Hi Simon,
On Tue, May 1, 2018 at 1:13 AM, Simon Glass <s...@chromium.org> wrote:
> Hi Mario,
>
> On 27 April 2018 at 06:52, Mario Six <mario....@gdsys.cc> wrote:
>> Add a timer driver for the MPC83xx architecture.
>>
>> Signed-off-by: Mario Six <mario....@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 <s...@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....@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?
>
True; same with the timestamp variable a bit below. I copied that part verbatim
from arch/powerpc/lib/interrupts.c, so that's a general problem with the
powerpc arch. I see that x86 keeps, e.g. the clock rate in the global data. I
think this might be a way around this (two ulongs will hopefully still fit in
the GD).
>> +
>> +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....@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() ?
>
Indeed; will be fixed in v3.
>> + return -ENOENT;
>> +
>> + uclass_get_device_by_phandle(UCLASS_SIMPLE_BUS, board, "csb", &csb);
>> + clk_get_by_index(csb, 0, &clock);
>
> error checking
>
Will be fixed in v3.
>> +
>> + decrementer_count = (clk_get_rate(&clock) / 4) / CONFIG_SYS_HZ;
>> +
>> + /* Enable e300 time base */
>> +
>
> Drop blank line
>
Will be fixed in v3.
>> + 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
Best regards,
Mario
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