usb: typec: ucsi: add support for Cypress CCGx

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 <[email protected]>

---
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

drivers/usb/typec/ucsi/Kconfig +10 -0

index e36d6c7..7811888 100644
@@ -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

drivers/usb/typec/ucsi/Makefile +2 -0

index 7afbea5..2f4900b 100644
@@ -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

drivers/usb/typec/ucsi/ucsi_ccg.c new file +382 -0

new file mode 100644
index 0000000..65292bf
@@ -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 <[email protected]>
+ *
+ * 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 <[email protected]>");
+MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller");
+MODULE_LICENSE("GPL v2");

Signature · 1 line

2.7.4