diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c index 7104c1856987..173f79918741 100644 --- a/drivers/bus/mhi/host/init.c +++ b/drivers/bus/mhi/host/init.c @@ -541,11 +541,9 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl) dev_dbg(dev, "Initializing MHI registers\n"); /* Read channel db offset */ - ret = mhi_read_reg(mhi_cntrl, base, CHDBOFF, &val); - if (ret) { - dev_err(dev, "Unable to read CHDBOFF register\n"); - return -EIO; - } + ret = mhi_get_channel_doorbell_offset(mhi_cntrl, &val); + if (ret) + return ret; if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) { dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n", diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index 15d657af9b5b..4de75674f193 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -1691,3 +1691,19 @@ void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev) } } EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer); + +int mhi_get_channel_doorbell_offset(struct mhi_controller *mhi_cntrl, u32 *chdb_offset) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + void __iomem *base = mhi_cntrl->regs; + int ret; + + ret = mhi_read_reg(mhi_cntrl, base, CHDBOFF, chdb_offset); + if (ret) { + dev_err(dev, "Unable to read CHDBOFF register\n"); + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(mhi_get_channel_doorbell_offset); diff --git a/include/linux/mhi.h b/include/linux/mhi.h index d968e1ab44dc..b573f15762f8 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -816,4 +816,13 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir, */ bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir); +/** + * mhi_get_channel_doorbell_offset - Get the channel doorbell offset + * @mhi_cntrl: MHI controller + * @chdb_offset: Read channel doorbell offset + * + * Return: 0 if the read succeeds, a negative error code otherwise + */ +int mhi_get_channel_doorbell_offset(struct mhi_controller *mhi_cntrl, u32 *chdb_offset); + #endif /* _MHI_H_ */