Indirect access to upstream port

Signed-off-by: Marc Zyngier <maz@kernel.org>

3 files changed, 40 insertions, 24 deletions

diff --git a/m1-pd-bmc.h b/m1-pd-bmc.h
index 9c56f41..6edc509 100644
--- a/m1-pd-bmc.h
+++ b/m1-pd-bmc.h
@@ -45,17 +45,23 @@ void m1_pd_bmc_fusb_setup(unsigned int port,
 			  const struct hw_context *hw);
 void m1_pd_bmc_run(void);
 
-void usb_tx_bytes(int32_t port, const char *ptr, int len);
-void usb_tx_str(int32_t port, char *ptr);
-int32_t usb_rx_byte(int32_t port);
+struct upstream_ops {
+	void	(*tx_bytes)(int32_t port, const char *ptr, int len);
+	int32_t	(*rx_byte)(int32_t port);
+	void	(*flush)(void);
+};
+
+extern const struct upstream_ops *upstream_ops;
+
+void upstream_tx_str(int32_t port, const char *ptr);
 
 #define PRINTF_SIZE	512
 
 #define __printf(__p, __f, ...)	do {					\
 		char __str[PRINTF_SIZE];				\
 		snprintf(__str, PRINTF_SIZE, __f, ##__VA_ARGS__);	\
-		usb_tx_str(__p, __str);					\
-		tud_task();						\
+		upstream_tx_str(__p, __str);				\
+		upstream_ops->flush();					\
 	} while(0)
 
 #define ARRAY_SIZE(arr)	(sizeof(arr) / sizeof((arr)[0]))
diff --git a/start.c b/start.c
index 4db1d18..10c4394 100644
--- a/start.c
+++ b/start.c
@@ -101,7 +101,7 @@ static void __not_in_flash_func(uart_irq_fn)(int port,
 {
 	while (uart_is_readable(hw->uart)) {
 		char c = uart_getc(hw->uart);
-		usb_tx_bytes(port, &c, 1);
+		upstream_ops->tx_bytes(port, &c, 1);
 	}
 }
 
@@ -178,7 +178,7 @@ static void m1_pd_bmc_system_init(const struct hw_context *hw)
 		m1_pd_bmc_gpio_setup_one(&hw->pins[i]);
 }
 
-void usb_tx_bytes(int32_t port, const char *ptr, int len)
+static void usb_tx_bytes(int32_t port, const char *ptr, int len)
 {
         if (!tud_cdc_n_connected(port))
 		return;
@@ -200,41 +200,51 @@ void usb_tx_bytes(int32_t port, const char *ptr, int len)
         }
 }
 
-void usb_tx_str(int32_t port, char *str)
+static int32_t usb_rx_byte(int32_t port)
+{
+	uint8_t c;
+
+	if (!tud_cdc_n_connected(port) || !tud_cdc_n_available(port))
+		return -1;
+
+	tud_cdc_n_read(port, &c, 1);
+	return c;
+}
+
+static const struct upstream_ops usb_upstream_ops = {
+	.tx_bytes	= usb_tx_bytes,
+	.rx_byte	= usb_rx_byte,
+	.flush		= tud_task,
+};
+
+const struct upstream_ops *upstream_ops;
+
+void upstream_tx_str(int32_t port, const char *str)
 {
 	do {
-		char *cursor = str;
+		const char *cursor = str;
 
 		while (*cursor && *cursor != '\n')
 			cursor++;
 
-		usb_tx_bytes(port, str, cursor - str);
+		upstream_ops->tx_bytes(port, str, cursor - str);
 
 		if (!*cursor)
 			return;
 
-		usb_tx_bytes(port, "\n\r", 2);
+		upstream_ops->tx_bytes(port, "\n\r", 2);
 
 		str = cursor + 1;
 	} while (*str);
 }
 
-int32_t usb_rx_byte(int32_t port)
-{
-	uint8_t c;
-
-	if (!tud_cdc_n_connected(port) || !tud_cdc_n_available(port))
-		return -1;
-
-	tud_cdc_n_read(port, &c, 1);
-	return c;
-}
-
 int main(void)
 {
 	bool success;
 	int port;
 
+	upstream_ops = &usb_upstream_ops;
+
 	success = set_sys_clock_khz(133000, false);
 
 	board_init();
diff --git a/vdmtool.c b/vdmtool.c
index 5b7039c..54b2c26 100644
--- a/vdmtool.c
+++ b/vdmtool.c
@@ -517,7 +517,7 @@ static bool serial_handler(struct vdm_context *cxt)
 	bool uart_active = false;
 	int32_t c;
 
-	while ((c = usb_rx_byte(PORT(cxt))) != -1) {
+	while ((c = upstream_ops->rx_byte(PORT(cxt))) != -1) {
 		uart_active = true;
 
 		if ((!cxt->vdm_escape && c != 0x1f)) {
@@ -742,7 +742,7 @@ void m1_pd_bmc_run(void)
 			irq_set_enabled(cxt->hw->uart_irq, false);
 		}
 
-		tud_task();
+		upstream_ops->flush();
 
 		for_each_cxt(cxt)
 			irq_set_enabled(cxt->hw->uart_irq, true);