mfd_cells;
+	int n_mfd_cells;
+	int ret;
+
+	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, chip);
+	chip->dev = &client->dev;
+	chip->irq_base = -1;
+	chip->chip_irq = client->irq;
+	chip->chip_id = (enum max77620_chip_id)id->driver_data;
+
+	switch (chip->chip_id) {
+	case MAX77620:
+		mfd_cells = max77620_children;
+		n_mfd_cells = ARRAY_SIZE(max77620_children);
+		rmap_config = &max77620_regmap_config;
+		break;
+	case MAX20024:
+		mfd_cells = max20024_children;
+		n_mfd_cells = ARRAY_SIZE(max20024_children);
+		rmap_config = &max20024_regmap_config;
+		break;
+	default:
+		dev_err(chip->dev, "ChipID is invalid %d\n", chip->chip_id);
+		return -EINVAL;
+	}
+
+	chip->rmap = devm_regmap_init_i2c(client, rmap_config);
+	if (IS_ERR(chip->rmap)) {
+		ret = PTR_ERR(chip->rmap);
+		dev_err(chip->dev, "Failed to intialise regmap: %d\n", ret);
+		return ret;
+	}
+
+	ret = max77620_read_es_version(chip);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_regmap_add_irq_chip(chip->dev, chip->rmap, client->irq,
+				       IRQF_ONESHOT | IRQF_SHARED,
+				       chip->irq_base, &max77620_top_irq_chip,
+				       &chip->top_irq_data);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to add regmap irq: %d\n", ret);
+		return ret;
+	}
+
+	ret = max77620_initialise_fps(chip);
+	if (ret < 0)
+		return ret;
+
+	ret =  devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,
+				    mfd_cells, n_mfd_cells, NULL, 0,
+				    regmap_irq_get_domain(chip->top_irq_data));
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to add MFD children: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max77620_set_fps_period(struct max77620_chip *chip,
+				   int fps_id, int time_period)
+{
+	int period = max77620_get_fps_period_reg_value(chip, time_period);
+	int ret;
+
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_FPS_CFG0 + fps_id,
+				 MAX77620_FPS_TIME_PERIOD_MASK,
+				 period << MAX77620_FPS_TIME_PERIOD_SHIFT);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to update FPS period: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int max77620_i2c_suspend(struct device *dev)
+{
+	struct max77620_chip *chip = dev_get_drvdata(dev);
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned int config;
+	int fps;
+	int ret;
+
+	for (fps = 0; fps < MAX77620_FPS_COUNT; fps++) {
+		if (chip->suspend_fps_period[fps] < 0)
+			continue;
+
+		ret = max77620_set_fps_period(chip, fps,
+					      chip->suspend_fps_period[fps]);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * For MAX20024: No need to configure SLPEN on suspend as
+	 * it will be configured on Init.
+	 */
+	if (chip->chip_id == MAX20024)
+		goto out;
+
+	config = (chip->sleep_enable) ? MAX77620_ONOFFCNFG1_SLPEN : 0;
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG1,
+				 MAX77620_ONOFFCNFG1_SLPEN,
+				 config);
+	if (ret < 0) {
+		dev_err(dev, "Failed to configure sleep in suspend: %d\n", ret);
+		return ret;
+	}
+
+	/* Disable WK_EN0 */
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG2,
+				 MAX77620_ONOFFCNFG2_WK_EN0, 0);
+	if (ret < 0) {
+		dev_err(dev, "Failed to configure WK_EN in suspend: %d\n", ret);
+		return ret;
+	}
+
+out:
+	disable_irq(client->irq);
+
+	return 0;
+}
+
+static int max77620_i2c_resume(struct device *dev)
+{
+	struct max77620_chip *chip = dev_get_drvdata(dev);
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret;
+	int fps;
+
+	for (fps = 0; fps < MAX77620_FPS_COUNT; fps++) {
+		if (chip->shutdown_fps_period[fps] < 0)
+			continue;
+
+		ret = max77620_set_fps_period(chip, fps,
+					      chip->shutdown_fps_period[fps]);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * For MAX20024: No need to configure WKEN0 on resume as
+	 * it is configured on Init.
+	 */
+	if (chip->chip_id == MAX20024)
+		goto out;
+
+	/* Enable WK_EN0 */
+	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG2,
+				 MAX77620_ONOFFCNFG2_WK_EN0,
+				 MAX77620_ONOFFCNFG2_WK_EN0);
+	if (ret < 0) {
+		dev_err(dev, "Failed to configure WK_EN0 n resume: %d\n", ret);
+		return ret;
+	}
+
+out:
+	enable_irq(client->irq);
+
+	return 0;
+}
+#endif
+
+static const struct i2c_device_id max77620_id[] = {
+	{"max77620", MAX77620},
+	{"max20024", MAX20024},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, max77620_id);
+
+static const struct dev_pm_ops max77620_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(max77620_i2c_suspend, max77620_i2c_resume)
+};
+
+static struct i2c_driver max77620_driver = {
+	.driver = {
+		.name = "max77620",
+		.pm = &max77620_pm_ops,
+	},
+	.probe = max77620_probe,
+	.id_table = max77620_id,
+};
+
+module_i2c_driver(max77620_driver);
+
+MODULE_DESCRIPTION("MAX77620/MAX20024 Multi Function Device Core Driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_AUTHOR("Chaitanya Bandi <bandik@nvidia.com>");
+MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
+MODULE_LICENSE("GPL v2");