From bde98d9c2010b787a5f7173d315f221e2ad2a491 Mon Sep 17 00:00:00 2001 From: Jan Luebbe Date: Thu, 30 Jul 2015 17:30:26 +0200 Subject: watchdog: add davinci watchdog driver This driver is based on the Linux driver (v4.0). Signed-off-by: Jan Luebbe Signed-off-by: Sascha Hauer --- drivers/watchdog/Kconfig | 6 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/davinci_wdt.c | 172 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 179 insertions(+) create mode 100644 drivers/watchdog/davinci_wdt.c (limited to 'drivers') diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 7f7b02e306..582c6154e4 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -10,6 +10,12 @@ menuconfig WATCHDOG if WATCHDOG +config WATCHDOG_DAVINCI + bool "TI Davinci" + depends on ARCH_DAVINCI + help + Add support for watchdog on the TI Davinci SoC. + config WATCHDOG_MXS28 bool "i.MX28" depends on ARCH_IMX28 diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 865fc477b1..1e63c493fe 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_WATCHDOG) += wd_core.o +obj-$(CONFIG_WATCHDOG_DAVINCI) += davinci_wdt.o obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o obj-$(CONFIG_WATCHDOG_JZ4740) += jz4740.o obj-$(CONFIG_WATCHDOG_IMX_RESET_SOURCE) += imxwd.o diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c new file mode 100644 index 0000000000..ecf6e89b47 --- /dev/null +++ b/drivers/watchdog/davinci_wdt.c @@ -0,0 +1,172 @@ +/* + * drivers/char/watchdog/davinci_wdt.c + * + * Watchdog driver for DaVinci DM644x/DM646x processors + * + * Copyright (C) 2006-2013 Texas Instruments. + * Copyright (C) 2015 Jan Luebbe + * + * 2007 (c) MontaVista Software, Inc. This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whether express + * or implied. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include + +/* Timer register set definition */ +#define PID12 (0x0) +#define EMUMGT (0x4) +#define TIM12 (0x10) +#define TIM34 (0x14) +#define PRD12 (0x18) +#define PRD34 (0x1C) +#define TCR (0x20) +#define TGCR (0x24) +#define WDTCR (0x28) + +/* TCR bit definitions */ +#define ENAMODE12_DISABLED (0 << 6) +#define ENAMODE12_ONESHOT (1 << 6) +#define ENAMODE12_PERIODIC (2 << 6) + +/* TGCR bit definitions */ +#define TIM12RS_UNRESET (1 << 0) +#define TIM34RS_UNRESET (1 << 1) +#define TIMMODE_64BIT_WDOG (2 << 2) + +/* WDTCR bit definitions */ +#define WDEN (1 << 14) +#define WDFLAG (1 << 15) +#define WDKEY_SEQ0 (0xa5c6 << 16) +#define WDKEY_SEQ1 (0xda7e << 16) + +/* + * struct to hold data for each WDT device + * @wd - hold watchdog device as is in WDT core + * @base - base io address of WD device + * @clk - source clock of WDT + * @timeout - previously configured timeout + */ +struct davinci_wdt { + struct watchdog wd; + void __iomem *base; + struct clk *clk; + unsigned timeout; +}; + +#define to_davinci_wdt(h) container_of(h, struct davinci_wdt, wd) + +static int davinci_wdt_start(struct watchdog *wd) +{ + u32 tgcr; + u32 timer_margin; + unsigned long wdt_freq; + struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd); + + wdt_freq = clk_get_rate(davinci_wdt->clk); + + /* disable, internal clock source */ + iowrite32(0, davinci_wdt->base + TCR); + /* reset timer, set mode to 64-bit watchdog, and unreset */ + iowrite32(0, davinci_wdt->base + TGCR); + tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET; + iowrite32(tgcr, davinci_wdt->base + TGCR); + /* clear counter regs */ + iowrite32(0, davinci_wdt->base + TIM12); + iowrite32(0, davinci_wdt->base + TIM34); + /* set timeout period */ + timer_margin = (((u64)davinci_wdt->timeout * wdt_freq) & 0xffffffff); + iowrite32(timer_margin, davinci_wdt->base + PRD12); + timer_margin = (((u64)davinci_wdt->timeout * wdt_freq) >> 32); + iowrite32(timer_margin, davinci_wdt->base + PRD34); + /* enable run continuously */ + iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR); + /* Once the WDT is in pre-active state write to + * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are + * write protected (except for the WDKEY field) + */ + /* put watchdog in pre-active state */ + iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR); + /* put watchdog in active state */ + iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR); + return 0; +} + +static int davinci_wdt_ping(struct watchdog *wd) +{ + struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd); + + /* put watchdog in service state */ + iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR); + /* put watchdog in active state */ + iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR); + return 0; +} + +static int davinci_wdt_set_timeout(struct watchdog *wd, unsigned timeout) +{ + struct davinci_wdt *davinci_wdt = to_davinci_wdt(wd); + + if (!davinci_wdt->timeout) { + davinci_wdt->timeout = timeout; + davinci_wdt_start(wd); + } else { + davinci_wdt_ping(wd); + if (davinci_wdt->timeout != timeout) + pr_warn("watchdog timeout can not be changed (currently %d)\n", + davinci_wdt->timeout); + } + + return 0; +} + +static int davinci_wdt_probe(struct device_d *dev) +{ + int ret = 0; + struct davinci_wdt *davinci_wdt; + + davinci_wdt = xzalloc(sizeof(*davinci_wdt)); + + davinci_wdt->base = dev_request_mem_region(dev, 0); + if (IS_ERR(davinci_wdt->base)) + return PTR_ERR(davinci_wdt->base); + + davinci_wdt->clk = clk_get(dev, NULL); + if (WARN_ON(IS_ERR(davinci_wdt->clk))) + return PTR_ERR(davinci_wdt->clk); + + clk_enable(davinci_wdt->clk); + + davinci_wdt->wd.set_timeout = davinci_wdt_set_timeout; + + ret = watchdog_register(&davinci_wdt->wd); + if (ret < 0) + dev_err(dev, "cannot register watchdog device\n"); + + return ret; +} + +static __maybe_unused struct of_device_id davinci_wdt_of_match[] = { + { .compatible = "ti,davinci-wdt", }, + {}, +}; + +static struct driver_d platform_wdt_driver = { + .name = "davinci-wdt", + .of_compatible = DRV_OF_COMPAT(davinci_wdt_of_match), + .probe = davinci_wdt_probe, +}; +device_platform_driver(platform_wdt_driver); + +MODULE_AUTHOR("Texas Instruments"); +MODULE_DESCRIPTION("DaVinci Watchdog Driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3