[U-Boot] [PATCH v2 06/10] timer: Add MPC83xx timer driver
Simon Glass
sjg at chromium.org
Mon Apr 30 23:13:18 UTC 2018
Hi Mario,
On 27 April 2018 at 06:52, Mario Six <mario.six at gdsys.cc> wrote:
> Add a timer driver for the MPC83xx architecture.
>
> Signed-off-by: Mario Six <mario.six at gdsys.cc>
>
> ---
>
> v1 -> v2:
> * Removed now-superfluous comments
> * Removed usage of uclass_{first,next}_device_compat
> * Switched to usage of new board uclass (instead of devinfo)
>
> ---
> arch/powerpc/cpu/mpc83xx/cpu.c | 4 +-
> arch/powerpc/lib/Makefile | 4 ++
> arch/powerpc/lib/interrupts.c | 5 +-
> drivers/timer/Kconfig | 7 ++
> drivers/timer/Makefile | 1 +
> drivers/timer/mpc83xx_timer.c | 160 +++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 178 insertions(+), 3 deletions(-)
> create mode 100644 drivers/timer/mpc83xx_timer.c
Reviewed-by: Simon Glass <sjg at chromium.org>
Please see below.
>
> diff --git a/arch/powerpc/cpu/mpc83xx/cpu.c b/arch/powerpc/cpu/mpc83xx/cpu.c
> index 9a5c1b7d55..376483eda7 100644
> --- a/arch/powerpc/cpu/mpc83xx/cpu.c
> +++ b/arch/powerpc/cpu/mpc83xx/cpu.c
> @@ -176,12 +176,12 @@ do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
> /*
> * Get timebase clock frequency (like cpu_clk in Hz)
> */
> -
> +#ifndef CONFIG_TIMER
> unsigned long get_tbclk(void)
> {
> return (gd->bus_clk + 3L) / 4L;
> }
> -
> +#endif
>
> #if defined(CONFIG_WATCHDOG)
> void watchdog_reset (void)
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
> index 9a3043abf8..537693e3bc 100644
> --- a/arch/powerpc/lib/Makefile
> +++ b/arch/powerpc/lib/Makefile
> @@ -19,13 +19,17 @@ endif
>
> ifdef MINIMAL
> obj-y += cache.o time.o
> +ifndef CONFIG_TIMER
> obj-y += ticks.o
> +endif
> else
>
> obj-y += ppcstring.o
>
> obj-y += ppccache.o
> +ifndef CONFIG_TIMER
> obj-y += ticks.o
> +endif
> obj-y += reloc.o
>
> obj-$(CONFIG_BAT_RW) += bat_rw.o
> diff --git a/arch/powerpc/lib/interrupts.c b/arch/powerpc/lib/interrupts.c
> index e8784aa16e..56a697d28c 100644
> --- a/arch/powerpc/lib/interrupts.c
> +++ b/arch/powerpc/lib/interrupts.c
> @@ -15,6 +15,7 @@
> #include <status_led.h>
> #endif
>
> +#ifndef CONFIG_MPC83XX_TIMER
> #ifdef CONFIG_SHOW_ACTIVITY
> void board_show_activity (ulong) __attribute__((weak, alias("__board_show_activity")));
>
> @@ -45,7 +46,7 @@ static __inline__ void set_dec (unsigned long val)
> if (val)
> asm volatile ("mtdec %0"::"r" (val));
> }
> -
> +#endif /* !CONFIG_MPC83XX_TIMER */
>
> void enable_interrupts (void)
> {
> @@ -61,6 +62,7 @@ int disable_interrupts (void)
> return ((msr & MSR_EE) != 0);
> }
>
> +#ifndef CONFIG_MPC83XX_TIMER
> int interrupt_init (void)
> {
> /* call cpu specific function from $(CPU)/interrupts.c */
> @@ -103,3 +105,4 @@ ulong get_timer (ulong base)
> {
> return (timestamp - base);
> }
> +#endif /* !CONFIG_MPC83XX_TIMER */
> diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
> index 2c96896726..1b78ce784a 100644
> --- a/drivers/timer/Kconfig
> +++ b/drivers/timer/Kconfig
> @@ -126,4 +126,11 @@ config STM32_TIMER
> Select this to enable support for the timer found on
> STM32 devices.
>
> +config MPC83XX_TIMER
> + bool "MPC83xx timer support"
> + depends on TIMER
> + help
> + Select this to enable support for the timer found on
> + devices based on the MPC83xx family of SoCs.
> +
> endmenu
> diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
> index a6e7832154..d35d235195 100644
> --- a/drivers/timer/Makefile
> +++ b/drivers/timer/Makefile
> @@ -17,3 +17,4 @@ obj-$(CONFIG_ATCPIT100_TIMER) += atcpit100_timer.o
> obj-$(CONFIG_ROCKCHIP_TIMER) += rockchip_timer.o
> obj-$(CONFIG_ATMEL_PIT_TIMER) += atmel_pit_timer.o
> obj-$(CONFIG_STM32_TIMER) += stm32_timer.o
> +obj-$(CONFIG_MPC83XX_TIMER) += mpc83xx_timer.o
> diff --git a/drivers/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c
> new file mode 100644
> index 0000000000..c3dd306c5b
> --- /dev/null
> +++ b/drivers/timer/mpc83xx_timer.c
> @@ -0,0 +1,160 @@
> +/*
> + * (C) Copyright 2018
> + * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <clk.h>
> +#include <timer.h>
> +#include <watchdog.h>
> +#include <board.h>
> +
> +struct mpc83xx_timer_priv {
> +};
> +
> +static uint decrementer_count; /* count value for 1e6/HZ microseconds */
Have a static var in BSS means it cannot be used before relocation, or
in SPL, right?
> +
> +static inline unsigned long get_dec(void)
> +{
> + unsigned long val;
> +
> + asm volatile ("mfdec %0":"=r" (val):);
> +
> + return val;
> +}
> +
> +static inline void set_dec(unsigned long val)
> +{
> + if (val)
> + asm volatile ("mtdec %0"::"r" (val));
> +}
> +
> +/* TODO(mario.six at gdsys.cc): This should really be done by timer_init, and the
> + * interrupt init should go into a interrupt driver.
> + */
> +int interrupt_init(void)
> +{
> + immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
> + struct udevice *csb;
> + struct udevice *board;
> + struct clk clock;
> +
> + if (get_board(&board))
debug() ?
> + return -ENOENT;
> +
> + uclass_get_device_by_phandle(UCLASS_SIMPLE_BUS, board, "csb", &csb);
> + clk_get_by_index(csb, 0, &clock);
error checking
> +
> + decrementer_count = (clk_get_rate(&clock) / 4) / CONFIG_SYS_HZ;
> +
> + /* Enable e300 time base */
> +
Drop blank line
> + setbits_be32(&immr->sysconf.spcr, 0x00400000);
> +
> + set_dec(decrementer_count);
> +
> + set_msr(get_msr() | MSR_EE);
> +
> + return 0;
> +}
> +
> +static volatile ulong timestamp = 0;
> +
> +void timer_interrupt(struct pt_regs *regs)
> +{
> + /* Restore Decrementer Count */
> + set_dec(decrementer_count);
> +
> + timestamp++;
> +
> +#if defined(CONFIG_WATCHDOG) || defined(CONFIG_HW_WATCHDOG)
> + if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
> + WATCHDOG_RESET();
> +#endif /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
> +
> +#ifdef CONFIG_LED_STATUS
> + status_led_tick(timestamp);
> +#endif /* CONFIG_LED_STATUS */
> +
> +#ifdef CONFIG_SHOW_ACTIVITY
> + board_show_activity(timestamp);
> +#endif /* CONFIG_SHOW_ACTIVITY */
> +}
> +
> +ulong get_timer(ulong base)
> +{
> + return (timestamp - base);
> +}
> +
> +static inline u32 mftbu(void)
> +{
> + u32 rval;
> +
> + asm volatile("mftbu %0" : "=r" (rval));
> + return rval;
> +}
> +
> +static inline u32 mftb(void)
> +{
> + u32 rval;
> +
> + asm volatile("mftb %0" : "=r" (rval));
> + return rval;
> +}
> +
> +void wait_ticks(ulong ticks)
> +{
> + ulong end = get_ticks() + ticks;
> +
> + while (end > get_ticks())
> + WATCHDOG_RESET();
> +}
> +
> +static int mpc83xx_timer_get_count(struct udevice *dev, u64 *count)
> +{
> + u32 tbu, tbl;
> +
> + do {
> + tbu = mftbu();
> + tbl = mftb();
> + } while (tbu != mftbu());
> +
> + *count = (tbu * 0x10000ULL) + tbl;
> +
> + return 0;
> +}
> +
> +static int mpc83xx_timer_probe(struct udevice *dev)
> +{
> + struct timer_dev_priv *uc_priv = dev->uclass_priv;
> + struct clk clock;
> +
> + interrupt_init();
> +
> + clk_get_by_index(dev, 0, &clock);
> +
> + uc_priv->clock_rate = (clk_get_rate(&clock) + 3L) / 4L;
> +
> + return 0;
> +}
> +
> +static const struct timer_ops mpc83xx_timer_ops = {
> + .get_count = mpc83xx_timer_get_count,
> +};
> +
> +static const struct udevice_id mpc83xx_timer_ids[] = {
> + { .compatible = "fsl,mpc83xx-timer" },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(mpc83xx_timer) = {
> + .name = "mpc83xx_timer",
> + .id = UCLASS_TIMER,
> + .of_match = mpc83xx_timer_ids,
> + .probe = mpc83xx_timer_probe,
> + .ops = &mpc83xx_timer_ops,
> + .flags = DM_FLAG_PRE_RELOC,
> +};
> --
> 2.16.1
>
Regards,
Simon
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