drivers/i2c/tas5825m: Add driver for TI TAS5825M

This adds a driver for the TI TAS5825M smart amplifier [1].

The driver expects the mainboard using it to define tas5825m_setup(),
which uses the tas5825m_* functions to set configuration data. Each
mainboard may have very different configuration data, depending on
its audio hardware.

Tested on System76 addw1, bonw14, oryp5, and oryp6.

[1]: https://www.ti.com/product/TAS5825M

Signed-off-by: Jeremy Soller <jeremy@system76.com>
Signed-off-by: Tim Crawford <tcrawford@system76.com>
Change-Id: I896e8f272f18e64bfc90f406e7d4163010800aaf
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43614
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/i2c/tas5825m/Kconfig

@@ -0,0 +1,5 @@
+config DRIVERS_I2C_TAS5825M
+	bool
+	default n
+	help
+	  Enable support for TI TAS5825M Amplifier.

src/drivers/i2c/tas5825m/Makefile.inc

@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_I2C_TAS5825M) += tas5825m.c

src/drivers/i2c/tas5825m/chip.h

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+struct drivers_i2c_tas5825m_config {
+	// Used to uniquely identify the AMP
+	int id;
+};

src/drivers/i2c/tas5825m/tas5825m.c

@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <device/smbus.h>
+#include <device/pci.h>
+#include "chip.h"
+#include "tas5825m.h"
+
+int tas5825m_write_at(struct device *dev, uint8_t addr, uint8_t value)
+{
+	return smbus_write_byte(dev, addr, value);
+}
+
+//TODO: use I2C block write for better performance
+int tas5825m_write_block_at(struct device *dev, uint8_t addr,
+	const uint8_t *values, uint8_t length)
+{
+	int res = 0;
+	for (uint8_t i = 0; i < length; i++) {
+		res = smbus_write_byte(dev, addr + i, values[i]);
+		if (res < 0)
+			return res;
+	}
+	return (int)length;
+}
+
+int tas5825m_set_page(struct device *dev, uint8_t page)
+{
+	return tas5825m_write_at(dev, 0x00, page);
+}
+
+int tas5825m_set_book(struct device *dev, uint8_t book)
+{
+	int res = tas5825m_set_page(dev, 0x00);
+	if (res < 0)
+		return res;
+	return tas5825m_write_at(dev, 0x7F, book);
+}
+
+__weak int tas5825m_setup(struct device *dev, int id)
+{
+	printk(BIOS_ERR, "tas5825m: setup not implemented\n");
+	return -1;
+}
+
+static void tas5825m_init(struct device *dev)
+{
+	if (dev->enabled && dev->path.type == DEVICE_PATH_I2C &&
+		ops_smbus_bus(get_pbus_smbus(dev))) {
+		printk(BIOS_DEBUG, "tas5825m at %s\n", dev_path(dev));
+
+		struct drivers_i2c_tas5825m_config *config = dev->chip_info;
+		if (config) {
+			printk(BIOS_DEBUG, "tas5825m id %d\n", config->id);
+			int res = tas5825m_setup(dev, config->id);
+			if (res)
+				printk(BIOS_ERR, "tas5825m init failed: %d\n", res);
+			else
+				printk(BIOS_DEBUG, "tas5825m init successful\n");
+		} else {
+			printk(BIOS_ERR, "tas5825m: failed to find config\n");
+		}
+	}
+}
+
+static struct device_operations tas5825m_operations = {
+	.read_resources		= noop_read_resources,
+	.set_resources		= noop_set_resources,
+	.init			= tas5825m_init,
+};
+
+static void tas5825m_enable_dev(struct device *dev)
+{
+	dev->ops = &tas5825m_operations;
+}
+
+struct chip_operations drivers_i2c_tas5825m_ops = {
+	CHIP_NAME("TI TAS5825M Amplifier")
+	.enable_dev = tas5825m_enable_dev,
+};

src/drivers/i2c/tas5825m/tas5825m.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef TAS5825M_H
+#define TAS5825M_H
+
+#include <device/device.h>
+
+int tas5825m_write_at(struct device *dev, uint8_t addr, uint8_t value);
+int tas5825m_write_block_at(struct device *dev, uint8_t addr,
+	const uint8_t *values, uint8_t length);
+int tas5825m_set_page(struct device *dev, uint8_t page);
+int tas5825m_set_book(struct device *dev, uint8_t book);
+int tas5825m_setup(struct device *dev, int id);
+
+#endif // TAS5825M_H