x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 549 insertions, 0 deletions

diff --git a/drivers/mfd/max14577.c b/drivers/mfd/max14577.c
new file mode 100644
index 000000000..da275a04a
--- /dev/null
+++ b/drivers/mfd/max14577.c
@@ -0,0 +1,549 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// max14577.c - mfd core driver for the Maxim 14577/77836
+//
+// Copyright (C) 2014 Samsung Electronics
+// Chanwoo Choi <cw00.choi@samsung.com>
+// Krzysztof Kozlowski <krzk@kernel.org>
+//
+// This driver is based on max8997.c
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max14577.h>
+#include <linux/mfd/max14577-private.h>
+
+/*
+ * Table of valid charger currents for different Maxim chipsets.
+ * It is placed here because it is used by both charger and regulator driver.
+ */
+const struct maxim_charger_current maxim_charger_currents[] = {
+	[MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
+	[MAXIM_DEVICE_TYPE_MAX14577] = {
+		.min		= MAX14577_CHARGER_CURRENT_LIMIT_MIN,
+		.high_start	= MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START,
+		.high_step	= MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+		.max		= MAX14577_CHARGER_CURRENT_LIMIT_MAX,
+	},
+	[MAXIM_DEVICE_TYPE_MAX77836] = {
+		.min		= MAX77836_CHARGER_CURRENT_LIMIT_MIN,
+		.high_start	= MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START,
+		.high_step	= MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP,
+		.max		= MAX77836_CHARGER_CURRENT_LIMIT_MAX,
+	},
+};
+EXPORT_SYMBOL_GPL(maxim_charger_currents);
+
+/*
+ * maxim_charger_calc_reg_current - Calculate register value for current
+ * @limits:	constraints for charger, matching the MBCICHWRC register
+ * @min_ua:	minimal requested current, micro Amps
+ * @max_ua:	maximum requested current, micro Amps
+ * @dst:	destination to store calculated register value
+ *
+ * Calculates the value of MBCICHWRC (Fast Battery Charge Current) register
+ * for given current and stores it under pointed 'dst'. The stored value
+ * combines low bit (MBCICHWRCL) and high bits (MBCICHWRCH). It is also
+ * properly shifted.
+ *
+ * The calculated register value matches the current which:
+ *  - is always between <limits.min, limits.max>;
+ *  - is always less or equal to max_ua;
+ *  - is the highest possible value;
+ *  - may be lower than min_ua.
+ *
+ * On success returns 0. On error returns -EINVAL (requested min/max current
+ * is outside of given charger limits) and 'dst' is not set.
+ */
+int maxim_charger_calc_reg_current(const struct maxim_charger_current *limits,
+		unsigned int min_ua, unsigned int max_ua, u8 *dst)
+{
+	unsigned int current_bits;
+
+	if (min_ua > max_ua)
+		return -EINVAL;
+
+	if (min_ua > limits->max || max_ua < limits->min)
+		return -EINVAL;
+
+	if (max_ua < limits->high_start) {
+		/*
+		 * Less than high_start, so set the minimal current
+		 * (turn Low Bit off, 0 as high bits).
+		 */
+		*dst = 0x0;
+		return 0;
+	}
+
+	/* max_ua is in range: <high_start, infinite>, cut it to limits.max */
+	max_ua = min(limits->max, max_ua);
+	max_ua -= limits->high_start;
+	/*
+	 * There is no risk of overflow 'max_ua' here because:
+	 *  - max_ua >= limits.high_start
+	 *  - BUILD_BUG checks that 'limits' are: max >= high_start + high_step
+	 */
+	current_bits = max_ua / limits->high_step;
+
+	/* Turn Low Bit on (use range <limits.high_start, limits.max>) ... */
+	*dst = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
+	/* and set proper High Bits */
+	*dst |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(maxim_charger_calc_reg_current);
+
+static const struct mfd_cell max14577_devs[] = {
+	{
+		.name = "max14577-muic",
+		.of_compatible = "maxim,max14577-muic",
+	},
+	{
+		.name = "max14577-regulator",
+		.of_compatible = "maxim,max14577-regulator",
+	},
+	{
+		.name = "max14577-charger",
+		.of_compatible = "maxim,max14577-charger",
+	},
+};
+
+static const struct mfd_cell max77836_devs[] = {
+	{
+		.name = "max77836-muic",
+		.of_compatible = "maxim,max77836-muic",
+	},
+	{
+		.name = "max77836-regulator",
+		.of_compatible = "maxim,max77836-regulator",
+	},
+	{
+		.name = "max77836-charger",
+		.of_compatible = "maxim,max77836-charger",
+	},
+	{
+		.name = "max77836-battery",
+		.of_compatible = "maxim,max77836-battery",
+	},
+};
+
+static const struct of_device_id max14577_dt_match[] = {
+	{
+		.compatible = "maxim,max14577",
+		.data = (void *)MAXIM_DEVICE_TYPE_MAX14577,
+	},
+	{
+		.compatible = "maxim,max77836",
+		.data = (void *)MAXIM_DEVICE_TYPE_MAX77836,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, max14577_dt_match);
+
+static bool max14577_muic_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX14577_REG_INT1 ... MAX14577_REG_STATUS3:
+		return true;
+	default:
+		break;
+	}
+	return false;
+}
+
+static bool max77836_muic_volatile_reg(struct device *dev, unsigned int reg)
+{
+	/* Any max14577 volatile registers are also max77836 volatile. */
+	if (max14577_muic_volatile_reg(dev, reg))
+		return true;
+
+	switch (reg) {
+	case MAX77836_FG_REG_VCELL_MSB ... MAX77836_FG_REG_SOC_LSB:
+	case MAX77836_FG_REG_CRATE_MSB ... MAX77836_FG_REG_CRATE_LSB:
+	case MAX77836_FG_REG_STATUS_H ... MAX77836_FG_REG_STATUS_L:
+	case MAX77836_PMIC_REG_INTSRC:
+	case MAX77836_PMIC_REG_TOPSYS_INT:
+	case MAX77836_PMIC_REG_TOPSYS_STAT:
+		return true;
+	default:
+		break;
+	}
+	return false;
+}
+
+static const struct regmap_config max14577_muic_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.volatile_reg	= max14577_muic_volatile_reg,
+	.max_register	= MAX14577_REG_END,
+};
+
+static const struct regmap_config max77836_pmic_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.volatile_reg	= max77836_muic_volatile_reg,
+	.max_register	= MAX77836_PMIC_REG_END,
+};
+
+static const struct regmap_irq max14577_irqs[] = {
+	/* INT1 interrupts */
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADC_MASK, },
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADCLOW_MASK, },
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADCERR_MASK, },
+	/* INT2 interrupts */
+	{ .reg_offset = 1, .mask = MAX14577_INT2_CHGTYP_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_CHGDETRUN_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_DCDTMR_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_DBCHG_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_VBVOLT_MASK, },
+	/* INT3 interrupts */
+	{ .reg_offset = 2, .mask = MAX14577_INT3_EOC_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_CGMBC_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_OVP_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_MBCCHGERR_MASK, },
+};
+
+static const struct regmap_irq_chip max14577_irq_chip = {
+	.name			= "max14577",
+	.status_base		= MAX14577_REG_INT1,
+	.unmask_base		= MAX14577_REG_INTMASK1,
+	.num_regs		= 3,
+	.irqs			= max14577_irqs,
+	.num_irqs		= ARRAY_SIZE(max14577_irqs),
+};
+
+static const struct regmap_irq max77836_muic_irqs[] = {
+	/* INT1 interrupts */
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADC_MASK, },
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADCLOW_MASK, },
+	{ .reg_offset = 0, .mask = MAX14577_INT1_ADCERR_MASK, },
+	{ .reg_offset = 0, .mask = MAX77836_INT1_ADC1K_MASK, },
+	/* INT2 interrupts */
+	{ .reg_offset = 1, .mask = MAX14577_INT2_CHGTYP_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_CHGDETRUN_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_DCDTMR_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_DBCHG_MASK, },
+	{ .reg_offset = 1, .mask = MAX14577_INT2_VBVOLT_MASK, },
+	{ .reg_offset = 1, .mask = MAX77836_INT2_VIDRM_MASK, },
+	/* INT3 interrupts */
+	{ .reg_offset = 2, .mask = MAX14577_INT3_EOC_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_CGMBC_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_OVP_MASK, },
+	{ .reg_offset = 2, .mask = MAX14577_INT3_MBCCHGERR_MASK, },
+};
+
+static const struct regmap_irq_chip max77836_muic_irq_chip = {
+	.name			= "max77836-muic",
+	.status_base		= MAX14577_REG_INT1,
+	.unmask_base		= MAX14577_REG_INTMASK1,
+	.num_regs		= 3,
+	.irqs			= max77836_muic_irqs,
+	.num_irqs		= ARRAY_SIZE(max77836_muic_irqs),
+};
+
+static const struct regmap_irq max77836_pmic_irqs[] = {
+	{ .reg_offset = 0, .mask = MAX77836_TOPSYS_INT_T120C_MASK, },
+	{ .reg_offset = 0, .mask = MAX77836_TOPSYS_INT_T140C_MASK, },
+};
+
+static const struct regmap_irq_chip max77836_pmic_irq_chip = {
+	.name			= "max77836-pmic",
+	.status_base		= MAX77836_PMIC_REG_TOPSYS_INT,
+	.mask_base		= MAX77836_PMIC_REG_TOPSYS_INT_MASK,
+	.num_regs		= 1,
+	.irqs			= max77836_pmic_irqs,
+	.num_irqs		= ARRAY_SIZE(max77836_pmic_irqs),
+};
+
+static void max14577_print_dev_type(struct max14577 *max14577)
+{
+	u8 reg_data, vendor_id, device_id;
+	int ret;
+
+	ret = max14577_read_reg(max14577->regmap, MAX14577_REG_DEVICEID,
+			&reg_data);
+	if (ret) {
+		dev_err(max14577->dev,
+			"Failed to read DEVICEID register: %d\n", ret);
+		return;
+	}
+
+	vendor_id = ((reg_data & DEVID_VENDORID_MASK) >>
+				DEVID_VENDORID_SHIFT);
+	device_id = ((reg_data & DEVID_DEVICEID_MASK) >>
+				DEVID_DEVICEID_SHIFT);
+
+	dev_info(max14577->dev, "Device type: %u (ID: 0x%x, vendor: 0x%x)\n",
+			max14577->dev_type, device_id, vendor_id);
+}
+
+/*
+ * Max77836 specific initialization code for driver probe.
+ * Adds new I2C dummy device, regmap and regmap IRQ chip.
+ * Unmasks Interrupt Source register.
+ *
+ * On success returns 0.
+ * On failure returns errno and reverts any changes done so far (e.g. remove
+ * I2C dummy device), except masking the INT SRC register.
+ */
+static int max77836_init(struct max14577 *max14577)
+{
+	int ret;
+	u8 intsrc_mask;
+
+	max14577->i2c_pmic = i2c_new_dummy_device(max14577->i2c->adapter,
+			I2C_ADDR_PMIC);
+	if (IS_ERR(max14577->i2c_pmic)) {
+		dev_err(max14577->dev, "Failed to register PMIC I2C device\n");
+		return PTR_ERR(max14577->i2c_pmic);
+	}
+	i2c_set_clientdata(max14577->i2c_pmic, max14577);
+
+	max14577->regmap_pmic = devm_regmap_init_i2c(max14577->i2c_pmic,
+			&max77836_pmic_regmap_config);
+	if (IS_ERR(max14577->regmap_pmic)) {
+		ret = PTR_ERR(max14577->regmap_pmic);
+		dev_err(max14577->dev, "Failed to allocate PMIC register map: %d\n",
+				ret);
+		goto err;
+	}
+
+	/* Un-mask MAX77836 Interrupt Source register */
+	ret = max14577_read_reg(max14577->regmap_pmic,
+			MAX77836_PMIC_REG_INTSRC_MASK, &intsrc_mask);
+	if (ret < 0) {
+		dev_err(max14577->dev, "Failed to read PMIC register\n");
+		goto err;
+	}
+
+	intsrc_mask &= ~(MAX77836_INTSRC_MASK_TOP_INT_MASK);
+	intsrc_mask &= ~(MAX77836_INTSRC_MASK_MUIC_CHG_INT_MASK);
+	ret = max14577_write_reg(max14577->regmap_pmic,
+			MAX77836_PMIC_REG_INTSRC_MASK, intsrc_mask);
+	if (ret < 0) {
+		dev_err(max14577->dev, "Failed to write PMIC register\n");
+		goto err;
+	}
+
+	ret = regmap_add_irq_chip(max14577->regmap_pmic, max14577->irq,
+			IRQF_ONESHOT | IRQF_SHARED,
+			0, &max77836_pmic_irq_chip,
+			&max14577->irq_data_pmic);
+	if (ret != 0) {
+		dev_err(max14577->dev, "Failed to request PMIC IRQ %d: %d\n",
+				max14577->irq, ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	i2c_unregister_device(max14577->i2c_pmic);
+
+	return ret;
+}
+
+/*
+ * Max77836 specific de-initialization code for driver remove.
+ */
+static void max77836_remove(struct max14577 *max14577)
+{
+	regmap_del_irq_chip(max14577->irq, max14577->irq_data_pmic);
+	i2c_unregister_device(max14577->i2c_pmic);
+}
+
+static int max14577_i2c_probe(struct i2c_client *i2c)
+{
+	struct max14577 *max14577;
+	struct max14577_platform_data *pdata = dev_get_platdata(&i2c->dev);
+	struct device_node *np = i2c->dev.of_node;
+	int ret = 0;
+	const struct regmap_irq_chip *irq_chip;
+	const struct mfd_cell *mfd_devs;
+	unsigned int mfd_devs_size;
+	int irq_flags;
+
+	if (np) {
+		pdata = devm_kzalloc(&i2c->dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+		i2c->dev.platform_data = pdata;
+	}
+
+	if (!pdata) {
+		dev_err(&i2c->dev, "No platform data found.\n");
+		return -EINVAL;
+	}
+
+	max14577 = devm_kzalloc(&i2c->dev, sizeof(*max14577), GFP_KERNEL);
+	if (!max14577)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, max14577);
+	max14577->dev = &i2c->dev;
+	max14577->i2c = i2c;
+	max14577->irq = i2c->irq;
+
+	max14577->regmap = devm_regmap_init_i2c(i2c,
+			&max14577_muic_regmap_config);
+	if (IS_ERR(max14577->regmap)) {
+		ret = PTR_ERR(max14577->regmap);
+		dev_err(max14577->dev, "Failed to allocate register map: %d\n",
+				ret);
+		return ret;
+	}
+
+	max14577->dev_type = (kernel_ulong_t)i2c_get_match_data(i2c);
+
+	max14577_print_dev_type(max14577);
+
+	switch (max14577->dev_type) {
+	case MAXIM_DEVICE_TYPE_MAX77836:
+		irq_chip = &max77836_muic_irq_chip;
+		mfd_devs = max77836_devs;
+		mfd_devs_size = ARRAY_SIZE(max77836_devs);
+		irq_flags = IRQF_ONESHOT | IRQF_SHARED;
+		break;
+	case MAXIM_DEVICE_TYPE_MAX14577:
+	default:
+		irq_chip = &max14577_irq_chip;
+		mfd_devs = max14577_devs;
+		mfd_devs_size = ARRAY_SIZE(max14577_devs);
+		irq_flags = IRQF_ONESHOT;
+		break;
+	}
+
+	ret = regmap_add_irq_chip(max14577->regmap, max14577->irq,
+				  irq_flags, 0, irq_chip,
+				  &max14577->irq_data);
+	if (ret != 0) {
+		dev_err(&i2c->dev, "Failed to request IRQ %d: %d\n",
+				max14577->irq, ret);
+		return ret;
+	}
+
+	/* Max77836 specific initialization code (additional regmap) */
+	if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836) {
+		ret = max77836_init(max14577);
+		if (ret < 0)
+			goto err_max77836;
+	}
+
+	ret = mfd_add_devices(max14577->dev, -1, mfd_devs,
+			mfd_devs_size, NULL, 0, NULL);
+	if (ret < 0)
+		goto err_mfd;
+
+	device_init_wakeup(max14577->dev, 1);
+
+	return 0;
+
+err_mfd:
+	if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836)
+		max77836_remove(max14577);
+err_max77836:
+	regmap_del_irq_chip(max14577->irq, max14577->irq_data);
+
+	return ret;
+}
+
+static void max14577_i2c_remove(struct i2c_client *i2c)
+{
+	struct max14577 *max14577 = i2c_get_clientdata(i2c);
+
+	device_init_wakeup(max14577->dev, false);
+	mfd_remove_devices(max14577->dev);
+	regmap_del_irq_chip(max14577->irq, max14577->irq_data);
+	if (max14577->dev_type == MAXIM_DEVICE_TYPE_MAX77836)
+		max77836_remove(max14577);
+}
+
+static const struct i2c_device_id max14577_i2c_id[] = {
+	{ "max14577", MAXIM_DEVICE_TYPE_MAX14577, },
+	{ "max77836", MAXIM_DEVICE_TYPE_MAX77836, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max14577_i2c_id);
+
+static int max14577_suspend(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct max14577 *max14577 = i2c_get_clientdata(i2c);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(max14577->irq);
+	/*
+	 * MUIC IRQ must be disabled during suspend because if it happens
+	 * while suspended it will be handled before resuming I2C.
+	 *
+	 * When device is woken up from suspend (e.g. by ADC change),
+	 * an interrupt occurs before resuming I2C bus controller.
+	 * Interrupt handler tries to read registers but this read
+	 * will fail because I2C is still suspended.
+	 */
+	disable_irq(max14577->irq);
+
+	return 0;
+}
+
+static int max14577_resume(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct max14577 *max14577 = i2c_get_clientdata(i2c);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(max14577->irq);
+	enable_irq(max14577->irq);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max14577_pm, max14577_suspend, max14577_resume);
+
+static struct i2c_driver max14577_i2c_driver = {
+	.driver = {
+		.name = "max14577",
+		.pm = pm_sleep_ptr(&max14577_pm),
+		.of_match_table = max14577_dt_match,
+	},
+	.probe = max14577_i2c_probe,
+	.remove = max14577_i2c_remove,
+	.id_table = max14577_i2c_id,
+};
+
+static int __init max14577_i2c_init(void)
+{
+	BUILD_BUG_ON(ARRAY_SIZE(max14577_i2c_id) != MAXIM_DEVICE_TYPE_NUM);
+	BUILD_BUG_ON(ARRAY_SIZE(max14577_dt_match) != MAXIM_DEVICE_TYPE_NUM);
+
+	/* Valid charger current values must be provided for each chipset */
+	BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
+
+	/* Check for valid values for charger */
+	BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_START +
+			MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+			MAX14577_CHARGER_CURRENT_LIMIT_MAX);
+	BUILD_BUG_ON(MAX14577_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
+	BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_START +
+			MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP * 0xf !=
+			MAX77836_CHARGER_CURRENT_LIMIT_MAX);
+	BUILD_BUG_ON(MAX77836_CHARGER_CURRENT_LIMIT_HIGH_STEP == 0);
+
+	return i2c_add_driver(&max14577_i2c_driver);
+}
+module_init(max14577_i2c_init);
+
+static void __exit max14577_i2c_exit(void)
+{
+	i2c_del_driver(&max14577_i2c_driver);
+}
+module_exit(max14577_i2c_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>, Krzysztof Kozlowski <krzk@kernel.org>");
+MODULE_DESCRIPTION("Maxim 14577/77836 multi-function core driver");
+MODULE_LICENSE("GPL");