diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/cadence/cdns-mhdp-dp.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/cadence/cdns-mhdp-dp.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp-dp.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-dp.c new file mode 100644 index 000000000000..299e533d6b52 --- /dev/null +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp-dp.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <asm/unaligned.h> +#include <drm/bridge/cdns-mhdp.h> +#include <drm/drm_print.h> +#include <linux/io.h> + +#define LINK_TRAINING_TIMEOUT_MS 500 +#define LINK_TRAINING_RETRY_MS 20 + +int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp, + u32 addr, u8 *data, u16 len) +{ + u8 msg[5], reg[5]; + int ret; + + put_unaligned_be16(len, msg); + put_unaligned_be24(addr, msg + 2); + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_READ_DPCD, sizeof(msg), msg); + if (ret) + goto err_dpcd_read; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_READ_DPCD, + sizeof(reg) + len); + if (ret) + goto err_dpcd_read; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg)); + if (ret) + goto err_dpcd_read; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, data, len); + +err_dpcd_read: + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_dpcd_read); + +int cdns_mhdp_i2c_read(struct cdns_mhdp_device *mhdp, u8 addr, u8 *data, + u16 len, u8 mot, u16 *respLength) +{ + u8 msg[5], reg[3]; + int ret; + + put_unaligned_be16(len, msg); + msg[2] = addr; + msg[3] = mot; + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_I2C_READ, sizeof(msg), msg); + if (ret) + goto err_i2c_read; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_I2C_READ, + sizeof(reg) + len); + if (ret) + goto err_i2c_read; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg)); + if (ret) + goto err_i2c_read; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, data, len); + *respLength = (reg[0] << 8u) + reg[1]; + +err_i2c_read: + if (ret) + DRM_DEV_ERROR(mhdp->dev, "i2c read failed: %d\n", ret); + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_i2c_read); + +int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8 value) +{ + u8 msg[6], reg[5]; + int ret; + + put_unaligned_be16(1, msg); + put_unaligned_be24(addr, msg + 2); + msg[5] = value; + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_WRITE_DPCD, sizeof(msg), msg); + if (ret) + goto err_dpcd_write; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_WRITE_DPCD, sizeof(reg)); + if (ret) + goto err_dpcd_write; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg)); + if (ret) + goto err_dpcd_write; + + if (addr != get_unaligned_be24(reg + 2)) + ret = -EINVAL; + +err_dpcd_write: + if (ret) + DRM_DEV_ERROR(mhdp->dev, "dpcd write failed: %d\n", ret); + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_dpcd_write); + +int cdns_mhdp_i2c_write(struct cdns_mhdp_device *mhdp, u8 addr, u8 *value, + u8 mot, u16 len, u16 *respLength) +{ + u8 msg[4+DP_AUX_MAX_PAYLOAD_BYTES], reg[3]; + int ret; + + put_unaligned_be16(len, msg); + msg[2] = addr; + msg[3] = mot; + memcpy(&msg[4], value, len); + + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_I2C_WRITE, sizeof(msg), msg); + if (ret) + goto err_i2c_write; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_I2C_WRITE, sizeof(reg)); + if (ret) + goto err_i2c_write; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, reg, sizeof(reg)); + if (ret) + goto err_i2c_write; + + if (addr != reg[2]) + ret = -EINVAL; + + *respLength = (reg[0]<<8u) + reg[1]; + +err_i2c_write: + if (ret) + DRM_DEV_ERROR(mhdp->dev, "i2c write failed: %d\n", ret); + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_i2c_write); + + +int cdns_mhdp_get_last_i2c_status(struct cdns_mhdp_device *mhdp, u8 *resp) +{ + u8 status[1]; + int ret; + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_GET_LAST_I2C_STATUS, 0, NULL); + if (ret) + goto err_get_i2c_status; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_GET_LAST_I2C_STATUS, + sizeof(status)); + if (ret) + goto err_get_i2c_status; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, status, sizeof(status)); + if (ret) + goto err_get_i2c_status; + + *resp = status[0]; + +err_get_i2c_status: + if (ret) + DRM_DEV_ERROR(mhdp->dev, "get i2c status failed: %d\n", + ret); + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_get_last_i2c_status); + +static int cdns_mhdp_training_start(struct cdns_mhdp_device *mhdp) +{ + unsigned long timeout; + u8 msg, event[2]; + int ret; + + msg = LINK_TRAINING_RUN; + + /* start training */ + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_TRAINING_CONTROL, sizeof(msg), &msg); + if (ret) + goto err_training_start; + + timeout = jiffies + msecs_to_jiffies(LINK_TRAINING_TIMEOUT_MS); + while (time_before(jiffies, timeout)) { + msleep(LINK_TRAINING_RETRY_MS); + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_READ_EVENT, 0, NULL); + if (ret) + goto err_training_start; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, + MB_MODULE_ID_DP_TX, + DPTX_READ_EVENT, + sizeof(event)); + if (ret) + goto err_training_start; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, event, + sizeof(event)); + if (ret) + goto err_training_start; + + if (event[1] & CLK_RECOVERY_FAILED) + DRM_DEV_ERROR(mhdp->dev, "clock recovery failed\n"); + else if (event[1] & EQ_PHASE_FINISHED) + return 0; + } + + ret = -ETIMEDOUT; + +err_training_start: + DRM_DEV_ERROR(mhdp->dev, "training failed: %d\n", ret); + return ret; +} + +static int cdns_mhdp_get_training_status(struct cdns_mhdp_device *mhdp) +{ + u8 status[13]; + int ret; + + ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX, + DPTX_READ_LINK_STAT, 0, NULL); + if (ret) + goto err_get_training_status; + + ret = cdns_mhdp_mailbox_validate_receive(mhdp, MB_MODULE_ID_DP_TX, + DPTX_READ_LINK_STAT, + sizeof(status)); + if (ret) + goto err_get_training_status; + + ret = cdns_mhdp_mailbox_read_receive(mhdp, status, sizeof(status)); + if (ret) + goto err_get_training_status; + + mhdp->dp.rate = drm_dp_bw_code_to_link_rate(status[0]); + mhdp->dp.num_lanes = status[1]; + +err_get_training_status: + if (ret) + DRM_DEV_ERROR(mhdp->dev, "get training status failed: %d\n", + ret); + return ret; +} + +int cdns_mhdp_train_link(struct cdns_mhdp_device *mhdp) +{ + int ret; + + ret = cdns_mhdp_training_start(mhdp); + if (ret) { + DRM_DEV_ERROR(mhdp->dev, "Failed to start training %d\n", + ret); + return ret; + } + + ret = cdns_mhdp_get_training_status(mhdp); + if (ret) { + DRM_DEV_ERROR(mhdp->dev, "Failed to get training stat %d\n", + ret); + return ret; + } + + DRM_DEV_DEBUG_KMS(mhdp->dev, "rate:0x%x, lanes:%d\n", mhdp->dp.rate, + mhdp->dp.num_lanes); + return ret; +} +EXPORT_SYMBOL(cdns_mhdp_train_link); |