clk: msm: mdss: update the procedure for storing DSI PLL codes

In the current implementation, the DSI PLL codes are copied from
a CMA memory which has a no-map attribute. Update the logic by
reading the pre-calibrated DSI PLL codes from physical memory
which is re-mapped to virtual memory allocated in kernel using
ioremap_page_range. Once the DSI PLL codes are stored, free the
reserved CMA memory back to kernel.

Change-Id: Iaa0bbd600dd1a18497cd4dfd7830a9bf88ab0ead
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>

drivers/clk/msm/mdss/mdss-pll-util.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -19,6 +19,8 @@
 #include <linux/clk/msm-clock-generic.h>
 #include <linux/of_address.h>
 #include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/memblock.h>
 
 #include "mdss-pll.h"
 
@@ -329,12 +331,26 @@ clk_err:
 	return rc;
 }
 
+static void mdss_pll_free_bootmem(u32 mem_addr, u32 size)
+{
+	unsigned long pfn_start, pfn_end, pfn_idx;
+
+	pfn_start = mem_addr >> PAGE_SHIFT;
+	pfn_end = (mem_addr + size) >> PAGE_SHIFT;
+	for (pfn_idx = pfn_start; pfn_idx < pfn_end; pfn_idx++)
+		free_reserved_page(pfn_to_page(pfn_idx));
+}
+
 static int mdss_pll_util_parse_dt_dfps(struct platform_device *pdev,
 					struct mdss_pll_resources *pll_res)
 {
 	int rc = 0;
 	struct device_node *pnode;
-	void __iomem *addr;
+	const u32 *addr;
+	struct vm_struct *area;
+	u64 size;
+	u32 offsets[2];
+	unsigned long virt_add;
 
 	pnode = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
 	if (IS_ERR_OR_NULL(pnode)) {
@@ -342,13 +358,29 @@ static int mdss_pll_util_parse_dt_dfps(struct platform_device *pdev,
 		goto pnode_err;
 	}
 
-	/* get the physical address for pll codes */
+	addr = of_get_address(pnode, 0, &size, NULL);
-	addr = of_iomap(pnode, 0);
+	if (!addr) {
-	if (IS_ERR_OR_NULL(addr)) {
+		pr_err("failed to parse the dfps memory address\n");
-			rc = PTR_ERR(addr);
+		rc = -EINVAL;
-			pr_err("couldn't get dfps physical address\n");
+		goto pnode_err;
-			goto pnode_err;
+	}
-		}
+	/* maintain compatibility for 32/64 bit */
+	offsets[0] = (u32) of_read_ulong(addr, 2);
+	offsets[1] = (u32) size;
+
+	area = get_vm_area(offsets[1], VM_IOREMAP);
+	if (!area) {
+		rc = -ENOMEM;
+		goto dfps_mem_err;
+	}
+
+	virt_add = (unsigned long)area->addr;
+	rc = ioremap_page_range(virt_add, (virt_add + offsets[1]),
+			offsets[0], PAGE_KERNEL);
+	if (rc) {
+		rc = -ENOMEM;
+		goto ioremap_err;
+	}
 
 	pll_res->dfps = kzalloc(sizeof(struct dfps_info), GFP_KERNEL);
 	if (IS_ERR_OR_NULL(pll_res->dfps)) {
@@ -357,12 +389,19 @@ static int mdss_pll_util_parse_dt_dfps(struct platform_device *pdev,
 		goto addr_err;
 	}
 
-	/* memcopy complete dfps structure from physical memory */
+	/* memcopy complete dfps structure from kernel virtual memory */
-	memcpy_fromio(pll_res->dfps, addr, sizeof(struct dfps_info));
+	memcpy_fromio(pll_res->dfps, area->addr, sizeof(struct dfps_info));
 
 addr_err:
-	iounmap(addr);
+	if (virt_add)
-
+		unmap_kernel_range(virt_add, (unsigned long) size);
+ioremap_err:
+	if (area)
+		vfree(area->addr);
+dfps_mem_err:
+	/* free the dfps memory here */
+	memblock_free(offsets[0], offsets[1]);
+	mdss_pll_free_bootmem(offsets[0], offsets[1]);
 pnode_err:
 	if (pnode)
 		of_node_put(pnode);