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()
drivers/usb/typec/ucsi/Kconfig | 10 ++
drivers/usb/typec/ucsi/Makefile | 2 +
drivers/usb/typec/ucsi/ucsi_ccg.c | 335 ++++++++++++++++++++++++++++++++++++++
3 files changed, 347 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..387b6fd
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -0,0 +1,335 @@
+// 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[2];
+ struct i2c_msg msgs[] = {
+ {
+ .addr = client->addr,
+ .flags = 0x0,
+ .len = 0x2,
+ .buf = buf,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .buf = data,
+ },
+ };
+ u32 rlen, rem_len = len;
+ int status;
+
+ 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, 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[2];
+ struct i2c_msg msgs[] = {
+ {
+ .addr = client->addr,
+ .flags = 0x0,
+ .len = 0x2,
+ .buf = buf,
+ },
+ {
+ .addr = client->addr,
+ .flags = 0x0,
+ .buf = data,
+ .len = len,
+ },
+ };
+ int status;
+
+ 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;
+ }
+
+ return 0;
+}
+
+static int ucsi_ccg_init(struct ucsi_ccg *uc)
+{
+ struct device *dev = uc->dev;
+ unsigned int count = 10;
+ u8 data[64];
+ int status;
+
+ /*
+ * 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)
+ return status;
+
+ memset(data, 0, sizeof(data));
+ status = ccg_read(uc, CCGX_I2C_RAB_DEVICE_MODE, data, sizeof(data));
+ if (status < 0)
+ return status;
+
+ 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)
+ return status;
+
+ data[0] = CCGX_I2C_RAB_UCSI_CONTROL_STOP;
+ status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1);
+ if (status < 0)
+ return status;
+
+ data[0] = CCGX_I2C_RAB_UCSI_CONTROL_START;
+ status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1);
+ if (status < 0)
+ return status;
+
+ /*
+ * 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)
+ return status;
+
+ usleep_range(10000, 11000);
+
+ status = ccg_read(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1);
+ if (status < 0)
+ return status;
+ } while ((data[0] != 0x00) && count--);
+
+ return 0;
+}
+
+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[16];
+ unsigned char buf2[8];
+
+ memcpy(buf1, ((const void *)uc->ppm.data) + 0x20, sizeof(buf1));
+ memcpy(buf2, ((const void *)uc->ppm.data) + 0x8, sizeof(buf2));
+
+ status = ccg_write(uc, *(u16 *)buf, buf1, sizeof(buf1));
+ if (status < 0)
+ return status;
+
+ return ccg_write(uc, *(u16 *)(buf + 2), buf2, sizeof(buf2));
+}
+
+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[1] = {0x0};
+
+ status = ccg_read(uc, *(u16 *)buf, buf2, 0x1);
+ if (status < 0)
+ return status;
+
+ return ccg_write(uc, *(u16 *)buf, buf2, 0x1);
+}
+
+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
