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
Changes from v6 -> v7
None
Changes from v7 -> v8
Fixed review comments from Peter
- Removed empty STOP message
- Using stack memory for i2c_transfer()
Changes from v8 -> v9
None
Changes from v9 -> v10
Fixed review comments from Peter
- Use UCSI macros
- Cleanups
Changes from v10 -> v11
Fixed review comments from Peter
- Combined two writes into one
- Used offsetof() for ucsi_data struct
Changes from v11 -> v12
- some cleanup
Changes from v12 -> v13
- changed "u8 buf[1]" -> "u8 data"
Changes from v13 -> v14
- Fixed commend from Heikki and Andy
- Added i2c adapters quirks check in ccg_read
- Removed "irq" field from struct ucsi_ccg
- Reorganize do {} while (); loop
Changes from v14 -> v15
- Fix unnecessary check for "data" in while () condition
drivers/usb/typec/ucsi/Kconfig | 10 +
drivers/usb/typec/ucsi/Makefile | 2 +
drivers/usb/typec/ucsi/ucsi_ccg.c | 307 ++++++++++++++++++++++++++++++
3 files changed, 319 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 e36d6c73c4a4..78118883f96c 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 7afbea512207..2f4900b26210 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 000000000000..de8a43bdff68
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -0,0 +1,307 @@
+// 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;
+};
+
+#define CCGX_RAB_INTR_REG 0x06
+#define CCGX_RAB_UCSI_CONTROL 0x39
+#define CCGX_RAB_UCSI_CONTROL_START BIT(0)
+#define CCGX_RAB_UCSI_CONTROL_STOP BIT(1)
+#define CCGX_RAB_UCSI_DATA_BLOCK(offset) (0xf000 | ((offset) & 0xff))
+
+static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
+{
+ struct i2c_client *client = uc->client;
+ const struct i2c_adapter_quirks *quirks = client->adapter->quirks;
+ unsigned char buf[2];
+ struct i2c_msg msgs[] = {
+ {
+ .addr = client->addr,
+ .flags = 0x0,
+ .len = sizeof(buf),
+ .buf = buf,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .buf = data,
+ },
+ };
+ u32 rlen, rem_len = len, max_read_len = len;
+ int status;
+
+ /* check any max_read_len limitation on i2c adapter */
+ if (quirks && quirks->max_read_len)
+ max_read_len = quirks->max_read_len;
+
+ while (rem_len > 0) {
+ msgs[1].buf = &data[len - rem_len];
+ rlen = min_t(u16, rem_len, max_read_len);
+ msgs[1].len = rlen;
+ put_unaligned_le16(rab, buf);
+ status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (status < 0) {
+ dev_err(uc->dev, "i2c_transfer failed %d\n", status);
+ return status;
+ }
+ rab += rlen;
+ rem_len -= rlen;
+ }
+
+ 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[] = {
+ {
+ .addr = client->addr,
+ .flags = 0x0,
+ }
+ };
+ int status;
+
+ buf = kzalloc(len + sizeof(rab), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ put_unaligned_le16(rab, buf);
+ memcpy(buf + sizeof(rab), data, len);
+
+ msgs[0].len = len + sizeof(rab);
+ msgs[0].buf = buf;
+
+ status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (status < 0) {
+ dev_err(uc->dev, "i2c_transfer failed %d\n", status);
+ kfree(buf);
+ return status;
+ }
+
+ kfree(buf);
+ return 0;
+}
+
+static int ucsi_ccg_init(struct ucsi_ccg *uc)
+{
+ unsigned int count = 10;
+ u8 data;
+ int status;
+
+ data = CCGX_RAB_UCSI_CONTROL_STOP;
+ status = ccg_write(uc, CCGX_RAB_UCSI_CONTROL, &data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ data = CCGX_RAB_UCSI_CONTROL_START;
+ status = ccg_write(uc, CCGX_RAB_UCSI_CONTROL, &data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ /*
+ * Flush CCGx RESPONSE queue by acking interrupts. Above ucsi control
+ * register write will push response which must be cleared.
+ */
+ do {
+ status = ccg_read(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ if (!data)
+ return 0;
+
+ status = ccg_write(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ usleep_range(10000, 11000);
+ } while (--count);
+
+ return -ETIMEDOUT;
+}
+
+static int ucsi_ccg_send_data(struct ucsi_ccg *uc)
+{
+ u8 *ppm = (u8 *)uc->ppm.data;
+ int status;
+ u16 rab;
+
+ rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, message_out));
+ status = ccg_write(uc, rab, ppm +
+ offsetof(struct ucsi_data, message_out),
+ sizeof(uc->ppm.data->message_out));
+ if (status < 0)
+ return status;
+
+ rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, ctrl));
+ return ccg_write(uc, rab, ppm + offsetof(struct ucsi_data, ctrl),
+ sizeof(uc->ppm.data->ctrl));
+}
+
+static int ucsi_ccg_recv_data(struct ucsi_ccg *uc)
+{
+ u8 *ppm = (u8 *)uc->ppm.data;
+ int status;
+ u16 rab;
+
+ rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, cci));
+ status = ccg_read(uc, rab, ppm + offsetof(struct ucsi_data, cci),
+ sizeof(uc->ppm.data->cci));
+ if (status < 0)
+ return status;
+
+ rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, message_in));
+ return ccg_read(uc, rab, ppm + offsetof(struct ucsi_data, message_in),
+ sizeof(uc->ppm.data->message_in));
+}
+
+static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc)
+{
+ int status;
+ unsigned char data;
+
+ status = ccg_read(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ return ccg_write(uc, CCGX_RAB_INTR_REG, &data, sizeof(data));
+}
+
+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;
+ u16 rab;
+
+ 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;
+ }
+
+ status = devm_request_threaded_irq(dev, client->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);
+ }
+
+ rab = CCGX_RAB_UCSI_DATA_BLOCK(offsetof(struct ucsi_data, version));
+ status = ccg_read(uc, rab, (u8 *)(uc->ppm.data) +
+ offsetof(struct ucsi_data, version),
+ sizeof(uc->ppm.data->version));
+ if (status < 0) {
+ ucsi_unregister_ppm(uc->ucsi);
+ return status;
+ }
+
+ 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");
--
2.17.1
