Contributors: 3
Author Tokens Token Proportion Commits Commit Proportion
Fabrice Gasnier 3516 99.94% 2 50.00%
Uwe Kleine-König 1 0.03% 1 25.00%
Colin Ian King 1 0.03% 1 25.00%
Total 3518 4 


// SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
/*
 * UCSI driver for STMicroelectronics STM32G0 Type-C PD controller
 *
 * Copyright (C) 2022, STMicroelectronics - All Rights Reserved
 * Author: Fabrice Gasnier <fabrice.gasnier@foss.st.com>.
 */

#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <asm/unaligned.h>

#include "ucsi.h"

/* STM32G0 I2C bootloader addr: 0b1010001x (See AN2606) */
#define STM32G0_I2C_BL_ADDR	(0xa2 >> 1)

/* STM32G0 I2C bootloader max data size */
#define STM32G0_I2C_BL_SZ	256

/* STM32 I2C bootloader commands (See AN4221) */
#define STM32_CMD_GVR		0x01	/* Gets the bootloader version */
#define STM32_CMD_GVR_LEN	1
#define STM32_CMD_RM		0x11	/* Reag memory */
#define STM32_CMD_WM		0x31	/* Write memory */
#define STM32_CMD_ADDR_LEN	5	/* Address len for go, mem write... */
#define STM32_CMD_ERASE		0x44	/* Erase page, bank or all */
#define STM32_CMD_ERASE_SPECIAL_LEN	3
#define STM32_CMD_GLOBAL_MASS_ERASE	0xffff /* All-bank erase */

/* STM32 I2C bootloader answer status */
#define STM32G0_I2C_BL_ACK	0x79
#define STM32G0_I2C_BL_NACK	0x1f
#define STM32G0_I2C_BL_BUSY	0x76

/* STM32G0 flash definitions */
#define STM32G0_USER_OPTION_BYTES	0x1fff7800
#define STM32G0_USER_OB_NBOOT0		BIT(26)
#define STM32G0_USER_OB_NBOOT_SEL	BIT(24)
#define STM32G0_USER_OB_BOOT_MAIN	(STM32G0_USER_OB_NBOOT0 | STM32G0_USER_OB_NBOOT_SEL)
#define STM32G0_MAIN_MEM_ADDR		0x08000000

/* STM32 Firmware definitions: additional commands */
#define STM32G0_FW_GETVER	0x00	/* Gets the firmware version */
#define STM32G0_FW_GETVER_LEN	4
#define STM32G0_FW_RSTGOBL	0x21	/* Reset and go to bootloader */
#define STM32G0_FW_KEYWORD	0xa56959a6

/* ucsi_stm32g0_fw_info located at the end of the firmware */
struct ucsi_stm32g0_fw_info {
	u32 version;
	u32 keyword;
};

struct ucsi_stm32g0 {
	struct i2c_client *client;
	struct i2c_client *i2c_bl;
	bool in_bootloader;
	u8 bl_version;
	struct completion complete;
	struct device *dev;
	unsigned long flags;
	const char *fw_name;
	struct ucsi *ucsi;
	bool suspended;
	bool wakeup_event;
};

/*
 * Bootloader commands helpers:
 * - send command (2 bytes)
 * - check ack
 * Then either:
 * - receive data
 * - receive data + check ack
 * - send data + check ack
 * These operations depends on the command and have various length.
 */
static int ucsi_stm32g0_bl_check_ack(struct ucsi *ucsi)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->i2c_bl;
	unsigned char ack;
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = I2C_M_RD,
			.len	= 1,
			.buf	= &ack,
		},
	};
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(g0->dev, "i2c bl ack (%02x), error: %d\n", client->addr, ret);

		return ret < 0 ? ret : -EIO;
	}

	/* The 'ack' byte should contain bootloader answer: ack/nack/busy */
	switch (ack) {
	case STM32G0_I2C_BL_ACK:
		return 0;
	case STM32G0_I2C_BL_NACK:
		return -ENOENT;
	case STM32G0_I2C_BL_BUSY:
		return -EBUSY;
	default:
		dev_err(g0->dev, "i2c bl ack (%02x), invalid byte: %02x\n",
			client->addr, ack);
		return -EINVAL;
	}
}

static int ucsi_stm32g0_bl_cmd_check_ack(struct ucsi *ucsi, unsigned int cmd, bool check_ack)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->i2c_bl;
	unsigned char buf[2];
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = 0,
			.len	= sizeof(buf),
			.buf	= buf,
		},
	};
	int ret;

	/*
	 * Send STM32 bootloader command format is two bytes:
	 * - command code
	 * - XOR'ed command code
	 */
	buf[0] = cmd;
	buf[1] = cmd ^ 0xff;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_dbg(g0->dev, "i2c bl cmd %d (%02x), error: %d\n", cmd, client->addr, ret);

		return ret < 0 ? ret : -EIO;
	}

	if (check_ack)
		return ucsi_stm32g0_bl_check_ack(ucsi);

	return 0;
}

static int ucsi_stm32g0_bl_cmd(struct ucsi *ucsi, unsigned int cmd)
{
	return ucsi_stm32g0_bl_cmd_check_ack(ucsi, cmd, true);
}

static int ucsi_stm32g0_bl_rcv_check_ack(struct ucsi *ucsi, void *data, size_t len, bool check_ack)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->i2c_bl;
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = I2C_M_RD,
			.len	= len,
			.buf	= data,
		},
	};
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(g0->dev, "i2c bl rcv %02x, error: %d\n", client->addr, ret);

		return ret < 0 ? ret : -EIO;
	}

	if (check_ack)
		return ucsi_stm32g0_bl_check_ack(ucsi);

	return 0;
}

static int ucsi_stm32g0_bl_rcv(struct ucsi *ucsi, void *data, size_t len)
{
	return ucsi_stm32g0_bl_rcv_check_ack(ucsi, data, len, true);
}

static int ucsi_stm32g0_bl_rcv_woack(struct ucsi *ucsi, void *data, size_t len)
{
	return ucsi_stm32g0_bl_rcv_check_ack(ucsi, data, len, false);
}

static int ucsi_stm32g0_bl_send(struct ucsi *ucsi, void *data, size_t len)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->i2c_bl;
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = 0,
			.len	= len,
			.buf	= data,
		},
	};
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(g0->dev, "i2c bl send %02x, error: %d\n", client->addr, ret);

		return ret < 0 ? ret : -EIO;
	}

	return ucsi_stm32g0_bl_check_ack(ucsi);
}

/* Bootloader commands */
static int ucsi_stm32g0_bl_get_version(struct ucsi *ucsi, u8 *bl_version)
{
	int ret;

	ret = ucsi_stm32g0_bl_cmd(ucsi, STM32_CMD_GVR);
	if (ret)
		return ret;

	return ucsi_stm32g0_bl_rcv(ucsi, bl_version, STM32_CMD_GVR_LEN);
}

static int ucsi_stm32g0_bl_send_addr(struct ucsi *ucsi, u32 addr)
{
	u8 data8[STM32_CMD_ADDR_LEN];

	/* Address format: 4 bytes addr (MSB first) + XOR'ed addr bytes */
	put_unaligned_be32(addr, data8);
	data8[4] = data8[0] ^ data8[1] ^ data8[2] ^ data8[3];

	return ucsi_stm32g0_bl_send(ucsi, data8, STM32_CMD_ADDR_LEN);
}

static int ucsi_stm32g0_bl_global_mass_erase(struct ucsi *ucsi)
{
	u8 data8[4];
	u16 *data16 = (u16 *)&data8[0];
	int ret;

	data16[0] = STM32_CMD_GLOBAL_MASS_ERASE;
	data8[2] = data8[0] ^ data8[1];

	ret = ucsi_stm32g0_bl_cmd(ucsi, STM32_CMD_ERASE);
	if (ret)
		return ret;

	return ucsi_stm32g0_bl_send(ucsi, data8, STM32_CMD_ERASE_SPECIAL_LEN);
}

static int ucsi_stm32g0_bl_write(struct ucsi *ucsi, u32 addr, const void *data, size_t len)
{
	u8 *data8;
	int i, ret;

	if (!len || len > STM32G0_I2C_BL_SZ)
		return -EINVAL;

	/* Write memory: len bytes -1, data up to 256 bytes + XOR'ed bytes */
	data8 = kmalloc(STM32G0_I2C_BL_SZ + 2, GFP_KERNEL);
	if (!data8)
		return -ENOMEM;

	ret = ucsi_stm32g0_bl_cmd(ucsi, STM32_CMD_WM);
	if (ret)
		goto free;

	ret = ucsi_stm32g0_bl_send_addr(ucsi, addr);
	if (ret)
		goto free;

	data8[0] = len - 1;
	memcpy(data8 + 1, data, len);
	data8[len + 1] = data8[0];
	for (i = 1; i <= len; i++)
		data8[len + 1] ^= data8[i];

	ret = ucsi_stm32g0_bl_send(ucsi, data8, len + 2);
free:
	kfree(data8);

	return ret;
}

static int ucsi_stm32g0_bl_read(struct ucsi *ucsi, u32 addr, void *data, size_t len)
{
	int ret;

	if (!len || len > STM32G0_I2C_BL_SZ)
		return -EINVAL;

	ret = ucsi_stm32g0_bl_cmd(ucsi, STM32_CMD_RM);
	if (ret)
		return ret;

	ret = ucsi_stm32g0_bl_send_addr(ucsi, addr);
	if (ret)
		return ret;

	ret = ucsi_stm32g0_bl_cmd(ucsi, len - 1);
	if (ret)
		return ret;

	return ucsi_stm32g0_bl_rcv_woack(ucsi, data, len);
}

/* Firmware commands (the same address as the bootloader) */
static int ucsi_stm32g0_fw_cmd(struct ucsi *ucsi, unsigned int cmd)
{
	return ucsi_stm32g0_bl_cmd_check_ack(ucsi, cmd, false);
}

static int ucsi_stm32g0_fw_rcv(struct ucsi *ucsi, void *data, size_t len)
{
	return ucsi_stm32g0_bl_rcv_woack(ucsi, data, len);
}

/* UCSI ops */
static int ucsi_stm32g0_read(struct ucsi *ucsi, unsigned int offset, void *val, size_t len)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->client;
	u8 reg = offset;
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = 0,
			.len	= 1,
			.buf	= &reg,
		},
		{
			.addr	= client->addr,
			.flags  = I2C_M_RD,
			.len	= len,
			.buf	= val,
		},
	};
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(g0->dev, "i2c read %02x, %02x error: %d\n", client->addr, reg, ret);

		return ret < 0 ? ret : -EIO;
	}

	return 0;
}

static int ucsi_stm32g0_async_write(struct ucsi *ucsi, unsigned int offset, const void *val,
				    size_t len)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->client;
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags  = 0,
		}
	};
	unsigned char *buf;
	int ret;

	buf = kmalloc(len + 1, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	buf[0] = offset;
	memcpy(&buf[1], val, len);
	msg[0].len = len + 1;
	msg[0].buf = buf;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	kfree(buf);
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(g0->dev, "i2c write %02x, %02x error: %d\n", client->addr, offset, ret);

		return ret < 0 ? ret : -EIO;
	}

	return 0;
}

static int ucsi_stm32g0_sync_write(struct ucsi *ucsi, unsigned int offset, const void *val,
				   size_t len)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	int ret;

	set_bit(COMMAND_PENDING, &g0->flags);

	ret = ucsi_stm32g0_async_write(ucsi, offset, val, len);
	if (ret)
		goto out_clear_bit;

	if (!wait_for_completion_timeout(&g0->complete, msecs_to_jiffies(5000)))
		ret = -ETIMEDOUT;

out_clear_bit:
	clear_bit(COMMAND_PENDING, &g0->flags);

	return ret;
}

static irqreturn_t ucsi_stm32g0_irq_handler(int irq, void *data)
{
	struct ucsi_stm32g0 *g0 = data;
	u32 cci;
	int ret;

	if (g0->suspended)
		g0->wakeup_event = true;

	ret = ucsi_stm32g0_read(g0->ucsi, UCSI_CCI, &cci, sizeof(cci));
	if (ret)
		return IRQ_NONE;

	if (UCSI_CCI_CONNECTOR(cci))
		ucsi_connector_change(g0->ucsi, UCSI_CCI_CONNECTOR(cci));

	if (test_bit(COMMAND_PENDING, &g0->flags) &&
	    cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))
		complete(&g0->complete);

	return IRQ_HANDLED;
}

static const struct ucsi_operations ucsi_stm32g0_ops = {
	.read = ucsi_stm32g0_read,
	.sync_write = ucsi_stm32g0_sync_write,
	.async_write = ucsi_stm32g0_async_write,
};

static int ucsi_stm32g0_register(struct ucsi *ucsi)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->client;
	int ret;

	/* Request alert interrupt */
	ret = request_threaded_irq(client->irq, NULL, ucsi_stm32g0_irq_handler, IRQF_ONESHOT,
				   dev_name(g0->dev), g0);
	if (ret) {
		dev_err(g0->dev, "request IRQ failed: %d\n", ret);
		return ret;
	}

	ret = ucsi_register(ucsi);
	if (ret) {
		dev_err_probe(g0->dev, ret, "ucsi_register failed\n");
		free_irq(client->irq, g0);
		return ret;
	}

	return 0;
}

static void ucsi_stm32g0_unregister(struct ucsi *ucsi)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	struct i2c_client *client = g0->client;

	ucsi_unregister(ucsi);
	free_irq(client->irq, g0);
}

static void ucsi_stm32g0_fw_cb(const struct firmware *fw, void *context)
{
	struct ucsi_stm32g0 *g0;
	const u8 *data, *end;
	const struct ucsi_stm32g0_fw_info *fw_info;
	u32 addr = STM32G0_MAIN_MEM_ADDR, ob, fw_version;
	int ret, size;

	if (!context)
		return;

	g0 = ucsi_get_drvdata(context);

	if (!fw)
		goto fw_release;

	fw_info = (struct ucsi_stm32g0_fw_info *)(fw->data + fw->size - sizeof(*fw_info));

	if (!g0->in_bootloader) {
		/* Read running firmware version */
		ret = ucsi_stm32g0_fw_cmd(g0->ucsi, STM32G0_FW_GETVER);
		if (ret) {
			dev_err(g0->dev, "Get version cmd failed %d\n", ret);
			goto fw_release;
		}
		ret = ucsi_stm32g0_fw_rcv(g0->ucsi, &fw_version,
					  STM32G0_FW_GETVER_LEN);
		if (ret) {
			dev_err(g0->dev, "Get version failed %d\n", ret);
			goto fw_release;
		}

		/* Sanity check on keyword and firmware version */
		if (fw_info->keyword != STM32G0_FW_KEYWORD || fw_info->version == fw_version)
			goto fw_release;

		dev_info(g0->dev, "Flashing FW: %08x (%08x cur)\n", fw_info->version, fw_version);

		/* Switch to bootloader mode */
		ucsi_stm32g0_unregister(g0->ucsi);
		ret = ucsi_stm32g0_fw_cmd(g0->ucsi, STM32G0_FW_RSTGOBL);
		if (ret) {
			dev_err(g0->dev, "bootloader cmd failed %d\n", ret);
			goto fw_release;
		}
		g0->in_bootloader = true;

		/* STM32G0 reboot delay */
		msleep(100);
	}

	ret = ucsi_stm32g0_bl_global_mass_erase(g0->ucsi);
	if (ret) {
		dev_err(g0->dev, "Erase failed %d\n", ret);
		goto fw_release;
	}

	data = fw->data;
	end = fw->data + fw->size;
	while (data < end) {
		if ((end - data) < STM32G0_I2C_BL_SZ)
			size = end - data;
		else
			size = STM32G0_I2C_BL_SZ;

		ret = ucsi_stm32g0_bl_write(g0->ucsi, addr, data, size);
		if (ret) {
			dev_err(g0->dev, "Write failed %d\n", ret);
			goto fw_release;
		}
		addr += size;
		data += size;
	}

	dev_dbg(g0->dev, "Configure to boot from main flash\n");

	ret = ucsi_stm32g0_bl_read(g0->ucsi, STM32G0_USER_OPTION_BYTES, &ob, sizeof(ob));
	if (ret) {
		dev_err(g0->dev, "read user option bytes failed %d\n", ret);
		goto fw_release;
	}

	dev_dbg(g0->dev, "STM32G0_USER_OPTION_BYTES 0x%08x\n", ob);

	/* Configure user option bytes to boot from main flash next time */
	ob |= STM32G0_USER_OB_BOOT_MAIN;

	/* Writing option bytes will also reset G0 for updates to be loaded */
	ret = ucsi_stm32g0_bl_write(g0->ucsi, STM32G0_USER_OPTION_BYTES, &ob, sizeof(ob));
	if (ret) {
		dev_err(g0->dev, "write user option bytes failed %d\n", ret);
		goto fw_release;
	}

	dev_info(g0->dev, "Starting, option bytes:0x%08x\n", ob);

	/* STM32G0 FW boot delay */
	msleep(500);

	/* Register UCSI interface */
	if (!ucsi_stm32g0_register(g0->ucsi))
		g0->in_bootloader = false;

fw_release:
	release_firmware(fw);
}

static int ucsi_stm32g0_probe_bootloader(struct ucsi *ucsi)
{
	struct ucsi_stm32g0 *g0 = ucsi_get_drvdata(ucsi);
	int ret;
	u16 ucsi_version;

	/* firmware-name is optional */
	if (device_property_present(g0->dev, "firmware-name")) {
		ret = device_property_read_string(g0->dev, "firmware-name", &g0->fw_name);
		if (ret < 0)
			return dev_err_probe(g0->dev, ret, "Error reading firmware-name\n");
	}

	if (g0->fw_name) {
		/* STM32G0 in bootloader mode communicates at reserved address 0x51 */
		g0->i2c_bl = i2c_new_dummy_device(g0->client->adapter, STM32G0_I2C_BL_ADDR);
		if (IS_ERR(g0->i2c_bl)) {
			ret = dev_err_probe(g0->dev, PTR_ERR(g0->i2c_bl),
					    "Failed to register bootloader I2C address\n");
			return ret;
		}
	}

	/*
	 * Try to guess if the STM32G0 is running a UCSI firmware. First probe the UCSI FW at its
	 * i2c address. Fallback to bootloader i2c address only if firmware-name is specified.
	 */
	ret = ucsi_stm32g0_read(ucsi, UCSI_VERSION, &ucsi_version, sizeof(ucsi_version));
	if (!ret || !g0->fw_name)
		return ret;

	/* Speculatively read the bootloader version that has a known length. */
	ret = ucsi_stm32g0_bl_get_version(ucsi, &g0->bl_version);
	if (ret < 0) {
		i2c_unregister_device(g0->i2c_bl);
		return ret;
	}

	/* Device in bootloader mode */
	g0->in_bootloader = true;
	dev_info(g0->dev, "Bootloader Version 0x%02x\n", g0->bl_version);

	return 0;
}

static int ucsi_stm32g0_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct ucsi_stm32g0 *g0;
	int ret;

	g0 = devm_kzalloc(dev, sizeof(*g0), GFP_KERNEL);
	if (!g0)
		return -ENOMEM;

	g0->dev = dev;
	g0->client = client;
	init_completion(&g0->complete);
	i2c_set_clientdata(client, g0);

	g0->ucsi = ucsi_create(dev, &ucsi_stm32g0_ops);
	if (IS_ERR(g0->ucsi))
		return PTR_ERR(g0->ucsi);

	ucsi_set_drvdata(g0->ucsi, g0);

	ret = ucsi_stm32g0_probe_bootloader(g0->ucsi);
	if (ret < 0)
		goto destroy;

	/*
	 * Don't register in bootloader mode: wait for the firmware to be loaded and started before
	 * registering UCSI device.
	 */
	if (!g0->in_bootloader) {
		ret = ucsi_stm32g0_register(g0->ucsi);
		if (ret < 0)
			goto freei2c;
	}

	if (g0->fw_name) {
		/*
		 * Asynchronously flash (e.g. bootloader mode) or update the running firmware,
		 * not to hang the boot process
		 */
		ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT, g0->fw_name, g0->dev,
					      GFP_KERNEL, g0->ucsi, ucsi_stm32g0_fw_cb);
		if (ret < 0) {
			dev_err_probe(dev, ret, "firmware request failed\n");
			goto unregister;
		}
	}

	return 0;

unregister:
	if (!g0->in_bootloader)
		ucsi_stm32g0_unregister(g0->ucsi);
freei2c:
	if (g0->fw_name)
		i2c_unregister_device(g0->i2c_bl);
destroy:
	ucsi_destroy(g0->ucsi);

	return ret;
}

static void ucsi_stm32g0_remove(struct i2c_client *client)
{
	struct ucsi_stm32g0 *g0 = i2c_get_clientdata(client);

	if (!g0->in_bootloader)
		ucsi_stm32g0_unregister(g0->ucsi);
	if (g0->fw_name)
		i2c_unregister_device(g0->i2c_bl);
	ucsi_destroy(g0->ucsi);
}

static int ucsi_stm32g0_suspend(struct device *dev)
{
	struct ucsi_stm32g0 *g0 = dev_get_drvdata(dev);
	struct i2c_client *client = g0->client;

	if (g0->in_bootloader)
		return 0;

	/* Keep the interrupt disabled until the i2c bus has been resumed */
	disable_irq(client->irq);

	g0->suspended = true;
	g0->wakeup_event = false;

	if (device_may_wakeup(dev) || device_wakeup_path(dev))
		enable_irq_wake(client->irq);

	return 0;
}

static int ucsi_stm32g0_resume(struct device *dev)
{
	struct ucsi_stm32g0 *g0 = dev_get_drvdata(dev);
	struct i2c_client *client = g0->client;

	if (g0->in_bootloader)
		return 0;

	if (device_may_wakeup(dev) || device_wakeup_path(dev))
		disable_irq_wake(client->irq);

	enable_irq(client->irq);

	/* Enforce any pending handler gets called to signal a wakeup_event */
	synchronize_irq(client->irq);

	if (g0->wakeup_event)
		pm_wakeup_event(g0->dev, 0);

	g0->suspended = false;

	return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(ucsi_stm32g0_pm_ops, ucsi_stm32g0_suspend, ucsi_stm32g0_resume);

static const struct of_device_id __maybe_unused ucsi_stm32g0_typec_of_match[] = {
	{ .compatible = "st,stm32g0-typec" },
	{},
};
MODULE_DEVICE_TABLE(of, ucsi_stm32g0_typec_of_match);

static const struct i2c_device_id ucsi_stm32g0_typec_i2c_devid[] = {
	{"stm32g0-typec", 0},
	{},
};
MODULE_DEVICE_TABLE(i2c, ucsi_stm32g0_typec_i2c_devid);

static struct i2c_driver ucsi_stm32g0_i2c_driver = {
	.driver = {
		.name = "ucsi-stm32g0-i2c",
		.of_match_table = of_match_ptr(ucsi_stm32g0_typec_of_match),
		.pm = pm_sleep_ptr(&ucsi_stm32g0_pm_ops),
	},
	.probe = ucsi_stm32g0_probe,
	.remove = ucsi_stm32g0_remove,
	.id_table = ucsi_stm32g0_typec_i2c_devid
};
module_i2c_driver(ucsi_stm32g0_i2c_driver);

MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@foss.st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32G0 Type-C controller");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("platform:ucsi-stm32g0");