avr32: function for independently setting up SPI slaves

at32ap_spi_setup_slaves() is exposed to allow the addition of SPI slaves
to a SPI bus that has already been registered.  This is especially
useful for add-on cards, which have their own board setup function.
at32ap_spi_add_device() has been slightly re-organized, but should be
transparent to existing users.

So to add a SPI slave, after a SPI bus has already been registered:

	/* Configure the list of slaves on SPI controller "id" */
	at32_spi_setup_slaves(id,spi_board_info,ARRAY_SIZE(spi_board_info));
 	/* Register the list of slaves */
 	spi_register_board_info(spi_board_info,ARRAY_SIZE(spi_board_info));

Signed-off-by: Peter Ma <pma@mediamatech.com>
[haavard.skinnemoen@atmel.com: trivial whitespace fix]
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/mach-at32ap/at32ap700x.c

@@ -1181,19 +1181,32 @@ static struct resource atmel_spi1_resource[] = {
 DEFINE_DEV(atmel_spi, 1);
 DEV_CLK(spi_clk, atmel_spi1, pba, 1);
 
-static void __init
+void __init
-at32_spi_setup_slaves(unsigned int bus_num, struct spi_board_info *b,
+at32_spi_setup_slaves(unsigned int bus_num, struct spi_board_info *b, unsigned int n)
-		      unsigned int n, const u8 *pins)
 {
+	/*
+	 * Manage the chipselects as GPIOs, normally using the same pins
+	 * the SPI controller expects; but boards can use other pins.
+	 */
+	static u8 __initdata spi_pins[][4] = {
+		{ GPIO_PIN_PA(3), GPIO_PIN_PA(4),
+		  GPIO_PIN_PA(5), GPIO_PIN_PA(20) },
+		{ GPIO_PIN_PB(2), GPIO_PIN_PB(3),
+		  GPIO_PIN_PB(4), GPIO_PIN_PA(27) },
+	};
 	unsigned int pin, mode;
 
+	/* There are only 2 SPI controllers */
+	if (bus_num > 1)
+		return;
+
 	for (; n; n--, b++) {
 		b->bus_num = bus_num;
 		if (b->chip_select >= 4)
 			continue;
 		pin = (unsigned)b->controller_data;
 		if (!pin) {
-			pin = pins[b->chip_select];
+			pin = spi_pins[bus_num][b->chip_select];
 			b->controller_data = (void *)pin;
 		}
 		mode = AT32_GPIOF_OUTPUT;
@@ -1206,16 +1219,6 @@ at32_spi_setup_slaves(unsigned int bus_num, struct spi_board_info *b,
 struct platform_device *__init
 at32_add_device_spi(unsigned int id, struct spi_board_info *b, unsigned int n)
 {
-	/*
-	 * Manage the chipselects as GPIOs, normally using the same pins
-	 * the SPI controller expects; but boards can use other pins.
-	 */
-	static u8 __initdata spi0_pins[] =
-		{ GPIO_PIN_PA(3), GPIO_PIN_PA(4),
-		  GPIO_PIN_PA(5), GPIO_PIN_PA(20), };
-	static u8 __initdata spi1_pins[] =
-		{ GPIO_PIN_PB(2), GPIO_PIN_PB(3),
-		  GPIO_PIN_PB(4), GPIO_PIN_PA(27), };
 	struct platform_device *pdev;
 	u32 pin_mask;
 
@@ -1228,7 +1231,7 @@ at32_add_device_spi(unsigned int id, struct spi_board_info *b, unsigned int n)
 		select_peripheral(PIOA, (1 << 0), PERIPH_A, AT32_GPIOF_PULLUP);
 		select_peripheral(PIOA, pin_mask, PERIPH_A, 0);
 
-		at32_spi_setup_slaves(0, b, n, spi0_pins);
+		at32_spi_setup_slaves(0, b, n);
 		break;
 
 	case 1:
@@ -1239,7 +1242,7 @@ at32_add_device_spi(unsigned int id, struct spi_board_info *b, unsigned int n)
 		select_peripheral(PIOB, (1 << 0), PERIPH_B, AT32_GPIOF_PULLUP);
 		select_peripheral(PIOB, pin_mask, PERIPH_B, 0);
 
-		at32_spi_setup_slaves(1, b, n, spi1_pins);
+		at32_spi_setup_slaves(1, b, n);
 		break;
 
 	default:

arch/avr32/mach-at32ap/include/mach/board.h

@@ -49,6 +49,7 @@ at32_add_device_eth(unsigned int id, struct eth_platform_data *data);
 struct spi_board_info;
 struct platform_device *
 at32_add_device_spi(unsigned int id, struct spi_board_info *b, unsigned int n);
+void at32_spi_setup_slaves(unsigned int bus_num, struct spi_board_info *b, unsigned int n);
 
 struct atmel_lcdfb_info;
 struct platform_device *