2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
8 #include <linux/delay.h>
9 #include <linux/kernel.h>
10 #include <linux/spinlock.h>
12 #include <linux/errno.h>
14 #define PIC32_NULL 0x00
16 #define PIC32_SYSRD 0x02
18 #define PIC32_SYSWR 0x20
19 #define PIC32_IRQ_CLR 0x40
20 #define PIC32_STATUS 0x80
22 #define DELAY() udelay(100) /* FIXME: needed? */
24 /* spinlock to ensure atomic access to PIC32 */
25 static DEFINE_SPINLOCK(pic32_bus_lock);
27 /* FIXME: io_remap these */
28 static void __iomem *bus_xfer = (void __iomem *)0xbf000600;
29 static void __iomem *bus_status = (void __iomem *)0xbf000060;
31 static inline unsigned int ioready(void)
33 return readl(bus_status) & 1;
36 static inline void wait_ioready(void)
38 do { } while (!ioready());
41 static inline void wait_ioclear(void)
43 do { } while (ioready());
46 static inline void check_ioclear(void)
49 pr_debug("ioclear: initially busy\n");
51 (void) readl(bus_xfer);
54 pr_debug("ioclear: cleared busy\n");
58 u32 pic32_bus_readl(u32 reg)
63 spin_lock_irqsave(&pic32_bus_lock, flags);
67 writel((PIC32_RD << 24) | (reg & 0x00ffffff), bus_xfer);
70 status = readl(bus_xfer);
72 val = readl(bus_xfer);
75 pr_debug("pic32_bus_readl: *%x -> %x (status=%x)\n", reg, val, status);
77 spin_unlock_irqrestore(&pic32_bus_lock, flags);
82 void pic32_bus_writel(u32 val, u32 reg)
87 spin_lock_irqsave(&pic32_bus_lock, flags);
91 writel((PIC32_WR << 24) | (reg & 0x00ffffff), bus_xfer);
93 writel(val, bus_xfer);
96 status = readl(bus_xfer);
99 pr_debug("pic32_bus_writel: *%x <- %x (status=%x)\n", reg, val, status);
101 spin_unlock_irqrestore(&pic32_bus_lock, flags);