[PATCH v1 2/2] drm/bridge: it6505: Add MSSC suport

Pin-yen Lin treapking at chromium.org
Fri Sep 20 07:00:19 UTC 2024


On Thu, Sep 19, 2024 at 5:20 PM Hermes Wu <Hermes.Wu at ite.com.tw> wrote:
>
> From: "Hermes.Wu" <Hermes.wu at ite.com.tw>
>
> add AUX-I2C functionality to support MCCS.
>
> Change-Id: I63e1a0e5da67526f89f35605a82944be67dee8ac
Remove the Change-Id line. If you run scripts/checkpatch.pl, the
script should catch this for you.

> Signed-off-by: Hermes Wu <Hermes.wu at ite.com.tw>
> ---
>  drivers/gpu/drm/bridge/ite-it6505.c | 209 ++++++++++++++++++++++++++--
>  1 file changed, 200 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
> index cef02c8c363e..1a272c67e82b 100644
> --- a/drivers/gpu/drm/bridge/ite-it6505.c
> +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> @@ -127,6 +127,9 @@
>  #define REG_AUX_ADR_16_19 0x26
>  #define REG_AUX_OUT_DATA0 0x27
>
> +#define REG_AUX_I2C_ADR 0x25
> +#define REG_AUX_I2C_OP 0x26
> +
>  #define REG_AUX_CMD_REQ 0x2B
>  #define AUX_BUSY BIT(5)
>
> @@ -268,6 +271,19 @@
>  #define REG_SSC_CTRL1 0x189
>  #define REG_SSC_CTRL2 0x18A
>
> +#define REG_AUX_USER_CTRL 0x190
> +#define EN_USER_AUX BIT(0)
> +#define USER_AUX_DONE BIT(1)
> +#define AUX_EVENT BIT(4)
> +
> +#define REG_AUX_USER_DATA_REC 0x191
> +#define M_AUX_IN_REC   0xF0
> +#define M_AUX_OUT_REC  0x0F
> +
> +#define REG_AUX_USER_TXB 0x190
> +#define REG_AUX_USER_REPLY 0x19A
> +#define REG_AUX_USER_RXB(n) (n + 0x19B)
> +
>  #define RBR DP_LINK_BW_1_62
>  #define HBR DP_LINK_BW_2_7
>  #define HBR2 DP_LINK_BW_5_4
> @@ -303,6 +319,8 @@
>  #define MAX_EQ_LEVEL 0x03
>  #define AUX_WAIT_TIMEOUT_MS 15
>  #define AUX_FIFO_MAX_SIZE 16
> +#define AUX_I2C_MAX_SIZE 4
> +#define AUX_I2C_DEFER_RETRY 4
>  #define PIXEL_CLK_DELAY 1
>  #define PIXEL_CLK_INVERSE 0
>  #define ADJUST_PHASE_THRESHOLD 80000
> @@ -325,7 +343,12 @@
>  enum aux_cmd_type {
>         CMD_AUX_NATIVE_READ = 0x0,
>         CMD_AUX_NATIVE_WRITE = 0x5,
> +       CMD_AUX_GI2C_ADR = 0x08,
> +       CMD_AUX_GI2C_READ = 0x09,
> +       CMD_AUX_GI2C_WRITE = 0x0A,
>         CMD_AUX_I2C_EDID_READ = 0xB,
> +       CMD_AUX_I2C_READ = 0x0D,
> +       CMD_AUX_I2C_WRITE = 0x0C,
>
>         /*extend read ncommand */
>         CMD_AUX_GET_KSV_LIST = 0x10,
> @@ -333,8 +356,11 @@ enum aux_cmd_type {
>
>  enum aux_cmd_reply {
>         REPLY_ACK,
> -       REPLY_NACK,
> -       REPLY_DEFER,
> +       REPLY_NACK = 1,
> +       REPLY_DEFER = 2,
> +
> +       REPLY_I2C_NACK = 4,
> +       REPLY_I2C_DEFER = 8,
>  };
>
>  enum link_train_status {
> @@ -1087,7 +1113,6 @@ static ssize_t it6505_aux_do_transfer(struct it6505 *it6505,
>                                       size_t size, enum aux_cmd_reply *reply)
>  {
>         int i, ret_size, ret = 0, request_size;
> -       struct device *dev = &it6505->client->dev;
The drm-misc/drm-misc-next doesn't have it6505->client node. It's
already removed at commit d65feac281ab ("drm/bridge: Remove redundant
i2c_client in anx7625/it6505").

Please rebase your patch.
>
>         mutex_lock(&it6505->aux_lock);
>         for (i = 0; i < size; ) {
> @@ -1114,6 +1139,168 @@ static ssize_t it6505_aux_do_transfer(struct it6505 *it6505,
>         return ret;
>  }
>
> +
> +static int it6505_aux_i2c_wait(struct it6505 *it6505, u8 *reply)
> +{
> +       int err = 0;
> +       unsigned long timeout;
> +       struct device *dev = &it6505->client->dev;
> +
> +       timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
> +
> +       do {
> +               if (it6505_read(it6505, REG_AUX_USER_CTRL) & AUX_EVENT)
Do we need to assign err if it6505_read returns error?
> +                       break;
> +               if (time_after(jiffies, timeout)) {
> +                       dev_err(dev, "Timed out waiting AUX I2C, BUSY = %X\n",
> +                                       it6505_aux_op_finished(it6505));
> +                       err = -ETIMEDOUT;
> +                       goto end_aux_i2c_wait;
> +               }
> +               usleep_range(300, 800);
> +
> +       } while (!it6505_aux_op_finished(it6505));
Can this loop be changed to regmap_read_poll_timeout()?
> +
> +       if (reply == NULL)
> +               goto end_aux_i2c_wait;
If reply is NULL, then there will be a NULL pointer dereference at
it6505_aux_i2c_readb() anyway. From the usages in drm_dp_helper.c, I
doubt if this pointer is possible to be NULL. Even if it could, you
should have done this check earlier.
> +
> +       *reply = it6505_read(it6505, REG_AUX_USER_REPLY) >> 4;
> +
> +       if (*reply == 0)
> +               goto end_aux_i2c_wait;
> +
> +       if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
> +                       (*reply == DP_AUX_I2C_REPLY_DEFER))
> +               err = -EBUSY;
> +       else if ((*reply == DP_AUX_NATIVE_REPLY_NACK) ||
> +                       (*reply == DP_AUX_I2C_REPLY_NACK))
> +               err = -ENXIO;
> +
> +end_aux_i2c_wait:
> +       it6505_set_bits(it6505, REG_AUX_USER_CTRL, USER_AUX_DONE, USER_AUX_DONE);
> +       return err;
> +}
> +
> +static int it6505_aux_i2c_readb(struct it6505 *it6505, u8 *buf, size_t size, u8 *reply)
> +{
> +       int ret, i;
> +       int retry = 0;
> +
> +       for (retry = 0; retry < AUX_I2C_DEFER_RETRY; retry++) {
> +
Remove the blank line here.
> +               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_READ);
> +
> +               ret = it6505_aux_i2c_wait(it6505, reply);
> +
> +               if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
> +                       (*reply == DP_AUX_I2C_REPLY_DEFER))
> +                       continue;
> +
> +               if (ret >= 0)
> +                       break;
Should we check the return value before checking the reply?
> +       }
> +
> +       for (i = 0; i < size; i++)
> +               buf[i] =  (u8) it6505_read(it6505, REG_AUX_USER_RXB(0 + i));
> +
> +       return size;
> +}
> +
> +static int it6505_aux_i2c_writeb(struct it6505 *it6505, u8 *buf, size_t size, u8 *reply)
> +{
> +       int i, ret;
> +       int retry = 0;
> +
> +       for (i = 0; i < size; i++)
> +               it6505_write(it6505, REG_AUX_OUT_DATA0 + i, buf[i]);
> +
> +       for (retry = 0; retry < AUX_I2C_DEFER_RETRY; retry++) {
> +
ditto
> +               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_WRITE);
> +
> +               ret = it6505_aux_i2c_wait(it6505, reply);
> +
> +               if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
> +                       (*reply == DP_AUX_I2C_REPLY_DEFER))
> +                       continue;
> +
> +               if (ret >= 0)
> +                       break;
ditto
> +       }
> +       return size;
> +}
> +
> +static ssize_t it6505_aux_i2c_operation(struct it6505 *it6505,
> +                                       struct drm_dp_aux_msg *msg)
> +{
> +       int ret;
> +       ssize_t request_size, data_cnt = 0;
> +       struct device *dev = &it6505->client->dev;
> +       u8 *buffer = msg->buffer;
> +
> +       /* set AUX user mode */
> +       it6505_set_bits(it6505, REG_AUX_CTRL,
> +                       AUX_USER_MODE | AUX_NO_SEGMENT_WR, AUX_USER_MODE);
> +       it6505_set_bits(it6505, REG_AUX_USER_CTRL, EN_USER_AUX, EN_USER_AUX);
> +       /* clear AUX FIFO */
> +       it6505_set_bits(it6505, REG_AUX_CTRL,
> +                       AUX_EN_FIFO_READ | CLR_EDID_FIFO,
> +                       AUX_EN_FIFO_READ | CLR_EDID_FIFO);
> +
> +       it6505_set_bits(it6505, REG_AUX_CTRL,
> +                       AUX_EN_FIFO_READ | CLR_EDID_FIFO, 0x00);
> +
> +       it6505_write(it6505, REG_AUX_ADR_0_7, 0x00);
> +       it6505_write(it6505, REG_AUX_I2C_ADR, msg->address << 1);
> +
> +       if (msg->size == 0) {
> +               /* IIC Start/STOP dummy write */
> +               it6505_write(it6505, REG_AUX_I2C_OP, msg->request);
> +               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_ADR);
> +               ret = it6505_aux_i2c_wait(it6505, &msg->reply);
> +               goto end_aux_i2c_transfer;
> +       }
> +
> +       /* IIC data transfer */
> +       for (data_cnt = 0; data_cnt < msg->size; ) {
> +               request_size = min(msg->size - data_cnt, AUX_I2C_MAX_SIZE);
> +               it6505_write(it6505, REG_AUX_I2C_OP,
> +                                       (msg->request) | ((request_size - 1) << 4));
> +
> +               if ((msg->request & DP_AUX_I2C_READ) == DP_AUX_I2C_READ)
> +                       ret = it6505_aux_i2c_readb(it6505, &buffer[data_cnt],
> +                                                       request_size, &msg->reply);
> +               else
> +                       ret = it6505_aux_i2c_writeb(it6505, &buffer[data_cnt],
> +                                                       request_size, &msg->reply);
> +
Remove the blank line here. I don't think we need a blank line before
the return value check.
> +               if (ret < 0)
> +                       goto end_aux_i2c_transfer;
> +
> +               data_cnt += request_size;
> +       }
> +       ret = data_cnt;
> +end_aux_i2c_transfer:
> +
Remove the blank line.
> +       it6505_set_bits(it6505, REG_AUX_USER_CTRL, EN_USER_AUX, 0);
> +       it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, 0);
> +       return ret;
> +}
> +
> +
Remove one blank line.
> +static ssize_t it6505_aux_i2c_transfer(struct drm_dp_aux *aux,
> +                                  struct drm_dp_aux_msg *msg)
> +{
> +       struct it6505 *it6505 = container_of(aux, struct it6505, aux);
> +       int ret;
> +
> +       mutex_lock(&it6505->aux_lock);
> +       ret = it6505_aux_i2c_operation(it6505, msg);
> +       mutex_unlock(&it6505->aux_lock);
> +       return ret;
> +}
> +
> +
ditto.
>  static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
>                                    struct drm_dp_aux_msg *msg)
>  {
> @@ -1125,7 +1312,7 @@ static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
>
>         /* IT6505 doesn't support arbitrary I2C read / write. */
Update the comment above.
>         if (is_i2c)
> -               return -EINVAL;
> +               return it6505_aux_i2c_transfer(aux, msg);
>
>         switch (msg->request) {
>         case DP_AUX_NATIVE_READ:
> @@ -1153,6 +1340,8 @@ static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
>         case REPLY_DEFER:
>                 msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
>                 break;
> +       default:
> +               break;
>         }
>
>         return ret;
> @@ -1180,7 +1369,7 @@ static int it6505_get_edid_block(void *data, u8 *buf, unsigned int block,
>                 switch (reply) {
>                 case REPLY_ACK:
>                         DRM_DEV_DEBUG_DRIVER(dev, "[0x%02x]: %8ph", offset,
> -                                            buf + offset);
> +                                                               uf + offset);
This looks like a typo to me.
>                         offset += 8;
>                         aux_retry = 100;
>                         break;
> @@ -1190,6 +1379,8 @@ static int it6505_get_edid_block(void *data, u8 *buf, unsigned int block,
>                         msleep(20);
>                         if (!(--aux_retry))
>                                 return -EIO;
> +               default:
> +                       break;
>                 }
>         }
>
> @@ -2031,8 +2222,8 @@ static int it6505_setup_sha1_input(struct it6505 *it6505, u8 *sha1_input)
>
>
>         err =  it6505_get_ksvlist(it6505, sha1_input, down_stream_count * 5);
> -       if (err < 0)
> -               return err;
> +               if (err < 0)
> +                       return err;
Revert the indentation change here.
>
>         msg_count += down_stream_count * 5;
>
> @@ -2075,7 +2266,7 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505)
>         for (retry = 0; retry < 3; retry++) {
>
>                 err = it6505_get_dpcd(it6505, DP_AUX_HDCP_V_PRIME(0), (u8 *)bv,
> -                                       sizeof(bv));
> +                             sizeof(bv));
Same here.
>
>                 if (err < 0) {
>                         dev_err(dev, "Read V' value Fail %d", retry);
> @@ -2126,7 +2317,7 @@ static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
>
>         ksv_list_check = it6505_hdcp_part2_ksvlist_check(it6505);
>         DRM_DEV_DEBUG_DRIVER(dev, "ksv list ready, ksv list check %s",
> -                               ksv_list_check ? "pass" : "fail");
> +                            ksv_list_check ? "pass" : "fail");
The indentation here is correct on my drm-misc/drm-misc-next checkout.
Please rebase your patch and revisit this.

>
>         if (ksv_list_check)
>                 return;
> --
> 2.34.1
>

Regards,
Pin-yen


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