On Tue, Oct 01, 2024 at 02:43:02PM +0800, Hermes Wu wrote:
> From: Hermes Wu <Hermes.wu@xxxxxxxxxx>
>
> HDCP KSV list readback can choose to use AUX FIFO or general data register.
> For some DisplayPort devices, the KSV list must be read in 5 byte boundaries.
> The original AUX read command does not support these devices.
>
> The AUX command operation control register "REG_AUX_CMD_REQ" uses b[3:0] as AUX operacion control, and b[7:4] are status bits and read only.
> To change KSV read operation uses "CMD_AUX_NATIVE_READ" from using the data registers to using AUX FIFO.
> The extended command "CMD_AUX_GET_KSV_LIST" is added as "CMD_AUX_NATIVE_READ" with the 0x10 flag which selects AUX FIFO mode.
Please keep the commit message wrapped at 72-75 chars.
Other than that:
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
>
> Signed-off-by: Hermes Wu <Hermes.wu@xxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/ite-it6505.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
> index 864fab7e388f..9a022c095af4 100644
> --- a/drivers/gpu/drm/bridge/ite-it6505.c
> +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> @@ -126,6 +126,7 @@
> #define REG_AUX_OUT_DATA0 0x27
>
> #define REG_AUX_CMD_REQ 0x2B
> +#define M_AUX_REQ_CMD 0x0F
> #define AUX_BUSY BIT(5)
>
> #define REG_AUX_DATA_0_7 0x2C
> @@ -324,6 +325,9 @@ enum aux_cmd_type {
> CMD_AUX_NATIVE_READ = 0x0,
> CMD_AUX_NATIVE_WRITE = 0x5,
> CMD_AUX_I2C_EDID_READ = 0xB,
> +
> + /* KSV read with AUX FIFO extend from CMD_AUX_NATIVE_READ*/
> + CMD_AUX_GET_KSV_LIST = 0x10,
> };
>
> enum aux_cmd_reply {
> @@ -965,7 +969,8 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
> it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, AUX_USER_MODE);
>
> aux_op_start:
> - if (cmd == CMD_AUX_I2C_EDID_READ) {
> + /* HW AUX FIFO supports only EDID and DCPD KSV FIFO area */
> + if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
> /* AUX EDID FIFO has max length of AUX_FIFO_MAX_SIZE bytes. */
> size = min_t(size_t, size, AUX_FIFO_MAX_SIZE);
> /* Enable AUX FIFO read back and clear FIFO */
> @@ -996,7 +1001,7 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
> size);
>
> /* Aux Fire */
> - it6505_write(it6505, REG_AUX_CMD_REQ, cmd);
> + it6505_write(it6505, REG_AUX_CMD_REQ, FIELD_GET(M_AUX_REQ_CMD, cmd));
>
> ret = it6505_aux_wait(it6505);
> if (ret < 0)
> @@ -1030,7 +1035,7 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
> goto aux_op_start;
> }
>
> - if (cmd == CMD_AUX_I2C_EDID_READ) {
> + if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
> for (i = 0; i < size; i++) {
> ret = it6505_read(it6505, REG_AUX_DATA_FIFO);
> if (ret < 0)
> @@ -1055,7 +1060,7 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
> ret = i;
>
> aux_op_err:
> - if (cmd == CMD_AUX_I2C_EDID_READ) {
> + if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
> /* clear AUX FIFO */
> it6505_set_bits(it6505, REG_AUX_CTRL,
> AUX_EN_FIFO_READ | CLR_EDID_FIFO,
> @@ -1076,7 +1081,8 @@ 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;
> - int fifo_max_size = (cmd == CMD_AUX_I2C_EDID_READ) ? AUX_FIFO_MAX_SIZE : 4;
> + int fifo_max_size = (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) ?
> + AUX_FIFO_MAX_SIZE : 4;
>
> mutex_lock(&it6505->aux_lock);
> i = 0;
> --
> 2.34.1
>
--
With best wishes
Dmitry
