sram: adi: Adding v7 boards sram driver

Adding sram support for sc5xx arm v7 boards

Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>

Author: UtsavAgarwalADI

drivers/misc/adi/Kconfig

@@ -7,6 +7,13 @@ config ADI_SRAM_MMAP
 	help
 	  Enable the mmap driver for sc5xx on chip SRAM.
 
+config ADI_SRAM_MMAP_V7
+	bool "Legacy (armv7) mmap driver for sc5xx onchip SRAM"
+	depends on (ARCH_SC59X || ARCH_SC58X || ARCH_SC57X) && SRAM
+	default n
+	help
+	  Enable the mmap driver for sc5xx on chip SRAM.
+
 config ADI_SRAM_CONTROLLER
 	bool "/proc/sraminfo support for sc5xx onchip SRAM"
 	depends on (ARCH_SC59X_64 || ARCH_SC59X) && SRAM

drivers/misc/adi/Makefile

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)-or-later
 obj-$(CONFIG_ADI_SRAM_CONTROLLER)	+= sram.o
+obj-$(CONFIG_ADI_SRAM_MMAP_V7)		+= sram_mmap_v7.o
 obj-$(CONFIG_ADI_SRAM_MMAP)		+= sram_mmap.o
 

drivers/misc/adi/sram_mmap_v7.c

@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SRAM mmap misc driver for ADI processor on-chip memory
+ *
+ * (C) Copyright 2022 - Analog Devices, Inc.
+ *
+ * Written and/or maintained by Timesys Corporation
+ *
+ * Contact: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
+ * Contact: Greg Malysa <greg.malysa@timesys.com>
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/genalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/platform_device.h>
+
+#define SRAM_MMAP_DRV_NAME		"sram_mmap"
+
+struct adi_sram_mmap {
+	struct miscdevice miscdev;
+	struct gen_pool *sram_pool;
+};
+
+struct mmap_private_data {
+	struct gen_pool *pool;
+	unsigned long vaddr;
+};
+
+static void mmap_open(struct vm_area_struct *vma)
+{
+	struct mmap_private_data *pdata = vma->vm_private_data;
+	size_t sram_size = vma->vm_end - vma->vm_start;
+
+	/* Alloc the virtual address from specific sram_pool */
+	pdata->vaddr = gen_pool_alloc(pdata->pool, sram_size);
+	if (!pdata->vaddr)
+		pr_err("Failed to alloc memory from sram pool!\n");
+}
+
+static void mmap_close(struct vm_area_struct *vma)
+{
+	struct mmap_private_data *pdata = vma->vm_private_data;
+	size_t sram_size = vma->vm_end - vma->vm_start;
+
+	gen_pool_free(pdata->pool, pdata->vaddr, sram_size);
+	kfree(pdata);
+}
+
+const struct vm_operations_struct sram_mmap_vm_ops = {
+	.open =     mmap_open,
+	.close =    mmap_close,
+};
+
+static int sram_mmap(struct file *fp, struct vm_area_struct *vma)
+{
+	struct adi_sram_mmap *sram = container_of(fp->private_data,
+				struct adi_sram_mmap, miscdev);
+	struct mmap_private_data *pdata;
+	size_t sram_size = vma->vm_end - vma->vm_start;
+	unsigned long paddr;
+	int ret = 0;
+
+	/*  Allocate private pdata */
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->pool = sram->sram_pool;
+	vma->vm_private_data = pdata;
+	vma->vm_ops = &sram_mmap_vm_ops;
+	vma->vm_ops->open(vma);
+
+	if (!pdata->vaddr) {
+		ret = -EAGAIN;
+		goto out_free;
+	}
+
+	paddr = gen_pool_virt_to_phys(pdata->pool, pdata->vaddr);
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	if (io_remap_pfn_range(vma, vma->vm_start,
+				__phys_to_pfn(paddr), sram_size,
+				vma->vm_page_prot)) {
+		pr_err("Unable to mmap sram\n");
+		ret = -EAGAIN;
+		goto out_free;
+	}
+	pr_info("sram mmaped 0x%lx : 0x%lx successfully!\n",
+		paddr, paddr + sram_size);
+
+	return 0;
+
+out_free:
+	kfree(pdata);
+	return ret;
+}
+
+static const struct file_operations sram_fops = {
+	.mmap		= sram_mmap,
+};
+
+static const struct of_device_id adi_sram_mmap_of_match[] = {
+	{ .compatible = "adi,sram-mmap" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, adi_sram_mmap_of_match);
+
+static int adi_sram_mmap_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct adi_sram_mmap *sram;
+	const struct of_device_id *match;
+	struct device *dev;
+
+	dev = &pdev->dev;
+
+	/* Allocate sram device data */
+	sram = devm_kzalloc(dev, sizeof(*sram), GFP_KERNEL);
+	if (!sram)
+		return -ENOMEM;
+
+	match = of_match_device(of_match_ptr(adi_sram_mmap_of_match), &pdev->dev);
+	if (!match) {
+		pr_err("No sram mmap device defined in dts file\n");
+		return -ENODEV;
+	}
+	sram->sram_pool = of_gen_pool_get(dev->of_node, "adi,sram", 0);
+	if (!sram->sram_pool) {
+		pr_err("Unable to get sram pool!\n");
+		return -ENODEV;
+	}
+
+	dev_set_drvdata(&pdev->dev, sram);
+
+	sram->miscdev.minor = MISC_DYNAMIC_MINOR;
+	sram->miscdev.name = SRAM_MMAP_DRV_NAME;
+	sram->miscdev.fops = &sram_fops;
+	sram->miscdev.parent = dev;
+
+	ret = misc_register(&sram->miscdev);
+	if (ret < 0)
+		pr_err("Failed to register sram mmap misc device\n");
+
+	return ret;
+}
+
+static int adi_sram_mmap_remove(struct platform_device *pdev)
+{
+	struct adi_sram_mmap *sram = dev_get_drvdata(&pdev->dev);
+
+	misc_deregister(&sram->miscdev);
+
+	return 0;
+}
+
+static struct platform_driver adi_sram_mmap_driver = {
+	.probe = adi_sram_mmap_probe,
+	.remove = adi_sram_mmap_remove,
+	.driver = {
+		.name = SRAM_MMAP_DRV_NAME,
+		.of_match_table = of_match_ptr(adi_sram_mmap_of_match),
+	},
+};
+
+module_platform_driver(adi_sram_mmap_driver);
+MODULE_DESCRIPTION("SRAM mmap misc driver for ADI processor on-chip memory");
+MODULE_LICENSE("GPL");