Hi Andy, > > 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. > > > > Few comments below. > > > +#include <linux/platform_device.h> > > +#include <linux/module.h> > > +#include <linux/delay.h> > > +#include <linux/acpi.h> > > +#include <linux/i2c.h> > > +#include <linux/pci.h> > > Please, keep them ordered. > > > +#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 0x0 > > +#define CCGX_I2C_RAB_BOOT_MODE_REASON 0x1 > > +#define CCGX_I2C_RAB_READ_SILICON_ID 0x2 > > +#define CCGX_I2C_RAB_INTR_REG 0x6 > > +#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_STOP 0x2 > > +#define CCGX_I2C_RAB_UCSI_CONTROL_START 0x1 > > +#define CCGX_I2C_RAB_RESPONSE_REG 0x7E > > +#define CCGX_I2C_RAB_UCSI_DATA_BLOCK 0xf000 > > +#define CCGX_I2C_RAB_RESPONSE_REG_RESET_COMPLETE 0x80 > > Bits better to use BIT(), masks — GENMASK(), address offsets to have same > amount of digits (like, for example, > 0x000 followed by 0x104). Ok, will fix. > > +static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) > > +{ > > + struct device *dev = uc->dev; > > + 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 err = -EIO; > > + > > + while (rem_len > 0) { > > + msgs[1].buf = &data[len - rem_len]; > > + rlen = min_t(u16, rem_len, 4); > > + msgs[1].len = rlen; > > > + buf[0] = (rab >> 0) & 0xff; > > + buf[1] = (rab >> 8) & 0xff; > > Redundant & 0xff, put_unaligned_X()? Will fix > > > + err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); > > + if (err == ARRAY_SIZE(msgs)) { > > + err = 0; > > + } else if (err >= 0) { > > + dev_err(dev, "i2c_transfer failed, err %d\n", err); > > + return -EIO; > > + } > > + rab += rlen; > > + rem_len -= rlen; > > + } > > + > > + return err; > > +} > > + > > +static int ccg_write(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) > > +{ > > + struct device *dev = uc->dev; > > + 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, > > + }, > > + { > > + .addr = client->addr, > > + .flags = I2C_M_STOP, > > + }, > > + }; > > + int err; > > + > > + buf[0] = (rab >> 0) & 0xff; > > + buf[1] = (rab >> 8) & 0xff; > > Ditto. > > > + err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); > > + if (err == ARRAY_SIZE(msgs)) { > > + err = 0; > > + } else if (err >= 0) { > > + dev_err(dev, "i2c_transfer failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + return err; > > +} > > + > > +static int ucsi_ccg_init(struct ucsi_ccg *uc) { > > + struct device *dev = uc->dev; > > + u8 data[64]; > > + int i, err; > > + > > + /* selectively issue device reset > > Shouldn't be > > /* > * Selectively ... > > ? ok > > > + * - 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; > > + > > + err = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); > > + if (err < 0) { > > + dev_err(dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + memset(data, 0, sizeof(data)); > > + err = ccg_read(uc, CCGX_I2C_RAB_DEVICE_MODE, data, sizeof(data)); > > + if (err < 0) { > > + dev_err(dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + dev_info(dev, "Silicon id %02x %02x", > > + data[CCGX_I2C_RAB_READ_SILICON_ID + 0], > > + data[CCGX_I2C_RAB_READ_SILICON_ID + 1]); > > + > > > + dev_info(dev, "FW1 version %02x %02x %02x %02x %02x %02x %02x > %02x\n", > > + data[CCGX_I2C_RAB_FW1_VERSION + 0], > > + data[CCGX_I2C_RAB_FW1_VERSION + 1], > > + data[CCGX_I2C_RAB_FW1_VERSION + 2], > > + data[CCGX_I2C_RAB_FW1_VERSION + 3], > > + data[CCGX_I2C_RAB_FW1_VERSION + 4], > > + data[CCGX_I2C_RAB_FW1_VERSION + 5], > > + data[CCGX_I2C_RAB_FW1_VERSION + 6], > > + data[CCGX_I2C_RAB_FW1_VERSION + 7]); > > + > > + dev_info(dev, "FW2 version %02x %02x %02x %02x %02x %02x %02x > %02x\n", > > + data[CCGX_I2C_RAB_FW2_VERSION + 0], > > + data[CCGX_I2C_RAB_FW2_VERSION + 1], > > + data[CCGX_I2C_RAB_FW2_VERSION + 2], > > + data[CCGX_I2C_RAB_FW2_VERSION + 3], > > + data[CCGX_I2C_RAB_FW2_VERSION + 4], > > + data[CCGX_I2C_RAB_FW2_VERSION + 5], > > + data[CCGX_I2C_RAB_FW2_VERSION + 6], > > + data[CCGX_I2C_RAB_FW2_VERSION + 7]); > > NO! > Please, read printk-formats document to learn %*ph. > Hint: instead of * in above in your case you can hard code 8. sure > > > + > > + data[0] = 0x0; > > + data[1] = 0x0; > > + err = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); > > + if (err < 0) { > > + dev_err(dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_STOP; > > + err = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); > > + if (err < 0) { > > + dev_err(dev, "ccg_write failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_START; > > + err = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); > > + if (err < 0) { > > + dev_err(dev, "ccg_write failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + /* 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 > > + */ > > Comment style. > > > + data[0] = 0xff; > > + for (i = 0; (i < 10) && (data[0] != 0x00); i++) { > > Better to do timeout loops as > > unsigned int count = 10; > > do { > ... > } while (/*if needed: ... && */--count); Will fix > > > + err = ccg_write(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); > > + if (err < 0) { > > + dev_err(dev, "ccg_write failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + usleep_range(10000, 11000); > > + > > + err = ccg_read(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); > > + if (err < 0) { > > + dev_err(dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + } > > + return 0; > > +} > > + > > +static int ucsi_ccg_send_data(struct ucsi_ccg *uc) { > > + int err; > > + unsigned char buf[4] = { > > > + 0x20, (CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8), > > + 0x8, (CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8), > > Redundant parens. Will fix > > > + }; > > + unsigned char buf1[16]; > > + unsigned char buf2[8]; > > + > > > + memcpy(&buf1[0], ((const void *)uc->ppm.data) + 0x20, sizeof(buf1)); > > + memcpy(&buf2[0], ((const void *)uc->ppm.data) + 0x8, > > + sizeof(buf2)); > > &foo[0] == foo > > > + > > + err = ccg_write(uc, *(u16 *)buf, buf1, sizeof(buf1)); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_write failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + err = ccg_write(uc, *(u16 *)(buf + 2), buf2, sizeof(buf2)); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_write failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + return err; > > +} > > + > > +static int ucsi_ccg_recv_data(struct ucsi_ccg *uc) { > > + static int first = 1; > > + int err; > > + 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), > > Redundant parens. > > > + }; > > + u8 *ppm = (u8 *)uc->ppm.data; > > + > > + if (first) { > > + err = ccg_read(uc, *(u16 *)buf, ppm, 0x2); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + first = 1; > > + } > > + > > + err = ccg_read(uc, *(u16 *)(buf + 2), ppm + 0x4, 0x4); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + err = ccg_read(uc, *(u16 *)(buf + 4), ppm + 0x10, 0x10); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + return err; > > +} > > + > > +static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc) { > > + int err; > > > + unsigned char buf[3] = {(CCGX_I2C_RAB_INTR_REG & 0xff), > > + (CCGX_I2C_RAB_INTR_REG >> 8), 0x0}; > > Different style, redundant parens. > > > + > > + err = ccg_read(uc, *(u16 *)buf, &buf[2], 0x1); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + err = ccg_write(uc, *(u16 *)buf, &buf[2], 0x1); > > + if (err < 0) { > > + dev_err(uc->dev, "ccg_read failed, err %d\n", err); > > + return -EIO; > > + } > > + > > + return err; > > +} > > + > > +static int ucsi_ccg_sync(struct ucsi_ppm *ppm) { > > + struct ucsi_ccg *uc = container_of(ppm, > > + struct ucsi_ccg, ppm); > > + int err; > > + > > + err = ucsi_ccg_recv_data(uc); > > + if (err < 0) { > > + dev_err(uc->dev, "ucsi_ccg_recv_data() err %d\n", err); > > + return 0; > > + } > > + > > + /* ack interrupt to allow next command to run */ > > + err = ucsi_ccg_ack_interrupt(uc); > > + if (err < 0) > > + dev_err(uc->dev, "ucsi_ccg_ack_interrupt() err %d\n", > > + err); > > + > > + return 0; > > +} > > + > > +static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control > > +*ctrl) { > > > + struct ucsi_ccg *uc = container_of(ppm, > > + struct ucsi_ccg, ppm); > > Why not one line? sure > > > + int err = 0; > > + > > + ppm->data->ctrl.raw_cmd = ctrl->raw_cmd; > > + err = ucsi_ccg_send_data(uc); > > + > > + return err; > > +} > > + > > +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) > > One line? > > > +{ > > + 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, > > ONESHORT can be dropped here (it's set based on condition when irq handler > NULL and threadirq is not). Below error is seen if I drop ONESHOT "genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq 129" > > > + 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}, > > > + {}, > > Terminator line better without comma. Ok Thanks Ajay -- nvpublic -- > > > +}; > > +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