diff options
Diffstat (limited to 'drivers/net/pse-pd/realtek-pse-mcu-i2c.c')
| -rw-r--r-- | drivers/net/pse-pd/realtek-pse-mcu-i2c.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/net/pse-pd/realtek-pse-mcu-i2c.c b/drivers/net/pse-pd/realtek-pse-mcu-i2c.c new file mode 100644 index 000000000..b6769ac1d --- /dev/null +++ b/drivers/net/pse-pd/realtek-pse-mcu-i2c.c @@ -0,0 +1,148 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pse-pd/pse.h> + +#include "realtek-pse-mcu.h" + +/* + * The core has already waited RTPSE_MCU_RESPONSE_MS before calling us, so + * the response is normally ready on the very first read. For commands the + * MCU produces more slowly, keep polling at the typical response cadence + * up to the worst-case ceiling. + */ +#define RTPSE_MCU_I2C_RETRY_MS RTPSE_MCU_RESPONSE_MS +#define RTPSE_MCU_I2C_MAX_TRIES (RTPSE_MCU_RESPONSE_MAX_MS / RTPSE_MCU_I2C_RETRY_MS) + +static int rtpse_mcu_i2c_smbus_send(struct rtpse_mcu_ctrl *pse, const struct rtpse_mcu_msg *req) +{ + struct i2c_client *client = to_i2c_client(pse->dev); + + /* Send opcode as SMBus command byte; remaining 11 bytes as block data */ + return i2c_smbus_write_i2c_block_data(client, req->opcode, RTPSE_MCU_MSG_SIZE - 1, + (const u8 *)req + 1); +} + +static int rtpse_mcu_i2c_smbus_recv(struct rtpse_mcu_ctrl *pse, const struct rtpse_mcu_msg *req, + struct rtpse_mcu_msg *resp) +{ + struct i2c_client *client = to_i2c_client(pse->dev); + int tries, ret; + + for (tries = 0; tries < RTPSE_MCU_I2C_MAX_TRIES; tries++) { + if (tries > 0) + msleep(RTPSE_MCU_I2C_RETRY_MS); + + /* MCU needs 0x00 as command byte for read */ + ret = i2c_smbus_read_i2c_block_data(client, 0x00, + RTPSE_MCU_MSG_SIZE, + (u8 *)resp); + if (ret < 0) + return ret; + if (ret == RTPSE_MCU_MSG_SIZE && rtpse_mcu_resp_is_final(req, resp)) + return 0; + } + + return -ETIMEDOUT; +} + +static const struct rtpse_mcu_transport_ops rtpse_mcu_i2c_smbus_ops = { + .send = rtpse_mcu_i2c_smbus_send, + .recv = rtpse_mcu_i2c_smbus_recv, +}; + +static int rtpse_mcu_i2c_native_send(struct rtpse_mcu_ctrl *pse, const struct rtpse_mcu_msg *req) +{ + struct i2c_client *client = to_i2c_client(pse->dev); + int ret; + + ret = i2c_master_send(client, (const u8 *)req, RTPSE_MCU_MSG_SIZE); + if (ret < 0) + return ret; + return ret == RTPSE_MCU_MSG_SIZE ? 0 : -EIO; +} + +static int rtpse_mcu_i2c_native_recv(struct rtpse_mcu_ctrl *pse, const struct rtpse_mcu_msg *req, + struct rtpse_mcu_msg *resp) +{ + struct i2c_client *client = to_i2c_client(pse->dev); + int tries, ret; + + for (tries = 0; tries < RTPSE_MCU_I2C_MAX_TRIES; tries++) { + if (tries > 0) + msleep(RTPSE_MCU_I2C_RETRY_MS); + + ret = i2c_master_recv(client, (u8 *)resp, RTPSE_MCU_MSG_SIZE); + if (ret < 0) + return ret; + if (ret == RTPSE_MCU_MSG_SIZE && rtpse_mcu_resp_is_final(req, resp)) + return 0; + } + + return -ETIMEDOUT; +} + +static const struct rtpse_mcu_transport_ops rtpse_mcu_i2c_native_ops = { + .send = rtpse_mcu_i2c_native_send, + .recv = rtpse_mcu_i2c_native_recv, +}; + +static int rtpse_mcu_i2c_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + const struct rtpse_mcu_match_data *match; + struct rtpse_mcu_ctrl *pse; + bool use_native; + + match = device_get_match_data(dev); + if (!match) + return dev_err_probe(dev, -ENODEV, "missing match data\n"); + + /* The framing (raw I2C vs SMBus) is carried by the match data. */ + use_native = match->native_i2c; + if (use_native) { + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return dev_err_probe(dev, -EOPNOTSUPP, + "plain-I2C MCU protocol requires I2C-capable adapter\n"); + } else { + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) + return dev_err_probe(dev, -EOPNOTSUPP, + "SMBus MCU protocol requires SMBus I2C-block support\n"); + } + + pse = devm_kzalloc(dev, sizeof(*pse), GFP_KERNEL); + if (!pse) + return -ENOMEM; + + pse->dev = dev; + pse->pcdev.owner = THIS_MODULE; + pse->transport = use_native ? &rtpse_mcu_i2c_native_ops : &rtpse_mcu_i2c_smbus_ops; + + return rtpse_mcu_register(pse); +} + +static const struct of_device_id rtpse_mcu_i2c_of_match[] = { + { .compatible = "realtek,pse-mcu-gen1-smbus", .data = &rtpse_mcu_gen1_data }, + { .compatible = "realtek,pse-mcu-gen2-smbus", .data = &rtpse_mcu_gen2_data }, + { .compatible = "realtek,pse-mcu-gen2-i2c", .data = &rtpse_mcu_gen2_i2c_data }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rtpse_mcu_i2c_of_match); + +static struct i2c_driver rtpse_mcu_i2c_driver = { + .driver = { + .name = "realtek-pse-mcu-i2c", + .of_match_table = rtpse_mcu_i2c_of_match, + }, + .probe = rtpse_mcu_i2c_probe, +}; +module_i2c_driver(rtpse_mcu_i2c_driver); + +MODULE_AUTHOR("Jonas Jelonek <jelonek.jonas@gmail.com>"); +MODULE_DESCRIPTION("Realtek PSE MCU driver (I2C transport)"); +MODULE_LICENSE("GPL"); |