[PATCH V14 6/9] mfd: pm8008: Use i2c_new_dummy_device() API

[Satya Priya <quic_c_skakit@quicinc.com>]

Use i2c_new_dummy_device() to register pm8008-regulator
client present at a different address space, instead of
defining a separate DT node. This avoids calling the probe
twice for the same chip, once for each client pm8008-infra
and pm8008-regulator.

As a part of this define pm8008_regmap_init() to do regmap
init for both the clients and define pm8008_get_regmap() to
pass the regmap to the regulator driver.

Signed-off-by: Satya Priya <quic_c_skakit@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
---
Changes in V14:
 - None.

Changes in V13:
 - None.

Changes in V12:
 - Make chip as const in pm8008_get_regmap() definition.
 - Use EXPORT_SYMBOL_GPL() for pm8008_get_regmap.
 - Add linux/mfd/qcom_pm8008.h to avoid error.

Changes in V11:
 - Remove the for loop and register dummy directly as there are
   only 2 clients.
 - Define pm8008_regmap_init() API to do the redundant init part.

 drivers/mfd/qcom-pm8008.c       | 34 ++++++++++++++++++++++++++++++++--
 include/linux/mfd/qcom_pm8008.h |  9 +++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 include/linux/mfd/qcom_pm8008.h

diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c
index 569ffd50..55e2a8e 100644
--- a/drivers/mfd/qcom-pm8008.c
+++ b/drivers/mfd/qcom-pm8008.c
@@ -9,6 +9,7 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
+#include <linux/mfd/qcom_pm8008.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
@@ -57,6 +58,7 @@ enum {
 
 struct pm8008_data {
 	struct device *dev;
+	struct regmap *regulators_regmap;
 	int irq;
 	struct regmap_irq_chip_data *irq_data;
 };
@@ -150,6 +152,12 @@ static struct regmap_config qcom_mfd_regmap_cfg = {
 	.max_register	= 0xFFFF,
 };
 
+struct regmap *pm8008_get_regmap(const struct pm8008_data *chip)
+{
+	return chip->regulators_regmap;
+}
+EXPORT_SYMBOL_GPL(pm8008_get_regmap);
+
 static int pm8008_init(struct regmap *regmap)
 {
 	int rc;
@@ -217,11 +225,25 @@ static int pm8008_probe_irq_peripherals(struct pm8008_data *chip,
 	return 0;
 }
 
+static struct regmap *pm8008_regmap_init(struct i2c_client *client,
+							struct pm8008_data *chip)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &qcom_mfd_regmap_cfg);
+	if (!regmap)
+		return NULL;
+
+	i2c_set_clientdata(client, chip);
+	return regmap;
+}
+
 static int pm8008_probe(struct i2c_client *client)
 {
 	int rc;
 	struct pm8008_data *chip;
 	struct gpio_desc *reset_gpio;
+	struct i2c_client *regulators_client;
 	struct regmap *regmap;
 
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
@@ -229,11 +251,19 @@ static int pm8008_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	chip->dev = &client->dev;
-	regmap = devm_regmap_init_i2c(client, &qcom_mfd_regmap_cfg);
+	regmap = pm8008_regmap_init(client, chip);
 	if (!regmap)
 		return -ENODEV;
 
-	i2c_set_clientdata(client, chip);
+	regulators_client = i2c_new_dummy_device(client->adapter, client->addr + 1);
+	if (IS_ERR(regulators_client)) {
+		dev_err(&client->dev, "can't attach client\n");
+		return PTR_ERR(regulators_client);
+	}
+
+	chip->regulators_regmap = pm8008_regmap_init(regulators_client, chip);
+	if (!chip->regulators_regmap)
+		return -ENODEV;
 
 	reset_gpio = devm_gpiod_get(chip->dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(reset_gpio))
diff --git a/include/linux/mfd/qcom_pm8008.h b/include/linux/mfd/qcom_pm8008.h
new file mode 100644
index 0000000..3814bff
--- /dev/null
+++ b/include/linux/mfd/qcom_pm8008.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+#ifndef __QCOM_PM8008_H__
+#define __QCOM_PM8008_H__
+
+struct pm8008_data;
+struct regmap *pm8008_get_regmap(const struct pm8008_data *chip);
+
+#endif
-- 
2.7.4