1 files changed, 138 insertions, 0 deletions
diff --git a/board/nvidia/common/uart-spi-switch.c b/board/nvidia/common/uart-spi-switch.c
new file mode 100644
index 0000000000..23aa0b9d19
--- /dev/null
+++ b/board/nvidia/common/uart-spi-switch.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <ns16550.h>
+#include <asm/gpio.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/uart-spi-switch.h>
+#include <asm/arch/tegra2.h>
+#include <asm/arch/tegra2_spi.h>
+
+
+/* position of the UART/SPI select switch */
+enum spi_uart_switch {
+	SWITCH_UNKNOWN,
+	SWITCH_SPI,
+	SWITCH_UART,
+	SWITCH_BOTH
+};
+
+/* Information about the spi/uart switch */
+struct spi_uart {
+	int gpio;                       /* GPIO to control switch */
+	NS16550_t regs;                 /* Address of UART affected */
+	u32 port;                       /* Port number of UART affected */
+};
+
+static struct spi_uart local;
+static enum spi_uart_switch switch_pos; /* Current switch position */
+
+
+static void get_config(struct spi_uart *config)
+{
+#if defined CONFIG_SPI_CORRUPTS_UART
+	config->gpio = CONFIG_UART_DISABLE_GPIO;
+	config->regs = (NS16550_t)CONFIG_SPI_CORRUPTS_UART;
+	config->port = CONFIG_SPI_CORRUPTS_UART_NR;
+#else
+	config->gpio = -1;
+#endif
+}
+
+/*
+ * Init the UART / SPI switch. This can be called before relocation so we must
+ * not access BSS.
+ */
+void gpio_early_init_uart(void)
+{
+	struct spi_uart config;
+
+	get_config(&config);
+	if (config.gpio != -1) {
+		/* Cannot provide a label prior to relocation */
+		gpio_request(config.gpio, NULL);
+		gpio_direction_output(config.gpio, 0);
+	}
+}
+
+/*
+ * Configure the UART / SPI switch.
+ */
+void gpio_config_uart(void)
+{
+	get_config(&local);
+	if (local.gpio != -1) {
+		gpio_direction_output(local.gpio, 0);
+		switch_pos = SWITCH_UART;
+	} else {
+		/*
+		 * If we're here we don't have a SPI switch; go ahead and
+		 * enable the SPI now.  We didn't in spi_init() so we wouldn't
+		 * kill the UART.
+		 */
+		pinmux_set_func(PINGRP_GMC, PMUX_FUNC_SFLASH);
+		switch_pos = SWITCH_BOTH;
+	}
+}
+
+static void spi_uart_switch(struct spi_uart *config,
+			      enum spi_uart_switch new_pos)
+{
+	if (switch_pos == SWITCH_BOTH || new_pos == switch_pos)
+		return;
+
+	/* if the UART was selected, allow it to drain */
+	if (switch_pos == SWITCH_UART)
+		NS16550_drain(config->regs, config->port);
+
+	/* We need to dynamically change the pinmux, shared w/UART RXD/CTS */
+	pinmux_set_func(PINGRP_GMC, new_pos == SWITCH_SPI ?
+				PMUX_FUNC_SFLASH : PMUX_FUNC_UARTD);
+
+	/*
+	* On Seaboard, MOSI/MISO are shared w/UART.
+	* Use GPIO I3 (UART_DISABLE) to tristate UART during SPI activity.
+	* Enable UART later (cs_deactivate) so we can use it for U-Boot comms.
+	*/
+	gpio_direction_output(config->gpio, new_pos == SWITCH_SPI);
+	switch_pos = new_pos;
+
+	/* if the SPI was selected, clear any junk bytes in the UART */
+	if (switch_pos == SWITCH_UART) {
+		/* TODO: What if it is part-way through clocking in junk? */
+		udelay(100);
+		NS16550_clear(config->regs, config->port);
+	}
+}
+
+void pinmux_select_uart(NS16550_t regs)
+{
+	/* Also prevents calling spi_uart_switch() before relocation */
+	if (regs == local.regs)
+		spi_uart_switch(&local, SWITCH_UART);
+}
+
+void pinmux_select_spi(void)
+{
+	spi_uart_switch(&local, SWITCH_SPI);
+}