[U-Boot] [PATCH v2 06/10] timer: Add MPC83xx timer driver
Mario Six
mario.six at gdsys.cc
Fri Apr 27 12:52:23 UTC 2018
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
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 */
+
+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))
+ return -ENOENT;
+
+ uclass_get_device_by_phandle(UCLASS_SIMPLE_BUS, board, "csb", &csb);
+ clk_get_by_index(csb, 0, &clock);
+
+ decrementer_count = (clk_get_rate(&clock) / 4) / CONFIG_SYS_HZ;
+
+ /* Enable e300 time base */
+
+ 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
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