bcm2708: Allow option card devices to be configured via DT

If the kernel is built with Device Tree support, and if a DT blob
is provided for the kernel at boot time, then the platform devices
for option cards are not created. This avoids both the need to
blacklist unwanted devices, and the need to update the board
support code with each new device.

Author: Phil Elwell

arch/arm/mach-bcm2708/bcm2708.c

@@ -35,6 +35,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/spi/spi.h>
+#include <linux/gpio/machine.h>
 #include <linux/w1-gpio.h>
 
 #include <linux/version.h>
@@ -93,6 +94,8 @@ static unsigned reboot_part = 0;
 static unsigned w1_gpio_pin = W1_GPIO;
 static unsigned w1_gpio_pullup = W1_PULLUP;
 
+static unsigned use_dt = 0;
+
 static void __init bcm2708_init_led(void);
 
 void __init bcm2708_init_irq(void)
@@ -514,7 +517,6 @@ static struct platform_device bcm2708_alsa_devices[] = {
 	       },
 };
 
-#ifndef CONFIG_OF
 static struct resource bcm2708_spi_resources[] = {
 	{
 		.start = SPI0_BASE,
@@ -538,7 +540,6 @@ static struct platform_device bcm2708_spi_device = {
 		.dma_mask = &bcm2708_spi_dmamask,
 		.coherent_dma_mask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON)},
 };
-#endif
 
 #ifdef CONFIG_BCM2708_SPIDEV
 static struct spi_board_info bcm2708_spi_devices[] = {
@@ -560,7 +561,6 @@ static struct spi_board_info bcm2708_spi_devices[] = {
 };
 #endif
 
-#ifndef CONFIG_OF
 static struct resource bcm2708_bsc0_resources[] = {
 	{
 		.start = BSC0_BASE,
@@ -599,7 +599,6 @@ static struct platform_device bcm2708_bsc1_device = {
 	.num_resources = ARRAY_SIZE(bcm2708_bsc1_resources),
 	.resource = bcm2708_bsc1_resources,
 };
-#endif
 
 static struct platform_device bcm2835_hwmon_device = {
 	.name = "bcm2835_hwmon",
@@ -609,7 +608,7 @@ static struct platform_device bcm2835_thermal_device = {
 	.name = "bcm2835_thermal",
 };
 
-#ifdef CONFIG_SND_BCM2708_SOC_I2S_MODULE
+#if defined(CONFIG_SND_BCM2708_SOC_I2S) || defined(CONFIG_SND_BCM2708_SOC_I2S_MODULE)
 static struct resource bcm2708_i2s_resources[] = {
 	{
 		.start = I2S_BASE,
@@ -731,14 +730,14 @@ int __init bcm_register_device(struct platform_device *pdev)
 }
 
 /*
- * Use this macro for platform devices that are present in the Device Tree.
- * This way the device is only added on non-DT builds.
+ * Use these macros for platform and i2c devices that are present in the
+ * Device Tree. This way the devices are only added on non-DT systems.
  */
-#ifdef CONFIG_OF
-#define bcm_register_device_dt(pdev)
-#else
-#define bcm_register_device_dt(pdev) bcm_register_device(pdev)
-#endif
+#define bcm_register_device_dt(pdev) \
+    if (!use_dt) bcm_register_device(pdev)
+
+#define i2c_register_board_info_dt(busnum, info, n) \
+    if (!use_dt) i2c_register_board_info(busnum, info, n)
 
 int calc_rsts(int partition)
 {
@@ -814,7 +813,9 @@ static void __init bcm2708_dt_init(void)
 	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 	if (ret) {
 		pr_err("of_platform_populate failed: %d\n", ret);
-		BUG();
+		/* Proceed as if CONFIG_OF was not defined */
+	} else {
+		use_dt = 1;
 	}
 }
 #else
@@ -842,7 +843,7 @@ void __init bcm2708_init(void)
 #if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
 	w1_gpio_pdata.pin = w1_gpio_pin;
 	w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
-	platform_device_register(&w1_device);
+	bcm_register_device_dt(&w1_device);
 #endif
 	bcm_register_device(&bcm2708_systemtimer_device);
 	bcm_register_device(&bcm2708_fb_device);
@@ -857,46 +858,45 @@ void __init bcm2708_init(void)
 	for (i = 0; i < ARRAY_SIZE(bcm2708_alsa_devices); i++)
 		bcm_register_device(&bcm2708_alsa_devices[i]);
 
+	bcm_register_device(&bcm2835_hwmon_device);
+	bcm_register_device(&bcm2835_thermal_device);
+
 	bcm_register_device_dt(&bcm2708_spi_device);
 	bcm_register_device_dt(&bcm2708_bsc0_device);
 	bcm_register_device_dt(&bcm2708_bsc1_device);
 
-	bcm_register_device(&bcm2835_hwmon_device);
-	bcm_register_device(&bcm2835_thermal_device);
-
-#ifdef CONFIG_SND_BCM2708_SOC_I2S_MODULE
-	bcm_register_device(&bcm2708_i2s_device);
+#if defined(CONFIG_SND_BCM2708_SOC_I2S) || defined(CONFIG_SND_BCM2708_SOC_I2S_MODULE)
+	bcm_register_device_dt(&bcm2708_i2s_device);
 #endif
 
 #if defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DAC) || defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DAC_MODULE)
-        bcm_register_device(&snd_hifiberry_dac_device);
-        bcm_register_device(&snd_pcm5102a_codec_device);
+        bcm_register_device_dt(&snd_hifiberry_dac_device);
+        bcm_register_device_dt(&snd_pcm5102a_codec_device);
 #endif
 
 #if defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DACPLUS) || defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DACPLUS_MODULE)
-        bcm_register_device(&snd_rpi_hifiberry_dacplus_device);
-        i2c_register_board_info(1, snd_pcm512x_hbdacplus_i2c_devices, ARRAY_SIZE(snd_pcm512x_hbdacplus_i2c_devices));
+        bcm_register_device_dt(&snd_rpi_hifiberry_dacplus_device);
+        i2c_register_board_info_dt(1, snd_pcm512x_hbdacplus_i2c_devices, ARRAY_SIZE(snd_pcm512x_hbdacplus_i2c_devices));
 #endif
 
 #if defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DIGI) || defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DIGI_MODULE)
-        bcm_register_device(&snd_hifiberry_digi_device);
-        i2c_register_board_info(1, snd_wm8804_i2c_devices, ARRAY_SIZE(snd_wm8804_i2c_devices));
+        bcm_register_device_dt(&snd_hifiberry_digi_device);
+        i2c_register_board_info_dt(1, snd_wm8804_i2c_devices, ARRAY_SIZE(snd_wm8804_i2c_devices));
 #endif
 
 #if defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_AMP) || defined(CONFIG_SND_BCM2708_SOC_HIFIBERRY_AMP_MODULE)
-        bcm_register_device(&snd_hifiberry_amp_device);
-        i2c_register_board_info(1, snd_tas5713_i2c_devices, ARRAY_SIZE(snd_tas5713_i2c_devices));
+        bcm_register_device_dt(&snd_hifiberry_amp_device);
+        i2c_register_board_info_dt(1, snd_tas5713_i2c_devices, ARRAY_SIZE(snd_tas5713_i2c_devices));
 #endif
 
-
 #if defined(CONFIG_SND_BCM2708_SOC_RPI_DAC) || defined(CONFIG_SND_BCM2708_SOC_RPI_DAC_MODULE)
-        bcm_register_device(&snd_rpi_dac_device);
-        bcm_register_device(&snd_pcm1794a_codec_device);
+        bcm_register_device_dt(&snd_rpi_dac_device);
+        bcm_register_device_dt(&snd_pcm1794a_codec_device);
 #endif
 
 #if defined(CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC) || defined(CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC_MODULE)
-        bcm_register_device(&snd_rpi_iqaudio_dac_device);
-        i2c_register_board_info(1, snd_pcm512x_i2c_devices, ARRAY_SIZE(snd_pcm512x_i2c_devices));
+        bcm_register_device_dt(&snd_rpi_iqaudio_dac_device);
+        i2c_register_board_info_dt(1, snd_pcm512x_i2c_devices, ARRAY_SIZE(snd_pcm512x_i2c_devices));
 #endif
 
 
@@ -1040,9 +1040,9 @@ static struct platform_device bcm2708_led_device = {
 
 static void __init bcm2708_init_led(void)
 {
-  bcm2708_leds[0].gpio = disk_led_gpio;
-  bcm2708_leds[0].active_low = disk_led_active_low;
-  platform_device_register(&bcm2708_led_device);
+	bcm2708_leds[0].gpio = disk_led_gpio;
+	bcm2708_leds[0].active_low = disk_led_active_low;
+	bcm_register_device_dt(&bcm2708_led_device);
 }
 #else
 static inline void bcm2708_init_led(void)

drivers/dma/bcm2708-dmaengine.c

@@ -42,7 +42,7 @@
 #include <linux/io.h>
 #include <linux/spinlock.h>
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 
 /* dma manager */
 #include <mach/dma.h>
@@ -710,7 +710,7 @@ static int bcm2835_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 	}
 }
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq)
 {
 	struct bcm2835_chan *c;
@@ -773,7 +773,7 @@ static const struct of_device_id bcm2835_dma_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match);
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
 					   struct of_dma *ofdma)
 {
@@ -806,7 +806,7 @@ static int bcm2835_dma_device_slave_caps(struct dma_chan *dchan,
 static int bcm2835_dma_probe(struct platform_device *pdev)
 {
 	struct bcm2835_dmadev *od;
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 	struct resource *res;
 	void __iomem *base;
 	uint32_t chans_available;
@@ -819,10 +819,10 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
 	if (!pdev->dev.dma_mask)
 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
 
-	/* If CONFIG_OF is selected, device tree is used */
+	/* If CONFIG_ARCH_BCM2835 is selected, device tree is used */
 	/* hence the difference between probing */
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 
 	rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
 	if (rc)
@@ -976,7 +976,7 @@ static int bcm2835_dma_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 
 
 static struct platform_driver bcm2835_dma_driver = {

drivers/mmc/host/bcm2835-mmc.c

@@ -42,7 +42,7 @@
 #include "sdhci.h"
 
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
  #define BCM2835_CLOCK_FREQ 250000000
 #endif
 
@@ -662,7 +662,7 @@ void bcm2835_mmc_send_command(struct bcm2835_host *host, struct mmc_command *cmd
 	}
 
 	timeout = jiffies;
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 	if (!cmd->data && cmd->busy_timeout > 9000)
 		timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
 	else
@@ -957,7 +957,7 @@ static irqreturn_t bcm2835_mmc_irq(int irq, void *dev_id)
 	struct bcm2835_host *host = dev_id;
 	u32 intmask, mask, unexpected = 0;
 	int max_loops = 16;
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 	int cardint = 0;
 #endif
 
@@ -988,7 +988,7 @@ static irqreturn_t bcm2835_mmc_irq(int irq, void *dev_id)
 				mmc_hostname(host->mmc));
 
 		if (intmask & SDHCI_INT_CARD_INT) {
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 			cardint = 1;
 #else
 			bcm2835_mmc_enable_sdio_irq_nolock(host, false);
@@ -1021,15 +1021,15 @@ static irqreturn_t bcm2835_mmc_irq(int irq, void *dev_id)
 		bcm2835_mmc_dumpregs(host);
 	}
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 	if (cardint)
 		mmc_signal_sdio_irq(host->mmc);
 #endif
 
 	return result;
 }
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 static irqreturn_t bcm2835_mmc_thread_irq(int irq, void *dev_id)
 {
 	struct bcm2835_host *host = dev_id;
@@ -1278,7 +1278,7 @@ int bcm2835_mmc_add_host(struct bcm2835_host *host)
 
 	/* SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK */
 	host->timeout_clk = mmc->f_max / 1000;
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 	mmc->max_busy_timeout = (1 << 27) / host->timeout_clk;
 #endif
 	/* host controller capabilities */
@@ -1335,7 +1335,7 @@ int bcm2835_mmc_add_host(struct bcm2835_host *host)
 	init_waitqueue_head(&host->buf_ready_int);
 
 	bcm2835_mmc_init(host, 0);
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 	ret = request_irq(host->irq, bcm2835_mmc_irq, 0 /*IRQF_SHARED*/,
 				  mmc_hostname(mmc), host);
 #else
@@ -1364,7 +1364,7 @@ int bcm2835_mmc_add_host(struct bcm2835_host *host)
 static int bcm2835_mmc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-#ifdef CONFIG_OF
+#ifdef CONFIG_ARCH_BCM2835
 	struct device_node *node = dev->of_node;
 	struct clk *clk;
 #endif
@@ -1373,7 +1373,7 @@ static int bcm2835_mmc_probe(struct platform_device *pdev)
 
 	int ret;
 	struct mmc_host *mmc;
-#if !defined(CONFIG_OF) && !defined(FORCE_PIO)
+#if !defined(CONFIG_ARCH_BCM2835) && !defined(FORCE_PIO)
 	dma_cap_mask_t mask;
 #endif
 
@@ -1398,7 +1398,7 @@ static int bcm2835_mmc_probe(struct platform_device *pdev)
 
 	host->phys_addr = iomem->start + BCM2835_VCMMU_SHIFT;
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 #ifndef FORCE_PIO
 	dma_cap_zero(mask);
 	/* we don't care about the channel, any would work */
@@ -1448,7 +1448,7 @@ static int bcm2835_mmc_probe(struct platform_device *pdev)
 	}
 
 
-#ifndef CONFIG_OF
+#ifndef CONFIG_ARCH_BCM2835
 	mmc->caps |= MMC_CAP_4_BIT_DATA;
 #else
 	mmc_of_parse(mmc);

drivers/of/fdt.c

@@ -1083,8 +1083,12 @@ static struct debugfs_blob_wrapper flat_dt_blob;
 
 static int __init of_flat_dt_debugfs_export_fdt(void)
 {
-	struct dentry *d = debugfs_create_dir("device-tree", NULL);
+	struct dentry *d;
 
+	if (!initial_boot_params)
+		return -ENOENT;
+
+	d = debugfs_create_dir("device-tree", NULL);
 	if (!d)
 		return -ENOENT;