Which Linux Driver Supports Altera FPGA Generic Serial Flash Interface (GSFI) IP Core?

Hello,

I am working with an Altera (Intel) FPGA design that uses the Generic Serial Flash Interface (GSFI) IP core to connect to an external SPI NOR Flash device. I am looking for the appropriate Linux driver to support this interface.

I have checked the Linux 5.4 kernel source:

- In drivers/mtd/spi-nor/, I only found drivers for Intel PCH SPI controllers, but nothing specific for the Altera/Intel GSFI IP core.
- In drivers/spi/, there is an altera_spi driver, but it appears to be a generic SPI controller driver, not specifically for SPI NOR flash access.

My questions:
1. Is there an official or recommended Linux driver for the Altera/Intel FPGA Generic Serial Flash Interface (GSFI) IP core?
2. If so, where can I find it, or which kernel version includes it?
3. If not, is there any guidance or reference for adapting an existing driver (such as altera_spi or a generic SPI-mem driver) to support GSFI for SPI NOR flash access?

Any documentation, example device tree bindings, or reference designs would also be greatly appreciated.

Thank you!