introducing chip variant for stm32 family [1/3]

just rename STM32L to STM32.
Most of the STM32L15x code is common with STM32F1xx.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BUG=chrome-os-partner:9057
TEST=make BOARD=daisy ; make BOARD=adv ; make BOARD=discovery

Change-Id: I819eff5fcd23deff57f5f6dedcf37e6c421b96c2

1 files changed, 73 insertions, 0 deletions

diff --git a/chip/stm32/watchdog.c b/chip/stm32/watchdog.c
new file mode 100644
index 0000000000..9a2d76a422
--- /dev/null
+++ b/chip/stm32/watchdog.c
@@ -0,0 +1,73 @@
+/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Watchdog driver */
+
+#include "board.h"
+#include "common.h"
+#include "config.h"
+#include "registers.h"
+#include "gpio.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+
+/* LSI oscillator frequency is typically 38 kHz
+ * but might vary from 28 to 56kHz.
+ * So let's pick 56kHz to ensure we reload
+ * early enough.
+ */
+#define LSI_CLOCK 56000
+
+/* Prescaler divider = /256 */
+#define IWDG_PRESCALER 6
+#define IWDG_PRESCALER_DIV (1 << ((IWDG_PRESCALER) + 2))
+
+
+void watchdog_reload(void)
+{
+	/* Reload the watchdog */
+	STM32_IWDG_KR = 0xaaaa;
+}
+
+
+int watchdog_init(int period_ms)
+{
+	uint32_t watchdog_period;
+
+	/* set the time-out period */
+	watchdog_period = period_ms * (LSI_CLOCK / IWDG_PRESCALER_DIV) / 1000;
+
+	/* Unlock watchdog registers */
+	STM32_IWDG_KR = 0x5555;
+
+	/* Set the prescaler between the LSI clock and the watchdog counter */
+	STM32_IWDG_PR = IWDG_PRESCALER & 7;
+	/* Set the reload value of the watchdog counter */
+	STM32_IWDG_RLR = watchdog_period & 0x7FF ;
+
+	/* Start the watchdog (and re-lock registers) */
+	STM32_IWDG_KR = 0xcccc;
+
+	return EC_SUCCESS;
+}
+
+
+/* Low priority task to reload the watchdog */
+void watchdog_task(void)
+{
+	while (1) {
+#ifdef BOARD_discovery
+		gpio_set_level(GPIO_GREEN_LED, 1);
+#endif
+		usleep(500000);
+		watchdog_reload();
+#ifdef BOARD_discovery
+		gpio_set_level(GPIO_GREEN_LED, 0);
+#endif
+		usleep(500000);
+		watchdog_reload();
+	}
+}