dt-bindings: dma: renesas,usb-dmac: add r8a77961 support
[linux-2.6-microblaze.git] / drivers / dma / tegra20-apb-dma.c
index 3a45079..d4c6f13 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
+#include <linux/wait.h>
 
 #include "dmaengine.h"
 
@@ -59,7 +60,7 @@
 #define TEGRA_APBDMA_STATUS_COUNT_MASK         0xFFFC
 
 #define TEGRA_APBDMA_CHAN_CSRE                 0x00C
-#define TEGRA_APBDMA_CHAN_CSRE_PAUSE           (1 << 31)
+#define TEGRA_APBDMA_CHAN_CSRE_PAUSE           BIT(31)
 
 /* AHB memory address */
 #define TEGRA_APBDMA_CHAN_AHBPTR               0x010
@@ -120,21 +121,21 @@ struct tegra_dma;
  * @support_separate_wcount_reg: Support separate word count register.
  */
 struct tegra_dma_chip_data {
-       int nr_channels;
-       int channel_reg_size;
-       int max_dma_count;
+       unsigned int nr_channels;
+       unsigned int channel_reg_size;
+       unsigned int max_dma_count;
        bool support_channel_pause;
        bool support_separate_wcount_reg;
 };
 
 /* DMA channel registers */
 struct tegra_dma_channel_regs {
-       unsigned long   csr;
-       unsigned long   ahb_ptr;
-       unsigned long   apb_ptr;
-       unsigned long   ahb_seq;
-       unsigned long   apb_seq;
-       unsigned long   wcount;
+       u32 csr;
+       u32 ahb_ptr;
+       u32 apb_ptr;
+       u32 ahb_seq;
+       u32 apb_seq;
+       u32 wcount;
 };
 
 /*
@@ -168,7 +169,7 @@ struct tegra_dma_desc {
        struct list_head                node;
        struct list_head                tx_list;
        struct list_head                cb_node;
-       int                             cb_count;
+       unsigned int                    cb_count;
 };
 
 struct tegra_dma_channel;
@@ -181,8 +182,7 @@ struct tegra_dma_channel {
        struct dma_chan         dma_chan;
        char                    name[12];
        bool                    config_init;
-       int                     id;
-       int                     irq;
+       unsigned int            id;
        void __iomem            *chan_addr;
        spinlock_t              lock;
        bool                    busy;
@@ -202,7 +202,9 @@ struct tegra_dma_channel {
        /* Channel-slave specific configuration */
        unsigned int slave_id;
        struct dma_slave_config dma_sconfig;
-       struct tegra_dma_channel_regs   channel_reg;
+       struct tegra_dma_channel_regs channel_reg;
+
+       struct wait_queue_head wq;
 };
 
 /* tegra_dma: Tegra DMA specific information */
@@ -222,9 +224,6 @@ struct tegra_dma {
         */
        u32                             global_pause_count;
 
-       /* Some register need to be cache before suspend */
-       u32                             reg_gen;
-
        /* Last member of the structure */
        struct tegra_dma_channel channels[0];
 };
@@ -240,7 +239,7 @@ static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
 }
 
 static inline void tdc_write(struct tegra_dma_channel *tdc,
-               u32 reg, u32 val)
+                            u32 reg, u32 val)
 {
        writel(val, tdc->chan_addr + reg);
 }
@@ -255,8 +254,8 @@ static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
        return container_of(dc, struct tegra_dma_channel, dma_chan);
 }
 
-static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
-               struct dma_async_tx_descriptor *td)
+static inline struct tegra_dma_desc *
+txd_to_tegra_dma_desc(struct dma_async_tx_descriptor *td)
 {
        return container_of(td, struct tegra_dma_desc, txd);
 }
@@ -267,12 +266,9 @@ static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
 }
 
 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
-static int tegra_dma_runtime_suspend(struct device *dev);
-static int tegra_dma_runtime_resume(struct device *dev);
 
 /* Get DMA desc from free list, if not there then allocate it.  */
-static struct tegra_dma_desc *tegra_dma_desc_get(
-               struct tegra_dma_channel *tdc)
+static struct tegra_dma_desc *tegra_dma_desc_get(struct tegra_dma_channel *tdc)
 {
        struct tegra_dma_desc *dma_desc;
        unsigned long flags;
@@ -299,11 +295,12 @@ static struct tegra_dma_desc *tegra_dma_desc_get(
        dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
        dma_desc->txd.tx_submit = tegra_dma_tx_submit;
        dma_desc->txd.flags = 0;
+
        return dma_desc;
 }
 
 static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
-               struct tegra_dma_desc *dma_desc)
+                              struct tegra_dma_desc *dma_desc)
 {
        unsigned long flags;
 
@@ -314,29 +311,29 @@ static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
        spin_unlock_irqrestore(&tdc->lock, flags);
 }
 
-static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
-               struct tegra_dma_channel *tdc)
+static struct tegra_dma_sg_req *
+tegra_dma_sg_req_get(struct tegra_dma_channel *tdc)
 {
-       struct tegra_dma_sg_req *sg_req = NULL;
+       struct tegra_dma_sg_req *sg_req;
        unsigned long flags;
 
        spin_lock_irqsave(&tdc->lock, flags);
        if (!list_empty(&tdc->free_sg_req)) {
-               sg_req = list_first_entry(&tdc->free_sg_req,
-                                       typeof(*sg_req), node);
+               sg_req = list_first_entry(&tdc->free_sg_req, typeof(*sg_req),
+                                         node);
                list_del(&sg_req->node);
                spin_unlock_irqrestore(&tdc->lock, flags);
                return sg_req;
        }
        spin_unlock_irqrestore(&tdc->lock, flags);
 
-       sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
+       sg_req = kzalloc(sizeof(*sg_req), GFP_NOWAIT);
 
        return sg_req;
 }
 
 static int tegra_dma_slave_config(struct dma_chan *dc,
-               struct dma_slave_config *sconfig)
+                                 struct dma_slave_config *sconfig)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 
@@ -353,11 +350,12 @@ static int tegra_dma_slave_config(struct dma_chan *dc,
                tdc->slave_id = sconfig->slave_id;
        }
        tdc->config_init = true;
+
        return 0;
 }
 
 static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
-       bool wait_for_burst_complete)
+                                  bool wait_for_burst_complete)
 {
        struct tegra_dma *tdma = tdc->tdma;
 
@@ -392,13 +390,13 @@ out:
 }
 
 static void tegra_dma_pause(struct tegra_dma_channel *tdc,
-       bool wait_for_burst_complete)
+                           bool wait_for_burst_complete)
 {
        struct tegra_dma *tdma = tdc->tdma;
 
        if (tdma->chip_data->support_channel_pause) {
                tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
-                               TEGRA_APBDMA_CHAN_CSRE_PAUSE);
+                         TEGRA_APBDMA_CHAN_CSRE_PAUSE);
                if (wait_for_burst_complete)
                        udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
        } else {
@@ -410,17 +408,15 @@ static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 {
        struct tegra_dma *tdma = tdc->tdma;
 
-       if (tdma->chip_data->support_channel_pause) {
+       if (tdma->chip_data->support_channel_pause)
                tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
-       } else {
+       else
                tegra_dma_global_resume(tdc);
-       }
 }
 
 static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 {
-       u32 csr;
-       u32 status;
+       u32 csr, status;
 
        /* Disable interrupts */
        csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
@@ -441,7 +437,7 @@ static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 }
 
 static void tegra_dma_start(struct tegra_dma_channel *tdc,
-               struct tegra_dma_sg_req *sg_req)
+                           struct tegra_dma_sg_req *sg_req)
 {
        struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
 
@@ -455,11 +451,11 @@ static void tegra_dma_start(struct tegra_dma_channel *tdc,
 
        /* Start DMA */
        tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
-                               ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
+                 ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
 }
 
 static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
-               struct tegra_dma_sg_req *nsg_req)
+                                        struct tegra_dma_sg_req *nsg_req)
 {
        unsigned long status;
 
@@ -493,9 +489,9 @@ static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
        tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
        if (tdc->tdma->chip_data->support_separate_wcount_reg)
                tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
-                                               nsg_req->ch_regs.wcount);
+                         nsg_req->ch_regs.wcount);
        tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
-                               nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
+                 nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
        nsg_req->configured = true;
        nsg_req->words_xferred = 0;
 
@@ -506,11 +502,7 @@ static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 {
        struct tegra_dma_sg_req *sg_req;
 
-       if (list_empty(&tdc->pending_sg_req))
-               return;
-
-       sg_req = list_first_entry(&tdc->pending_sg_req,
-                                       typeof(*sg_req), node);
+       sg_req = list_first_entry(&tdc->pending_sg_req, typeof(*sg_req), node);
        tegra_dma_start(tdc, sg_req);
        sg_req->configured = true;
        sg_req->words_xferred = 0;
@@ -519,34 +511,32 @@ static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 
 static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
 {
-       struct tegra_dma_sg_req *hsgreq;
-       struct tegra_dma_sg_req *hnsgreq;
-
-       if (list_empty(&tdc->pending_sg_req))
-               return;
+       struct tegra_dma_sg_req *hsgreq, *hnsgreq;
 
        hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
        if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
-               hnsgreq = list_first_entry(&hsgreq->node,
-                                       typeof(*hnsgreq), node);
+               hnsgreq = list_first_entry(&hsgreq->node, typeof(*hnsgreq),
+                                          node);
                tegra_dma_configure_for_next(tdc, hnsgreq);
        }
 }
 
-static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
-       struct tegra_dma_sg_req *sg_req, unsigned long status)
+static inline unsigned int
+get_current_xferred_count(struct tegra_dma_channel *tdc,
+                         struct tegra_dma_sg_req *sg_req,
+                         unsigned long status)
 {
        return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
 }
 
 static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 {
-       struct tegra_dma_sg_req *sgreq;
        struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_sg_req *sgreq;
 
        while (!list_empty(&tdc->pending_sg_req)) {
-               sgreq = list_first_entry(&tdc->pending_sg_req,
-                                               typeof(*sgreq), node);
+               sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq),
+                                        node);
                list_move_tail(&sgreq->node, &tdc->free_sg_req);
                if (sgreq->last_sg) {
                        dma_desc = sgreq->dma_desc;
@@ -556,7 +546,7 @@ static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
                        /* Add in cb list if it is not there. */
                        if (!dma_desc->cb_count)
                                list_add_tail(&dma_desc->cb_node,
-                                                       &tdc->cb_desc);
+                                             &tdc->cb_desc);
                        dma_desc->cb_count++;
                }
        }
@@ -564,15 +554,9 @@ static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 }
 
 static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
-               struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
+                                          bool to_terminate)
 {
-       struct tegra_dma_sg_req *hsgreq = NULL;
-
-       if (list_empty(&tdc->pending_sg_req)) {
-               dev_err(tdc2dev(tdc), "DMA is running without req\n");
-               tegra_dma_stop(tdc);
-               return false;
-       }
+       struct tegra_dma_sg_req *hsgreq;
 
        /*
         * Check that head req on list should be in flight.
@@ -582,7 +566,8 @@ static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
        hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
        if (!hsgreq->configured) {
                tegra_dma_stop(tdc);
-               dev_err(tdc2dev(tdc), "Error in DMA transfer, aborting DMA\n");
+               pm_runtime_put(tdc->tdma->dev);
+               dev_err(tdc2dev(tdc), "DMA transfer underflow, aborting DMA\n");
                tegra_dma_abort_all(tdc);
                return false;
        }
@@ -590,14 +575,15 @@ static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
        /* Configure next request */
        if (!to_terminate)
                tdc_configure_next_head_desc(tdc);
+
        return true;
 }
 
 static void handle_once_dma_done(struct tegra_dma_channel *tdc,
-       bool to_terminate)
+                                bool to_terminate)
 {
-       struct tegra_dma_sg_req *sgreq;
        struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_sg_req *sgreq;
 
        tdc->busy = false;
        sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
@@ -616,17 +602,22 @@ static void handle_once_dma_done(struct tegra_dma_channel *tdc,
        list_add_tail(&sgreq->node, &tdc->free_sg_req);
 
        /* Do not start DMA if it is going to be terminate */
-       if (to_terminate || list_empty(&tdc->pending_sg_req))
+       if (to_terminate)
+               return;
+
+       if (list_empty(&tdc->pending_sg_req)) {
+               pm_runtime_put(tdc->tdma->dev);
                return;
+       }
 
        tdc_start_head_req(tdc);
 }
 
 static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
-               bool to_terminate)
+                                           bool to_terminate)
 {
-       struct tegra_dma_sg_req *sgreq;
        struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_sg_req *sgreq;
        bool st;
 
        sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
@@ -647,7 +638,7 @@ static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
        if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
                list_move_tail(&sgreq->node, &tdc->pending_sg_req);
                sgreq->configured = false;
-               st = handle_continuous_head_request(tdc, sgreq, to_terminate);
+               st = handle_continuous_head_request(tdc, to_terminate);
                if (!st)
                        dma_desc->dma_status = DMA_ERROR;
        }
@@ -658,13 +649,13 @@ static void tegra_dma_tasklet(unsigned long data)
        struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
        struct dmaengine_desc_callback cb;
        struct tegra_dma_desc *dma_desc;
+       unsigned int cb_count;
        unsigned long flags;
-       int cb_count;
 
        spin_lock_irqsave(&tdc->lock, flags);
        while (!list_empty(&tdc->cb_desc)) {
-               dma_desc  = list_first_entry(&tdc->cb_desc,
-                                       typeof(*dma_desc), cb_node);
+               dma_desc = list_first_entry(&tdc->cb_desc, typeof(*dma_desc),
+                                           cb_node);
                list_del(&dma_desc->cb_node);
                dmaengine_desc_get_callback(&dma_desc->txd, &cb);
                cb_count = dma_desc->cb_count;
@@ -682,10 +673,9 @@ static void tegra_dma_tasklet(unsigned long data)
 static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 {
        struct tegra_dma_channel *tdc = dev_id;
-       unsigned long status;
-       unsigned long flags;
+       u32 status;
 
-       spin_lock_irqsave(&tdc->lock, flags);
+       spin_lock(&tdc->lock);
 
        trace_tegra_dma_isr(&tdc->dma_chan, irq);
        status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
@@ -693,13 +683,15 @@ static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
                tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
                tdc->isr_handler(tdc, false);
                tasklet_schedule(&tdc->tasklet);
-               spin_unlock_irqrestore(&tdc->lock, flags);
+               wake_up_all(&tdc->wq);
+               spin_unlock(&tdc->lock);
                return IRQ_HANDLED;
        }
 
-       spin_unlock_irqrestore(&tdc->lock, flags);
-       dev_info(tdc2dev(tdc),
-               "Interrupt already served status 0x%08lx\n", status);
+       spin_unlock(&tdc->lock);
+       dev_info(tdc2dev(tdc), "Interrupt already served status 0x%08x\n",
+                status);
+
        return IRQ_NONE;
 }
 
@@ -715,6 +707,7 @@ static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
        cookie = dma_cookie_assign(&dma_desc->txd);
        list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
        spin_unlock_irqrestore(&tdc->lock, flags);
+
        return cookie;
 }
 
@@ -722,6 +715,7 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
        unsigned long flags;
+       int err;
 
        spin_lock_irqsave(&tdc->lock, flags);
        if (list_empty(&tdc->pending_sg_req)) {
@@ -729,6 +723,12 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
                goto end;
        }
        if (!tdc->busy) {
+               err = pm_runtime_get_sync(tdc->tdma->dev);
+               if (err < 0) {
+                       dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
+                       goto end;
+               }
+
                tdc_start_head_req(tdc);
 
                /* Continuous single mode: Configure next req */
@@ -748,11 +748,10 @@ end:
 static int tegra_dma_terminate_all(struct dma_chan *dc)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
-       struct tegra_dma_sg_req *sgreq;
        struct tegra_dma_desc *dma_desc;
+       struct tegra_dma_sg_req *sgreq;
        unsigned long flags;
-       unsigned long status;
-       unsigned long wcount;
+       u32 status, wcount;
        bool was_busy;
 
        spin_lock_irqsave(&tdc->lock, flags);
@@ -782,30 +781,60 @@ static int tegra_dma_terminate_all(struct dma_chan *dc)
        tegra_dma_stop(tdc);
 
        if (!list_empty(&tdc->pending_sg_req) && was_busy) {
-               sgreq = list_first_entry(&tdc->pending_sg_req,
-                                       typeof(*sgreq), node);
+               sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq),
+                                        node);
                sgreq->dma_desc->bytes_transferred +=
                                get_current_xferred_count(tdc, sgreq, wcount);
        }
        tegra_dma_resume(tdc);
 
+       pm_runtime_put(tdc->tdma->dev);
+       wake_up_all(&tdc->wq);
+
 skip_dma_stop:
        tegra_dma_abort_all(tdc);
 
        while (!list_empty(&tdc->cb_desc)) {
-               dma_desc  = list_first_entry(&tdc->cb_desc,
-                                       typeof(*dma_desc), cb_node);
+               dma_desc = list_first_entry(&tdc->cb_desc, typeof(*dma_desc),
+                                           cb_node);
                list_del(&dma_desc->cb_node);
                dma_desc->cb_count = 0;
        }
        spin_unlock_irqrestore(&tdc->lock, flags);
+
        return 0;
 }
 
+static bool tegra_dma_eoc_interrupt_deasserted(struct tegra_dma_channel *tdc)
+{
+       unsigned long flags;
+       u32 status;
+
+       spin_lock_irqsave(&tdc->lock, flags);
+       status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
+       spin_unlock_irqrestore(&tdc->lock, flags);
+
+       return !(status & TEGRA_APBDMA_STATUS_ISE_EOC);
+}
+
+static void tegra_dma_synchronize(struct dma_chan *dc)
+{
+       struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+
+       /*
+        * CPU, which handles interrupt, could be busy in
+        * uninterruptible state, in this case sibling CPU
+        * should wait until interrupt is handled.
+        */
+       wait_event(tdc->wq, tegra_dma_eoc_interrupt_deasserted(tdc));
+
+       tasklet_kill(&tdc->tasklet);
+}
+
 static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
                                               struct tegra_dma_sg_req *sg_req)
 {
-       unsigned long status, wcount = 0;
+       u32 status, wcount = 0;
 
        if (!list_is_first(&sg_req->node, &tdc->pending_sg_req))
                return 0;
@@ -862,7 +891,8 @@ static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
 }
 
 static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
-       dma_cookie_t cookie, struct dma_tx_state *txstate)
+                                          dma_cookie_t cookie,
+                                          struct dma_tx_state *txstate)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
        struct tegra_dma_desc *dma_desc;
@@ -909,11 +939,12 @@ found:
 
        trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
        spin_unlock_irqrestore(&tdc->lock, flags);
+
        return ret;
 }
 
-static inline int get_bus_width(struct tegra_dma_channel *tdc,
-               enum dma_slave_buswidth slave_bw)
+static inline unsigned int get_bus_width(struct tegra_dma_channel *tdc,
+                                        enum dma_slave_buswidth slave_bw)
 {
        switch (slave_bw) {
        case DMA_SLAVE_BUSWIDTH_1_BYTE:
@@ -926,16 +957,17 @@ static inline int get_bus_width(struct tegra_dma_channel *tdc,
                return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
        default:
                dev_warn(tdc2dev(tdc),
-                       "slave bw is not supported, using 32bits\n");
+                        "slave bw is not supported, using 32bits\n");
                return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
        }
 }
 
-static inline int get_burst_size(struct tegra_dma_channel *tdc,
-       u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
+static inline unsigned int get_burst_size(struct tegra_dma_channel *tdc,
+                                         u32 burst_size,
+                                         enum dma_slave_buswidth slave_bw,
+                                         u32 len)
 {
-       int burst_byte;
-       int burst_ahb_width;
+       unsigned int burst_byte, burst_ahb_width;
 
        /*
         * burst_size from client is in terms of the bus_width.
@@ -962,9 +994,12 @@ static inline int get_burst_size(struct tegra_dma_channel *tdc,
 }
 
 static int get_transfer_param(struct tegra_dma_channel *tdc,
-       enum dma_transfer_direction direction, unsigned long *apb_addr,
-       unsigned long *apb_seq, unsigned long *csr, unsigned int *burst_size,
-       enum dma_slave_buswidth *slave_bw)
+                             enum dma_transfer_direction direction,
+                             u32 *apb_addr,
+                             u32 *apb_seq,
+                             u32 *csr,
+                             unsigned int *burst_size,
+                             enum dma_slave_buswidth *slave_bw)
 {
        switch (direction) {
        case DMA_MEM_TO_DEV:
@@ -985,13 +1020,15 @@ static int get_transfer_param(struct tegra_dma_channel *tdc,
 
        default:
                dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
-               return -EINVAL;
+               break;
        }
+
        return -EINVAL;
 }
 
 static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
-       struct tegra_dma_channel_regs *ch_regs, u32 len)
+                                 struct tegra_dma_channel_regs *ch_regs,
+                                 u32 len)
 {
        u32 len_field = (len - 4) & 0xFFFC;
 
@@ -1001,20 +1038,23 @@ static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
                ch_regs->csr |= len_field;
 }
 
-static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
-       struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
-       enum dma_transfer_direction direction, unsigned long flags,
-       void *context)
+static struct dma_async_tx_descriptor *
+tegra_dma_prep_slave_sg(struct dma_chan *dc,
+                       struct scatterlist *sgl,
+                       unsigned int sg_len,
+                       enum dma_transfer_direction direction,
+                       unsigned long flags,
+                       void *context)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+       struct tegra_dma_sg_req *sg_req = NULL;
+       u32 csr, ahb_seq, apb_ptr, apb_seq;
+       enum dma_slave_buswidth slave_bw;
        struct tegra_dma_desc *dma_desc;
-       unsigned int i;
-       struct scatterlist *sg;
-       unsigned long csr, ahb_seq, apb_ptr, apb_seq;
        struct list_head req_list;
-       struct tegra_dma_sg_req  *sg_req = NULL;
-       u32 burst_size;
-       enum dma_slave_buswidth slave_bw;
+       struct scatterlist *sg;
+       unsigned int burst_size;
+       unsigned int i;
 
        if (!tdc->config_init) {
                dev_err(tdc2dev(tdc), "DMA channel is not configured\n");
@@ -1026,7 +1066,7 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
        }
 
        if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
-                               &burst_size, &slave_bw) < 0)
+                              &burst_size, &slave_bw) < 0)
                return NULL;
 
        INIT_LIST_HEAD(&req_list);
@@ -1072,7 +1112,7 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
                len = sg_dma_len(sg);
 
                if ((len & 3) || (mem & 3) ||
-                               (len > tdc->tdma->chip_data->max_dma_count)) {
+                   len > tdc->tdma->chip_data->max_dma_count) {
                        dev_err(tdc2dev(tdc),
                                "DMA length/memory address is not supported\n");
                        tegra_dma_desc_put(tdc, dma_desc);
@@ -1124,20 +1164,21 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
        return &dma_desc->txd;
 }
 
-static struct dma_async_tx_descriptor *tegra_dma_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)
+static struct dma_async_tx_descriptor *
+tegra_dma_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_dma_channel *tdc = to_tegra_dma_chan(dc);
-       struct tegra_dma_desc *dma_desc = NULL;
        struct tegra_dma_sg_req *sg_req = NULL;
-       unsigned long csr, ahb_seq, apb_ptr, apb_seq;
-       int len;
-       size_t remain_len;
-       dma_addr_t mem = buf_addr;
-       u32 burst_size;
+       u32 csr, ahb_seq, apb_ptr, apb_seq;
        enum dma_slave_buswidth slave_bw;
+       struct tegra_dma_desc *dma_desc;
+       dma_addr_t mem = buf_addr;
+       unsigned int burst_size;
+       size_t len, remain_len;
 
        if (!buf_len || !period_len) {
                dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
@@ -1171,13 +1212,13 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
 
        len = period_len;
        if ((len & 3) || (buf_addr & 3) ||
-                       (len > tdc->tdma->chip_data->max_dma_count)) {
+           len > tdc->tdma->chip_data->max_dma_count) {
                dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
                return NULL;
        }
 
        if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
-                               &burst_size, &slave_bw) < 0)
+                              &burst_size, &slave_bw) < 0)
                return NULL;
 
        ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
@@ -1263,15 +1304,8 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
 static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
-       struct tegra_dma *tdma = tdc->tdma;
-       int ret;
 
        dma_cookie_init(&tdc->dma_chan);
-       tdc->config_init = false;
-
-       ret = pm_runtime_get_sync(tdma->dev);
-       if (ret < 0)
-               return ret;
 
        return 0;
 }
@@ -1279,33 +1313,29 @@ static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
 static void tegra_dma_free_chan_resources(struct dma_chan *dc)
 {
        struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
-       struct tegra_dma *tdma = tdc->tdma;
        struct tegra_dma_desc *dma_desc;
        struct tegra_dma_sg_req *sg_req;
        struct list_head dma_desc_list;
        struct list_head sg_req_list;
-       unsigned long flags;
 
        INIT_LIST_HEAD(&dma_desc_list);
        INIT_LIST_HEAD(&sg_req_list);
 
        dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
 
-       if (tdc->busy)
-               tegra_dma_terminate_all(dc);
+       tegra_dma_terminate_all(dc);
+       tasklet_kill(&tdc->tasklet);
 
-       spin_lock_irqsave(&tdc->lock, flags);
        list_splice_init(&tdc->pending_sg_req, &sg_req_list);
        list_splice_init(&tdc->free_sg_req, &sg_req_list);
        list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
        INIT_LIST_HEAD(&tdc->cb_desc);
        tdc->config_init = false;
        tdc->isr_handler = NULL;
-       spin_unlock_irqrestore(&tdc->lock, flags);
 
        while (!list_empty(&dma_desc_list)) {
-               dma_desc = list_first_entry(&dma_desc_list,
-                                       typeof(*dma_desc), node);
+               dma_desc = list_first_entry(&dma_desc_list, typeof(*dma_desc),
+                                           node);
                list_del(&dma_desc->node);
                kfree(dma_desc);
        }
@@ -1315,7 +1345,6 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
                list_del(&sg_req->node);
                kfree(sg_req);
        }
-       pm_runtime_put(tdma->dev);
 
        tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
 }
@@ -1324,8 +1353,8 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
                                           struct of_dma *ofdma)
 {
        struct tegra_dma *tdma = ofdma->of_dma_data;
-       struct dma_chan *chan;
        struct tegra_dma_channel *tdc;
+       struct dma_chan *chan;
 
        if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
                dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
@@ -1378,23 +1407,48 @@ static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
        .support_separate_wcount_reg = true,
 };
 
+static int tegra_dma_init_hw(struct tegra_dma *tdma)
+{
+       int err;
+
+       err = reset_control_assert(tdma->rst);
+       if (err) {
+               dev_err(tdma->dev, "failed to assert reset: %d\n", err);
+               return err;
+       }
+
+       err = clk_enable(tdma->dma_clk);
+       if (err) {
+               dev_err(tdma->dev, "failed to enable clk: %d\n", err);
+               return err;
+       }
+
+       /* reset DMA controller */
+       udelay(2);
+       reset_control_deassert(tdma->rst);
+
+       /* enable global DMA registers */
+       tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
+       tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
+       tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFF);
+
+       clk_disable(tdma->dma_clk);
+
+       return 0;
+}
+
 static int tegra_dma_probe(struct platform_device *pdev)
 {
-       struct resource *res;
+       const struct tegra_dma_chip_data *cdata;
        struct tegra_dma *tdma;
+       unsigned int i;
+       size_t size;
        int ret;
-       int i;
-       const struct tegra_dma_chip_data *cdata;
 
        cdata = of_device_get_match_data(&pdev->dev);
-       if (!cdata) {
-               dev_err(&pdev->dev, "Error: No device match data found\n");
-               return -ENODEV;
-       }
+       size = struct_size(tdma, channels, cdata->nr_channels);
 
-       tdma = devm_kzalloc(&pdev->dev,
-                           struct_size(tdma, channels, cdata->nr_channels),
-                           GFP_KERNEL);
+       tdma = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
        if (!tdma)
                return -ENOMEM;
 
@@ -1402,8 +1456,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
        tdma->chip_data = cdata;
        platform_set_drvdata(pdev, tdma);
 
-       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
+       tdma->base_addr = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(tdma->base_addr))
                return PTR_ERR(tdma->base_addr);
 
@@ -1421,64 +1474,55 @@ static int tegra_dma_probe(struct platform_device *pdev)
 
        spin_lock_init(&tdma->global_lock);
 
-       pm_runtime_enable(&pdev->dev);
-       if (!pm_runtime_enabled(&pdev->dev))
-               ret = tegra_dma_runtime_resume(&pdev->dev);
-       else
-               ret = pm_runtime_get_sync(&pdev->dev);
-
-       if (ret < 0) {
-               pm_runtime_disable(&pdev->dev);
+       ret = clk_prepare(tdma->dma_clk);
+       if (ret)
                return ret;
-       }
-
-       /* Reset DMA controller */
-       reset_control_assert(tdma->rst);
-       udelay(2);
-       reset_control_deassert(tdma->rst);
 
-       /* Enable global DMA registers */
-       tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
-       tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
-       tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
+       ret = tegra_dma_init_hw(tdma);
+       if (ret)
+               goto err_clk_unprepare;
 
-       pm_runtime_put(&pdev->dev);
+       pm_runtime_irq_safe(&pdev->dev);
+       pm_runtime_enable(&pdev->dev);
 
        INIT_LIST_HEAD(&tdma->dma_dev.channels);
        for (i = 0; i < cdata->nr_channels; i++) {
                struct tegra_dma_channel *tdc = &tdma->channels[i];
+               int irq;
 
                tdc->chan_addr = tdma->base_addr +
                                 TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
                                 (i * cdata->channel_reg_size);
 
-               res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
-               if (!res) {
-                       ret = -EINVAL;
+               irq = platform_get_irq(pdev, i);
+               if (irq < 0) {
+                       ret = irq;
                        dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
-                       goto err_irq;
+                       goto err_pm_disable;
                }
-               tdc->irq = res->start;
+
                snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
-               ret = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
+               ret = devm_request_irq(&pdev->dev, irq, tegra_dma_isr, 0,
+                                      tdc->name, tdc);
                if (ret) {
                        dev_err(&pdev->dev,
                                "request_irq failed with err %d channel %d\n",
                                ret, i);
-                       goto err_irq;
+                       goto err_pm_disable;
                }
 
                tdc->dma_chan.device = &tdma->dma_dev;
                dma_cookie_init(&tdc->dma_chan);
                list_add_tail(&tdc->dma_chan.device_node,
-                               &tdma->dma_dev.channels);
+                             &tdma->dma_dev.channels);
                tdc->tdma = tdma;
                tdc->id = i;
                tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
 
                tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
-                               (unsigned long)tdc);
+                            (unsigned long)tdc);
                spin_lock_init(&tdc->lock);
+               init_waitqueue_head(&tdc->wq);
 
                INIT_LIST_HEAD(&tdc->pending_sg_req);
                INIT_LIST_HEAD(&tdc->free_sg_req);
@@ -1510,6 +1554,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
        tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
        tdma->dma_dev.device_config = tegra_dma_slave_config;
        tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
+       tdma->dma_dev.device_synchronize = tegra_dma_synchronize;
        tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
        tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
 
@@ -1517,7 +1562,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
        if (ret < 0) {
                dev_err(&pdev->dev,
                        "Tegra20 APB DMA driver registration failed %d\n", ret);
-               goto err_irq;
+               goto err_pm_disable;
        }
 
        ret = of_dma_controller_register(pdev->dev.of_node,
@@ -1528,118 +1573,92 @@ static int tegra_dma_probe(struct platform_device *pdev)
                goto err_unregister_dma_dev;
        }
 
-       dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
-                       cdata->nr_channels);
+       dev_info(&pdev->dev, "Tegra20 APB DMA driver registered %u channels\n",
+                cdata->nr_channels);
+
        return 0;
 
 err_unregister_dma_dev:
        dma_async_device_unregister(&tdma->dma_dev);
-err_irq:
-       while (--i >= 0) {
-               struct tegra_dma_channel *tdc = &tdma->channels[i];
-
-               free_irq(tdc->irq, tdc);
-               tasklet_kill(&tdc->tasklet);
-       }
 
+err_pm_disable:
        pm_runtime_disable(&pdev->dev);
-       if (!pm_runtime_status_suspended(&pdev->dev))
-               tegra_dma_runtime_suspend(&pdev->dev);
+
+err_clk_unprepare:
+       clk_unprepare(tdma->dma_clk);
+
        return ret;
 }
 
 static int tegra_dma_remove(struct platform_device *pdev)
 {
        struct tegra_dma *tdma = platform_get_drvdata(pdev);
-       int i;
-       struct tegra_dma_channel *tdc;
 
+       of_dma_controller_free(pdev->dev.of_node);
        dma_async_device_unregister(&tdma->dma_dev);
-
-       for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
-               tdc = &tdma->channels[i];
-               free_irq(tdc->irq, tdc);
-               tasklet_kill(&tdc->tasklet);
-       }
-
        pm_runtime_disable(&pdev->dev);
-       if (!pm_runtime_status_suspended(&pdev->dev))
-               tegra_dma_runtime_suspend(&pdev->dev);
+       clk_unprepare(tdma->dma_clk);
 
        return 0;
 }
 
-static int tegra_dma_runtime_suspend(struct device *dev)
+static int __maybe_unused tegra_dma_runtime_suspend(struct device *dev)
 {
        struct tegra_dma *tdma = dev_get_drvdata(dev);
-       int i;
-
-       tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
-       for (i = 0; i < tdma->chip_data->nr_channels; i++) {
-               struct tegra_dma_channel *tdc = &tdma->channels[i];
-               struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
-
-               /* Only save the state of DMA channels that are in use */
-               if (!tdc->config_init)
-                       continue;
-
-               ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
-               ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
-               ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
-               ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
-               ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
-               if (tdma->chip_data->support_separate_wcount_reg)
-                       ch_reg->wcount = tdc_read(tdc,
-                                                 TEGRA_APBDMA_CHAN_WCOUNT);
-       }
 
-       clk_disable_unprepare(tdma->dma_clk);
+       clk_disable(tdma->dma_clk);
 
        return 0;
 }
 
-static int tegra_dma_runtime_resume(struct device *dev)
+static int __maybe_unused tegra_dma_runtime_resume(struct device *dev)
 {
        struct tegra_dma *tdma = dev_get_drvdata(dev);
-       int i, ret;
 
-       ret = clk_prepare_enable(tdma->dma_clk);
-       if (ret < 0) {
-               dev_err(dev, "clk_enable failed: %d\n", ret);
-               return ret;
-       }
+       return clk_enable(tdma->dma_clk);
+}
 
-       tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
-       tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
-       tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
+static int __maybe_unused tegra_dma_dev_suspend(struct device *dev)
+{
+       struct tegra_dma *tdma = dev_get_drvdata(dev);
+       unsigned long flags;
+       unsigned int i;
+       bool busy;
 
        for (i = 0; i < tdma->chip_data->nr_channels; i++) {
                struct tegra_dma_channel *tdc = &tdma->channels[i];
-               struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
-
-               /* Only restore the state of DMA channels that are in use */
-               if (!tdc->config_init)
-                       continue;
-
-               if (tdma->chip_data->support_separate_wcount_reg)
-                       tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
-                                 ch_reg->wcount);
-               tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
-               tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
-               tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
-               tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
-               tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
-                       (ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
+
+               tasklet_kill(&tdc->tasklet);
+
+               spin_lock_irqsave(&tdc->lock, flags);
+               busy = tdc->busy;
+               spin_unlock_irqrestore(&tdc->lock, flags);
+
+               if (busy) {
+                       dev_err(tdma->dev, "channel %u busy\n", i);
+                       return -EBUSY;
+               }
        }
 
-       return 0;
+       return pm_runtime_force_suspend(dev);
+}
+
+static int __maybe_unused tegra_dma_dev_resume(struct device *dev)
+{
+       struct tegra_dma *tdma = dev_get_drvdata(dev);
+       int err;
+
+       err = tegra_dma_init_hw(tdma);
+       if (err)
+               return err;
+
+       return pm_runtime_force_resume(dev);
 }
 
 static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
                           NULL)
-       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
-                               pm_runtime_force_resume)
+       SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_dev_suspend, tegra_dma_dev_resume)
 };
 
 static const struct of_device_id tegra_dma_of_match[] = {
@@ -1672,7 +1691,6 @@ static struct platform_driver tegra_dmac_driver = {
 
 module_platform_driver(tegra_dmac_driver);
 
-MODULE_ALIAS("platform:tegra20-apbdma");
 MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 MODULE_LICENSE("GPL v2");