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authorJeffrey Hugo <quic_jhugo@quicinc.com>2024-02-19 11:07:48 -0700
committerManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>2024-02-21 11:22:25 +0530
commitf0397e27d1204a7e6581d140c2de7fd11383c6ba (patch)
tree88c064c97f53505cd2c900feb72f3744cb60d014 /drivers/bus
parentceeb64f41fe6a1eb9fc56d583983a81f8f3dd058 (diff)
Revert "bus: mhi: core: Add support for reading MHI info from device"
This reverts commit 3316ab2b45f6bf4797d8d65b22fda3cc13318890. The MHI spec owner pointed out that the SOC_HW_VERSION register is part of the BHIe segment, and only valid on devices which implement BHIe. Only a small subset of MHI devices implement BHIe so blindly accessing the register for all devices is not correct. Also, since the BHIe segment offset is not used when accessing the register, any implementation which moves the BHIe segment will result in accessing some other register. We've seen that accessing this register on AIC100 which does not support BHIe can result in initialization failures. We could try to put checks into the code to address these issues, but in the roughly 4 years this functionality has existed, no one has used it. Easier to drop this dead code and address the issues if anyone comes up with a real world use for it. Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/20240219180748.1591527-1-quic_jhugo@quicinc.com Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/mhi/host/init.c12
-rw-r--r--drivers/bus/mhi/host/internal.h6
2 files changed, 0 insertions, 18 deletions
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 944da46e6f11..44f934981de8 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -914,7 +914,6 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan;
struct mhi_cmd *mhi_cmd;
struct mhi_device *mhi_dev;
- u32 soc_info;
int ret, i;
if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
@@ -989,17 +988,6 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
}
- /* Read the MHI device info */
- ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
- SOC_HW_VERSION_OFFS, &soc_info);
- if (ret)
- goto err_destroy_wq;
-
- mhi_cntrl->family_number = FIELD_GET(SOC_HW_VERSION_FAM_NUM_BMSK, soc_info);
- mhi_cntrl->device_number = FIELD_GET(SOC_HW_VERSION_DEV_NUM_BMSK, soc_info);
- mhi_cntrl->major_version = FIELD_GET(SOC_HW_VERSION_MAJOR_VER_BMSK, soc_info);
- mhi_cntrl->minor_version = FIELD_GET(SOC_HW_VERSION_MINOR_VER_BMSK, soc_info);
-
mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
if (mhi_cntrl->index < 0) {
ret = mhi_cntrl->index;
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 091244cf17c6..5fe49311b8eb 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -15,12 +15,6 @@ extern struct bus_type mhi_bus_type;
#define MHI_SOC_RESET_REQ_OFFSET 0xb0
#define MHI_SOC_RESET_REQ BIT(0)
-#define SOC_HW_VERSION_OFFS 0x224
-#define SOC_HW_VERSION_FAM_NUM_BMSK GENMASK(31, 28)
-#define SOC_HW_VERSION_DEV_NUM_BMSK GENMASK(27, 16)
-#define SOC_HW_VERSION_MAJOR_VER_BMSK GENMASK(15, 8)
-#define SOC_HW_VERSION_MINOR_VER_BMSK GENMASK(7, 0)
-
struct mhi_ctxt {
struct mhi_event_ctxt *er_ctxt;
struct mhi_chan_ctxt *chan_ctxt;