On Thu, Sep 6, 2018 at 1:22 AM Ajay Gupta <ajayg@xxxxxxxxxx> 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. > FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> for either version you choose (stack or heap). > 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 > > 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 > > 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..65292bf > --- /dev/null > +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c > @@ -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 <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; > + 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 <ajayg@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 > -- With Best Regards, Andy Shevchenko