diff options
Diffstat (limited to 'drivers/timer/arm_twd_timer.c')
| -rw-r--r-- | drivers/timer/arm_twd_timer.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/timer/arm_twd_timer.c b/drivers/timer/arm_twd_timer.c new file mode 100644 index 00000000000..2b2f3591173 --- /dev/null +++ b/drivers/timer/arm_twd_timer.c @@ -0,0 +1,107 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2017-2022 Weidmüller Interface GmbH & Co. KG + * Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com> + * + * Copyright (C) 2012 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2011-2017 Xilinx, Inc. All rights reserved. + * + * (C) Copyright 2008 + * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de> + * + * (C) Copyright 2004 + * Philippe Robin, ARM Ltd. <philippe.robin@arm.com> + * + * (C) Copyright 2002-2004 + * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> + * + * (C) Copyright 2003 + * Texas Instruments <www.ti.com> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + */ + +#include <dm.h> +#include <fdtdec.h> +#include <timer.h> +#include <linux/bitops.h> + +#include <asm/io.h> + +#define SCUTIMER_CONTROL_PRESCALER_MASK 0x0000FF00 /* Prescaler */ +#define SCUTIMER_CONTROL_AUTO_RELOAD_MASK 0x00000002 /* Auto-reload */ +#define SCUTIMER_CONTROL_ENABLE_MASK 0x00000001 /* Timer enable */ + +#define TIMER_LOAD_VAL 0xFFFFFFFF + +struct arm_twd_timer_regs { + u32 load; /* Timer Load Register */ + u32 counter; /* Timer Counter Register */ + u32 control; /* Timer Control Register */ +}; + +struct arm_twd_timer_priv { + struct arm_twd_timer_regs *base; +}; + +static u64 arm_twd_timer_get_count(struct udevice *dev) +{ + struct arm_twd_timer_priv *priv = dev_get_priv(dev); + struct arm_twd_timer_regs *regs = priv->base; + u32 count = TIMER_LOAD_VAL - readl(®s->counter); + + return timer_conv_64(count); +} + +static int arm_twd_timer_probe(struct udevice *dev) +{ + struct arm_twd_timer_priv *priv = dev_get_priv(dev); + struct arm_twd_timer_regs *regs; + fdt_addr_t addr; + + addr = dev_read_addr(dev); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + + priv->base = (struct arm_twd_timer_regs *)addr; + + regs = priv->base; + + /* Load the timer counter register */ + writel(0xFFFFFFFF, ®s->load); + + /* + * Start the A9Timer device + * Enable Auto reload mode, Clear prescaler control bits + * Set prescaler value, Enable the decrementer + */ + clrsetbits_le32(®s->control, SCUTIMER_CONTROL_PRESCALER_MASK, + SCUTIMER_CONTROL_AUTO_RELOAD_MASK | + SCUTIMER_CONTROL_ENABLE_MASK); + + return 0; +} + +static const struct timer_ops arm_twd_timer_ops = { + .get_count = arm_twd_timer_get_count, +}; + +static const struct udevice_id arm_twd_timer_ids[] = { + { .compatible = "arm,cortex-a9-twd-timer" }, + {} +}; + +U_BOOT_DRIVER(arm_twd_timer) = { + .name = "arm_twd_timer", + .id = UCLASS_TIMER, + .of_match = arm_twd_timer_ids, + .priv_auto = sizeof(struct arm_twd_timer_priv), + .probe = arm_twd_timer_probe, + .ops = &arm_twd_timer_ops, +}; |