diff options
| -rw-r--r-- | drivers/timer/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/timer/Makefile | 1 | ||||
| -rw-r--r-- | drivers/timer/nomadik-mtu-timer.c | 114 |
3 files changed, 124 insertions, 0 deletions
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig index 96cc49273f..637024445c 100644 --- a/drivers/timer/Kconfig +++ b/drivers/timer/Kconfig @@ -127,6 +127,15 @@ config X86_TSC_TIMER_EARLY_FREQ hardware ways, nor got from device tree at the time when device tree is not available yet. +config NOMADIK_MTU_TIMER + bool "Nomadik MTU Timer" + depends on TIMER + help + Enables support for the Nomadik Multi Timer Unit (MTU), + used in ST-Ericsson Ux500 SoCs. + The MTU provides 4 decrementing free-running timers. + At the moment, only the first timer is used by the driver. + config OMAP_TIMER bool "Omap timer support" depends on TIMER diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile index fa35bea6c5..c22ffebcde 100644 --- a/drivers/timer/Makefile +++ b/drivers/timer/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_ATMEL_PIT_TIMER) += atmel_pit_timer.o obj-$(CONFIG_CADENCE_TTC_TIMER) += cadence-ttc.o obj-$(CONFIG_DESIGNWARE_APB_TIMER) += dw-apb-timer.o obj-$(CONFIG_MPC83XX_TIMER) += mpc83xx_timer.o +obj-$(CONFIG_NOMADIK_MTU_TIMER) += nomadik-mtu-timer.o obj-$(CONFIG_OMAP_TIMER) += omap-timer.o obj-$(CONFIG_RENESAS_OSTM_TIMER) += ostm_timer.o obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o diff --git a/drivers/timer/nomadik-mtu-timer.c b/drivers/timer/nomadik-mtu-timer.c new file mode 100644 index 0000000000..8648f1f1df --- /dev/null +++ b/drivers/timer/nomadik-mtu-timer.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net> + * + * Based on arch/arm/cpu/armv7/u8500/timer.c: + * Copyright (C) 2010 Linaro Limited + * John Rigby <john.rigby@linaro.org> + * + * Based on Linux kernel source and internal ST-Ericsson U-Boot source: + * Copyright (C) 2009 Alessandro Rubini + * Copyright (C) 2010 ST-Ericsson + * Copyright (C) 2010 Linus Walleij for ST-Ericsson + */ + +#include <common.h> +#include <dm.h> +#include <timer.h> +#include <asm/io.h> + +#define MTU_NUM_TIMERS 4 + +/* The timers */ +struct nomadik_mtu_timer_regs { + u32 lr; /* Load register */ + u32 cv; /* Current value */ + u32 cr; /* Control register */ + u32 bglr; /* Background load register */ +}; + +/* The MTU that contains the timers */ +struct nomadik_mtu_regs { + u32 imsc; /* Interrupt mask set/clear */ + u32 ris; /* Raw interrupt status */ + u32 mis; /* Masked interrupt status */ + u32 icr; /* Interrupt clear register */ + + struct nomadik_mtu_timer_regs timers[MTU_NUM_TIMERS]; +}; + +/* Bits for the control register */ +#define MTU_CR_ONESHOT BIT(0) /* if 0 = wraps reloading from BGLR */ +#define MTU_CR_32BITS BIT(1) /* if 0 = 16-bit counter */ + +#define MTU_CR_PRESCALE_SHIFT 2 +#define MTU_CR_PRESCALE_1 (0 << MTU_CR_PRESCALE_SHIFT) +#define MTU_CR_PRESCALE_16 (1 << MTU_CR_PRESCALE_SHIFT) +#define MTU_CR_PRESCALE_256 (2 << MTU_CR_PRESCALE_SHIFT) + +#define MTU_CR_PERIODIC BIT(6) /* if 0 = free-running */ +#define MTU_CR_ENABLE BIT(7) + +struct nomadik_mtu_priv { + struct nomadik_mtu_timer_regs *timer; +}; + +static int nomadik_mtu_get_count(struct udevice *dev, u64 *count) +{ + struct nomadik_mtu_priv *priv = dev_get_priv(dev); + + /* Decrementing counter: invert the value */ + *count = timer_conv_64(~readl(&priv->timer->cv)); + + return 0; +} + +static int nomadik_mtu_probe(struct udevice *dev) +{ + struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); + struct nomadik_mtu_priv *priv = dev_get_priv(dev); + struct nomadik_mtu_regs *mtu; + fdt_addr_t addr; + u32 prescale; + + addr = dev_read_addr(dev); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + + mtu = (struct nomadik_mtu_regs *)addr; + priv->timer = mtu->timers; /* Use first timer */ + + if (!uc_priv->clock_rate) + return -EINVAL; + + /* Use divide-by-16 counter if tick rate is more than 32 MHz */ + if (uc_priv->clock_rate > 32000000) { + uc_priv->clock_rate /= 16; + prescale = MTU_CR_PRESCALE_16; + } else { + prescale = MTU_CR_PRESCALE_1; + } + + /* Configure a free-running, auto-wrap counter with selected prescale */ + writel(MTU_CR_ENABLE | prescale | MTU_CR_32BITS, &priv->timer->cr); + + return 0; +} + +static const struct timer_ops nomadik_mtu_ops = { + .get_count = nomadik_mtu_get_count, +}; + +static const struct udevice_id nomadik_mtu_ids[] = { + { .compatible = "st,nomadik-mtu" }, + {} +}; + +U_BOOT_DRIVER(nomadik_mtu) = { + .name = "nomadik_mtu", + .id = UCLASS_TIMER, + .of_match = nomadik_mtu_ids, + .priv_auto_alloc_size = sizeof(struct nomadik_mtu_priv), + .probe = nomadik_mtu_probe, + .ops = &nomadik_mtu_ops, +}; |