[PATCH v4 10/11] regulator: Add Renesas PMIC RAA215300 driver

From: Biju Das <biju.das.jz@bp.renesas.com>
To: Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>
Cc: Biju Das <biju.das.jz@bp.renesas.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Magnus Damm <magnus.damm@gmail.com>,
	linux-renesas-soc@vger.kernel.org,
	Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Subject: [PATCH v4 10/11] regulator: Add Renesas PMIC RAA215300 driver
Date: Thu, 18 May 2023 12:36:42 +0100	[thread overview]
Message-ID: <20230518113643.420806-11-biju.das.jz@bp.renesas.com> (raw)
In-Reply-To: <20230518113643.420806-1-biju.das.jz@bp.renesas.com>

The RAA215300 is a 9-channel PMIC that consists of
 * Internally compensated regulators
 * built-in Real Time Clock (RTC)
 * 32kHz crystal oscillator
 * coin cell battery charger

The RTC on RAA215300 is similar to the IP found in the ISL1208.
The existing driver for the ISL1208 works for this PMIC too,
however the RAA215300 exposes two devices via I2C, one for the RTC
IP, and one for everything else. The RTC IP has to be enabled
by the other I2C device, therefore this driver is necessary to get
the RTC to work.

The external oscillator bit is inverted on PMIC version 0x11.

Add PMIC RAA215300 driver for enabling RTC block and instantiating
RTC device based on PMIC version.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v3->v4:
 * Moved from mfd->regulator as it doesn't use MFD APIs
 * Dropped handling "renesas,rtc-enabled" property and instead used
   clock-names to determine RTC is enabled or not and then instantiating
   RTC device.
v2->v3:
 * Updated commit description
 * Added support for handling "renesas,rtc-enabled" property.
 * Based on PMIC version, it instantiates rtc device by calling i2c_new_
   ancillary_device().
RFC->V2:
 * Dropped MODULE_SOFTDEP from the driver as it is added in RTC platform
   driver.
---
 drivers/regulator/Kconfig     |   7 ++
 drivers/regulator/Makefile    |   1 +
 drivers/regulator/raa215300.c | 118 ++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 drivers/regulator/raa215300.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7bbaf5991268..99fd45ae2625 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1033,6 +1033,13 @@ config REGULATOR_QCOM_USB_VBUS
 	  Say M here if you want to include support for enabling the VBUS output
 	  as a module. The module will be named "qcom_usb_vbus_regulator".
 
+config REGULATOR_RAA215300
+	tristate "Renesas RAA215300 driver"
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Support for the Renesas RAA215300 PMIC.
+
 config REGULATOR_RASPBERRYPI_TOUCHSCREEN_ATTINY
 	tristate "Raspberry Pi 7-inch touchscreen panel ATTINY regulator"
 	depends on BACKLIGHT_CLASS_DEVICE
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 0b3ad1b0a999..1b885d6a050c 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_REGULATOR_TPS51632) += tps51632-regulator.o
 obj-$(CONFIG_REGULATOR_PBIAS) += pbias-regulator.o
 obj-$(CONFIG_REGULATOR_PCAP) += pcap-regulator.o
 obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o
+obj-$(CONFIG_REGULATOR_RAA215300)	+= raa215300.o
 obj-$(CONFIG_REGULATOR_RASPBERRYPI_TOUCHSCREEN_ATTINY)  += rpi-panel-attiny-regulator.o
 obj-$(CONFIG_REGULATOR_RC5T583)  += rc5t583-regulator.o
 obj-$(CONFIG_REGULATOR_RK808)   += rk808-regulator.o
diff --git a/drivers/regulator/raa215300.c b/drivers/regulator/raa215300.c
new file mode 100644
index 000000000000..cdbbbb63daec
--- /dev/null
+++ b/drivers/regulator/raa215300.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RAA215300 PMIC driver
+ *
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#define RAA215300_REG_BLOCK_EN	0x6c
+#define RAA215300_HW_REV	0xf8
+
+#define RAA215300_RTC_DEFAULT_ADDR 0x6f
+#define RAA215300_REG_BLOCK_EN_RTC_EN	BIT(6)
+
+static bool raa215300_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	return true;
+}
+
+static const struct regmap_config raa215300_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.volatile_reg = raa215300_is_volatile_reg,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static void raa215300_rtc_unregister_device(void *data)
+{
+	i2c_unregister_device(data);
+}
+
+static int raa215300_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	unsigned int pmic_version;
+	bool int_osc_en = true;
+	struct regmap *regmap;
+	struct clk *clkin;
+	struct clk *xin;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -EOPNOTSUPP;
+
+	regmap = devm_regmap_init_i2c(client, &raa215300_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "regmap i2c init failed\n");
+
+	ret = regmap_read(regmap, RAA215300_HW_REV, &pmic_version);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "HW rev read failed\n");
+
+	dev_dbg(dev, "RAA215300 PMIC version 0x%04x\n", pmic_version);
+
+	xin = devm_clk_get_optional(&client->dev, "xin");
+	if (IS_ERR_OR_NULL(xin)) {
+		clkin = devm_clk_get(&client->dev, "clkin");
+		if (IS_ERR(clkin))
+			return PTR_ERR(clkin);
+
+		int_osc_en = false;
+		xin = NULL;
+	} else {
+		clkin = NULL;
+	}
+
+	if (xin || clkin)  {
+		struct i2c_client *rtc_client;
+
+		/* Enable RTC block */
+		regmap_update_bits(regmap, RAA215300_REG_BLOCK_EN,
+				   RAA215300_REG_BLOCK_EN_RTC_EN,
+				   RAA215300_REG_BLOCK_EN_RTC_EN);
+
+		rtc_client = i2c_new_ancillary_device(client, "rtc",
+						      RAA215300_RTC_DEFAULT_ADDR,
+						      pmic_version >= 0x12 ?
+						      "isl1208" : "raa215300_a0");
+		if (IS_ERR(rtc_client))
+			return PTR_ERR(rtc_client);
+
+		ret = devm_add_action_or_reset(dev,
+					       raa215300_rtc_unregister_device,
+					       rtc_client);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id raa215300_dt_match[] = {
+	{ .compatible = "renesas,raa215300" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, raa215300_dt_match);
+
+static struct i2c_driver raa215300_i2c_driver = {
+	.driver = {
+		.name = "raa215300",
+		.of_match_table = raa215300_dt_match,
+	},
+	.probe_new = raa215300_i2c_probe,
+};
+module_i2c_driver(raa215300_i2c_driver);
+
+MODULE_DESCRIPTION("Renesas RAA215300 PMIC driver");
+MODULE_AUTHOR("Fabrizio Castro <fabrizio.castro.jz@renesas.com>");
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_LICENSE("GPL");
-- 
2.25.1

