fdt: Use device tree to provide SPI switch details

Rather than having the Seaboard SPI/UART switch in CONFIG options in the
header files, use the device tree to configure this

BUG=chromium-os:11623
TEST=build and boot U-Boot on Seaboard

Change-Id: If3b92b685b5fe31a97ef4bc3578a6aa00208d827
Reviewed-on: http://gerrit.chromium.org/gerrit/1661
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

5 files changed, 89 insertions, 26 deletions

diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
index e68dcfdfeba..679ac3ded32 100644
--- a/board/nvidia/common/board.c
+++ b/board/nvidia/common/board.c
@@ -145,14 +145,15 @@ static void pinmux_init(int uart_ids)
 	pin_mux_uart(uart_ids);
 }
 
-/*
- * Routine: gpio_init
- * Description: Do individual peripheral GPIO configs
+/**
+ * Do individual peripheral GPIO configs
+ *
+ * @param blob	FDT blob with configuration information
  */
-static void gpio_init(void)
+static void gpio_init(const void *blob)
 {
 #ifdef CONFIG_SPI_UART_SWITCH
-	gpio_early_init_uart();
+	gpio_early_init_uart(blob);
 #endif
 }
 
@@ -168,7 +169,7 @@ int board_init(void)
 	gd->bd->bi_arch_number = CONFIG_MACH_TYPE;
 
 #ifdef CONFIG_SPI_UART_SWITCH
-	gpio_config_uart();
+	gpio_config_uart(gd->blob);
 #endif
 #ifdef CONFIG_USB_EHCI_TEGRA
 	board_usb_init();
@@ -204,7 +205,7 @@ int board_early_init_f(void)
 	pinmux_init(uart_ids);
 
 	/* Initialize periph GPIOs */
-	gpio_init();
+	gpio_init(gd->blob);
 
 	return 0;
 }
diff --git a/board/nvidia/common/board.h b/board/nvidia/common/board.h
index 5c23d41b10b..c406c892298 100644
--- a/board/nvidia/common/board.h
+++ b/board/nvidia/common/board.h
@@ -25,7 +25,7 @@
 #define _BOARD_H_
 
 void tegra2_start(void);
-void gpio_config_uart(void);
-void gpio_early_init_uart(void);
+void gpio_config_uart(const void *blob);
+void gpio_early_init_uart(const void *blob);
 
 #endif	/* BOARD_H */
diff --git a/board/nvidia/common/uart-spi-fix.c b/board/nvidia/common/uart-spi-fix.c
index 4f022158c4b..051f7492304 100644
--- a/board/nvidia/common/uart-spi-fix.c
+++ b/board/nvidia/common/uart-spi-fix.c
@@ -24,6 +24,7 @@
 #include <asm/io.h>
 #include <ns16550.h>
 #include <libfdt.h>
+#include <fdt_decode.h>
 #include <fdt_support.h>
 #include <asm/arch/bitfield.h>
 #include <asm/arch/gpio.h>
@@ -41,20 +42,14 @@ enum spi_uart_switch {
 	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 struct fdt_spi_uart local;
 static enum spi_uart_switch switch_pos; /* Current switch position */
 
-
-static void get_config(struct spi_uart *config)
+static void get_config(const void *blob, struct fdt_spi_uart *config)
 {
-#if defined CONFIG_SPI_CORRUPTS_UART
+#ifdef CONFIG_OF_CONTROL
+	fdt_decode_get_spi_switch(blob, config);
+#elif defined CONFIG_SPI_CORRUPTS_UART
 	config->gpio = UART_DISABLE_GPIO;
 	config->regs = (NS16550_t)CONFIG_SPI_CORRUPTS_UART;
 	config->port = CONFIG_SPI_CORRUPTS_UART_NR;
@@ -67,11 +62,11 @@ static void get_config(struct spi_uart *config)
  * Init the UART / SPI switch. This can be called before relocation so we must
  * not access BSS.
  */
-void gpio_early_init_uart(void)
+void gpio_early_init_uart(const void *blob)
 {
-	struct spi_uart config;
+	struct fdt_spi_uart config;
 
-	get_config(&config);
+	get_config(blob, &config);
 	if (config.gpio != -1)
 		gpio_direction_output(config.gpio, 0);
 	switch_pos = SWITCH_BOTH;
@@ -80,9 +75,9 @@ void gpio_early_init_uart(void)
 /*
  * Configure the UART / SPI switch.
  */
-void gpio_config_uart(void)
+void gpio_config_uart(const void *blob)
 {
-	get_config(&local);
+	get_config(blob, &local);
 	switch_pos = SWITCH_BOTH;
 	if (local.gpio != -1) {
 		gpio_direction_output(local.gpio, 0);
@@ -92,7 +87,7 @@ void gpio_config_uart(void)
 
 #ifdef CONFIG_SPI_UART_SWITCH
 
-static void spi_uart_switch(struct spi_uart *config,
+static void spi_uart_switch(struct fdt_spi_uart *config,
 			      enum spi_uart_switch new_pos)
 {
 	if (switch_pos == SWITCH_BOTH || new_pos == switch_pos)
diff --git a/common/fdt_decode.c b/common/fdt_decode.c
index d316d918d86..6af6af9907b 100644
--- a/common/fdt_decode.c
+++ b/common/fdt_decode.c
@@ -31,6 +31,7 @@
  */
 static struct fdt_compat compat_types[] = {
 	{ COMPAT_UNKNOWN, "<none>" },
+	{ COMPAT_SPI_UART_SWITCH, "spi-uart-select" },
 };
 
 /**
@@ -99,6 +100,28 @@ static s32 get_int(const void *blob, int node, const char *prop_name,
 }
 
 /**
+ * Look up a phandle and follow it to its node. Then return the offset
+ * of that node.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param prop_name	name of property to find
+ * @return node offset if found, -ve error code on error
+ */
+static int lookup_phandle(const void *blob, int node, const char *prop_name)
+{
+	const u32 *phandle;
+	int lookup;
+
+	phandle = fdt_getprop(blob, node, prop_name, NULL);
+	if (!phandle)
+		return -FDT_ERR_NOTFOUND;
+
+	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
+	return lookup;
+}
+
+/**
  * Checks whether a node is enabled.
  * This looks for a 'status' property. If this exists, then returns 1 if
  * the status is 'ok' and 0 otherwise. If there is no status property,
@@ -164,3 +187,27 @@ enum fdt_compat_id fdt_decode_lookup(const void *blob, int node)
 			return id;
 	return COMPAT_UNKNOWN;
 }
+
+int fdt_decode_get_spi_switch(const void *blob, struct fdt_spi_uart *config)
+{
+	int node, uart_node;
+	const u32 *gpio;
+
+	node = fdt_node_offset_by_compatible(blob, 0,
+					     "nvidia,spi-uart-switch");
+	if (node < 0)
+		return node;
+
+	uart_node = lookup_phandle(blob, node, "uart");
+	if (uart_node < 0)
+		return uart_node;
+	config->port = get_int(blob, uart_node, "id", -1);
+	if (config->port == -1)
+		return -FDT_ERR_NOTFOUND;
+	config->gpio = -1;
+	config->regs = (NS16550_t)get_addr(blob, uart_node, "reg");
+	gpio = fdt_getprop(blob, node, "gpios", NULL);
+	if (gpio)
+		config->gpio = fdt32_to_cpu(gpio[1]);
+	return 0;
+}
diff --git a/include/fdt_decode.h b/include/fdt_decode.h
index 303d5a8d332..7f9c1d5821e 100644
--- a/include/fdt_decode.h
+++ b/include/fdt_decode.h
@@ -28,6 +28,8 @@
  * changes to support FDT are minimized.
  */
 
+#include <ns16550.h>
+
 /* A typedef for a physical address. We should move it to a generic place */
 #ifdef CONFIG_PHYS_64BIT
 typedef u64 addr_t;
@@ -46,6 +48,7 @@ typedef u32 addr_t;
  */
 enum fdt_compat_id {
 	COMPAT_UNKNOWN,
+	COMPAT_SPI_UART_SWITCH,		/* SPI / UART switch */
 
 	COMPAT_COUNT,
 };
@@ -71,6 +74,13 @@ struct fdt_uart {
 	enum fdt_compat_id compat; /* our selected driver */
 };
 
+/* Information about the spi/uart switch */
+struct fdt_spi_uart {
+	int gpio;			/* GPIO to control switch */
+	NS16550_t regs;			/* Address of UART affected */
+	u32 port;			/* Port number of UART affected */
+};
+
 /**
  * Return information from the FDT about the console UART. This looks for
  * an alias node called 'console' which must point to a UART. It then reads
@@ -115,3 +125,13 @@ void fdt_decode_uart_calc_divisor(struct fdt_uart *uart);
  * determining which driver will implement the decide described by the node.
  */
 enum fdt_compat_id fdt_decode_lookup(const void *blob, int node);
+
+/**
+ * Returns information from the FDT about the SPI / UART switch on tegra
+ * platforms.
+ *
+ * @param blob		FDT blob to use
+ * @param config	structure to use to return information
+ * @returns 0 on success, -ve on error, in which case config is unchanged
+ */
+int fdt_decode_get_spi_switch(const void *blob, struct fdt_spi_uart *config);