diff options
Diffstat (limited to 'arch/arm/mach-prima2/rtciobrg.c')
| -rw-r--r-- | arch/arm/mach-prima2/rtciobrg.c | 140 | 
1 files changed, 140 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/rtciobrg.c b/arch/arm/mach-prima2/rtciobrg.c new file mode 100644 index 00000000000..a17c88b74fa --- /dev/null +++ b/arch/arm/mach-prima2/rtciobrg.c @@ -0,0 +1,140 @@ +/* + * 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\n"); + +	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 v2");  | 
