drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

1 files changed, 568 insertions, 0 deletions

diff --git a/drivers/regulator/lp3972.c b/drivers/regulator/lp3972.c
new file mode 100644
index 000000000..235c640ba
--- /dev/null
+++ b/drivers/regulator/lp3972.c
@@ -0,0 +1,568 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Regulator driver for National Semiconductors LP3972 PMIC chip
+ *
+ * Based on lp3971.c
+ */
+
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/lp3972.h>
+#include <linux/slab.h>
+
+struct lp3972 {
+	struct device *dev;
+	struct mutex io_lock;
+	struct i2c_client *i2c;
+};
+
+/* LP3972 Control Registers */
+#define LP3972_SCR_REG		0x07
+#define LP3972_OVER1_REG	0x10
+#define LP3972_OVSR1_REG	0x11
+#define LP3972_OVER2_REG	0x12
+#define LP3972_OVSR2_REG	0x13
+#define LP3972_VCC1_REG		0x20
+#define LP3972_ADTV1_REG	0x23
+#define LP3972_ADTV2_REG	0x24
+#define LP3972_AVRC_REG		0x25
+#define LP3972_CDTC1_REG	0x26
+#define LP3972_CDTC2_REG	0x27
+#define LP3972_SDTV1_REG	0x29
+#define LP3972_SDTV2_REG	0x2A
+#define LP3972_MDTV1_REG	0x32
+#define LP3972_MDTV2_REG	0x33
+#define LP3972_L2VCR_REG	0x39
+#define LP3972_L34VCR_REG	0x3A
+#define LP3972_SCR1_REG		0x80
+#define LP3972_SCR2_REG		0x81
+#define LP3972_OEN3_REG		0x82
+#define LP3972_OSR3_REG		0x83
+#define LP3972_LOER4_REG	0x84
+#define LP3972_B2TV_REG		0x85
+#define LP3972_B3TV_REG		0x86
+#define LP3972_B32RC_REG	0x87
+#define LP3972_ISRA_REG		0x88
+#define LP3972_BCCR_REG		0x89
+#define LP3972_II1RR_REG	0x8E
+#define LP3972_II2RR_REG	0x8F
+
+#define LP3972_SYS_CONTROL1_REG		LP3972_SCR1_REG
+/* System control register 1 initial value,
+ * bits 5, 6 and 7 are EPROM programmable */
+#define SYS_CONTROL1_INIT_VAL		0x02
+#define SYS_CONTROL1_INIT_MASK		0x1F
+
+#define LP3972_VOL_CHANGE_REG		LP3972_VCC1_REG
+#define LP3972_VOL_CHANGE_FLAG_GO	0x01
+#define LP3972_VOL_CHANGE_FLAG_MASK	0x03
+
+/* LDO output enable mask */
+#define LP3972_OEN3_L1EN	BIT(0)
+#define LP3972_OVER2_LDO2_EN	BIT(2)
+#define LP3972_OVER2_LDO3_EN	BIT(3)
+#define LP3972_OVER2_LDO4_EN	BIT(4)
+#define LP3972_OVER1_S_EN	BIT(2)
+
+static const unsigned int ldo1_voltage_map[] = {
+	1700000, 1725000, 1750000, 1775000, 1800000, 1825000, 1850000, 1875000,
+	1900000, 1925000, 1950000, 1975000, 2000000,
+};
+
+static const unsigned int ldo23_voltage_map[] = {
+	1800000, 1900000, 2000000, 2100000, 2200000, 2300000, 2400000, 2500000,
+	2600000, 2700000, 2800000, 2900000, 3000000, 3100000, 3200000, 3300000,
+};
+
+static const unsigned int ldo4_voltage_map[] = {
+	1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1350000,
+	1400000, 1500000, 1800000, 1900000, 2500000, 2800000, 3000000, 3300000,
+};
+
+static const unsigned int ldo5_voltage_map[] = {
+	      0,       0,       0,       0,       0,  850000,  875000,  900000,
+	 925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
+	1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
+	1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
+};
+
+static const unsigned int buck1_voltage_map[] = {
+	 725000,  750000,  775000,  800000,  825000,  850000,  875000,  900000,
+	 925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
+	1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
+	1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
+};
+
+static const unsigned int buck23_voltage_map[] = {
+	      0,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
+	1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
+	1550000, 1600000, 1650000, 1700000, 1800000, 1900000, 2500000, 2800000,
+	3000000, 3300000,
+};
+
+static const int ldo_output_enable_mask[] = {
+	LP3972_OEN3_L1EN,
+	LP3972_OVER2_LDO2_EN,
+	LP3972_OVER2_LDO3_EN,
+	LP3972_OVER2_LDO4_EN,
+	LP3972_OVER1_S_EN,
+};
+
+static const int ldo_output_enable_addr[] = {
+	LP3972_OEN3_REG,
+	LP3972_OVER2_REG,
+	LP3972_OVER2_REG,
+	LP3972_OVER2_REG,
+	LP3972_OVER1_REG,
+};
+
+static const int ldo_vol_ctl_addr[] = {
+	LP3972_MDTV1_REG,
+	LP3972_L2VCR_REG,
+	LP3972_L34VCR_REG,
+	LP3972_L34VCR_REG,
+	LP3972_SDTV1_REG,
+};
+
+static const int buck_vol_enable_addr[] = {
+	LP3972_OVER1_REG,
+	LP3972_OEN3_REG,
+	LP3972_OEN3_REG,
+};
+
+static const int buck_base_addr[] = {
+	LP3972_ADTV1_REG,
+	LP3972_B2TV_REG,
+	LP3972_B3TV_REG,
+};
+
+#define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
+#define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])
+
+/*	LDO voltage control registers shift:
+	LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
+	LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
+	LP3972_LDO5 -> 0
+*/
+#define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
+#define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
+#define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)
+
+#define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
+#define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
+#define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)
+
+#define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
+#define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
+#define LP3972_BUCK_VOL_MASK 0x1f
+
+static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
+	u16 *dest)
+{
+	int ret;
+
+	if (count != 1)
+		return -EIO;
+	ret = i2c_smbus_read_byte_data(i2c, reg);
+	if (ret < 0)
+		return ret;
+
+	*dest = ret;
+	return 0;
+}
+
+static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
+	const u16 *src)
+{
+	if (count != 1)
+		return -EIO;
+	return i2c_smbus_write_byte_data(i2c, reg, *src);
+}
+
+static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
+{
+	u16 val = 0;
+
+	mutex_lock(&lp3972->io_lock);
+
+	lp3972_i2c_read(lp3972->i2c, reg, 1, &val);
+
+	dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
+		(unsigned)val & 0xff);
+
+	mutex_unlock(&lp3972->io_lock);
+
+	return val & 0xff;
+}
+
+static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
+{
+	u16 tmp;
+	int ret;
+
+	mutex_lock(&lp3972->io_lock);
+
+	ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
+	if (ret == 0) {
+		tmp = (tmp & ~mask) | val;
+		ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
+		dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
+			(unsigned)val & 0xff);
+	}
+	mutex_unlock(&lp3972->io_lock);
+
+	return ret;
+}
+
+static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int ldo = rdev_get_id(dev) - LP3972_LDO1;
+	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
+	u16 val;
+
+	val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
+	return !!(val & mask);
+}
+
+static int lp3972_ldo_enable(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int ldo = rdev_get_id(dev) - LP3972_LDO1;
+	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
+
+	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
+				mask, mask);
+}
+
+static int lp3972_ldo_disable(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int ldo = rdev_get_id(dev) - LP3972_LDO1;
+	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
+
+	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
+				mask, 0);
+}
+
+static int lp3972_ldo_get_voltage_sel(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int ldo = rdev_get_id(dev) - LP3972_LDO1;
+	u16 mask = LP3972_LDO_VOL_MASK(ldo);
+	u16 val, reg;
+
+	reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
+	val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;
+
+	return val;
+}
+
+static int lp3972_ldo_set_voltage_sel(struct regulator_dev *dev,
+				      unsigned int selector)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int ldo = rdev_get_id(dev) - LP3972_LDO1;
+	int shift, ret;
+
+	shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
+	ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
+		LP3972_LDO_VOL_MASK(ldo) << shift, selector << shift);
+
+	if (ret)
+		return ret;
+
+	/*
+	 * LDO1 and LDO5 support voltage control by either target voltage1
+	 * or target voltage2 register.
+	 * We use target voltage1 register for LDO1 and LDO5 in this driver.
+	 * We need to update voltage change control register(0x20) to enable
+	 * LDO1 and LDO5 to change to their programmed target values.
+	 */
+	switch (ldo) {
+	case LP3972_LDO1:
+	case LP3972_LDO5:
+		shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
+		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
+			LP3972_VOL_CHANGE_FLAG_MASK << shift,
+			LP3972_VOL_CHANGE_FLAG_GO << shift);
+		if (ret)
+			return ret;
+
+		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
+			LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
+		break;
+	}
+
+	return ret;
+}
+
+static const struct regulator_ops lp3972_ldo_ops = {
+	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
+	.is_enabled = lp3972_ldo_is_enabled,
+	.enable = lp3972_ldo_enable,
+	.disable = lp3972_ldo_disable,
+	.get_voltage_sel = lp3972_ldo_get_voltage_sel,
+	.set_voltage_sel = lp3972_ldo_set_voltage_sel,
+};
+
+static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int buck = rdev_get_id(dev) - LP3972_DCDC1;
+	u16 mask = 1 << (buck * 2);
+	u16 val;
+
+	val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
+	return !!(val & mask);
+}
+
+static int lp3972_dcdc_enable(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int buck = rdev_get_id(dev) - LP3972_DCDC1;
+	u16 mask = 1 << (buck * 2);
+	u16 val;
+
+	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
+				mask, mask);
+	return val;
+}
+
+static int lp3972_dcdc_disable(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int buck = rdev_get_id(dev) - LP3972_DCDC1;
+	u16 mask = 1 << (buck * 2);
+	u16 val;
+
+	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
+				mask, 0);
+	return val;
+}
+
+static int lp3972_dcdc_get_voltage_sel(struct regulator_dev *dev)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int buck = rdev_get_id(dev) - LP3972_DCDC1;
+	u16 reg;
+
+	reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
+	reg &= LP3972_BUCK_VOL_MASK;
+
+	return reg;
+}
+
+static int lp3972_dcdc_set_voltage_sel(struct regulator_dev *dev,
+				       unsigned int selector)
+{
+	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
+	int buck = rdev_get_id(dev) - LP3972_DCDC1;
+	int ret;
+
+	ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
+				LP3972_BUCK_VOL_MASK, selector);
+	if (ret)
+		return ret;
+
+	if (buck != 0)
+		return ret;
+
+	ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
+		LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
+	if (ret)
+		return ret;
+
+	return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
+				LP3972_VOL_CHANGE_FLAG_MASK, 0);
+}
+
+static const struct regulator_ops lp3972_dcdc_ops = {
+	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
+	.is_enabled = lp3972_dcdc_is_enabled,
+	.enable = lp3972_dcdc_enable,
+	.disable = lp3972_dcdc_disable,
+	.get_voltage_sel = lp3972_dcdc_get_voltage_sel,
+	.set_voltage_sel = lp3972_dcdc_set_voltage_sel,
+};
+
+static const struct regulator_desc regulators[] = {
+	{
+		.name = "LDO1",
+		.id = LP3972_LDO1,
+		.ops = &lp3972_ldo_ops,
+		.n_voltages = ARRAY_SIZE(ldo1_voltage_map),
+		.volt_table = ldo1_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO2",
+		.id = LP3972_LDO2,
+		.ops = &lp3972_ldo_ops,
+		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),
+		.volt_table = ldo23_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO3",
+		.id = LP3972_LDO3,
+		.ops = &lp3972_ldo_ops,
+		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),
+		.volt_table = ldo23_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO4",
+		.id = LP3972_LDO4,
+		.ops = &lp3972_ldo_ops,
+		.n_voltages = ARRAY_SIZE(ldo4_voltage_map),
+		.volt_table = ldo4_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO5",
+		.id = LP3972_LDO5,
+		.ops = &lp3972_ldo_ops,
+		.n_voltages = ARRAY_SIZE(ldo5_voltage_map),
+		.volt_table = ldo5_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "DCDC1",
+		.id = LP3972_DCDC1,
+		.ops = &lp3972_dcdc_ops,
+		.n_voltages = ARRAY_SIZE(buck1_voltage_map),
+		.volt_table = buck1_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "DCDC2",
+		.id = LP3972_DCDC2,
+		.ops = &lp3972_dcdc_ops,
+		.n_voltages = ARRAY_SIZE(buck23_voltage_map),
+		.volt_table = buck23_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "DCDC3",
+		.id = LP3972_DCDC3,
+		.ops = &lp3972_dcdc_ops,
+		.n_voltages = ARRAY_SIZE(buck23_voltage_map),
+		.volt_table = buck23_voltage_map,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int setup_regulators(struct lp3972 *lp3972,
+	struct lp3972_platform_data *pdata)
+{
+	int i, err;
+
+	/* Instantiate the regulators */
+	for (i = 0; i < pdata->num_regulators; i++) {
+		struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
+		struct regulator_config config = { };
+		struct regulator_dev *rdev;
+
+		config.dev = lp3972->dev;
+		config.init_data = reg->initdata;
+		config.driver_data = lp3972;
+
+		rdev = devm_regulator_register(lp3972->dev,
+					       &regulators[reg->id], &config);
+		if (IS_ERR(rdev)) {
+			err = PTR_ERR(rdev);
+			dev_err(lp3972->dev, "regulator init failed: %d\n",
+				err);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int lp3972_i2c_probe(struct i2c_client *i2c)
+{
+	struct lp3972 *lp3972;
+	struct lp3972_platform_data *pdata = dev_get_platdata(&i2c->dev);
+	int ret;
+	u16 val;
+
+	if (!pdata) {
+		dev_dbg(&i2c->dev, "No platform init data supplied\n");
+		return -ENODEV;
+	}
+
+	lp3972 = devm_kzalloc(&i2c->dev, sizeof(struct lp3972), GFP_KERNEL);
+	if (!lp3972)
+		return -ENOMEM;
+
+	lp3972->i2c = i2c;
+	lp3972->dev = &i2c->dev;
+
+	mutex_init(&lp3972->io_lock);
+
+	/* Detect LP3972 */
+	ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
+	if (ret == 0 &&
+		(val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
+		ret = -ENODEV;
+		dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
+	}
+	if (ret < 0) {
+		dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = setup_regulators(lp3972, pdata);
+	if (ret < 0)
+		return ret;
+
+	i2c_set_clientdata(i2c, lp3972);
+	return 0;
+}
+
+static const struct i2c_device_id lp3972_i2c_id[] = {
+	{ .name = "lp3972" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);
+
+static struct i2c_driver lp3972_i2c_driver = {
+	.driver = {
+		.name = "lp3972",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.probe = lp3972_i2c_probe,
+	.id_table = lp3972_i2c_id,
+};
+
+static int __init lp3972_module_init(void)
+{
+	return i2c_add_driver(&lp3972_i2c_driver);
+}
+subsys_initcall(lp3972_module_init);
+
+static void __exit lp3972_module_exit(void)
+{
+	i2c_del_driver(&lp3972_i2c_driver);
+}
+module_exit(lp3972_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
+MODULE_DESCRIPTION("LP3972 PMIC driver");