#if defined(CONFIG_BCM_KF_OPTEE_414_BACKPORTS)
/*
 * Copyright (c) 2015, Linaro Limited
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/arm-smccc.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "optee_private.h"
#include "optee_smc.h"

#define DRIVER_NAME "optee"

#define OPTEE_SHM_NUM_PRIV_PAGES	1

#if defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE)
#include <asm/page.h>
#include <asm/setup.h>  /* for meminfo */
#include <linux/device.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/mm.h>   /* for high_memory */
#include <linux/of_address.h>
#include <linux/of_fdt.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/vme.h>

static int pte_callback(pte_t *pte, unsigned long x, unsigned long y,
			struct mm_walk *walk)
{
	const pgprot_t pte_prot = __pgprot(*pte);
	const pgprot_t req_prot = *((pgprot_t *)walk->private);
#if defined(CONFIG_ARM64)
	const pgprot_t prot_msk = PROT_DEFAULT | PTE_VALID;
#else
    const pgprot_t prot_msk = L_PTE_MT_MASK | L_PTE_VALID;
#endif

	return (((pte_prot ^ req_prot) & prot_msk) == 0) ? 0 : -1;
}

static void *page_to_virt_contig(const struct page *page, unsigned int pg_cnt,
					pgprot_t pgprot)
{
	int rc;
	struct mm_walk walk;
	unsigned long pfn;
	unsigned long pfn_start;
	unsigned long pfn_end;
	unsigned long va_start;
	unsigned long va_end;

	if ((page == NULL) || !pg_cnt)
		return ERR_PTR(-EINVAL);

	pfn_start = page_to_pfn(page);
	pfn_end = pfn_start + pg_cnt;
	for (pfn = pfn_start; pfn < pfn_end; pfn++) {
		const struct page *cur_pg = pfn_to_page(pfn);
		phys_addr_t pa;

		/* Verify range is in low memory only */
		if (PageHighMem(cur_pg))
			return NULL;

		/* Must be mapped */
		pa = page_to_phys(cur_pg);
		if (page_address(cur_pg) == NULL)
			return NULL;
	}

	/*
	 * Aliased mappings with different cacheability attributes on ARM can
	 * lead to trouble!
	 */
	memset(&walk, 0, sizeof(walk));
	walk.pte_entry = &pte_callback;
	walk.private = (void *)&pgprot;
	walk.mm = current->mm;
	va_start = (unsigned long)page_address(page);
	va_end = (unsigned long)(page_address(page) + (pg_cnt << PAGE_SHIFT));
	rc = walk_page_range(va_start,
			     va_end,
			     &walk);
	if (rc)
		pr_debug("cacheability mismatch\n");

	return rc ? NULL : page_address(page);
}

static struct page **get_pages(struct page *page, int num_pages)
{
	struct page **pages;
	long pfn;
	int i;

	if (num_pages == 0) {
		pr_err("bad count\n");
		return NULL;
	}

	if (page == NULL) {
		pr_err("bad page\n");
		return NULL;
	}

	pages = vmalloc(sizeof(struct page *) * num_pages);
	if (pages == NULL)
		return NULL;

	pfn = page_to_pfn(page);
	for (i = 0; i < num_pages; i++) {
		/*
		 * pfn_to_page() should resolve to simple arithmetic for the
		 * FLATMEM memory model.
		 */
		pages[i] = pfn_to_page(pfn++);
	}

	return pages;
}

/*
 * Basically just vmap() without checking that count < totalram_pages,
 * since we want to be able to map pages that aren't managed by Linux
 */
static void *brcmstb_memory_vmap(struct page **pages, unsigned int count,
		unsigned long flags, pgprot_t prot)
{
	struct vm_struct *area;

	might_sleep();

	area = get_vm_area_caller((count << PAGE_SHIFT), flags,
					__builtin_return_address(0));
	if (!area)
		return NULL;

	if (map_vm_area(area, prot, pages)) {
		vunmap(area->addr);
		return NULL;
	}

	return area->addr;
}

/**
 * brcmstb_memory_kva_map() - Map page(s) to a kernel virtual address
 *
 * @page: A struct page * that points to the beginning of a chunk of physical
 * contiguous memory.
 * @num_pages: Number of pages
 * @pgprot: Page protection bits
 *
 * Return: pointer to mapping, or NULL on failure
 */
void *brcmstb_memory_kva_map(struct page *page, int num_pages, pgprot_t pgprot)
{
	void *va;

	/* get the virtual address for this range if it exists */
	va = page_to_virt_contig(page, num_pages, pgprot);
	if (IS_ERR(va)) {
		pr_debug("page_to_virt_contig() failed (%ld)\n", PTR_ERR(va));
		return NULL;
	} else if (va == NULL || is_vmalloc_addr(va)) {
		struct page **pages;

		pages = get_pages(page, num_pages);
		if (pages == NULL) {
			pr_err("couldn't get pages\n");
			return NULL;
		}

		va = brcmstb_memory_vmap(pages, num_pages, 0, pgprot);

		vfree(pages);

		if (va == NULL) {
			pr_err("vmap failed (num_pgs=%d)\n", num_pages);
			return NULL;
		}
	}

	return va;
}
EXPORT_SYMBOL(brcmstb_memory_kva_map);

/**
 * brcmstb_memory_kva_map_phys() - map phys range to kernel virtual address
 *
 * @phys: physical address base
 * @size: size of range to map
 * @cached: whether to use cached or uncached mapping
 *
 * Return: NULL on failure, err on success
 */
void *brcmstb_memory_kva_map_phys(phys_addr_t phys, size_t size, bool cached)
{
	void *addr = NULL;
	unsigned long pfn = PFN_DOWN(phys);

	if (!cached) {
		/*
		 * This could be supported for MIPS by using ioremap instead,
		 * but that cannot be done on ARM if you want O_DIRECT support
		 * because having multiple mappings to the same memory with
		 * different cacheability will result in undefined behavior.
		 */
		return NULL;
	}

	if (pfn_valid(pfn)) {
		addr = brcmstb_memory_kva_map(pfn_to_page(pfn),
				size / PAGE_SIZE, PAGE_KERNEL);
	}
	return addr;
}
EXPORT_SYMBOL(brcmstb_memory_kva_map_phys);

/**
 * brcmstb_memory_kva_unmap() - Unmap a kernel virtual address associated
 * to physical pages mapped by brcmstb_memory_kva_map()
 *
 * @kva: Kernel virtual address previously mapped by brcmstb_memory_kva_map()
 *
 * Return: 0 on success, negative on failure.
 */
int brcmstb_memory_kva_unmap(const void *kva)
{
	if (kva == NULL)
		return -EINVAL;

	if (!is_vmalloc_addr(kva)) {
		/* unmapping not necessary for low memory VAs */
		return 0;
	}

	vunmap(kva);

	return 0;
}
EXPORT_SYMBOL(brcmstb_memory_kva_unmap);

extern void *brcmstb_memory_kva_map_phys(phys_addr_t phys, size_t size, bool cached);
extern int brcmstb_memory_kva_unmap(const void *kva);
#endif /* defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE) */

/**
 * optee_from_msg_param() - convert from OPTEE_MSG parameters to
 *			    struct tee_param
 * @params:	subsystem internal parameter representation
 * @num_params:	number of elements in the parameter arrays
 * @msg_params:	OPTEE_MSG parameters
 * Returns 0 on success or <0 on failure
 */
int optee_from_msg_param(struct tee_param *params, size_t num_params,
			 const struct optee_msg_param *msg_params)
{
	int rc;
	size_t n;
	struct tee_shm *shm;
	phys_addr_t pa;

	for (n = 0; n < num_params; n++) {
		struct tee_param *p = params + n;
		const struct optee_msg_param *mp = msg_params + n;
		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;

		switch (attr) {
		case OPTEE_MSG_ATTR_TYPE_NONE:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
			memset(&p->u, 0, sizeof(p->u));
			break;
		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
				  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
			p->u.value.a = mp->u.value.a;
			p->u.value.b = mp->u.value.b;
			p->u.value.c = mp->u.value.c;
			break;
		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
				  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
			p->u.memref.size = mp->u.tmem.size;
			shm = (struct tee_shm *)(unsigned long)
				mp->u.tmem.shm_ref;
			if (!shm) {
				p->u.memref.shm_offs = 0;
				p->u.memref.shm = NULL;
				break;
			}
			rc = tee_shm_get_pa(shm, 0, &pa);
			if (rc)
				return rc;
			p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
			p->u.memref.shm = shm;

			/* Check that the memref is covered by the shm object */
			if (p->u.memref.size) {
				size_t o = p->u.memref.shm_offs +
					   p->u.memref.size - 1;

				rc = tee_shm_get_pa(shm, o, NULL);
				if (rc)
					return rc;
			}
			break;
		default:
			return -EINVAL;
		}
	}
	return 0;
}

/**
 * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
 * @msg_params:	OPTEE_MSG parameters
 * @num_params:	number of elements in the parameter arrays
 * @params:	subsystem itnernal parameter representation
 * Returns 0 on success or <0 on failure
 */
int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
		       const struct tee_param *params)
{
	int rc;
	size_t n;
	phys_addr_t pa;

	for (n = 0; n < num_params; n++) {
		const struct tee_param *p = params + n;
		struct optee_msg_param *mp = msg_params + n;

		switch (p->attr) {
		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
			memset(&mp->u, 0, sizeof(mp->u));
			break;
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
				   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
			mp->u.value.a = p->u.value.a;
			mp->u.value.b = p->u.value.b;
			mp->u.value.c = p->u.value.c;
			break;
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
			mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT +
				   p->attr -
				   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
			mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
			mp->u.tmem.size = p->u.memref.size;
			if (!p->u.memref.shm) {
				mp->u.tmem.buf_ptr = 0;
				break;
			}
			rc = tee_shm_get_pa(p->u.memref.shm,
					    p->u.memref.shm_offs, &pa);
			if (rc)
				return rc;
			mp->u.tmem.buf_ptr = pa;
			mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
					OPTEE_MSG_ATTR_CACHE_SHIFT;
			break;
		default:
			return -EINVAL;
		}
	}
	return 0;
}

static void optee_get_version(struct tee_device *teedev,
			      struct tee_ioctl_version_data *vers)
{
	struct tee_ioctl_version_data v = {
		.impl_id = TEE_IMPL_ID_OPTEE,
		.impl_caps = TEE_OPTEE_CAP_TZ,
		.gen_caps = TEE_GEN_CAP_GP,
	};
	*vers = v;
}

static int optee_open(struct tee_context *ctx)
{
	struct optee_context_data *ctxdata;
	struct tee_device *teedev = ctx->teedev;
	struct optee *optee = tee_get_drvdata(teedev);

	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
	if (!ctxdata)
		return -ENOMEM;

	if (teedev == optee->supp_teedev) {
		bool busy = true;

		mutex_lock(&optee->supp.ctx_mutex);
		if (!optee->supp.ctx) {
			busy = false;
			optee->supp.ctx = ctx;
		}
		mutex_unlock(&optee->supp.ctx_mutex);
		if (busy) {
			kfree(ctxdata);
			return -EBUSY;
		}
	}

	mutex_init(&ctxdata->mutex);
	INIT_LIST_HEAD(&ctxdata->sess_list);

	ctx->data = ctxdata;
	return 0;
}

static void optee_release(struct tee_context *ctx)
{
	struct optee_context_data *ctxdata = ctx->data;
	struct tee_device *teedev = ctx->teedev;
	struct optee *optee = tee_get_drvdata(teedev);
	struct tee_shm *shm;
	struct optee_msg_arg *arg = NULL;
	phys_addr_t parg;
	struct optee_session *sess;
	struct optee_session *sess_tmp;

	if (!ctxdata)
		return;

	shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED);
	if (!IS_ERR(shm)) {
		arg = tee_shm_get_va(shm, 0);
		/*
		 * If va2pa fails for some reason, we can't call into
		 * secure world, only free the memory. Secure OS will leak
		 * sessions and finally refuse more sessions, but we will
		 * at least let normal world reclaim its memory.
		 */
		if (!IS_ERR(arg))
			if (tee_shm_va2pa(shm, arg, &parg))
				arg = NULL; /* prevent usage of parg below */
	}

	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
				 list_node) {
		list_del(&sess->list_node);
		if (!IS_ERR_OR_NULL(arg)) {
			memset(arg, 0, sizeof(*arg));
			arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
			arg->session = sess->session_id;
			optee_do_call_with_arg(ctx, parg);
		}
		kfree(sess);
	}
	kfree(ctxdata);

	if (!IS_ERR(shm))
		tee_shm_free(shm);

	ctx->data = NULL;

	if (teedev == optee->supp_teedev) {
		mutex_lock(&optee->supp.ctx_mutex);
		optee->supp.ctx = NULL;
		mutex_unlock(&optee->supp.ctx_mutex);
	}
}

static const struct tee_driver_ops optee_ops = {
	.get_version = optee_get_version,
	.open = optee_open,
	.release = optee_release,
	.open_session = optee_open_session,
	.close_session = optee_close_session,
	.invoke_func = optee_invoke_func,
	.cancel_req = optee_cancel_req,
};

static const struct tee_desc optee_desc = {
	.name = DRIVER_NAME "-clnt",
	.ops = &optee_ops,
	.owner = THIS_MODULE,
};

static const struct tee_driver_ops optee_supp_ops = {
	.get_version = optee_get_version,
	.open = optee_open,
	.release = optee_release,
	.supp_recv = optee_supp_recv,
	.supp_send = optee_supp_send,
};

static const struct tee_desc optee_supp_desc = {
	.name = DRIVER_NAME "-supp",
	.ops = &optee_supp_ops,
	.owner = THIS_MODULE,
	.flags = TEE_DESC_PRIVILEGED,
};

static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
{
	struct arm_smccc_res res;

	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);

	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
		return true;
	return false;
}

static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_calls_revision_result result;
	} res;

	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);

	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
		return true;
	return false;
}

static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
					    u32 *sec_caps)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_exchange_capabilities_result result;
	} res;
	u32 a1 = 0;

	/*
	 * TODO This isn't enough to tell if it's UP system (from kernel
	 * point of view) or not, is_smp() returns the the information
	 * needed, but can't be called directly from here.
	 */
	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;

	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
		  &res.smccc);

	if (res.result.status != OPTEE_SMC_RETURN_OK)
		return false;

	*sec_caps = res.result.capabilities;
	return true;
}

static struct tee_shm_pool *
optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_get_shm_config_result result;
	} res;
	struct tee_shm_pool *pool;
	unsigned long vaddr;
	phys_addr_t paddr;
	size_t size;
	phys_addr_t begin;
	phys_addr_t end;
	void *va;
	struct tee_shm_pool_mem_info priv_info;
	struct tee_shm_pool_mem_info dmabuf_info;

	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
	if (res.result.status != OPTEE_SMC_RETURN_OK) {
		pr_info("shm service not available\n");
		return ERR_PTR(-ENOENT);
	}

	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
		pr_err("only normal cached shared memory supported\n");
		return ERR_PTR(-EINVAL);
	}

	begin = roundup(res.result.start, PAGE_SIZE);
	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
	paddr = begin;
	size = end - begin;

	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
		pr_err("too small shared memory area\n");
		return ERR_PTR(-EINVAL);
	}

#if defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE)
	va = brcmstb_memory_kva_map_phys(paddr, size, true);
#else
	va = memremap(paddr, size, MEMREMAP_WB);
#endif
	if (!va) {
		pr_err("shared memory ioremap failed\n");
		return ERR_PTR(-EINVAL);
	}
	vaddr = (unsigned long)va;

	priv_info.vaddr = vaddr;
	priv_info.paddr = paddr;
	priv_info.size = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
	dmabuf_info.vaddr = vaddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
	dmabuf_info.paddr = paddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
	dmabuf_info.size = size - OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;

	pool = tee_shm_pool_alloc_res_mem(&priv_info, &dmabuf_info);
	if (IS_ERR(pool)) {
#if defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE)
		brcmstb_memory_kva_unmap(va);
#else
		memunmap(va);
#endif
		goto out;
	}

	*memremaped_shm = va;
out:
	return pool;
}

/* Simple wrapper functions to be able to use a function pointer */
static void optee_smccc_smc(unsigned long a0, unsigned long a1,
			    unsigned long a2, unsigned long a3,
			    unsigned long a4, unsigned long a5,
			    unsigned long a6, unsigned long a7,
			    struct arm_smccc_res *res)
{
#if defined(CONFIG_BCM_KF_OPTEE)
	extern char _stext[], _etext[];
#if defined(CONFIG_ARM64)
	register long ret_addr asm ("x30");

	/* Make SMC call and save x0-x3 into res */
	__asm__ volatile(
					"smc #0                    \n"
					"mov x8, %0                \n"
					"stp x0, x1, [x8]          \n"
					"stp x2, x3, [x8, #0x10]   \n"
					: : "r" (res) : "x8");
#else
	register long ret_addr asm ("r14");

	/* Make SMC call (opcode: 0xE1600070) and save r0-r3 into res */
	__asm__ volatile(
					".long 0xE1600070          \n"
					"mov r8, %0                \n"
					"stm r8, {r0-r3}           \n"
					: : "r" (res) : "r8");
#endif
	/* Make sure, this function was called from signed address range */
	if ( (char*)ret_addr < _stext || (char*)ret_addr > _etext){
		pr_info("ALERT!! System intrution detected by OP-TEE\n");
		res->a0 = OPTEE_SMC_RETURN_UNKNOWN_FUNCTION;
		return;
	}
#else
	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
#endif
}

static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
			    unsigned long a2, unsigned long a3,
			    unsigned long a4, unsigned long a5,
			    unsigned long a6, unsigned long a7,
			    struct arm_smccc_res *res)
{
	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
}

static optee_invoke_fn *get_invoke_func(struct device_node *np)
{
	const char *method;

	pr_info("probing for conduit method from DT.\n");

	if (of_property_read_string(np, "method", &method)) {
		pr_warn("missing \"method\" property\n");
		return ERR_PTR(-ENXIO);
	}

	if (!strcmp("hvc", method))
		return optee_smccc_hvc;
	else if (!strcmp("smc", method))
		return optee_smccc_smc;

	pr_warn("invalid \"method\" property: %s\n", method);
	return ERR_PTR(-EINVAL);
}

#if defined(CONFIG_BCM_KF_OPTEE)
struct optee *optee_probe(struct device_node *np)
#else
static struct optee *optee_probe(struct device_node *np)
#endif
{
	optee_invoke_fn *invoke_fn;
	struct tee_shm_pool *pool;
	struct optee *optee = NULL;
	void *memremaped_shm = NULL;
	struct tee_device *teedev;
	u32 sec_caps;
	int rc;

	invoke_fn = get_invoke_func(np);
	if (IS_ERR(invoke_fn))
		return (void *)invoke_fn;

	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
		pr_warn("api uid mismatch\n");
		return ERR_PTR(-EINVAL);
	}

	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
		pr_warn("api revision mismatch\n");
		return ERR_PTR(-EINVAL);
	}

	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
		pr_warn("capabilities mismatch\n");
		return ERR_PTR(-EINVAL);
	}

	/*
	 * We have no other option for shared memory, if secure world
	 * doesn't have any reserved memory we can use we can't continue.
	 */
	if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
		return ERR_PTR(-EINVAL);

	pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
	if (IS_ERR(pool))
		return (void *)pool;

	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
	if (!optee) {
		rc = -ENOMEM;
		goto err;
	}

	optee->invoke_fn = invoke_fn;

	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
	if (IS_ERR(teedev)) {
		rc = PTR_ERR(teedev);
		goto err;
	}
	optee->teedev = teedev;

	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
	if (IS_ERR(teedev)) {
		rc = PTR_ERR(teedev);
		goto err;
	}
	optee->supp_teedev = teedev;

	rc = tee_device_register(optee->teedev);
	if (rc)
		goto err;

	rc = tee_device_register(optee->supp_teedev);
	if (rc)
		goto err;

	mutex_init(&optee->call_queue.mutex);
	INIT_LIST_HEAD(&optee->call_queue.waiters);
	optee_wait_queue_init(&optee->wait_queue);
	optee_supp_init(&optee->supp);
	optee->memremaped_shm = memremaped_shm;
	optee->pool = pool;

	optee_enable_shm_cache(optee);

	pr_info("initialized driver\n");
	return optee;
err:
	if (optee) {
		/*
		 * tee_device_unregister() is safe to call even if the
		 * devices hasn't been registered with
		 * tee_device_register() yet.
		 */
		tee_device_unregister(optee->supp_teedev);
		tee_device_unregister(optee->teedev);
		kfree(optee);
	}
	if (pool)
		tee_shm_pool_free(pool);
	if (memremaped_shm)
#if defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE)
		iounmap(memremaped_shm);
#else
		memunmap(memremaped_shm);
#endif
	return ERR_PTR(rc);
}

static void optee_remove(struct optee *optee)
{
	/*
	 * Ask OP-TEE to free all cached shared memory objects to decrease
	 * reference counters and also avoid wild pointers in secure world
	 * into the old shared memory range.
	 */
	optee_disable_shm_cache(optee);

	/*
	 * The two devices has to be unregistered before we can free the
	 * other resources.
	 */
	tee_device_unregister(optee->supp_teedev);
	tee_device_unregister(optee->teedev);

	tee_shm_pool_free(optee->pool);
	if (optee->memremaped_shm)
#if defined(CONFIG_BCM_KF_OPTEE) && defined(CONFIG_OPTEE)
		iounmap(optee->memremaped_shm);
#else
		memunmap(optee->memremaped_shm);
#endif
	optee_wait_queue_exit(&optee->wait_queue);
	optee_supp_uninit(&optee->supp);
	mutex_destroy(&optee->call_queue.mutex);

	kfree(optee);
}

static const struct of_device_id optee_match[] = {
	{ .compatible = "linaro,optee-tz" },
	{},
};

static struct optee *optee_svc;

static int __init optee_driver_init(void)
{
	struct device_node *fw_np;
	struct device_node *np;
	struct optee *optee;

	/* Node is supposed to be below /firmware */
	fw_np = of_find_node_by_name(NULL, "firmware");
	if (!fw_np)
		return -ENODEV;

	np = of_find_matching_node(fw_np, optee_match);
	of_node_put(fw_np);
	if (!np)
		return -ENODEV;

	optee = optee_probe(np);
	of_node_put(np);

	if (IS_ERR(optee))
		return PTR_ERR(optee);

	optee_svc = optee;

	return 0;
}
module_init(optee_driver_init);

static void __exit optee_driver_exit(void)
{
	struct optee *optee = optee_svc;

	optee_svc = NULL;
	if (optee)
		optee_remove(optee);
}
module_exit(optee_driver_exit);

MODULE_AUTHOR("Linaro");
MODULE_DESCRIPTION("OP-TEE driver");
MODULE_SUPPORTED_DEVICE("");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL v2");
#endif /* CONFIG_BCM_KF_OPTEE_414_BACKPORTS */