dmaengine: tegra-adma: Add support for Tegra210 ADMA
authorJon Hunter <jonathanh@nvidia.com>
Thu, 12 May 2016 17:02:23 +0000 (18:02 +0100)
committerVinod Koul <vinod.koul@intel.com>
Fri, 13 May 2016 09:26:24 +0000 (14:56 +0530)
Add support for the Tegra210 Audio DMA controller that is used for
transferring data between system memory and the Audio sub-system.
The driver only supports cyclic transfers because this is being solely
used for audio.

This driver is based upon the work by Dara Ramesh <dramesh@nvidia.com>.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
drivers/dma/Kconfig
drivers/dma/Makefile
drivers/dma/tegra210-adma.c [new file with mode: 0644]

index d96d87c..16bd369 100644 (file)
@@ -467,6 +467,20 @@ config TEGRA20_APB_DMA
          This DMA controller transfers data from memory to peripheral fifo
          or vice versa. It does not support memory to memory data transfer.
 
          This DMA controller transfers data from memory to peripheral fifo
          or vice versa. It does not support memory to memory data transfer.
 
+config TEGRA210_ADMA
+       bool "NVIDIA Tegra210 ADMA support"
+       depends on ARCH_TEGRA_210_SOC
+       select DMA_ENGINE
+       select DMA_VIRTUAL_CHANNELS
+       select PM_CLK
+       help
+         Support for the NVIDIA Tegra210 ADMA controller driver. The
+         DMA controller has multiple DMA channels and is used to service
+         various audio clients in the Tegra210 audio processing engine
+         (APE). This DMA controller transfers data from memory to
+         peripheral and vice versa. It does not support memory to
+         memory data transfer.
+
 config TIMB_DMA
        tristate "Timberdale FPGA DMA support"
        depends on MFD_TIMBERDALE
 config TIMB_DMA
        tristate "Timberdale FPGA DMA support"
        depends on MFD_TIMBERDALE
index 6084127..614f28b 100644 (file)
@@ -59,6 +59,7 @@ obj-$(CONFIG_STM32_DMA) += stm32-dma.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
+obj-$(CONFIG_TEGRA210_ADMA) += tegra210-adma.o
 obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_TI_CPPI41) += cppi41.o
 obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
 obj-$(CONFIG_TIMB_DMA) += timb_dma.o
 obj-$(CONFIG_TI_CPPI41) += cppi41.o
 obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
new file mode 100644 (file)
index 0000000..c4b121c
--- /dev/null
@@ -0,0 +1,840 @@
+/*
+ * ADMA driver for Nvidia's Tegra210 ADMA controller.
+ *
+ * Copyright (c) 2016, 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/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/of_irq.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "virt-dma.h"
+
+#define ADMA_CH_CMD                                    0x00
+#define ADMA_CH_STATUS                                 0x0c
+#define ADMA_CH_STATUS_XFER_EN                         BIT(0)
+
+#define ADMA_CH_INT_STATUS                             0x10
+#define ADMA_CH_INT_STATUS_XFER_DONE                   BIT(0)
+
+#define ADMA_CH_INT_CLEAR                              0x1c
+#define ADMA_CH_CTRL                                   0x24
+#define ADMA_CH_CTRL_TX_REQ(val)                       (((val) & 0xf) << 28)
+#define ADMA_CH_CTRL_TX_REQ_MAX                                10
+#define ADMA_CH_CTRL_RX_REQ(val)                       (((val) & 0xf) << 24)
+#define ADMA_CH_CTRL_RX_REQ_MAX                                10
+#define ADMA_CH_CTRL_DIR(val)                          (((val) & 0xf) << 12)
+#define ADMA_CH_CTRL_DIR_AHUB2MEM                      2
+#define ADMA_CH_CTRL_DIR_MEM2AHUB                      4
+#define ADMA_CH_CTRL_MODE_CONTINUOUS                   (2 << 8)
+#define ADMA_CH_CTRL_FLOWCTRL_EN                       BIT(1)
+
+#define ADMA_CH_CONFIG                                 0x28
+#define ADMA_CH_CONFIG_SRC_BUF(val)                    (((val) & 0x7) << 28)
+#define ADMA_CH_CONFIG_TRG_BUF(val)                    (((val) & 0x7) << 24)
+#define ADMA_CH_CONFIG_BURST_SIZE(val)                 (((val) & 0x7) << 20)
+#define ADMA_CH_CONFIG_BURST_16                                5
+#define ADMA_CH_CONFIG_WEIGHT_FOR_WRR(val)             ((val) & 0xf)
+#define ADMA_CH_CONFIG_MAX_BUFS                                8
+
+#define ADMA_CH_FIFO_CTRL                              0x2c
+#define ADMA_CH_FIFO_CTRL_OVRFW_THRES(val)             (((val) & 0xf) << 24)
+#define ADMA_CH_FIFO_CTRL_STARV_THRES(val)             (((val) & 0xf) << 16)
+#define ADMA_CH_FIFO_CTRL_TX_SIZE(val)                 (((val) & 0xf) << 8)
+#define ADMA_CH_FIFO_CTRL_RX_SIZE(val)                 ((val) & 0xf)
+
+#define ADMA_CH_LOWER_SRC_ADDR                         0x34
+#define ADMA_CH_LOWER_TRG_ADDR                         0x3c
+#define ADMA_CH_TC                                     0x44
+#define ADMA_CH_TC_COUNT_MASK                          0x3ffffffc
+
+#define ADMA_CH_XFER_STATUS                            0x54
+#define ADMA_CH_XFER_STATUS_COUNT_MASK                 0xffff
+
+#define ADMA_GLOBAL_CMD                                        0xc00
+#define ADMA_GLOBAL_SOFT_RESET                         0xc04
+#define ADMA_GLOBAL_INT_CLEAR                          0xc20
+#define ADMA_GLOBAL_CTRL                               0xc24
+
+#define ADMA_CH_REG_OFFSET(a)                          (a * 0x80)
+
+#define ADMA_CH_FIFO_CTRL_DEFAULT      (ADMA_CH_FIFO_CTRL_OVRFW_THRES(1) | \
+                                        ADMA_CH_FIFO_CTRL_STARV_THRES(1) | \
+                                        ADMA_CH_FIFO_CTRL_TX_SIZE(3)     | \
+                                        ADMA_CH_FIFO_CTRL_RX_SIZE(3))
+struct tegra_adma;
+
+/*
+ * struct tegra_adma_chip_data - Tegra chip specific data
+ * @nr_channels: Number of DMA channels available.
+ */
+struct tegra_adma_chip_data {
+       int nr_channels;
+};
+
+/*
+ * struct tegra_adma_chan_regs - Tegra ADMA channel registers
+ */
+struct tegra_adma_chan_regs {
+       unsigned int ctrl;
+       unsigned int config;
+       unsigned int src_addr;
+       unsigned int trg_addr;
+       unsigned int fifo_ctrl;
+       unsigned int tc;
+};
+
+/*
+ * struct tegra_adma_desc - Tegra ADMA descriptor to manage transfer requests.
+ */
+struct tegra_adma_desc {
+       struct virt_dma_desc            vd;
+       struct tegra_adma_chan_regs     ch_regs;
+       size_t                          buf_len;
+       size_t                          period_len;
+       size_t                          num_periods;
+};
+
+/*
+ * struct tegra_adma_chan - Tegra ADMA channel information
+ */
+struct tegra_adma_chan {
+       struct virt_dma_chan            vc;
+       struct tegra_adma_desc          *desc;
+       struct tegra_adma               *tdma;
+       int                             irq;
+       void __iomem                    *chan_addr;
+
+       /* Slave channel configuration info */
+       struct dma_slave_config         sconfig;
+       enum dma_transfer_direction     sreq_dir;
+       unsigned int                    sreq_index;
+       bool                            sreq_reserved;
+
+       /* Transfer count and position info */
+       unsigned int                    tx_buf_count;
+       unsigned int                    tx_buf_pos;
+};
+
+/*
+ * struct tegra_adma - Tegra ADMA controller information
+ */
+struct tegra_adma {
+       struct dma_device               dma_dev;
+       struct device                   *dev;
+       void __iomem                    *base_addr;
+       unsigned int                    nr_channels;
+       unsigned long                   rx_requests_reserved;
+       unsigned long                   tx_requests_reserved;
+
+       /* Used to store global command register state when suspending */
+       unsigned int                    global_cmd;
+
+       /* Last member of the structure */
+       struct tegra_adma_chan          channels[0];
+};
+
+static inline void tdma_write(struct tegra_adma *tdma, u32 reg, u32 val)
+{
+       writel(val, tdma->base_addr + reg);
+}
+
+static inline u32 tdma_read(struct tegra_adma *tdma, u32 reg)
+{
+       return readl(tdma->base_addr + reg);
+}
+
+static inline void tdma_ch_write(struct tegra_adma_chan *tdc, u32 reg, u32 val)
+{
+       writel(val, tdc->chan_addr + reg);
+}
+
+static inline u32 tdma_ch_read(struct tegra_adma_chan *tdc, u32 reg)
+{
+       return readl(tdc->chan_addr + reg);
+}
+
+static inline struct tegra_adma_chan *to_tegra_adma_chan(struct dma_chan *dc)
+{
+       return container_of(dc, struct tegra_adma_chan, vc.chan);
+}
+
+static inline struct tegra_adma_desc *to_tegra_adma_desc(
+               struct dma_async_tx_descriptor *td)
+{
+       return container_of(td, struct tegra_adma_desc, vd.tx);
+}
+
+static inline struct device *tdc2dev(struct tegra_adma_chan *tdc)
+{
+       return tdc->tdma->dev;
+}
+
+static void tegra_adma_desc_free(struct virt_dma_desc *vd)
+{
+       kfree(container_of(vd, struct tegra_adma_desc, vd));
+}
+
+static int tegra_adma_slave_config(struct dma_chan *dc,
+                                  struct dma_slave_config *sconfig)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+
+       memcpy(&tdc->sconfig, sconfig, sizeof(*sconfig));
+
+       return 0;
+}
+
+static int tegra_adma_init(struct tegra_adma *tdma)
+{
+       u32 status;
+       int ret;
+
+       /* Clear any interrupts */
+       tdma_write(tdma, ADMA_GLOBAL_INT_CLEAR, 0x1);
+
+       /* Assert soft reset */
+       tdma_write(tdma, ADMA_GLOBAL_SOFT_RESET, 0x1);
+
+       /* Wait for reset to clear */
+       ret = readx_poll_timeout(readl,
+                                tdma->base_addr + ADMA_GLOBAL_SOFT_RESET,
+                                status, status == 0, 20, 10000);
+       if (ret)
+               return ret;
+
+       /* Enable global ADMA registers */
+       tdma_write(tdma, ADMA_GLOBAL_CMD, 1);
+
+       return 0;
+}
+
+static int tegra_adma_request_alloc(struct tegra_adma_chan *tdc,
+                                   enum dma_transfer_direction direction)
+{
+       struct tegra_adma *tdma = tdc->tdma;
+       unsigned int sreq_index = tdc->sreq_index;
+
+       if (tdc->sreq_reserved)
+               return tdc->sreq_dir == direction ? 0 : -EINVAL;
+
+       switch (direction) {
+       case DMA_MEM_TO_DEV:
+               if (sreq_index > ADMA_CH_CTRL_TX_REQ_MAX) {
+                       dev_err(tdma->dev, "invalid DMA request\n");
+                       return -EINVAL;
+               }
+
+               if (test_and_set_bit(sreq_index, &tdma->tx_requests_reserved)) {
+                       dev_err(tdma->dev, "DMA request reserved\n");
+                       return -EINVAL;
+               }
+               break;
+
+       case DMA_DEV_TO_MEM:
+               if (sreq_index > ADMA_CH_CTRL_RX_REQ_MAX) {
+                       dev_err(tdma->dev, "invalid DMA request\n");
+                       return -EINVAL;
+               }
+
+               if (test_and_set_bit(sreq_index, &tdma->rx_requests_reserved)) {
+                       dev_err(tdma->dev, "DMA request reserved\n");
+                       return -EINVAL;
+               }
+               break;
+
+       default:
+               dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
+                        dma_chan_name(&tdc->vc.chan));
+               return -EINVAL;
+       }
+
+       tdc->sreq_dir = direction;
+       tdc->sreq_reserved = true;
+
+       return 0;
+}
+
+static void tegra_adma_request_free(struct tegra_adma_chan *tdc)
+{
+       struct tegra_adma *tdma = tdc->tdma;
+
+       if (!tdc->sreq_reserved)
+               return;
+
+       switch (tdc->sreq_dir) {
+       case DMA_MEM_TO_DEV:
+               clear_bit(tdc->sreq_index, &tdma->tx_requests_reserved);
+               break;
+
+       case DMA_DEV_TO_MEM:
+               clear_bit(tdc->sreq_index, &tdma->rx_requests_reserved);
+               break;
+
+       default:
+               dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
+                        dma_chan_name(&tdc->vc.chan));
+               return;
+       }
+
+       tdc->sreq_reserved = false;
+}
+
+static u32 tegra_adma_irq_status(struct tegra_adma_chan *tdc)
+{
+       u32 status = tdma_ch_read(tdc, ADMA_CH_INT_STATUS);
+
+       return status & ADMA_CH_INT_STATUS_XFER_DONE;
+}
+
+static u32 tegra_adma_irq_clear(struct tegra_adma_chan *tdc)
+{
+       u32 status = tegra_adma_irq_status(tdc);
+
+       if (status)
+               tdma_ch_write(tdc, ADMA_CH_INT_CLEAR, status);
+
+       return status;
+}
+
+static void tegra_adma_stop(struct tegra_adma_chan *tdc)
+{
+       unsigned int status;
+
+       /* Disable ADMA */
+       tdma_ch_write(tdc, ADMA_CH_CMD, 0);
+
+       /* Clear interrupt status */
+       tegra_adma_irq_clear(tdc);
+
+       if (readx_poll_timeout_atomic(readl, tdc->chan_addr + ADMA_CH_STATUS,
+                       status, !(status & ADMA_CH_STATUS_XFER_EN),
+                       20, 10000)) {
+               dev_err(tdc2dev(tdc), "unable to stop DMA channel\n");
+               return;
+       }
+
+       kfree(tdc->desc);
+       tdc->desc = NULL;
+}
+
+static void tegra_adma_start(struct tegra_adma_chan *tdc)
+{
+       struct virt_dma_desc *vd = vchan_next_desc(&tdc->vc);
+       struct tegra_adma_chan_regs *ch_regs;
+       struct tegra_adma_desc *desc;
+
+       if (!vd)
+               return;
+
+       list_del(&vd->node);
+
+       desc = to_tegra_adma_desc(&vd->tx);
+
+       if (!desc) {
+               dev_warn(tdc2dev(tdc), "unable to start DMA, no descriptor\n");
+               return;
+       }
+
+       ch_regs = &desc->ch_regs;
+
+       tdc->tx_buf_pos = 0;
+       tdc->tx_buf_count = 0;
+       tdma_ch_write(tdc, ADMA_CH_TC, ch_regs->tc);
+       tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);
+       tdma_ch_write(tdc, ADMA_CH_LOWER_SRC_ADDR, ch_regs->src_addr);
+       tdma_ch_write(tdc, ADMA_CH_LOWER_TRG_ADDR, ch_regs->trg_addr);
+       tdma_ch_write(tdc, ADMA_CH_FIFO_CTRL, ch_regs->fifo_ctrl);
+       tdma_ch_write(tdc, ADMA_CH_CONFIG, ch_regs->config);
+
+       /* Start ADMA */
+       tdma_ch_write(tdc, ADMA_CH_CMD, 1);
+
+       tdc->desc = desc;
+}
+
+static unsigned int tegra_adma_get_residue(struct tegra_adma_chan *tdc)
+{
+       struct tegra_adma_desc *desc = tdc->desc;
+       unsigned int max = ADMA_CH_XFER_STATUS_COUNT_MASK + 1;
+       unsigned int pos = tdma_ch_read(tdc, ADMA_CH_XFER_STATUS);
+       unsigned int periods_remaining;
+
+       /*
+        * Handle wrap around of buffer count register
+        */
+       if (pos < tdc->tx_buf_pos)
+               tdc->tx_buf_count += pos + (max - tdc->tx_buf_pos);
+       else
+               tdc->tx_buf_count += pos - tdc->tx_buf_pos;
+
+       periods_remaining = tdc->tx_buf_count % desc->num_periods;
+       tdc->tx_buf_pos = pos;
+
+       return desc->buf_len - (periods_remaining * desc->period_len);
+}
+
+static irqreturn_t tegra_adma_isr(int irq, void *dev_id)
+{
+       struct tegra_adma_chan *tdc = dev_id;
+       unsigned long status;
+       unsigned long flags;
+
+       spin_lock_irqsave(&tdc->vc.lock, flags);
+
+       status = tegra_adma_irq_clear(tdc);
+       if (status == 0 || !tdc->desc) {
+               spin_unlock_irqrestore(&tdc->vc.lock, flags);
+               return IRQ_NONE;
+       }
+
+       vchan_cyclic_callback(&tdc->desc->vd);
+
+       spin_unlock_irqrestore(&tdc->vc.lock, flags);
+
+       return IRQ_HANDLED;
+}
+
+static void tegra_adma_issue_pending(struct dma_chan *dc)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&tdc->vc.lock, flags);
+
+       if (vchan_issue_pending(&tdc->vc)) {
+               if (!tdc->desc)
+                       tegra_adma_start(tdc);
+       }
+
+       spin_unlock_irqrestore(&tdc->vc.lock, flags);
+}
+
+static int tegra_adma_terminate_all(struct dma_chan *dc)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+       unsigned long flags;
+       LIST_HEAD(head);
+
+       spin_lock_irqsave(&tdc->vc.lock, flags);
+
+       if (tdc->desc)
+               tegra_adma_stop(tdc);
+
+       tegra_adma_request_free(tdc);
+       vchan_get_all_descriptors(&tdc->vc, &head);
+       spin_unlock_irqrestore(&tdc->vc.lock, flags);
+       vchan_dma_desc_free_list(&tdc->vc, &head);
+
+       return 0;
+}
+
+static enum dma_status tegra_adma_tx_status(struct dma_chan *dc,
+                                           dma_cookie_t cookie,
+                                           struct dma_tx_state *txstate)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+       struct tegra_adma_desc *desc;
+       struct virt_dma_desc *vd;
+       enum dma_status ret;
+       unsigned long flags;
+       unsigned int residual;
+
+       ret = dma_cookie_status(dc, cookie, txstate);
+       if (ret == DMA_COMPLETE || !txstate)
+               return ret;
+
+       spin_lock_irqsave(&tdc->vc.lock, flags);
+
+       vd = vchan_find_desc(&tdc->vc, cookie);
+       if (vd) {
+               desc = to_tegra_adma_desc(&vd->tx);
+               residual = desc->ch_regs.tc;
+       } else if (tdc->desc && tdc->desc->vd.tx.cookie == cookie) {
+               residual = tegra_adma_get_residue(tdc);
+       } else {
+               residual = 0;
+       }
+
+       spin_unlock_irqrestore(&tdc->vc.lock, flags);
+
+       dma_set_residue(txstate, residual);
+
+       return ret;
+}
+
+static int tegra_adma_set_xfer_params(struct tegra_adma_chan *tdc,
+                                     struct tegra_adma_desc *desc,
+                                     dma_addr_t buf_addr,
+                                     enum dma_transfer_direction direction)
+{
+       struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;
+       unsigned int burst_size, adma_dir;
+
+       if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS)
+               return -EINVAL;
+
+       switch (direction) {
+       case DMA_MEM_TO_DEV:
+               adma_dir = ADMA_CH_CTRL_DIR_MEM2AHUB;
+               burst_size = fls(tdc->sconfig.dst_maxburst);
+               ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(desc->num_periods - 1);
+               ch_regs->ctrl = ADMA_CH_CTRL_TX_REQ(tdc->sreq_index);
+               ch_regs->src_addr = buf_addr;
+               break;
+
+       case DMA_DEV_TO_MEM:
+               adma_dir = ADMA_CH_CTRL_DIR_AHUB2MEM;
+               burst_size = fls(tdc->sconfig.src_maxburst);
+               ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(desc->num_periods - 1);
+               ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index);
+               ch_regs->trg_addr = buf_addr;
+               break;
+
+       default:
+               dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
+               return -EINVAL;
+       }
+
+       if (!burst_size || burst_size > ADMA_CH_CONFIG_BURST_16)
+               burst_size = ADMA_CH_CONFIG_BURST_16;
+
+       ch_regs->ctrl |= ADMA_CH_CTRL_DIR(adma_dir) |
+                        ADMA_CH_CTRL_MODE_CONTINUOUS |
+                        ADMA_CH_CTRL_FLOWCTRL_EN;
+       ch_regs->config |= ADMA_CH_CONFIG_BURST_SIZE(burst_size);
+       ch_regs->config |= ADMA_CH_CONFIG_WEIGHT_FOR_WRR(1);
+       ch_regs->fifo_ctrl = ADMA_CH_FIFO_CTRL_DEFAULT;
+       ch_regs->tc = desc->period_len & ADMA_CH_TC_COUNT_MASK;
+
+       return tegra_adma_request_alloc(tdc, direction);
+}
+
+static struct dma_async_tx_descriptor *tegra_adma_prep_dma_cyclic(
+       struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
+       size_t period_len, enum dma_transfer_direction direction,
+       unsigned long flags)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+       struct tegra_adma_desc *desc = NULL;
+
+       if (!buf_len || !period_len || period_len > ADMA_CH_TC_COUNT_MASK) {
+               dev_err(tdc2dev(tdc), "invalid buffer/period len\n");
+               return NULL;
+       }
+
+       if (buf_len % period_len) {
+               dev_err(tdc2dev(tdc), "buf_len not a multiple of period_len\n");
+               return NULL;
+       }
+
+       if (!IS_ALIGNED(buf_addr, 4)) {
+               dev_err(tdc2dev(tdc), "invalid buffer alignment\n");
+               return NULL;
+       }
+
+       desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+       if (!desc)
+               return NULL;
+
+       desc->buf_len = buf_len;
+       desc->period_len = period_len;
+       desc->num_periods = buf_len / period_len;
+
+       if (tegra_adma_set_xfer_params(tdc, desc, buf_addr, direction)) {
+               kfree(desc);
+               return NULL;
+       }
+
+       return vchan_tx_prep(&tdc->vc, &desc->vd, flags);
+}
+
+static int tegra_adma_alloc_chan_resources(struct dma_chan *dc)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+       int ret;
+
+       ret = request_irq(tdc->irq, tegra_adma_isr, 0, dma_chan_name(dc), tdc);
+       if (ret) {
+               dev_err(tdc2dev(tdc), "failed to get interrupt for %s\n",
+                       dma_chan_name(dc));
+               return ret;
+       }
+
+       ret = pm_runtime_get_sync(tdc2dev(tdc));
+       if (ret < 0) {
+               free_irq(tdc->irq, tdc);
+               return ret;
+       }
+
+       dma_cookie_init(&tdc->vc.chan);
+
+       return 0;
+}
+
+static void tegra_adma_free_chan_resources(struct dma_chan *dc)
+{
+       struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
+
+       tegra_adma_terminate_all(dc);
+       vchan_free_chan_resources(&tdc->vc);
+       tasklet_kill(&tdc->vc.task);
+       free_irq(tdc->irq, tdc);
+       pm_runtime_put(tdc2dev(tdc));
+
+       tdc->sreq_index = 0;
+       tdc->sreq_dir = DMA_TRANS_NONE;
+}
+
+static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
+                                          struct of_dma *ofdma)
+{
+       struct tegra_adma *tdma = ofdma->of_dma_data;
+       struct tegra_adma_chan *tdc;
+       struct dma_chan *chan;
+       unsigned int sreq_index;
+
+       if (dma_spec->args_count != 1)
+               return NULL;
+
+       sreq_index = dma_spec->args[0];
+
+       if (sreq_index == 0) {
+               dev_err(tdma->dev, "DMA request must not be 0\n");
+               return NULL;
+       }
+
+       chan = dma_get_any_slave_channel(&tdma->dma_dev);
+       if (!chan)
+               return NULL;
+
+       tdc = to_tegra_adma_chan(chan);
+       tdc->sreq_index = sreq_index;
+
+       return chan;
+}
+
+static int tegra_adma_runtime_suspend(struct device *dev)
+{
+       struct tegra_adma *tdma = dev_get_drvdata(dev);
+
+       tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
+
+       return pm_clk_suspend(dev);
+}
+
+static int tegra_adma_runtime_resume(struct device *dev)
+{
+       struct tegra_adma *tdma = dev_get_drvdata(dev);
+       int ret;
+
+       ret = pm_clk_resume(dev);
+       if (ret)
+               return ret;
+
+       tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);
+
+       return 0;
+}
+
+static const struct tegra_adma_chip_data tegra210_chip_data = {
+       .nr_channels = 22,
+};
+
+static const struct of_device_id tegra_adma_of_match[] = {
+       { .compatible = "nvidia,tegra210-adma", .data = &tegra210_chip_data },
+       { },
+};
+MODULE_DEVICE_TABLE(of, tegra_adma_of_match);
+
+static int tegra_adma_probe(struct platform_device *pdev)
+{
+       const struct tegra_adma_chip_data *cdata;
+       struct tegra_adma *tdma;
+       struct resource *res;
+       struct clk *clk;
+       int ret, i;
+
+       cdata = of_device_get_match_data(&pdev->dev);
+       if (!cdata) {
+               dev_err(&pdev->dev, "device match data not found\n");
+               return -ENODEV;
+       }
+
+       tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
+                           sizeof(struct tegra_adma_chan), GFP_KERNEL);
+       if (!tdma)
+               return -ENOMEM;
+
+       tdma->dev = &pdev->dev;
+       tdma->nr_channels = cdata->nr_channels;
+       platform_set_drvdata(pdev, tdma);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(tdma->base_addr))
+               return PTR_ERR(tdma->base_addr);
+
+       ret = pm_clk_create(&pdev->dev);
+       if (ret)
+               return ret;
+
+       clk = clk_get(&pdev->dev, "d_audio");
+       if (IS_ERR(clk)) {
+               dev_err(&pdev->dev, "ADMA clock not found\n");
+               ret = PTR_ERR(clk);
+               goto clk_destroy;
+       }
+
+       ret = pm_clk_add_clk(&pdev->dev, clk);
+       if (ret) {
+               clk_put(clk);
+               goto clk_destroy;
+       }
+
+       pm_runtime_enable(&pdev->dev);
+
+       ret = pm_runtime_get_sync(&pdev->dev);
+       if (ret < 0)
+               goto rpm_disable;
+
+       ret = tegra_adma_init(tdma);
+       if (ret)
+               goto rpm_put;
+
+       INIT_LIST_HEAD(&tdma->dma_dev.channels);
+       for (i = 0; i < tdma->nr_channels; i++) {
+               struct tegra_adma_chan *tdc = &tdma->channels[i];
+
+               tdc->chan_addr = tdma->base_addr + ADMA_CH_REG_OFFSET(i);
+
+               tdc->irq = of_irq_get(pdev->dev.of_node, i);
+               if (tdc->irq < 0) {
+                       ret = tdc->irq;
+                       goto irq_dispose;
+               }
+
+               vchan_init(&tdc->vc, &tdma->dma_dev);
+               tdc->vc.desc_free = tegra_adma_desc_free;
+               tdc->tdma = tdma;
+       }
+
+       dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
+       dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
+       dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
+
+       tdma->dma_dev.dev = &pdev->dev;
+       tdma->dma_dev.device_alloc_chan_resources =
+                                       tegra_adma_alloc_chan_resources;
+       tdma->dma_dev.device_free_chan_resources =
+                                       tegra_adma_free_chan_resources;
+       tdma->dma_dev.device_issue_pending = tegra_adma_issue_pending;
+       tdma->dma_dev.device_prep_dma_cyclic = tegra_adma_prep_dma_cyclic;
+       tdma->dma_dev.device_config = tegra_adma_slave_config;
+       tdma->dma_dev.device_tx_status = tegra_adma_tx_status;
+       tdma->dma_dev.device_terminate_all = tegra_adma_terminate_all;
+       tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+       tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+       tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+       tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+
+       ret = dma_async_device_register(&tdma->dma_dev);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "ADMA registration failed: %d\n", ret);
+               goto irq_dispose;
+       }
+
+       ret = of_dma_controller_register(pdev->dev.of_node,
+                                        tegra_dma_of_xlate, tdma);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "ADMA OF registration failed %d\n", ret);
+               goto dma_remove;
+       }
+
+       pm_runtime_put(&pdev->dev);
+
+       dev_info(&pdev->dev, "Tegra210 ADMA driver registered %d channels\n",
+                tdma->nr_channels);
+
+       return 0;
+
+dma_remove:
+       dma_async_device_unregister(&tdma->dma_dev);
+irq_dispose:
+       while (--i >= 0)
+               irq_dispose_mapping(tdma->channels[i].irq);
+rpm_put:
+       pm_runtime_put_sync(&pdev->dev);
+rpm_disable:
+       pm_runtime_disable(&pdev->dev);
+clk_destroy:
+       pm_clk_destroy(&pdev->dev);
+
+       return ret;
+}
+
+static int tegra_adma_remove(struct platform_device *pdev)
+{
+       struct tegra_adma *tdma = platform_get_drvdata(pdev);
+       int i;
+
+       dma_async_device_unregister(&tdma->dma_dev);
+
+       for (i = 0; i < tdma->nr_channels; ++i)
+               irq_dispose_mapping(tdma->channels[i].irq);
+
+       pm_runtime_put_sync(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
+       pm_clk_destroy(&pdev->dev);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_adma_pm_suspend(struct device *dev)
+{
+       return pm_runtime_suspended(dev) == false;
+}
+#endif
+
+static const struct dev_pm_ops tegra_adma_dev_pm_ops = {
+       SET_RUNTIME_PM_OPS(tegra_adma_runtime_suspend,
+                          tegra_adma_runtime_resume, NULL)
+       SET_SYSTEM_SLEEP_PM_OPS(tegra_adma_pm_suspend, NULL)
+};
+
+static struct platform_driver tegra_admac_driver = {
+       .driver = {
+               .name   = "tegra-adma",
+               .pm     = &tegra_adma_dev_pm_ops,
+               .of_match_table = tegra_adma_of_match,
+       },
+       .probe          = tegra_adma_probe,
+       .remove         = tegra_adma_remove,
+};
+
+module_platform_driver(tegra_admac_driver);
+
+MODULE_ALIAS("platform:tegra210-adma");
+MODULE_DESCRIPTION("NVIDIA Tegra ADMA driver");
+MODULE_AUTHOR("Dara Ramesh <dramesh@nvidia.com>");
+MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
+MODULE_LICENSE("GPL v2");