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kernel/linux-imx6_3.14.28/arch/arm/mach-prima2/rtciobrg.c 3.43 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * RTC I/O Bridge interfaces for CSR SiRFprimaII
   * ARM access the registers of SYSRTC, GPSRTC and PWRC through this module
   *
   * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
   *
   * Licensed under GPLv2 or later.
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  #include <linux/of_device.h>
  #include <linux/of_platform.h>
  
  #define SIRFSOC_CPUIOBRG_CTRL           0x00
  #define SIRFSOC_CPUIOBRG_WRBE           0x04
  #define SIRFSOC_CPUIOBRG_ADDR           0x08
  #define SIRFSOC_CPUIOBRG_DATA           0x0c
  
  /*
   * suspend asm codes will access this address to make system deepsleep
   * after DRAM becomes self-refresh
   */
  void __iomem *sirfsoc_rtciobrg_base;
  static DEFINE_SPINLOCK(rtciobrg_lock);
  
  /*
   * symbols without lock are only used by suspend asm codes
   * and these symbols are not exported too
   */
  void sirfsoc_rtc_iobrg_wait_sync(void)
  {
  	while (readl_relaxed(sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_CTRL))
  		cpu_relax();
  }
  
  void sirfsoc_rtc_iobrg_besyncing(void)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&rtciobrg_lock, flags);
  
  	sirfsoc_rtc_iobrg_wait_sync();
  
  	spin_unlock_irqrestore(&rtciobrg_lock, flags);
  }
  EXPORT_SYMBOL_GPL(sirfsoc_rtc_iobrg_besyncing);
  
  u32 __sirfsoc_rtc_iobrg_readl(u32 addr)
  {
  	sirfsoc_rtc_iobrg_wait_sync();
  
  	writel_relaxed(0x00, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_WRBE);
  	writel_relaxed(addr, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_ADDR);
  	writel_relaxed(0x01, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_CTRL);
  
  	sirfsoc_rtc_iobrg_wait_sync();
  
  	return readl_relaxed(sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_DATA);
  }
  
  u32 sirfsoc_rtc_iobrg_readl(u32 addr)
  {
  	unsigned long flags, val;
  
  	spin_lock_irqsave(&rtciobrg_lock, flags);
  
  	val = __sirfsoc_rtc_iobrg_readl(addr);
  
  	spin_unlock_irqrestore(&rtciobrg_lock, flags);
  
  	return val;
  }
  EXPORT_SYMBOL_GPL(sirfsoc_rtc_iobrg_readl);
  
  void sirfsoc_rtc_iobrg_pre_writel(u32 val, u32 addr)
  {
  	sirfsoc_rtc_iobrg_wait_sync();
  
  	writel_relaxed(0xf1, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_WRBE);
  	writel_relaxed(addr, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_ADDR);
  
  	writel_relaxed(val, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_DATA);
  }
  
  void sirfsoc_rtc_iobrg_writel(u32 val, u32 addr)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&rtciobrg_lock, flags);
  
  	sirfsoc_rtc_iobrg_pre_writel(val, addr);
  
  	writel_relaxed(0x01, sirfsoc_rtciobrg_base + SIRFSOC_CPUIOBRG_CTRL);
  
  	sirfsoc_rtc_iobrg_wait_sync();
  
  	spin_unlock_irqrestore(&rtciobrg_lock, flags);
  }
  EXPORT_SYMBOL_GPL(sirfsoc_rtc_iobrg_writel);
  
  static const struct of_device_id rtciobrg_ids[] = {
  	{ .compatible = "sirf,prima2-rtciobg" },
  	{ .compatible = "sirf,marco-rtciobg" },
  	{}
  };
  
  static int sirfsoc_rtciobrg_probe(struct platform_device *op)
  {
  	struct device_node *np = op->dev.of_node;
  
  	sirfsoc_rtciobrg_base = of_iomap(np, 0);
  	if (!sirfsoc_rtciobrg_base)
  		panic("unable to map rtc iobrg registers
  ");
  
  	return 0;
  }
  
  static struct platform_driver sirfsoc_rtciobrg_driver = {
  	.probe		= sirfsoc_rtciobrg_probe,
  	.driver = {
  		.name = "sirfsoc-rtciobrg",
  		.owner = THIS_MODULE,
  		.of_match_table	= rtciobrg_ids,
  	},
  };
  
  static int __init sirfsoc_rtciobrg_init(void)
  {
  	return platform_driver_register(&sirfsoc_rtciobrg_driver);
  }
  postcore_initcall(sirfsoc_rtciobrg_init);
  
  MODULE_AUTHOR("Zhiwu Song <zhiwu.song@csr.com>, "
  		"Barry Song <baohua.song@csr.com>");
  MODULE_DESCRIPTION("CSR SiRFprimaII rtc io bridge");
  MODULE_LICENSE("GPL");