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 <ajayg@nvidia.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Ajay Gupta 2018-10-26 09:36:59 -07:00 committed by Wolfram Sang
parent caccdcc5db
commit 247c554a14
3 changed files with 319 additions and 0 deletions

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@ -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

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@ -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

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@ -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@nvidia.com>
*
* 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@nvidia.com>");
MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller");
MODULE_LICENSE("GPL v2");