diff options
Diffstat (limited to 'arch/arm/mach-prima2/rtciobrg.c')
| -rw-r--r-- | arch/arm/mach-prima2/rtciobrg.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/rtciobrg.c b/arch/arm/mach-prima2/rtciobrg.c new file mode 100644 index 000000000..97c0e333e --- /dev/null +++ b/arch/arm/mach-prima2/rtciobrg.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * RTC I/O Bridge interfaces for CSR SiRFprimaII/atlas7 + * ARM access the registers of SYSRTC, GPSRTC and PWRC through this module + * + * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/regmap.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; + + /* TODO: add hwspinlock to sync with M3 */ + 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; + + /* TODO: add hwspinlock to sync with M3 */ + 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 int regmap_iobg_regwrite(void *context, unsigned int reg, + unsigned int val) +{ + sirfsoc_rtc_iobrg_writel(val, reg); + return 0; +} + +static int regmap_iobg_regread(void *context, unsigned int reg, + unsigned int *val) +{ + *val = (u32)sirfsoc_rtc_iobrg_readl(reg); + return 0; +} + +static struct regmap_bus regmap_iobg = { + .reg_write = regmap_iobg_regwrite, + .reg_read = regmap_iobg_regread, +}; + +/** + * devm_regmap_init_iobg(): Initialise managed register map + * + * @iobg: Device that will be interacted with + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer + * to a struct regmap. The regmap will be automatically freed by the + * device management code. + */ +struct regmap *devm_regmap_init_iobg(struct device *dev, + const struct regmap_config *config) +{ + const struct regmap_bus *bus = ®map_iobg; + + return devm_regmap_init(dev, bus, dev, config); +} +EXPORT_SYMBOL_GPL(devm_regmap_init_iobg); + +static const struct of_device_id rtciobrg_ids[] = { + { .compatible = "sirf,prima2-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", + .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>"); +MODULE_AUTHOR("Barry Song <baohua.song@csr.com>"); +MODULE_DESCRIPTION("CSR SiRFprimaII rtc io bridge"); +MODULE_LICENSE("GPL v2"); |