On Fri, Oct 26, 2018 at 09:36:59AM -0700, Ajay Gupta wrote: > 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]>
Acked-by: Heikki Krogerus <[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 > 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 <[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; > +}; > + > +#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 <[email protected]>"); > +MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller"); > +MODULE_LICENSE("GPL v2"); > -- > 2.17.1 thanks, -- heikki
