mfd: tps6594: Add driver for TI TPS6594 PMIC

This patch adds support for TPS6594 PMIC MFD core. It provides
communication through the I2C and SPI interfaces, and supports
protocols with embedded CRC data fields for safety applications.
Signed-off-by: Julien Panis <jpanis@baylibre.com>
Link: https://lore.kernel.org/r/20230511095126.105104-3-jpanis@baylibre.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/Kconfig

@@ -1679,6 +1679,38 @@ 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-i2c.c

+// 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 <jpanis@baylibre.com>");
+MODULE_DESCRIPTION("TPS6594 I2C Interface Driver");
+MODULE_LICENSE("GPL");

drivers/mfd/tps6594-spi.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SPI access driver for TI TPS6594/TPS6593/LP8764 PMICs
+ *
+ * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
+ */
+
+#include <linux/crc8.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <linux/mfd/tps6594.h>
+
+#define TPS6594_SPI_PAGE_SHIFT	5
+#define TPS6594_SPI_READ_BIT	BIT(4)
+
+static bool enable_crc;
+module_param(enable_crc, bool, 0444);
+MODULE_PARM_DESC(enable_crc, "Enable CRC feature for SPI interface");
+
+DECLARE_CRC8_TABLE(tps6594_spi_crc_table);
+
+static int tps6594_spi_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct spi_device *spi = context;
+	struct tps6594 *tps = spi_get_drvdata(spi);
+	u8 buf[4] = { 0 };
+	size_t count_rx = 1;
+	int ret;
+
+	buf[0] = reg;
+	buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT | TPS6594_SPI_READ_BIT;
+
+	if (tps->use_crc)
+		count_rx++;
+
+	ret = spi_write_then_read(spi, buf, 2, buf + 2, count_rx);
+	if (ret < 0)
+		return ret;
+
+	if (tps->use_crc && buf[3] != crc8(tps6594_spi_crc_table, buf, 3, CRC8_INIT_VALUE))
+		return -EIO;
+
+	*val = buf[2];
+
+	return 0;
+}
+
+static int tps6594_spi_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct spi_device *spi = context;
+	struct tps6594 *tps = spi_get_drvdata(spi);
+	u8 buf[4] = { 0 };
+	size_t count = 3;
+
+	buf[0] = reg;
+	buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT;
+	buf[2] = val;
+
+	if (tps->use_crc)
+		buf[3] = crc8(tps6594_spi_crc_table, buf, count++, CRC8_INIT_VALUE);
+
+	return spi_write(spi, buf, count);
+}
+
+static const struct regmap_config tps6594_spi_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 8,
+	.max_register = TPS6594_REG_DWD_FAIL_CNT_REG,
+	.volatile_reg = tps6594_is_volatile_reg,
+	.reg_read = tps6594_spi_reg_read,
+	.reg_write = tps6594_spi_reg_write,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+
+static const struct of_device_id tps6594_spi_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_spi_of_match_table);
+
+static int tps6594_spi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct tps6594 *tps;
+	const struct of_device_id *match;
+
+	tps = devm_kzalloc(dev, sizeof(*tps), GFP_KERNEL);
+	if (!tps)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, tps);
+
+	tps->dev = dev;
+	tps->reg = spi->chip_select;
+	tps->irq = spi->irq;
+
+	tps->regmap = devm_regmap_init(dev, NULL, spi, &tps6594_spi_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_spi_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_spi_crc_table, TPS6594_CRC8_POLYNOMIAL);
+
+	return tps6594_device_init(tps, enable_crc);
+}
+
+static struct spi_driver tps6594_spi_driver = {
+	.driver	= {
+		.name = "tps6594",
+		.of_match_table = tps6594_spi_of_match_table,
+	},
+	.probe = tps6594_spi_probe,
+};
+module_spi_driver(tps6594_spi_driver);
+
+MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
+MODULE_DESCRIPTION("TPS6594 SPI Interface Driver");
+MODULE_LICENSE("GPL");