Latest NVIDIA GPU cards have a Cypress CCGx Type-C controller over I2C interface. This UCSI I2C driver uses I2C bus driver interface for communicating with Type-C controller. Signed-off-by: Ajay Gupta <ajayg@xxxxxxxxxx> --- Changes from v1 -> v2 Fixed identation in drivers/usb/typec/ucsi/Kconfig Changes from v2 -> v3 Fixed most of comments from Heikki Rename ucsi_i2c_ccg.c -> ucsi_ccg.c Changes from v3 -> v4 Fixed comments from Andy Changes from v4 -> v5 Fixed comments from Andy Changes from v5 -> v6 Fixed review comments from Greg drivers/usb/typec/ucsi/Kconfig | 10 + drivers/usb/typec/ucsi/Makefile | 2 + drivers/usb/typec/ucsi/ucsi_ccg.c | 382 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 394 insertions(+) create mode 100644 drivers/usb/typec/ucsi/ucsi_ccg.c diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig index e36d6c7..7811888 100644 --- a/drivers/usb/typec/ucsi/Kconfig +++ b/drivers/usb/typec/ucsi/Kconfig @@ -23,6 +23,16 @@ config TYPEC_UCSI if TYPEC_UCSI +config UCSI_CCG + tristate "UCSI Interface Driver for Cypress CCGx" + depends on I2C + help + This driver enables UCSI support on platforms that expose a + Cypress CCGx Type-C controller over I2C interface. + + To compile the driver as a module, choose M here: the module will be + called ucsi_ccg. + config UCSI_ACPI tristate "UCSI ACPI Interface Driver" depends on ACPI diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile index 7afbea5..2f4900b 100644 --- a/drivers/usb/typec/ucsi/Makefile +++ b/drivers/usb/typec/ucsi/Makefile @@ -8,3 +8,5 @@ typec_ucsi-y := ucsi.o typec_ucsi-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o + +obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c new file mode 100644 index 0000000..65292bf --- /dev/null +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * UCSI driver for Cypress CCGx Type-C controller + * + * Copyright (C) 2017-2018 NVIDIA Corporation. All rights reserved. + * Author: Ajay Gupta <ajayg@xxxxxxxxxx> + * + * Some code borrowed from drivers/usb/typec/ucsi/ucsi_acpi.c + */ +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/platform_device.h> + +#include <asm/unaligned.h> +#include "ucsi.h" + +struct ucsi_ccg { + struct device *dev; + struct ucsi *ucsi; + struct ucsi_ppm ppm; + struct i2c_client *client; + int irq; +}; + +#define CCGX_I2C_RAB_DEVICE_MODE 0x00 +#define CCGX_I2C_RAB_READ_SILICON_ID 0x2 +#define CCGX_I2C_RAB_INTR_REG 0x06 +#define CCGX_I2C_RAB_FW1_VERSION 0x28 +#define CCGX_I2C_RAB_FW2_VERSION 0x20 +#define CCGX_I2C_RAB_UCSI_CONTROL 0x39 +#define CCGX_I2C_RAB_UCSI_CONTROL_START BIT(0) +#define CCGX_I2C_RAB_UCSI_CONTROL_STOP BIT(1) +#define CCGX_I2C_RAB_RESPONSE_REG 0x7E +#define CCGX_I2C_RAB_UCSI_DATA_BLOCK 0xf000 + +static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) +{ + struct i2c_client *client = uc->client; + unsigned char *buf; + struct i2c_msg *msgs; + u32 rlen, rem_len = len; + int status; + + buf = kzalloc(2, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + msgs = kcalloc(2, sizeof(struct i2c_msg), GFP_KERNEL); + if (!msgs) { + kfree(buf); + return -ENOMEM; + } + + msgs[0].addr = client->addr; + msgs[0].len = 2; + msgs[0].buf = buf; + msgs[1].addr = client->addr; + msgs[1].flags = I2C_M_RD; + + while (rem_len > 0) { + msgs[1].buf = &data[len - rem_len]; + rlen = min_t(u16, rem_len, 4); + msgs[1].len = rlen; + put_unaligned_le16(rab, buf); + status = i2c_transfer(client->adapter, msgs, 2); + if (status < 0) { + dev_err(uc->dev, "i2c_transfer failed %d", status); + kfree(buf); + kfree(msgs); + return status; + } + rab += rlen; + rem_len -= rlen; + } + + kfree(buf); + kfree(msgs); + return 0; +} + +static int ccg_write(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) +{ + struct i2c_client *client = uc->client; + unsigned char *buf; + struct i2c_msg *msgs; + int status; + + buf = kzalloc(2, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + msgs = kcalloc(3, sizeof(struct i2c_msg), GFP_KERNEL); + if (!msgs) { + kfree(buf); + return -ENOMEM; + } + + msgs[0].addr = client->addr; + msgs[0].len = 2; + msgs[0].buf = buf; + msgs[1].addr = client->addr; + msgs[1].len = len; + msgs[1].buf = data; + msgs[2].addr = client->addr; + msgs[2].flags = I2C_M_STOP; + + put_unaligned_le16(rab, buf); + status = i2c_transfer(client->adapter, msgs, 3); + if (status < 0) { + dev_err(uc->dev, "i2c_transfer failed %d", status); + kfree(buf); + kfree(msgs); + return status; + } + + kfree(buf); + kfree(msgs); + return 0; +} + +static int ucsi_ccg_init(struct ucsi_ccg *uc) +{ + struct device *dev = uc->dev; + unsigned int count = 10; + u8 *data; + int status; + + data = kzalloc(64, GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* + * Selectively issue device reset + * - if RESPONSE register is RESET_COMPLETE, do not issue device reset + * (will cause usb device disconnect / reconnect) + * - if RESPONSE register is not RESET_COMPLETE, issue device reset + * (causes PPC to resync device connect state by re-issuing + * set mux command) + */ + data[0] = 0x00; + data[1] = 0x00; + + status = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); + if (status < 0) + goto free_mem; + + memset(data, 0, 64); + status = ccg_read(uc, CCGX_I2C_RAB_DEVICE_MODE, data, sizeof(data)); + if (status < 0) + goto free_mem; + + dev_dbg(dev, "Silicon id %2ph", data + CCGX_I2C_RAB_READ_SILICON_ID); + dev_dbg(dev, "FW1 version %8ph\n", data + CCGX_I2C_RAB_FW1_VERSION); + dev_dbg(dev, "FW2 version %8ph\n", data + CCGX_I2C_RAB_FW2_VERSION); + + data[0] = 0x0; + data[1] = 0x0; + status = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); + if (status < 0) + goto free_mem; + + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_STOP; + status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); + if (status < 0) + goto free_mem; + + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_START; + status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); + if (status < 0) + goto free_mem; + + /* + * Flush CCGx RESPONSE queue by acking interrupts + * - above ucsi control register write will push response + * which must be flushed + * - affects f/w update which reads response register + */ + data[0] = 0xff; + do { + status = ccg_write(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); + if (status < 0) + goto free_mem; + + usleep_range(10000, 11000); + + status = ccg_read(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); + if (status < 0) + goto free_mem; + } while ((data[0] != 0x00) && count--); + +free_mem: + kfree(data); + return status; +} + +static int ucsi_ccg_send_data(struct ucsi_ccg *uc) +{ + int status; + unsigned char buf[4] = { + 0x20, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x8, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + }; + unsigned char *buf1; + unsigned char *buf2; + + buf1 = kzalloc(16, GFP_KERNEL); + if (!buf1) + return -ENOMEM; + + buf2 = kzalloc(8, GFP_KERNEL); + if (!buf2) { + kfree(buf1); + return -ENOMEM; + } + + memcpy(buf1, ((const void *)uc->ppm.data) + 0x20, 16); + memcpy(buf2, ((const void *)uc->ppm.data) + 0x8, 8); + + status = ccg_write(uc, *(u16 *)buf, buf1, 16); + if (status < 0) + goto free_mem; + + status = ccg_write(uc, *(u16 *)(buf + 2), buf2, 8); + +free_mem: + kfree(buf1); + kfree(buf2); + return status; +} + +static int ucsi_ccg_recv_data(struct ucsi_ccg *uc) +{ + u8 *ppm = (u8 *)uc->ppm.data; + int status; + unsigned char buf[6] = { + 0x0, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x4, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x10, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + }; + + status = ccg_read(uc, *(u16 *)buf, ppm, 0x2); + if (status < 0) + return status; + + status = ccg_read(uc, *(u16 *)(buf + 2), ppm + 0x4, 0x4); + if (status < 0) + return status; + + return ccg_read(uc, *(u16 *)(buf + 4), ppm + 0x10, 0x10); +} + +static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc) +{ + int status; + unsigned char buf[2] = { + CCGX_I2C_RAB_INTR_REG, CCGX_I2C_RAB_INTR_REG >> 8}; + unsigned char *buf2; + + buf2 = kzalloc(1, GFP_KERNEL); + if (!buf2) + return -ENOMEM; + + status = ccg_read(uc, *(u16 *)buf, buf2, 0x1); + if (status < 0) + goto free_mem; + + status = ccg_write(uc, *(u16 *)buf, buf2, 0x1); + +free_mem: + kfree(buf2); + return status; +} + +static int ucsi_ccg_sync(struct ucsi_ppm *ppm) +{ + struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm); + int status; + + status = ucsi_ccg_recv_data(uc); + if (status < 0) + return status; + + /* ack interrupt to allow next command to run */ + return ucsi_ccg_ack_interrupt(uc); +} + +static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl) +{ + struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm); + + ppm->data->ctrl.raw_cmd = ctrl->raw_cmd; + return ucsi_ccg_send_data(uc); +} + +static irqreturn_t ccg_irq_handler(int irq, void *data) +{ + struct ucsi_ccg *uc = data; + + ucsi_notify(uc->ucsi); + + return IRQ_HANDLED; +} + +static int ucsi_ccg_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct ucsi_ccg *uc; + int status; + + uc = devm_kzalloc(dev, sizeof(*uc), GFP_KERNEL); + if (!uc) + return -ENOMEM; + + uc->ppm.data = devm_kzalloc(dev, sizeof(struct ucsi_data), GFP_KERNEL); + if (!uc->ppm.data) + return -ENOMEM; + + uc->ppm.cmd = ucsi_ccg_cmd; + uc->ppm.sync = ucsi_ccg_sync; + uc->dev = dev; + uc->client = client; + + /* reset ccg device and initialize ucsi */ + status = ucsi_ccg_init(uc); + if (status < 0) { + dev_err(uc->dev, "ucsi_ccg_init failed - %d\n", status); + return status; + } + + uc->irq = client->irq; + + status = devm_request_threaded_irq(dev, uc->irq, NULL, ccg_irq_handler, + IRQF_ONESHOT | IRQF_TRIGGER_HIGH, + dev_name(dev), uc); + if (status < 0) { + dev_err(uc->dev, "request_threaded_irq failed - %d\n", status); + return status; + } + + uc->ucsi = ucsi_register_ppm(dev, &uc->ppm); + if (IS_ERR(uc->ucsi)) { + dev_err(uc->dev, "ucsi_register_ppm failed\n"); + return PTR_ERR(uc->ucsi); + } + + i2c_set_clientdata(client, uc); + return 0; +} + +static int ucsi_ccg_remove(struct i2c_client *client) +{ + struct ucsi_ccg *uc = i2c_get_clientdata(client); + + ucsi_unregister_ppm(uc->ucsi); + + return 0; +} + +static const struct i2c_device_id ucsi_ccg_device_id[] = { + {"ccgx-ucsi", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, ucsi_ccg_device_id); + +static struct i2c_driver ucsi_ccg_driver = { + .driver = { + .name = "ucsi_ccg", + }, + .probe = ucsi_ccg_probe, + .remove = ucsi_ccg_remove, + .id_table = ucsi_ccg_device_id, +}; + +module_i2c_driver(ucsi_ccg_driver); + +MODULE_AUTHOR("Ajay Gupta <ajayg@xxxxxxxxxx>"); +MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller"); +MODULE_LICENSE("GPL v2"); -- 2.7.4