Mon, Jul 11, 2022 at 02:01:20PM +0200, Fabrice Gasnier kirjoitti:
> STM32G0 provides an integrated USB Type-C and power delivery interface.
> It can be programmed with a firmware to handle UCSI protocol over I2C
> interface. A GPIO is used as an interrupt line.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> Christophe's remarks:
> - use kmalloc instead of kzalloc
> - Use-after-free of buf: directly print the offset
> ---
> drivers/usb/typec/ucsi/Kconfig | 10 ++
> drivers/usb/typec/ucsi/Makefile | 1 +
> drivers/usb/typec/ucsi/ucsi_stm32g0.c | 218 ++++++++++++++++++++++++++
> 3 files changed, 229 insertions(+)
> create mode 100644 drivers/usb/typec/ucsi/ucsi_stm32g0.c
>
> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index 5e9b37b3f25e1..8f9c4b9f31f79 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -48,4 +48,14 @@ config UCSI_ACPI
> To compile the driver as a module, choose M here: the module will be
> called ucsi_acpi
>
> +config UCSI_STM32G0
> + tristate "UCSI Interface Driver for STM32G0"
> + depends on I2C
> + help
> + This driver enables UCSI support on platforms that expose a STM32G0
> + Type-C controller over I2C interface.
> +
> + To compile the driver as a module, choose M here: the module will be
> + called ucsi_stm32g0.
> +
> endif
> diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> index 8a8eb5cb8e0f0..480d533d762fe 100644
> --- a/drivers/usb/typec/ucsi/Makefile
> +++ b/drivers/usb/typec/ucsi/Makefile
> @@ -17,3 +17,4 @@ endif
>
> obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o
> obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o
> +obj-$(CONFIG_UCSI_STM32G0) += ucsi_stm32g0.o
> diff --git a/drivers/usb/typec/ucsi/ucsi_stm32g0.c b/drivers/usb/typec/ucsi/ucsi_stm32g0.c
> new file mode 100644
> index 0000000000000..bb5271bf7cdcf
> --- /dev/null
> +++ b/drivers/usb/typec/ucsi/ucsi_stm32g0.c
> @@ -0,0 +1,218 @@
> +// 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@xxxxxxxxxxx>.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#include "ucsi.h"
> +
> +struct ucsi_stm32g0 {
> + struct i2c_client *client;
> + struct completion complete;
> + struct device *dev;
> + unsigned long flags;
> + struct ucsi *ucsi;
> +};
> +
> +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 = ®,
> + },
> + {
> + .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;
> +
> + 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_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);
> +
> + /* Request alert interrupt */
> + ret = request_threaded_irq(client->irq, NULL, ucsi_stm32g0_irq_handler, IRQF_ONESHOT,
> + dev_name(&client->dev), g0);
> + if (ret) {
> + dev_err_probe(dev, ret, "request IRQ failed\n");
> + goto destroy;
> + }
> +
> + ret = ucsi_register(g0->ucsi);
> + if (ret) {
> + dev_err_probe(dev, ret, "ucsi_register failed\n");
> + goto freeirq;
> + }
> +
> + return 0;
> +
> +freeirq:
> + free_irq(client->irq, g0);
> +destroy:
> + ucsi_destroy(g0->ucsi);
> +
> + return ret;
> +}
> +
> +static int ucsi_stm32g0_remove(struct i2c_client *client)
> +{
> + struct ucsi_stm32g0 *g0 = i2c_get_clientdata(client);
> +
> + ucsi_unregister(g0->ucsi);
> + free_irq(client->irq, g0);
> + ucsi_destroy(g0->ucsi);
> +
> + return 0;
> +}
> +
> +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),
> + },
> + .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@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("STMicroelectronics STM32G0 Type-C controller");
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_ALIAS("platform:ucsi-stm32g0");
> --
> 2.25.1
--
heikki
