ASoC: tegra: add tegra30-ahub driver

The AHUB (Audio Hub) is a mux/crossbar which links all audio-related
devices except the HDA controller on Tegra30. The devices include the
DMA FIFOs, DAM (Digital Audio Mixers), I2S controllers, and SPDIF
controller. Audio data may be routed between these devices in various
combinations as required by board design/application.

Includes a squashed bugfix from Nikesh Oswal <noswal@nvidia.com>
Includes squashed bugfixes from Sumit Bhattacharya <sumitb@nvidia.com>

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 631 insertions, 0 deletions

diff --git a/sound/soc/tegra/tegra30_ahub.c b/sound/soc/tegra/tegra30_ahub.c
new file mode 100644
index 000000000000..57cd419f743e
--- /dev/null
+++ b/sound/soc/tegra/tegra30_ahub.c
@@ -0,0 +1,631 @@
+/*
+ * tegra30_ahub.c - Tegra30 AHUB driver
+ *
+ * Copyright (c) 2011,2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <mach/clk.h>
+#include <mach/dma.h>
+#include <sound/soc.h>
+#include "tegra30_ahub.h"
+
+#define DRV_NAME "tegra30-ahub"
+
+static struct tegra30_ahub *ahub;
+
+static inline void tegra30_apbif_write(u32 reg, u32 val)
+{
+	regmap_write(ahub->regmap_apbif, reg, val);
+}
+
+static inline u32 tegra30_apbif_read(u32 reg)
+{
+	u32 val;
+	regmap_read(ahub->regmap_apbif, reg, &val);
+	return val;
+}
+
+static inline void tegra30_audio_write(u32 reg, u32 val)
+{
+	regmap_write(ahub->regmap_ahub, reg, val);
+}
+
+static int tegra30_ahub_runtime_suspend(struct device *dev)
+{
+	regcache_cache_only(ahub->regmap_apbif, true);
+	regcache_cache_only(ahub->regmap_ahub, true);
+
+	clk_disable(ahub->clk_apbif);
+	clk_disable(ahub->clk_d_audio);
+
+	return 0;
+}
+
+/*
+ * clk_apbif isn't required for an I2S<->I2S configuration where no PCM data
+ * is read from or sent to memory. However, that's not something the rest of
+ * the driver supports right now, so we'll just treat the two clocks as one
+ * for now.
+ *
+ * These functions should not be a plain ref-count. Instead, each active stream
+ * contributes some requirement to the minimum clock rate, so starting or
+ * stopping streams should dynamically adjust the clock as required.  However,
+ * this is not yet implemented.
+ */
+static int tegra30_ahub_runtime_resume(struct device *dev)
+{
+	int ret;
+
+	ret = clk_enable(ahub->clk_d_audio);
+	if (ret) {
+		dev_err(dev, "clk_enable d_audio failed: %d\n", ret);
+		return ret;
+	}
+	ret = clk_enable(ahub->clk_apbif);
+	if (ret) {
+		dev_err(dev, "clk_enable apbif failed: %d\n", ret);
+		clk_disable(ahub->clk_d_audio);
+		return ret;
+	}
+
+	regcache_cache_only(ahub->regmap_apbif, false);
+	regcache_cache_only(ahub->regmap_ahub, false);
+
+	return 0;
+}
+
+int tegra30_ahub_allocate_rx_fifo(enum tegra30_ahub_rxcif *rxcif,
+				  unsigned long *fiforeg,
+				  unsigned long *reqsel)
+{
+	int channel;
+	u32 reg, val;
+
+	channel = find_first_zero_bit(ahub->rx_usage,
+				      TEGRA30_AHUB_CHANNEL_CTRL_COUNT);
+	if (channel >= TEGRA30_AHUB_CHANNEL_CTRL_COUNT)
+		return -EBUSY;
+
+	__set_bit(channel, ahub->rx_usage);
+
+	*rxcif = TEGRA30_AHUB_RXCIF_APBIF_RX0 + channel;
+	*fiforeg = ahub->apbif_addr + TEGRA30_AHUB_CHANNEL_RXFIFO +
+		   (channel * TEGRA30_AHUB_CHANNEL_RXFIFO_STRIDE);
+	*reqsel = ahub->dma_sel + channel;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val &= ~(TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_MASK |
+		 TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_MASK);
+	val |= (7 << TEGRA30_AHUB_CHANNEL_CTRL_RX_THRESHOLD_SHIFT) |
+	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_EN |
+	       TEGRA30_AHUB_CHANNEL_CTRL_RX_PACK_16;
+	tegra30_apbif_write(reg, val);
+
+	reg = TEGRA30_AHUB_CIF_RX_CTRL +
+	      (channel * TEGRA30_AHUB_CIF_RX_CTRL_STRIDE);
+	val = (0 << TEGRA30_AUDIOCIF_CTRL_FIFO_THRESHOLD_SHIFT) |
+	      (1 << TEGRA30_AUDIOCIF_CTRL_AUDIO_CHANNELS_SHIFT) |
+	      (1 << TEGRA30_AUDIOCIF_CTRL_CLIENT_CHANNELS_SHIFT) |
+	      TEGRA30_AUDIOCIF_CTRL_AUDIO_BITS_16 |
+	      TEGRA30_AUDIOCIF_CTRL_CLIENT_BITS_16 |
+	      TEGRA30_AUDIOCIF_CTRL_DIRECTION_RX;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_allocate_rx_fifo);
+
+int tegra30_ahub_enable_rx_fifo(enum tegra30_ahub_rxcif rxcif)
+{
+	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
+	int reg, val;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val |= TEGRA30_AHUB_CHANNEL_CTRL_RX_EN;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_enable_rx_fifo);
+
+int tegra30_ahub_disable_rx_fifo(enum tegra30_ahub_rxcif rxcif)
+{
+	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
+	int reg, val;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val &= ~TEGRA30_AHUB_CHANNEL_CTRL_RX_EN;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_disable_rx_fifo);
+
+int tegra30_ahub_free_rx_fifo(enum tegra30_ahub_rxcif rxcif)
+{
+	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
+
+	__clear_bit(channel, ahub->rx_usage);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_free_rx_fifo);
+
+int tegra30_ahub_allocate_tx_fifo(enum tegra30_ahub_txcif *txcif,
+				  unsigned long *fiforeg,
+				  unsigned long *reqsel)
+{
+	int channel;
+	u32 reg, val;
+
+	channel = find_first_zero_bit(ahub->tx_usage,
+				      TEGRA30_AHUB_CHANNEL_CTRL_COUNT);
+	if (channel >= TEGRA30_AHUB_CHANNEL_CTRL_COUNT)
+		return -EBUSY;
+
+	__set_bit(channel, ahub->tx_usage);
+
+	*txcif = TEGRA30_AHUB_TXCIF_APBIF_TX0 + channel;
+	*fiforeg = ahub->apbif_addr + TEGRA30_AHUB_CHANNEL_TXFIFO +
+		   (channel * TEGRA30_AHUB_CHANNEL_TXFIFO_STRIDE);
+	*reqsel = ahub->dma_sel + channel;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val &= ~(TEGRA30_AHUB_CHANNEL_CTRL_TX_THRESHOLD_MASK |
+		 TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_MASK);
+	val |= (7 << TEGRA30_AHUB_CHANNEL_CTRL_TX_THRESHOLD_SHIFT) |
+	       TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_EN |
+	       TEGRA30_AHUB_CHANNEL_CTRL_TX_PACK_16;
+	tegra30_apbif_write(reg, val);
+
+	reg = TEGRA30_AHUB_CIF_TX_CTRL +
+	      (channel * TEGRA30_AHUB_CIF_TX_CTRL_STRIDE);
+	val = (0 << TEGRA30_AUDIOCIF_CTRL_FIFO_THRESHOLD_SHIFT) |
+	      (1 << TEGRA30_AUDIOCIF_CTRL_AUDIO_CHANNELS_SHIFT) |
+	      (1 << TEGRA30_AUDIOCIF_CTRL_CLIENT_CHANNELS_SHIFT) |
+	      TEGRA30_AUDIOCIF_CTRL_AUDIO_BITS_16 |
+	      TEGRA30_AUDIOCIF_CTRL_CLIENT_BITS_16 |
+	      TEGRA30_AUDIOCIF_CTRL_DIRECTION_TX;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_allocate_tx_fifo);
+
+int tegra30_ahub_enable_tx_fifo(enum tegra30_ahub_txcif txcif)
+{
+	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
+	int reg, val;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val |= TEGRA30_AHUB_CHANNEL_CTRL_TX_EN;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_enable_tx_fifo);
+
+int tegra30_ahub_disable_tx_fifo(enum tegra30_ahub_txcif txcif)
+{
+	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
+	int reg, val;
+
+	reg = TEGRA30_AHUB_CHANNEL_CTRL +
+	      (channel * TEGRA30_AHUB_CHANNEL_CTRL_STRIDE);
+	val = tegra30_apbif_read(reg);
+	val &= ~TEGRA30_AHUB_CHANNEL_CTRL_TX_EN;
+	tegra30_apbif_write(reg, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_disable_tx_fifo);
+
+int tegra30_ahub_free_tx_fifo(enum tegra30_ahub_txcif txcif)
+{
+	int channel = txcif - TEGRA30_AHUB_TXCIF_APBIF_TX0;
+
+	__clear_bit(channel, ahub->tx_usage);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_free_tx_fifo);
+
+int tegra30_ahub_set_rx_cif_source(enum tegra30_ahub_rxcif rxcif,
+				   enum tegra30_ahub_txcif txcif)
+{
+	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
+	int reg;
+
+	reg = TEGRA30_AHUB_AUDIO_RX +
+	      (channel * TEGRA30_AHUB_AUDIO_RX_STRIDE);
+	tegra30_audio_write(reg, 1 << txcif);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_set_rx_cif_source);
+
+int tegra30_ahub_unset_rx_cif_source(enum tegra30_ahub_rxcif rxcif)
+{
+	int channel = rxcif - TEGRA30_AHUB_RXCIF_APBIF_RX0;
+	int reg;
+
+	reg = TEGRA30_AHUB_AUDIO_RX +
+	      (channel * TEGRA30_AHUB_AUDIO_RX_STRIDE);
+	tegra30_audio_write(reg, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra30_ahub_unset_rx_cif_source);
+
+static const char * const configlink_clocks[] __devinitconst = {
+	"i2s0",
+	"i2s1",
+	"i2s2",
+	"i2s3",
+	"i2s4",
+	"dam0",
+	"dam1",
+	"dam2",
+	"spdif_in",
+};
+
+struct of_dev_auxdata ahub_auxdata[] __devinitdata = {
+	OF_DEV_AUXDATA("nvidia,tegra30-i2s", 0x70080300, "tegra30-i2s.0", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra30-i2s", 0x70080400, "tegra30-i2s.1", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra30-i2s", 0x70080500, "tegra30-i2s.2", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra30-i2s", 0x70080600, "tegra30-i2s.3", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra30-i2s", 0x70080700, "tegra30-i2s.4", NULL),
+	{}
+};
+
+#define LAST_REG(name) \
+	(TEGRA30_AHUB_##name + \
+	 (TEGRA30_AHUB_##name##_STRIDE * TEGRA30_AHUB_##name##_COUNT) - 4)
+
+#define REG_IN_ARRAY(reg, name) \
+	((reg >= TEGRA30_AHUB_##name) && \
+	 (reg <= LAST_REG(name) && \
+	 (!((reg - TEGRA30_AHUB_##name) % TEGRA30_AHUB_##name##_STRIDE))))
+
+static bool tegra30_ahub_apbif_wr_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case TEGRA30_AHUB_CONFIG_LINK_CTRL:
+	case TEGRA30_AHUB_MISC_CTRL:
+	case TEGRA30_AHUB_APBDMA_LIVE_STATUS:
+	case TEGRA30_AHUB_I2S_LIVE_STATUS:
+	case TEGRA30_AHUB_SPDIF_LIVE_STATUS:
+	case TEGRA30_AHUB_I2S_INT_MASK:
+	case TEGRA30_AHUB_DAM_INT_MASK:
+	case TEGRA30_AHUB_SPDIF_INT_MASK:
+	case TEGRA30_AHUB_APBIF_INT_MASK:
+	case TEGRA30_AHUB_I2S_INT_STATUS:
+	case TEGRA30_AHUB_DAM_INT_STATUS:
+	case TEGRA30_AHUB_SPDIF_INT_STATUS:
+	case TEGRA30_AHUB_APBIF_INT_STATUS:
+	case TEGRA30_AHUB_I2S_INT_SOURCE:
+	case TEGRA30_AHUB_DAM_INT_SOURCE:
+	case TEGRA30_AHUB_SPDIF_INT_SOURCE:
+	case TEGRA30_AHUB_APBIF_INT_SOURCE:
+	case TEGRA30_AHUB_I2S_INT_SET:
+	case TEGRA30_AHUB_DAM_INT_SET:
+	case TEGRA30_AHUB_SPDIF_INT_SET:
+	case TEGRA30_AHUB_APBIF_INT_SET:
+		return true;
+	default:
+		break;
+	};
+
+	if (REG_IN_ARRAY(reg, CHANNEL_CTRL) ||
+	    REG_IN_ARRAY(reg, CHANNEL_CLEAR) ||
+	    REG_IN_ARRAY(reg, CHANNEL_STATUS) ||
+	    REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
+	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO) ||
+	    REG_IN_ARRAY(reg, CIF_TX_CTRL) ||
+	    REG_IN_ARRAY(reg, CIF_RX_CTRL) ||
+	    REG_IN_ARRAY(reg, DAM_LIVE_STATUS))
+		return true;
+
+	return false;
+}
+
+static bool tegra30_ahub_apbif_volatile_reg(struct device *dev,
+					    unsigned int reg)
+{
+	switch (reg) {
+	case TEGRA30_AHUB_CONFIG_LINK_CTRL:
+	case TEGRA30_AHUB_MISC_CTRL:
+	case TEGRA30_AHUB_APBDMA_LIVE_STATUS:
+	case TEGRA30_AHUB_I2S_LIVE_STATUS:
+	case TEGRA30_AHUB_SPDIF_LIVE_STATUS:
+	case TEGRA30_AHUB_I2S_INT_STATUS:
+	case TEGRA30_AHUB_DAM_INT_STATUS:
+	case TEGRA30_AHUB_SPDIF_INT_STATUS:
+	case TEGRA30_AHUB_APBIF_INT_STATUS:
+	case TEGRA30_AHUB_I2S_INT_SET:
+	case TEGRA30_AHUB_DAM_INT_SET:
+	case TEGRA30_AHUB_SPDIF_INT_SET:
+	case TEGRA30_AHUB_APBIF_INT_SET:
+		return true;
+	default:
+		break;
+	};
+
+	if (REG_IN_ARRAY(reg, CHANNEL_CLEAR) ||
+	    REG_IN_ARRAY(reg, CHANNEL_STATUS) ||
+	    REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
+	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO) ||
+	    REG_IN_ARRAY(reg, DAM_LIVE_STATUS))
+		return true;
+
+	return false;
+}
+
+static bool tegra30_ahub_apbif_precious_reg(struct device *dev,
+					    unsigned int reg)
+{
+	if (REG_IN_ARRAY(reg, CHANNEL_TXFIFO) ||
+	    REG_IN_ARRAY(reg, CHANNEL_RXFIFO))
+		return true;
+
+	return false;
+}
+
+static const struct regmap_config tegra30_ahub_apbif_regmap_config = {
+	.name = "apbif",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = TEGRA30_AHUB_APBIF_INT_SET,
+	.writeable_reg = tegra30_ahub_apbif_wr_rd_reg,
+	.readable_reg = tegra30_ahub_apbif_wr_rd_reg,
+	.volatile_reg = tegra30_ahub_apbif_volatile_reg,
+	.precious_reg = tegra30_ahub_apbif_precious_reg,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static bool tegra30_ahub_ahub_wr_rd_reg(struct device *dev, unsigned int reg)
+{
+	if (REG_IN_ARRAY(reg, AUDIO_RX))
+		return true;
+
+	return false;
+}
+
+static const struct regmap_config tegra30_ahub_ahub_regmap_config = {
+	.name = "ahub",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = LAST_REG(AUDIO_RX),
+	.writeable_reg = tegra30_ahub_ahub_wr_rd_reg,
+	.readable_reg = tegra30_ahub_ahub_wr_rd_reg,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int __devinit tegra30_ahub_probe(struct platform_device *pdev)
+{
+	struct clk *clk;
+	int i;
+	struct resource *res0, *res1, *region;
+	u32 of_dma[2];
+	void __iomem *regs_apbif, *regs_ahub;
+	int ret = 0;
+
+	if (ahub)
+		return -ENODEV;
+
+	/*
+	 * The AHUB hosts a register bus: the "configlink". For this to
+	 * operate correctly, all devices on this bus must be out of reset.
+	 * Ensure that here.
+	 */
+	for (i = 0; i < ARRAY_SIZE(configlink_clocks); i++) {
+		clk = clk_get_sys(NULL, configlink_clocks[i]);
+		if (IS_ERR(clk)) {
+			dev_err(&pdev->dev, "Can't get clock %s\n",
+				configlink_clocks[i]);
+			ret = PTR_ERR(clk);
+			goto err;
+		}
+		tegra_periph_reset_deassert(clk);
+		clk_put(clk);
+	}
+
+	ahub = devm_kzalloc(&pdev->dev, sizeof(struct tegra30_ahub),
+			    GFP_KERNEL);
+	if (!ahub) {
+		dev_err(&pdev->dev, "Can't allocate tegra30_ahub\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+	dev_set_drvdata(&pdev->dev, ahub);
+
+	ahub->dev = &pdev->dev;
+
+	ahub->clk_d_audio = clk_get(&pdev->dev, "d_audio");
+	if (IS_ERR(ahub->clk_d_audio)) {
+		dev_err(&pdev->dev, "Can't retrieve ahub d_audio clock\n");
+		ret = PTR_ERR(ahub->clk_d_audio);
+		goto err;
+	}
+
+	ahub->clk_apbif = clk_get(&pdev->dev, "apbif");
+	if (IS_ERR(ahub->clk_apbif)) {
+		dev_err(&pdev->dev, "Can't retrieve ahub apbif clock\n");
+		ret = PTR_ERR(ahub->clk_apbif);
+		goto err_clk_put_d_audio;
+	}
+
+	if (of_property_read_u32_array(pdev->dev.of_node,
+				"nvidia,dma-request-selector",
+				of_dma, 2) < 0) {
+		dev_err(&pdev->dev,
+			"Missing property nvidia,dma-request-selector\n");
+		ret = -ENODEV;
+		goto err_clk_put_d_audio;
+	}
+	ahub->dma_sel = of_dma[1];
+
+	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res0) {
+		dev_err(&pdev->dev, "No apbif memory resource\n");
+		ret = -ENODEV;
+		goto err_clk_put_apbif;
+	}
+
+	region = devm_request_mem_region(&pdev->dev, res0->start,
+					 resource_size(res0), DRV_NAME);
+	if (!region) {
+		dev_err(&pdev->dev, "request region apbif failed\n");
+		ret = -EBUSY;
+		goto err_clk_put_apbif;
+	}
+	ahub->apbif_addr = res0->start;
+
+	regs_apbif = devm_ioremap(&pdev->dev, res0->start,
+				  resource_size(res0));
+	if (!regs_apbif) {
+		dev_err(&pdev->dev, "ioremap apbif failed\n");
+		ret = -ENOMEM;
+		goto err_clk_put_apbif;
+	}
+
+	ahub->regmap_apbif = devm_regmap_init_mmio(&pdev->dev, regs_apbif,
+					&tegra30_ahub_apbif_regmap_config);
+	if (IS_ERR(ahub->regmap_apbif)) {
+		dev_err(&pdev->dev, "apbif regmap init failed\n");
+		ret = PTR_ERR(ahub->regmap_apbif);
+		goto err_clk_put_apbif;
+	}
+	regcache_cache_only(ahub->regmap_apbif, true);
+
+	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res1) {
+		dev_err(&pdev->dev, "No ahub memory resource\n");
+		ret = -ENODEV;
+		goto err_clk_put_apbif;
+	}
+
+	region = devm_request_mem_region(&pdev->dev, res1->start,
+					 resource_size(res1), DRV_NAME);
+	if (!region) {
+		dev_err(&pdev->dev, "request region ahub failed\n");
+		ret = -EBUSY;
+		goto err_clk_put_apbif;
+	}
+
+	regs_ahub = devm_ioremap(&pdev->dev, res1->start,
+				 resource_size(res1));
+	if (!regs_ahub) {
+		dev_err(&pdev->dev, "ioremap ahub failed\n");
+		ret = -ENOMEM;
+		goto err_clk_put_apbif;
+	}
+
+	ahub->regmap_ahub = devm_regmap_init_mmio(&pdev->dev, regs_ahub,
+					&tegra30_ahub_ahub_regmap_config);
+	if (IS_ERR(ahub->regmap_ahub)) {
+		dev_err(&pdev->dev, "ahub regmap init failed\n");
+		ret = PTR_ERR(ahub->regmap_ahub);
+		goto err_clk_put_apbif;
+	}
+	regcache_cache_only(ahub->regmap_ahub, true);
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = tegra30_ahub_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+
+	of_platform_populate(pdev->dev.of_node, NULL, ahub_auxdata,
+			     &pdev->dev);
+
+	return 0;
+
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+err_clk_put_apbif:
+	clk_put(ahub->clk_apbif);
+err_clk_put_d_audio:
+	clk_put(ahub->clk_d_audio);
+	ahub = 0;
+err:
+	return ret;
+}
+
+static int __devexit tegra30_ahub_remove(struct platform_device *pdev)
+{
+	if (!ahub)
+		return -ENODEV;
+
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		tegra30_ahub_runtime_suspend(&pdev->dev);
+
+	clk_put(ahub->clk_apbif);
+	clk_put(ahub->clk_d_audio);
+
+	ahub = 0;
+
+	return 0;
+}
+
+static const struct of_device_id tegra30_ahub_of_match[] __devinitconst = {
+	{ .compatible = "nvidia,tegra30-ahub", },
+	{},
+};
+
+static const struct dev_pm_ops tegra30_ahub_pm_ops __devinitconst = {
+	SET_RUNTIME_PM_OPS(tegra30_ahub_runtime_suspend,
+			   tegra30_ahub_runtime_resume, NULL)
+};
+
+static struct platform_driver tegra30_ahub_driver = {
+	.probe = tegra30_ahub_probe,
+	.remove = __devexit_p(tegra30_ahub_remove),
+	.driver = {
+		.name = DRV_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = tegra30_ahub_of_match,
+		.pm = &tegra30_ahub_pm_ops,
+	},
+};
+module_platform_driver(tegra30_ahub_driver);
+
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_DESCRIPTION("Tegra30 AHUB driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);