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 <[email protected]>");
> > +MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4
> >
>
>
> --
> With Best Regards,
> Andy Shevchenko
