LXR linux/arch/sh/boards/mach-sdk7786/sram.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SDK7786 FPGA SRAM Support.
   4 *
   5 * Copyright (C) 2010  Paul Mundt
   6 */
   7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/types.h>
  12#include <linux/io.h>
  13#include <linux/string.h>
  14#include <mach/fpga.h>
  15#include <asm/sram.h>
  16#include <linux/sizes.h>
  17
  18static int __init fpga_sram_init(void)
  19{
  20        unsigned long phys;
  21        unsigned int area;
  22        void __iomem *vaddr;
  23        int ret;
  24        u16 data;
  25
  26        /* Enable FPGA SRAM */
  27        data = fpga_read_reg(LCLASR);
  28        data |= LCLASR_FRAMEN;
  29        fpga_write_reg(data, LCLASR);
  30
  31        /*
  32         * FPGA_SEL determines the area mapping
  33         */
  34        area = (data & LCLASR_FPGA_SEL_MASK) >> LCLASR_FPGA_SEL_SHIFT;
  35        if (unlikely(area == LCLASR_AREA_MASK)) {
  36                pr_err("FPGA memory unmapped.\n");
  37                return -ENXIO;
  38        }
  39
  40        /*
  41         * The memory itself occupies a 2KiB range at the top of the area
  42         * immediately below the system registers.
  43         */
  44        phys = (area << 26) + SZ_64M - SZ_4K;
  45
  46        /*
  47         * The FPGA SRAM resides in translatable physical space, so set
  48         * up a mapping prior to inserting it in to the pool.
  49         */
  50        vaddr = ioremap(phys, SZ_2K);
  51        if (unlikely(!vaddr)) {
  52                pr_err("Failed remapping FPGA memory.\n");
  53                return -ENXIO;
  54        }
  55
  56        pr_info("Adding %dKiB of FPGA memory at 0x%08lx-0x%08lx "
  57                "(area %d) to pool.\n",
  58                SZ_2K >> 10, phys, phys + SZ_2K - 1, area);
  59
  60        ret = gen_pool_add(sram_pool, (unsigned long)vaddr, SZ_2K, -1);
  61        if (unlikely(ret < 0)) {
  62                pr_err("Failed adding memory\n");
  63                iounmap(vaddr);
  64                return ret;
  65        }
  66
  67        return 0;
  68}
  69postcore_initcall(fpga_sram_init);
  70