driver: timer: Add the Atmel PIT timer driver

Add the new Atmel PIT timer driver, which supports the driver model
and device tree.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>

diff --git a/arch/arm/mach-at91/arm926ejs/Makefile b/arch/arm/mach-at91/arm926ejs/Makefile
index 624ccd7c2f38fdceda9f0481f085d6615324b542..dc935fd9e543d2094d0e9862d26d6e26da0262a8 100644 (file)
--- a/arch/arm/mach-at91/arm926ejs/Makefile
+++ b/arch/arm/mach-at91/arm926ejs/Makefile
@@ -22,7 +22,9 @@ obj-y += cache.o
 obj-y += clock.o
 obj-y += cpu.o
 obj-y  += reset.o
+ifeq ($(CONFIG_ATMEL_PIT_TIMER),)
 obj-y  += timer.o
+endif
 
 ifndef CONFIG_SKIP_LOWLEVEL_INIT
 obj-y  += lowlevel_init.o

diff --git a/arch/arm/mach-at91/armv7/Makefile b/arch/arm/mach-at91/armv7/Makefile
index 9538bc1fad2a536ec28eceff761a7bbcbe9c7e5c..1ede4cb10abe9ec5bd7113652646a82af535d39a 100644 (file)
--- a/arch/arm/mach-at91/armv7/Makefile
+++ b/arch/arm/mach-at91/armv7/Makefile
@@ -14,4 +14,6 @@ obj-$(CONFIG_SAMA5D4) += sama5d4_devices.o
 obj-y += clock.o
 obj-y += cpu.o
 obj-y += reset.o
+ifeq ($(CONFIG_ATMEL_PIT_TIMER),)
 obj-y += timer.o
+endif

diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 13f122350b2f86086555230c21e2e32bb0eba4ed..6305bbf01cde236a721200cc200a2e0906949b63 100644 (file)
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -44,6 +44,14 @@ config ALTERA_TIMER
          Select this to enable a timer for Altera devices. Please find
          details on the "Embedded Peripherals IP User Guide" of Altera.
 
+config ATMEL_PIT_TIMER
+       bool "Atmel periodic interval timer support"
+       depends on TIMER
+       help
+         Select this to enable a periodic interval timer for Atmel devices,
+         it is designed to offer maximum accuracy and efficient management,
+         even for systems with long response time.
+
 config SANDBOX_TIMER
        bool "Sandbox timer support"
        depends on SANDBOX && TIMER

diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
index fa7ce7c835838eb07dc0d4c95cf1e1bf2bd7ab41..69e8961a7ba774bb0f6c6d8bf16aec53a03139ec 100644 (file)
--- a/drivers/timer/Makefile
+++ b/drivers/timer/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_ARC_TIMER)       += arc_timer.o
 obj-$(CONFIG_AG101P_TIMER) += ag101p_timer.o
 obj-$(CONFIG_AE3XX_TIMER) += ae3xx_timer.o
 obj-$(CONFIG_ROCKCHIP_TIMER) += rockchip_timer.o
+obj-$(CONFIG_ATMEL_PIT_TIMER) += atmel_pit_timer.o

diff --git a/drivers/timer/atmel_pit_timer.c b/drivers/timer/atmel_pit_timer.c
new file mode 100644 (file)
index 0000000..999717b
--- /dev/null
+++ b/drivers/timer/atmel_pit_timer.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2017 Microchip Corporation
+ *                   Wenyou.Yang <wenyou.yang@microchip.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <timer.h>
+#include <asm/io.h>
+
+#define AT91_PIT_VALUE         0xfffff
+#define AT91_PIT_PITEN         BIT(24)         /* Timer Enabled */
+
+struct atmel_pit_regs {
+       u32     mode;
+       u32     status;
+       u32     value;
+       u32     value_image;
+};
+
+struct atmel_pit_platdata {
+       struct atmel_pit_regs *regs;
+};
+
+static int atmel_pit_get_count(struct udevice *dev, u64 *count)
+{
+       struct atmel_pit_platdata *plat = dev_get_platdata(dev);
+       struct atmel_pit_regs *const regs = plat->regs;
+       u32 val = readl(&regs->value_image);
+
+       *count = timer_conv_64(val);
+
+       return 0;
+}
+
+static int atmel_pit_probe(struct udevice *dev)
+{
+       struct atmel_pit_platdata *plat = dev_get_platdata(dev);
+       struct atmel_pit_regs *const regs = plat->regs;
+       struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+       struct clk clk;
+       ulong clk_rate;
+       int ret;
+
+       ret = clk_get_by_index(dev, 0, &clk);
+       if (ret)
+               return -EINVAL;
+
+       clk_rate = clk_get_rate(&clk);
+       if (!clk_rate)
+               return -EINVAL;
+
+       uc_priv->clock_rate = clk_rate / 16;
+
+       writel(AT91_PIT_VALUE | AT91_PIT_PITEN, &regs->mode);
+
+       return 0;
+}
+
+static int atmel_pit_ofdata_to_platdata(struct udevice *dev)
+{
+       struct atmel_pit_platdata *plat = dev_get_platdata(dev);
+
+       plat->regs = (struct atmel_pit_regs *)devfdt_get_addr_ptr(dev);
+
+       return 0;
+}
+
+static const struct timer_ops atmel_pit_ops = {
+       .get_count = atmel_pit_get_count,
+};
+
+static const struct udevice_id atmel_pit_ids[] = {
+       { .compatible = "atmel,at91sam9260-pit" },
+       { }
+};
+
+U_BOOT_DRIVER(atmel_pit) = {
+       .name   = "atmel_pit",
+       .id     = UCLASS_TIMER,
+       .of_match = atmel_pit_ids,
+       .ofdata_to_platdata = atmel_pit_ofdata_to_platdata,
+       .platdata_auto_alloc_size = sizeof(struct atmel_pit_platdata),
+       .probe  = atmel_pit_probe,
+       .ops    = &atmel_pit_ops,
+       .flags  = DM_FLAG_PRE_RELOC,
+};