On Thu, Aug 30, 2018 at 3:36 AM <ajaykuee@xxxxxxxxx> wrote: > > From: Ajay Gupta <ajayg@xxxxxxxxxx> > > 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). > +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()? > + 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 ... ? > + * - 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. > + > + 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); > + 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. > + }; > + 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? > + 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). > + 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. > +}; > +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