dm: implement a Timer uclass

Implement a Timer uclass to work with lib/time.c.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/Kconfig b/drivers/Kconfig
index c02f3231e07f753a365eb3ea235d64e9cf912a4b..ba88b5ea3710a6716afe762916fce6b3f0a72fce 100644 (file)
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -58,6 +58,8 @@ 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 1a30ad1d147b54bb438b31ce5cec38ae1cac9955..4f49bfddb861afdc16c8679b42ea30550a504adb 100644 (file)
--- 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 (file)
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 (file)
index 0000000..afb0009
--- /dev/null
+++ b/drivers/timer/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2015 Thomas Chou <thomas@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 (file)
index 0000000..12aee5b
--- /dev/null
+++ b/drivers/timer/timer-uclass.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 Thomas Chou <thomas@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 21552650025a108f4136267e4c63ea01584ea34c..d0383f3d7693bebbd8e757a5027e7c9fb26a721c 100644 (file)
--- 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 da41499872483a669ba66ceb3fb320e8daebb490..330ecd2388a5d480493965af3e2c3974d2dd9cce 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -57,6 +57,7 @@ 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 (file)
index 0000000..cdf385d
--- /dev/null
+++ b/include/timer.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 Thomas Chou <thomas@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 477440de16faa3319852a6119935628f63aa8531..b001745203e85c2c6f944e5d470291660eae0af6 100644 (file)
--- 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 dm_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 = dm_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 = dm_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();