mtd: add driver for intel graphics non-volatile memory device (ceb5ab3c) · Commits · git / linux-nf

MAINTAINERS

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		@@ -12086,6 +12086,13 @@ L: linux-kernel@vger.kernel.org
		S: Supported
		F: arch/x86/include/asm/intel-family.h

		INTEL DISCRETE GRAPHICS NVM MTD DRIVER
		M: Alexander Usyskin <alexander.usyskin@intel.com>
		L: linux-mtd@lists.infradead.org
		S: Supported
		F: drivers/mtd/devices/mtd_intel_dg.c
		F: include/linux/intel_dg_nvm_aux.h

		INTEL DRM DISPLAY FOR XE AND I915 DRIVERS
		M: Jani Nikula <jani.nikula@linux.intel.com>
		M: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/mtd/devices/Kconfig

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		@@ -183,6 +183,17 @@ config MTD_POWERNV_FLASH
		platforms from Linux. This device abstracts away the
		firmware interface for flash access.

		config MTD_INTEL_DG
		tristate "Intel Discrete Graphics non-volatile memory driver"
		depends on AUXILIARY_BUS
		depends on MTD
		help
		This provides an MTD device to access Intel Discrete Graphics
		non-volatile memory.

		To compile this driver as a module, choose M here: the module
		will be called mtd-intel-dg.

		comment "Disk-On-Chip Device Drivers"

		config MTD_DOCG3

drivers/mtd/devices/Makefile

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		@@ -18,6 +18,7 @@ obj-$(CONFIG_MTD_SST25L) += sst25l.o
		obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o
		obj-$(CONFIG_MTD_ST_SPI_FSM) += st_spi_fsm.o
		obj-$(CONFIG_MTD_POWERNV_FLASH) += powernv_flash.o
		obj-$(CONFIG_MTD_INTEL_DG) += mtd_intel_dg.o


		CFLAGS_docg3.o += -I$(src)

drivers/mtd/devices/mtd_intel_dg.c

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
		*/

		#include <linux/device.h>
		#include <linux/intel_dg_nvm_aux.h>
		#include <linux/io.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/string.h>
		#include <linux/slab.h>
		#include <linux/types.h>

		struct intel_dg_nvm {
		struct kref refcnt;
		void __iomem *base;
		size_t size;
		unsigned int nregions;
		struct {
		const char *name;
		u8 id;
		u64 offset;
		u64 size;
		} regions[] __counted_by(nregions);
		};

		static void intel_dg_nvm_release(struct kref *kref)
		{
		struct intel_dg_nvm *nvm = container_of(kref, struct intel_dg_nvm, refcnt);
		int i;

		pr_debug("freeing intel_dg nvm\n");
		for (i = 0; i < nvm->nregions; i++)
		kfree(nvm->regions[i].name);
		kfree(nvm);
		}

		static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
		const struct auxiliary_device_id *aux_dev_id)
		{
		struct intel_dg_nvm_dev *invm = auxiliary_dev_to_intel_dg_nvm_dev(aux_dev);
		struct intel_dg_nvm *nvm;
		struct device *device;
		unsigned int nregions;
		unsigned int i, n;
		int ret;

		device = &aux_dev->dev;

		/* count available regions */
		for (nregions = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
		if (invm->regions[i].name)
		nregions++;
		}

		if (!nregions) {
		dev_err(device, "no regions defined\n");
		return -ENODEV;
		}

		nvm = kzalloc(struct_size(nvm, regions, nregions), GFP_KERNEL);
		if (!nvm)
		return -ENOMEM;

		kref_init(&nvm->refcnt);

		for (n = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
		if (!invm->regions[i].name)
		continue;

		char *name = kasprintf(GFP_KERNEL, "%s.%s",
		dev_name(&aux_dev->dev), invm->regions[i].name);
		if (!name)
		continue;
		nvm->regions[n].name = name;
		nvm->regions[n].id = i;
		n++;
		}
		nvm->nregions = n; /* in case where kasprintf fail */

		nvm->base = devm_ioremap_resource(device, &invm->bar);
		if (IS_ERR(nvm->base)) {
		ret = PTR_ERR(nvm->base);
		goto err;
		}

		dev_set_drvdata(&aux_dev->dev, nvm);

		return 0;

		err:
		kref_put(&nvm->refcnt, intel_dg_nvm_release);
		return ret;
		}

		static void intel_dg_mtd_remove(struct auxiliary_device *aux_dev)
		{
		struct intel_dg_nvm *nvm = dev_get_drvdata(&aux_dev->dev);

		if (!nvm)
		return;

		dev_set_drvdata(&aux_dev->dev, NULL);

		kref_put(&nvm->refcnt, intel_dg_nvm_release);
		}

		static const struct auxiliary_device_id intel_dg_mtd_id_table[] = {
		{
		.name = "i915.nvm",
		},
		{
		.name = "xe.nvm",
		},
		{
		/* sentinel */
		}
		};
		MODULE_DEVICE_TABLE(auxiliary, intel_dg_mtd_id_table);

		static struct auxiliary_driver intel_dg_mtd_driver = {
		.probe = intel_dg_mtd_probe,
		.remove = intel_dg_mtd_remove,
		.driver = {
		/* auxiliary_driver_register() sets .name to be the modname */
		},
		.id_table = intel_dg_mtd_id_table
		};
		module_auxiliary_driver(intel_dg_mtd_driver);

		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Intel Corporation");
		MODULE_DESCRIPTION("Intel DGFX MTD driver");

include/linux/intel_dg_nvm_aux.h

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		/* SPDX-License-Identifier: MIT */
		/*
		* Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
		*/

		#ifndef __INTEL_DG_NVM_AUX_H__
		#define __INTEL_DG_NVM_AUX_H__

		#include <linux/auxiliary_bus.h>
		#include <linux/container_of.h>
		#include <linux/ioport.h>
		#include <linux/types.h>

		#define INTEL_DG_NVM_REGIONS 13

		struct intel_dg_nvm_region {
		const char *name;
		};

		struct intel_dg_nvm_dev {
		struct auxiliary_device aux_dev;
		bool writable_override;
		struct resource bar;
		const struct intel_dg_nvm_region *regions;
		};

		#define auxiliary_dev_to_intel_dg_nvm_dev(auxiliary_dev) \
		container_of(auxiliary_dev, struct intel_dg_nvm_dev, aux_dev)

		#endif /* __INTEL_DG_NVM_AUX_H__ */