TI TPS6594 PMIC support (RTC, pinctrl, regulators)

Merge series from Esteban Blanc <[email protected]>:

TPS6594 is a Power Management IC which provides regulators and others
features like GPIOs, RTC, watchdog, ESMs (Error Signal Monitor), and
PFSM (Pre-configurable Finite State Machine). The SoC and the PMIC can
communicate through the I2C or SPI interfaces.
TPS6594 is the super-set device while TPS6593 and LP8764 are derivatives.

This series adds support to TI TPS6594 PMIC and its derivatives.

Author: broonie

drivers/mfd/Kconfig

@@ -1698,6 +1698,38 @@ config MFD_TPS65912_SPI
 	  If you say yes here you get support for the TPS65912 series of
 	  PM chips with SPI interface.
 
+config MFD_TPS6594
+	tristate
+	select MFD_CORE
+	select REGMAP
+	select REGMAP_IRQ
+
+config MFD_TPS6594_I2C
+	tristate "TI TPS6594 Power Management chip with I2C"
+	select MFD_TPS6594
+	select REGMAP_I2C
+	select CRC8
+	depends on I2C
+	help
+	  If you say yes here you get support for the TPS6594 series of
+	  PM chips with I2C interface.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tps6594-i2c.
+
+config MFD_TPS6594_SPI
+	tristate "TI TPS6594 Power Management chip with SPI"
+	select MFD_TPS6594
+	select REGMAP_SPI
+	select CRC8
+	depends on SPI_MASTER
+	help
+	  If you say yes here you get support for the TPS6594 series of
+	  PM chips with SPI interface.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tps6594-spi.
+
 config TWL4030_CORE
 	bool "TI TWL4030/TWL5030/TWL6030/TPS659x0 Support"
 	depends on I2C=y

drivers/mfd/Makefile

@@ -96,6 +96,9 @@ obj-$(CONFIG_MFD_TPS65910)	+= tps65910.o
 obj-$(CONFIG_MFD_TPS65912)	+= tps65912-core.o
 obj-$(CONFIG_MFD_TPS65912_I2C)	+= tps65912-i2c.o
 obj-$(CONFIG_MFD_TPS65912_SPI)  += tps65912-spi.o
+obj-$(CONFIG_MFD_TPS6594)	+= tps6594-core.o
+obj-$(CONFIG_MFD_TPS6594_I2C)	+= tps6594-i2c.o
+obj-$(CONFIG_MFD_TPS6594_SPI)	+= tps6594-spi.o
 obj-$(CONFIG_MENELAUS)		+= menelaus.o
 
 obj-$(CONFIG_TWL4030_CORE)	+= twl-core.o twl4030-irq.o twl6030-irq.o

drivers/mfd/tps6594-core.c

@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * I2C access driver for TI TPS6594/TPS6593/LP8764 PMICs
+ *
+ * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
+ */
+
+#include <linux/crc8.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/tps6594.h>
+
+static bool enable_crc;
+module_param(enable_crc, bool, 0444);
+MODULE_PARM_DESC(enable_crc, "Enable CRC feature for I2C interface");
+
+DECLARE_CRC8_TABLE(tps6594_i2c_crc_table);
+
+static int tps6594_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	int ret = i2c_transfer(adap, msgs, num);
+
+	if (ret == num)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int tps6594_i2c_reg_read_with_crc(struct i2c_client *client, u8 page, u8 reg, u8 *val)
+{
+	struct i2c_msg msgs[2];
+	u8 buf_rx[] = { 0, 0 };
+	/* I2C address = I2C base address + Page index */
+	const u8 addr = client->addr + page;
+	/*
+	 * CRC is calculated from every bit included in the protocol
+	 * except the ACK bits from the target. Byte stream is:
+	 * - B0: (I2C_addr_7bits << 1) | WR_bit, with WR_bit = 0
+	 * - B1: reg
+	 * - B2: (I2C_addr_7bits << 1) | RD_bit, with RD_bit = 1
+	 * - B3: val
+	 * - B4: CRC from B0-B1-B2-B3
+	 */
+	u8 crc_data[] = { addr << 1, reg, addr << 1 | 1, 0 };
+	int ret;
+
+	/* Write register */
+	msgs[0].addr = addr;
+	msgs[0].flags = 0;
+	msgs[0].len = 1;
+	msgs[0].buf = &reg;
+
+	/* Read data and CRC */
+	msgs[1].addr = msgs[0].addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = 2;
+	msgs[1].buf = buf_rx;
+
+	ret = tps6594_i2c_transfer(client->adapter, msgs, 2);
+	if (ret < 0)
+		return ret;
+
+	crc_data[sizeof(crc_data) - 1] = *val = buf_rx[0];
+	if (buf_rx[1] != crc8(tps6594_i2c_crc_table, crc_data, sizeof(crc_data), CRC8_INIT_VALUE))
+		return -EIO;
+
+	return ret;
+}
+
+static int tps6594_i2c_reg_write_with_crc(struct i2c_client *client, u8 page, u8 reg, u8 val)
+{
+	struct i2c_msg msg;
+	u8 buf[] = { reg, val, 0 };
+	/* I2C address = I2C base address + Page index */
+	const u8 addr = client->addr + page;
+	/*
+	 * CRC is calculated from every bit included in the protocol
+	 * except the ACK bits from the target. Byte stream is:
+	 * - B0: (I2C_addr_7bits << 1) | WR_bit, with WR_bit = 0
+	 * - B1: reg
+	 * - B2: val
+	 * - B3: CRC from B0-B1-B2
+	 */
+	const u8 crc_data[] = { addr << 1, reg, val };
+
+	/* Write register, data and CRC */
+	msg.addr = addr;
+	msg.flags = client->flags & I2C_M_TEN;
+	msg.len = sizeof(buf);
+	msg.buf = buf;
+
+	buf[msg.len - 1] = crc8(tps6594_i2c_crc_table, crc_data, sizeof(crc_data), CRC8_INIT_VALUE);
+
+	return tps6594_i2c_transfer(client->adapter, &msg, 1);
+}
+
+static int tps6594_i2c_read(void *context, const void *reg_buf, size_t reg_size,
+			    void *val_buf, size_t val_size)
+{
+	struct i2c_client *client = context;
+	struct tps6594 *tps = i2c_get_clientdata(client);
+	struct i2c_msg msgs[2];
+	const u8 *reg_bytes = reg_buf;
+	u8 *val_bytes = val_buf;
+	const u8 page = reg_bytes[1];
+	u8 reg = reg_bytes[0];
+	int ret = 0;
+	int i;
+
+	if (tps->use_crc) {
+		/*
+		 * Auto-increment feature does not support CRC protocol.
+		 * Converts the bulk read operation into a series of single read operations.
+		 */
+		for (i = 0 ; ret == 0 && i < val_size ; i++)
+			ret = tps6594_i2c_reg_read_with_crc(client, page, reg + i, val_bytes + i);
+
+		return ret;
+	}
+
+	/* Write register: I2C address = I2C base address + Page index */
+	msgs[0].addr = client->addr + page;
+	msgs[0].flags = 0;
+	msgs[0].len = 1;
+	msgs[0].buf = &reg;
+
+	/* Read data */
+	msgs[1].addr = msgs[0].addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = val_size;
+	msgs[1].buf = val_bytes;
+
+	return tps6594_i2c_transfer(client->adapter, msgs, 2);
+}
+
+static int tps6594_i2c_write(void *context, const void *data, size_t count)
+{
+	struct i2c_client *client = context;
+	struct tps6594 *tps = i2c_get_clientdata(client);
+	struct i2c_msg msg;
+	const u8 *bytes = data;
+	u8 *buf;
+	const u8 page = bytes[1];
+	const u8 reg = bytes[0];
+	int ret = 0;
+	int i;
+
+	if (tps->use_crc) {
+		/*
+		 * Auto-increment feature does not support CRC protocol.
+		 * Converts the bulk write operation into a series of single write operations.
+		 */
+		for (i = 0 ; ret == 0 && i < count - 2 ; i++)
+			ret = tps6594_i2c_reg_write_with_crc(client, page, reg + i, bytes[i + 2]);
+
+		return ret;
+	}
+
+	/* Setup buffer: page byte is not sent */
+	buf = kzalloc(--count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	buf[0] = reg;
+	for (i = 0 ; i < count - 1 ; i++)
+		buf[i + 1] = bytes[i + 2];
+
+	/* Write register and data: I2C address = I2C base address + Page index */
+	msg.addr = client->addr + page;
+	msg.flags = client->flags & I2C_M_TEN;
+	msg.len = count;
+	msg.buf = buf;
+
+	ret = tps6594_i2c_transfer(client->adapter, &msg, 1);
+
+	kfree(buf);
+	return ret;
+}
+
+static const struct regmap_config tps6594_i2c_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 8,
+	.max_register = TPS6594_REG_DWD_FAIL_CNT_REG,
+	.volatile_reg = tps6594_is_volatile_reg,
+	.read = tps6594_i2c_read,
+	.write = tps6594_i2c_write,
+};
+
+static const struct of_device_id tps6594_i2c_of_match_table[] = {
+	{ .compatible = "ti,tps6594-q1", .data = (void *)TPS6594, },
+	{ .compatible = "ti,tps6593-q1", .data = (void *)TPS6593, },
+	{ .compatible = "ti,lp8764-q1",  .data = (void *)LP8764,  },
+	{}
+};
+MODULE_DEVICE_TABLE(of, tps6594_i2c_of_match_table);
+
+static int tps6594_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct tps6594 *tps;
+	const struct of_device_id *match;
+
+	tps = devm_kzalloc(dev, sizeof(*tps), GFP_KERNEL);
+	if (!tps)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, tps);
+
+	tps->dev = dev;
+	tps->reg = client->addr;
+	tps->irq = client->irq;
+
+	tps->regmap = devm_regmap_init(dev, NULL, client, &tps6594_i2c_regmap_config);
+	if (IS_ERR(tps->regmap))
+		return dev_err_probe(dev, PTR_ERR(tps->regmap), "Failed to init regmap\n");
+
+	match = of_match_device(tps6594_i2c_of_match_table, dev);
+	if (!match)
+		return dev_err_probe(dev, PTR_ERR(match), "Failed to find matching chip ID\n");
+	tps->chip_id = (unsigned long)match->data;
+
+	crc8_populate_msb(tps6594_i2c_crc_table, TPS6594_CRC8_POLYNOMIAL);
+
+	return tps6594_device_init(tps, enable_crc);
+}
+
+static struct i2c_driver tps6594_i2c_driver = {
+	.driver	= {
+		.name = "tps6594",
+		.of_match_table = tps6594_i2c_of_match_table,
+	},
+	.probe_new = tps6594_i2c_probe,
+};
+module_i2c_driver(tps6594_i2c_driver);
+
+MODULE_AUTHOR("Julien Panis <[email protected]>");
+MODULE_DESCRIPTION("TPS6594 I2C Interface Driver");
+MODULE_LICENSE("GPL");