1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * MX25 CPU type detection 4 * 5 * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de> 6 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved 7 */ 8 #include <linux/module.h> 9 #include <linux/io.h> 10 #include <linux/of.h> 11 #include <linux/of_address.h> 12 13 #include "iim.h" 14 #include "hardware.h" 15 16 static int mx25_cpu_rev = -1; 17 18 static int mx25_read_cpu_rev(void) 19 { 20 u32 rev; 21 void __iomem *iim_base; 22 struct device_node *np; 23 24 np = of_find_compatible_node(NULL, NULL, "fsl,imx25-iim"); 25 iim_base = of_iomap(np, 0); 26 BUG_ON(!iim_base); 27 rev = readl(iim_base + MXC_IIMSREV); 28 iounmap(iim_base); 29 30 switch (rev) { 31 case 0x00: 32 return IMX_CHIP_REVISION_1_0; 33 case 0x01: 34 return IMX_CHIP_REVISION_1_1; 35 default: 36 return IMX_CHIP_REVISION_UNKNOWN; 37 } 38 } 39 40 int mx25_revision(void) 41 { 42 if (mx25_cpu_rev == -1) 43 mx25_cpu_rev = mx25_read_cpu_rev(); 44 45 return mx25_cpu_rev; 46 } 47 EXPORT_SYMBOL(mx25_revision); 48