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
