This watchdog is always enabled after reset and can be configured only once.
Signed-off-by: Juergen Borleis <[email protected]> --- drivers/watchdog/Kconfig | 6 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/mpc5125.c | 148 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 155 insertions(+) create mode 100644 drivers/watchdog/mpc5125.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 7f7b02e..4c57111 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -28,4 +28,10 @@ config WATCHDOG_JZ4740 help Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs. +config WATCHDOG_MPC5125 + bool "MPC5125 SoC hardware watchdog" + depends on SOC_MPC5125 + help + Hardware driver for the built-in watchdog timer on MPC5125 SoCs. + endif diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 865fc47..b7aa549 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_WATCHDOG) += wd_core.o obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o obj-$(CONFIG_WATCHDOG_JZ4740) += jz4740.o obj-$(CONFIG_WATCHDOG_IMX_RESET_SOURCE) += imxwd.o +obj-$(CONFIG_WATCHDOG_MPC5125) += mpc5125.o diff --git a/drivers/watchdog/mpc5125.c b/drivers/watchdog/mpc5125.c new file mode 100644 index 0000000..7fefa21 --- /dev/null +++ b/drivers/watchdog/mpc5125.c @@ -0,0 +1,148 @@ +/* + * (c) 2014 Juergen Borleis <[email protected]> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Note: this driver works for the MPC5125. It might work for the + * MPC512X SoCs as well, but is not tested yet. + */ +#include <common.h> +#include <init.h> +#include <io.h> +#include <errno.h> +#include <malloc.h> +#include <watchdog.h> +#include <mach/clocks.h> + +/* WD register description */ +struct wdt { + u32 res0; + u32 swcrr; /* note: read often, write once */ + u32 swcnr; + u16 res1; + u16 swsrr; +}; + +struct mpc5125_wd { + struct watchdog wd; + struct wdt *regs; + bool re_configured; +}; + +#define WDT_SWCRR_GET_SWTC(x) ((x) >> 16) +#define WDT_SWCRR_SET_SWTC(x) ((x) << 16) +#define WDT_SWCRR_SWEN (1 << 2) +#define WDT_SWCRR_SWRI (1 << 1) +#define WDT_SWCRR_SWPR (1 << 0) + +#define MPC5125_WDT_RESET1_MAGIC 0x556c +#define MPC5125_WDT_RESET2_MAGIC 0xaa39 + +#define MPC5125_WDT_PRESCALE 0x10000 + +#define to_mpc5125_wd(h) container_of(h, struct mpc5125_wd, wd) + +static void mpc5125_wd_retrigger(struct mpc5125_wd *wd) +{ + out_be16(&wd->regs->swsrr, 0x556c); + out_be16(&wd->regs->swsrr, 0xaa39); +} + +/* note: setting a new timeout is an irreversible step! */ +static int mpc5125_watchdog_set_timeout(struct watchdog *wd, unsigned timeout) +{ + struct mpc5125_wd *pwd = (struct mpc5125_wd *)to_mpc5125_wd(wd); + unsigned cnt_val, time; + uint64_t new_cnt_val; + u32 swcrr; + + /* + * what does the user wants us to do? + * - just retrigger? + * - or re-programming to a different timout value? + * + * Due to the fact we can program the SWCRR register only once we + * must detect a difference between the given timeout and the time + * which is currently in use to have the latter case. + * If the given timeout is "nealy" the same then currently used, just + * a re-trigger should occure (first case). + */ + swcrr = in_be32(&pwd->regs->swcrr); + cnt_val = WDT_SWCRR_GET_SWTC(swcrr); + + if (swcrr & WDT_SWCRR_SWPR) + time = (cnt_val * MPC5125_WDT_PRESCALE) / get_timebase_clock(); + else + time = cnt_val / get_timebase_clock(); + + if (time != timeout) { + /* it seems the user wants a new timout value */ + if (pwd->re_configured) { + pr_err("Cannot configure the watchdog twice. " + "Still sticked to %u seconds.\n", time); + return -EINVAL; + } + /* + * we always need the prescaler enabled, because without it + * the timeout is far below a second... + */ + new_cnt_val = timeout * get_timebase_clock(); + if (new_cnt_val >= 0xffff0000) { + time = 0xffff0000 / get_timebase_clock(); + pr_err("Invalid timout value. Max value is " + "%u seconds.\n", time); + return -EINVAL; + } + new_cnt_val /= MPC5125_WDT_PRESCALE; + out_be32(&pwd->regs->swcrr, WDT_SWCRR_SET_SWTC(new_cnt_val) | + WDT_SWCRR_SWPR | WDT_SWCRR_SWEN | WDT_SWCRR_SWRI); + pwd->re_configured = true; + } + + mpc5125_wd_retrigger(pwd); + + return 0; +} + +static int mpc5125_wd_probe(struct device_d *dev) +{ + struct mpc5125_wd *priv; + int rc; + + priv = xzalloc(sizeof(struct mpc5125_wd)); + priv->regs = dev_request_mem_region(dev, 0); + priv->wd.set_timeout = mpc5125_watchdog_set_timeout; + + rc = watchdog_register(&priv->wd); + if (rc != 0) + goto on_error; + + dev->priv = priv; + return 0; + +on_error: + free(priv); + return rc; +} + +static void mpc5125_wd_remove(struct device_d *dev) +{ + struct mpc5125_wd *priv= dev->priv; + watchdog_deregister(&priv->wd); + free(priv); +} + +static struct driver_d mpc5125_wd_driver = { + .name = "mpc5125wd", + .probe = mpc5125_wd_probe, + .remove = mpc5125_wd_remove, +}; +device_platform_driver(mpc5125_wd_driver); -- 2.1.0 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
