[U-Boot] [PATCH v6 1/3] dm: implement a Timer uclass
Thomas Chou
thomas at wytron.com.tw
Fri Oct 9 03:17:55 CEST 2015
Implement a Timer uclass to work with lib/time.c.
Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
Acked-by: Simon Glass <sjg at chromium.org>
---
v2
fix coding style.
v3
add description to Kconfig as Simon suggested.
move timer.c code to lib/time.c.
add dm_timer dev to global data.
remove timer_init().
change API name get_clock.
v4
add comment about timer hardware.
v5
revert to get_rate and use uclass priv to store the clock_rate.
split gd->dm_timer renewal to anohter patch.
v6
rename to CONFIG_TIMER as Simon suggested.
drivers/Kconfig | 2 ++
drivers/Makefile | 1 +
drivers/timer/Kconfig | 12 +++++++++
drivers/timer/Makefile | 7 ++++++
drivers/timer/timer-uclass.c | 42 +++++++++++++++++++++++++++++++
include/asm-generic/global_data.h | 3 +++
include/dm/uclass-id.h | 1 +
include/timer.h | 52 +++++++++++++++++++++++++++++++++++++++
lib/time.c | 49 ++++++++++++++++++++++++++++++++++++
9 files changed, 169 insertions(+)
create mode 100644 drivers/timer/Kconfig
create mode 100644 drivers/timer/Makefile
create mode 100644 drivers/timer/timer-uclass.c
create mode 100644 include/timer.h
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 63c92c5..f9496f7 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -56,6 +56,8 @@ source "drivers/spi/Kconfig"
source "drivers/thermal/Kconfig"
+source "drivers/timer/Kconfig"
+
source "drivers/tpm/Kconfig"
source "drivers/usb/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 9d0a595..692da78 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -48,6 +48,7 @@ obj-y += pcmcia/
obj-y += dfu/
obj-y += rtc/
obj-y += sound/
+obj-y += timer/
obj-y += tpm/
obj-y += twserial/
obj-y += video/
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
new file mode 100644
index 0000000..8e8d600
--- /dev/null
+++ b/drivers/timer/Kconfig
@@ -0,0 +1,12 @@
+menu "Timer Support"
+
+config TIMER
+ bool "Enable Driver Model for Timer drivers"
+ depends on DM
+ help
+ Enable driver model for Timer access. It uses the same API as
+ lib/time.c. But now implemented by the uclass. The first timer
+ will be used. The timer is usually a 32 bits free-running up
+ counter. There may be no real tick, and no timer interrupt.
+
+endmenu
diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
new file mode 100644
index 0000000..afb0009
--- /dev/null
+++ b/drivers/timer/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2015 Thomas Chou <thomas at wytron.com.tw>
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-$(CONFIG_TIMER) += timer-uclass.o
diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
new file mode 100644
index 0000000..ed7ebd6
--- /dev/null
+++ b/drivers/timer/timer-uclass.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 Thomas Chou <thomas at wytron.com.tw>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <timer.h>
+
+/*
+ * Implement a Timer uclass to work with lib/time.c. The timer is usually
+ * a 32 bits free-running up counter. The get_rate() method is used to get
+ * the input clock frequency of the timer. The get_count() method is used
+ * get the current 32 bits count value. If the hardware is counting down,
+ * the value should be inversed inside the method. There may be no real
+ * tick, and no timer interrupt.
+ */
+
+int timer_get_count(struct udevice *dev, unsigned long *count)
+{
+ const struct TIMER_ops *ops = device_get_ops(dev);
+
+ if (!ops->get_count)
+ return -ENOSYS;
+
+ return ops->get_count(dev, count);
+}
+
+unsigned long timer_get_rate(struct udevice *dev)
+{
+ struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+ return uc_priv->clock_rate;
+}
+
+UCLASS_DRIVER(timer) = {
+ .id = UCLASS_TIMER,
+ .name = "timer",
+ .per_device_auto_alloc_size = sizeof(struct timer_dev_priv),
+};
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 2155265..4d109fb 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -69,6 +69,9 @@ typedef struct global_data {
struct udevice *dm_root_f; /* Pre-relocation root instance */
struct list_head uclass_root; /* Head of core tree */
#endif
+#ifdef CONFIG_TIMER
+ struct udevice *TIMER; /* Timer instance for Driver Model */
+#endif
const void *fdt_blob; /* Our device tree, NULL if none */
void *new_fdt; /* Relocated FDT */
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 1eeec74..aff34a4 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -56,6 +56,7 @@ enum uclass_id {
UCLASS_SPI_GENERIC, /* Generic SPI flash target */
UCLASS_SYSCON, /* System configuration device */
UCLASS_THERMAL, /* Thermal sensor */
+ UCLASS_TIMER, /* Timer device */
UCLASS_TPM, /* Trusted Platform Module TIS interface */
UCLASS_USB, /* USB bus */
UCLASS_USB_DEV_GENERIC, /* USB generic device */
diff --git a/include/timer.h b/include/timer.h
new file mode 100644
index 0000000..677b360
--- /dev/null
+++ b/include/timer.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 Thomas Chou <thomas at wytron.com.tw>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef _TIMER_H_
+#define _TIMER_H_
+
+/*
+ * Get the current timer count
+ *
+ * @dev: The Timer device
+ * @count: pointer that returns the current timer count
+ * @return: 0 if OK, -ve on error
+ */
+int timer_get_count(struct udevice *dev, unsigned long *count);
+/*
+ * Get the timer input clock frequency
+ *
+ * @dev: The Timer device
+ * @return: the timer input clock frequency
+ */
+unsigned long timer_get_rate(struct udevice *dev);
+
+/*
+ * struct TIMER_ops - Driver model Timer operations
+ *
+ * The uclass interface is implemented by all Timer devices which use
+ * driver model.
+ */
+struct TIMER_ops {
+ /*
+ * Get the current timer count
+ *
+ * @dev: The Timer device
+ * @count: pointer that returns the current timer count
+ * @return: 0 if OK, -ve on error
+ */
+ int (*get_count)(struct udevice *dev, unsigned long *count);
+};
+
+/*
+ * struct timer_dev_priv - information about a device used by the uclass
+ *
+ * @clock_rate: the timer input clock frequency
+ */
+struct timer_dev_priv {
+ unsigned long clock_rate;
+};
+
+#endif /* _TIMER_H_ */
diff --git a/lib/time.c b/lib/time.c
index 477440d..8665e6e 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -6,6 +6,9 @@
*/
#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <timer.h>
#include <watchdog.h>
#include <div64.h>
#include <asm/io.h>
@@ -37,6 +40,52 @@ unsigned long notrace timer_read_counter(void)
extern unsigned long __weak timer_read_counter(void);
#endif
+#ifdef CONFIG_TIMER
+static int notrace TIMER_init(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ if (!gd->TIMER) {
+ ret = uclass_first_device(UCLASS_TIMER, &dev);
+ if (ret)
+ return ret;
+ if (!dev)
+ return -ENODEV;
+ gd->TIMER = dev;
+ }
+
+ return 0;
+}
+
+ulong notrace get_tbclk(void)
+{
+ int ret;
+
+ ret = TIMER_init();
+ if (ret)
+ return ret;
+
+ return timer_get_rate(gd->TIMER);
+}
+
+unsigned long notrace timer_read_counter(void)
+{
+ unsigned long count;
+ int ret;
+
+ ret = TIMER_init();
+ if (ret)
+ return ret;
+
+ ret = timer_get_count(gd->TIMER, &count);
+ if (ret)
+ return ret;
+
+ return count;
+}
+#endif /* CONFIG_TIMER */
+
uint64_t __weak notrace get_ticks(void)
{
unsigned long now = timer_read_counter();
--
2.1.4
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