bus: mhi: core: Add missing checks for MMIO register entries

commit 8de5ad9 upstream.

As per documentation, fields marked as (required) in an MHI
controller structure need to be populated by the controller driver
before calling mhi_register_controller(). Ensure all required
pointers and non-zero fields are present in the controller before
proceeding with the registration.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1615315490-36017-1-git-send-email-bbhatt@codeaurora.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/init.c

@@ -876,12 +876,10 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	u32 soc_info;
 	int ret, i;
 
-	if (!mhi_cntrl)
-		return -EINVAL;
-
-	if (!mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
+	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
+	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
-	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs)
+	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs || !mhi_cntrl->irq)
 		return -EINVAL;
 
 	ret = parse_config(mhi_cntrl, config);