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From:   Flavio Suligoi <f.suligoi@asem.it>
To:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>
CC:     <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        Flavio Suligoi <f.suligoi@asem.it>
Subject: [PATCH v1] mtd: spi-nor: add ACPI support for non-JEDEC SPI-NOR
Date:   Tue, 26 Jan 2021 15:37:48 +0100
Message-ID: <20210126143748.1546187-1-f.suligoi@asem.it>
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In a x86 machine, an additional device can be described
inside the BIOS ACPI tables.
For example, an I2C GPIO expander, a LED, etc.,
can be successfully declared in ACPI, so that the related
device driver can start automatically at the boot.

But for the SPI NOR devices, the ACPI description works
for JEDEC-compatible devices only.

For example, an Everspin MR25H40 MRAM device (non-JEDEC
compatible), declared using the following table,
does not work:

    Scope (\_SB.SPI1)
    {
        Device (NVR0)
        {
            Name (_HID, "PRP0001")
            Name (_DDN, "Everspin MR25H40 MRAM")
            Name (_CRS, ResourceTemplate () {
                SpiSerialBus (
                1,                      // Chip select
                PolarityLow,            // Chip select is active low
                FourWireMode,           // Full duplex
                8,                      // Bits per word is 8 (byte)
                ControllerInitiated,    // Don't care
                10000000,               // 10 MHz
                ClockPolarityLow,       // SPI mode 0 ClockPolarityLow
                ClockPhaseFirst,        // SPI mode 0 ClockPhaseFirst
                "\\_SB.SPI1",           // SPI host controller
                0,                      // Must be 0
                ResourceConsumer,
                ,
                )
            })

            Name (_DSD, Package () {
                ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
                Package () {
                    Package () {"compatible", "mr25h40"},
                }
            })
        }
    }

To enable the detection of a non-JEDEC device described
in a BIOS ACPI table, it is necessary to add its id name
in the spi_nor_of_table structure.
With this change, all the SPI NOR devices (JEDEC and
non-JEDEC) can be detected by the kernel (and the above
example of ACPI table finally works).

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
---
 drivers/mtd/spi-nor/core.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 6ae7d4c2d2b6..b6fb8b15c439 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3755,6 +3755,19 @@ static const struct of_device_id spi_nor_of_table[] = {
 	 * JEDEC READ ID opcode (0x9F). Use this, if possible.
 	 */
 	{ .compatible = "jedec,spi-nor" },
+	{ .compatible = "m25p05-nonjedec" },
+	{ .compatible = "m25p10-nonjedec" },
+	{ .compatible = "m25p20-nonjedec" },
+	{ .compatible = "m25p40-nonjedec" },
+	{ .compatible = "m25p80-nonjedec" },
+	{ .compatible = "m25p16-nonjedec" },
+	{ .compatible = "m25p32-nonjedec" },
+	{ .compatible = "m25p64-nonjedec" },
+	{ .compatible = "m25p128-nonjedec" },
+	{ .compatible = "mr25h128" },
+	{ .compatible = "mr25h256" },
+	{ .compatible = "mr25h10" },
+	{ .compatible = "mr25h40" },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, spi_nor_of_table);
-- 
2.25.1