1 files changed, 146 insertions, 0 deletions
diff --git a/chip/stm32/usart-stm32f0.c b/chip/stm32/usart-stm32f0.c
new file mode 100644
index 0000000000..d0688d4d9e
--- /dev/null
+++ b/chip/stm32/usart-stm32f0.c
@@ -0,0 +1,146 @@
+/* Copyright (c) 2014 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.
+ */
+#include "usart-stm32f0.h"
+
+#include "common.h"
+#include "hooks.h"
+#include "registers.h"
+#include "task.h"
+#include "util.h"
+
+/*
+ * This configs array stores the currently active usart_config structure for
+ * each USART, an entry will be NULL if no USART driver is initialized for the
+ * corresponding hardware instance.
+ */
+static struct usart_config const *configs[STM32_USARTS_MAX];
+
+static void usart_variant_enable(struct usart_config const *config)
+{
+	/*
+	 * Make sure we register this config before enabling the HW.
+	 * If we did it the other way around the FREQ_CHANGE hook could be
+	 * called before we update the configs array and we would miss the
+	 * clock frequency change event, leaving our baud rate divisor wrong.
+	 */
+	configs[config->hw->index] = config;
+
+	usart_set_baud_f0_l(config);
+
+	task_enable_irq(config->hw->irq);
+}
+
+static void usart_variant_disable(struct usart_config const *config)
+{
+	int index = config->hw->index;
+
+	/*
+	 * Only disable the shared interupt for USART3/4 if both USARTs are
+	 * now disabled.
+	 */
+	if ((index == 0) ||
+	    (index == 1) ||
+	    (index == 2 && configs[3] == NULL) ||
+	    (index == 3 && configs[2] == NULL))
+		task_disable_irq(config->hw->irq);
+
+	configs[index] = NULL;
+}
+
+static struct usart_hw_ops const usart_variant_hw_ops = {
+	.enable  = usart_variant_enable,
+	.disable = usart_variant_disable,
+};
+
+static void freq_change(void)
+{
+	size_t	i;
+
+	for (i = 0; i < ARRAY_SIZE(configs); ++i)
+		if (configs[i])
+			usart_set_baud_f0_l(configs[i]);
+}
+
+DECLARE_HOOK(HOOK_FREQ_CHANGE, freq_change, HOOK_PRIO_DEFAULT);
+
+/*
+ * USART interrupt bindings.  These functions can not be defined as static or
+ * they will be removed by the linker because of the way that DECLARE_IRQ works.
+ */
+#if defined(CONFIG_STREAM_USART1)
+struct usart_hw_config const usart1_hw = {
+	.index          = 0,
+	.base           = STM32_USART1_BASE,
+	.irq            = STM32_IRQ_USART1,
+	.clock_register = &STM32_RCC_APB2ENR,
+	.clock_enable   = STM32_RCC_PB2_USART1,
+	.ops            = &usart_variant_hw_ops,
+};
+
+void usart1_interrupt(void)
+{
+	usart_interrupt(configs[0]);
+}
+
+DECLARE_IRQ(STM32_IRQ_USART1, usart1_interrupt, 2);
+#endif
+
+#if defined(CONFIG_STREAM_USART2)
+struct usart_hw_config const usart2_hw = {
+	.index          = 1,
+	.base           = STM32_USART2_BASE,
+	.irq            = STM32_IRQ_USART2,
+	.clock_register = &STM32_RCC_APB1ENR,
+	.clock_enable   = STM32_RCC_PB1_USART2,
+	.ops            = &usart_variant_hw_ops,
+};
+
+void usart2_interrupt(void)
+{
+	usart_interrupt(configs[1]);
+}
+
+DECLARE_IRQ(STM32_IRQ_USART2, usart2_interrupt, 2);
+#endif
+
+#if defined(CONFIG_STREAM_USART3)
+struct usart_hw_config const usart3_hw = {
+	.index          = 2,
+	.base           = STM32_USART3_BASE,
+	.irq            = STM32_IRQ_USART3_4,
+	.clock_register = &STM32_RCC_APB1ENR,
+	.clock_enable   = STM32_RCC_PB1_USART3,
+	.ops            = &usart_variant_hw_ops,
+};
+#endif
+
+#if defined(CONFIG_STREAM_USART4)
+struct usart_hw_config const usart4_hw = {
+	.index          = 3,
+	.base           = STM32_USART4_BASE,
+	.irq            = STM32_IRQ_USART3_4,
+	.clock_register = &STM32_RCC_APB1ENR,
+	.clock_enable   = STM32_RCC_PB1_USART4,
+	.ops            = &usart_variant_hw_ops,
+};
+#endif
+
+#if defined(CONFIG_STREAM_USART3) || defined(CONFIG_STREAM_USART4)
+void usart3_4_interrupt(void)
+{
+	/*
+	 * This interrupt handler could be called with one of these configs
+	 * not initialized, so we need to check here and only call the generic
+	 * USART interrupt handler for initialized configs.
+	 */
+	if (configs[2])
+		usart_interrupt(configs[2]);
+
+	if (configs[3])
+		usart_interrupt(configs[3]);
+}
+
+DECLARE_IRQ(STM32_IRQ_USART3_4, usart3_4_interrupt, 2);
+#endif