dmaengine: imx-sdma: factor out a struct sdma_desc from struct sdma_channel

This is a preparation step to make the adding of virt-dma easier.
We create a struct sdma_desc, move some fields from struct sdma_channel
there and add a pointer from the former to the latter. For now we
allocate the data statically in struct sdma_channel, but with
virt-dma support it will be dynamically allocated.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 83 insertions, 54 deletions

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index f077992635c2..19c351f3b4bc 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -289,6 +289,30 @@ struct sdma_context_data {
 struct sdma_engine;
 
 /**
+ * struct sdma_desc - descriptor structor for one transfer
+ * @vd                  descriptor for virt dma
+ * @num_bd              max NUM_BD. number of descriptors currently handling
+ * @buf_tail            ID of the buffer that was processed
+ * @buf_ptail           ID of the previous buffer that was processed
+ * @period_len          period length, used in cyclic.
+ * @chn_real_count      the real count updated from bd->mode.count
+ * @chn_count           the transfer count setuped
+ * @sdmac               sdma_channel pointer
+ * @bd                  pointer of alloced bd
+ */
+struct sdma_desc {
+        unsigned int            num_bd;
+        dma_addr_t              bd_phys;
+        unsigned int            buf_tail;
+        unsigned int            buf_ptail;
+        unsigned int            period_len;
+        unsigned int            chn_real_count;
+        unsigned int            chn_count;
+        struct sdma_channel     *sdmac;
+        struct sdma_buffer_descriptor *bd;
+};
+
+/**
  * struct sdma_channel - housekeeping for a SDMA channel
  *
  * @sdma                pointer to the SDMA engine for this channel
@@ -298,11 +322,10 @@ struct sdma_engine;
  * @event_id0           aka dma request line
  * @event_id1           for channels that use 2 events
  * @word_size           peripheral access size
- * @buf_tail            ID of the buffer that was processed
- * @buf_ptail           ID of the previous buffer that was processed
- * @num_bd              max NUM_BD. number of descriptors currently handling
  */
 struct sdma_channel {
+        struct sdma_desc                *desc;
+        struct sdma_desc                _desc;
         struct sdma_engine              *sdma;
         unsigned int                    channel;
         enum dma_transfer_direction             direction;
@@ -310,12 +333,6 @@ struct sdma_channel {
         unsigned int                    event_id0;
         unsigned int                    event_id1;
         enum dma_slave_buswidth         word_size;
-        unsigned int                    buf_tail;
-        unsigned int                    buf_ptail;
-        unsigned int                    num_bd;
-        unsigned int                    period_len;
-        struct sdma_buffer_descriptor   *bd;
-        dma_addr_t                      bd_phys;
         unsigned int                    pc_from_device, pc_to_device;
         unsigned int                    device_to_device;
         unsigned long                   flags;
@@ -325,10 +342,8 @@ struct sdma_channel {
         u32                             shp_addr, per_addr;
         struct dma_chan                 chan;
         spinlock_t                      lock;
-        struct dma_async_tx_descriptor  desc;
+        struct dma_async_tx_descriptor  txdesc;
         enum dma_status                 status;
-        unsigned int                    chn_count;
-        unsigned int                    chn_real_count;
         struct tasklet_struct           tasklet;
         struct imx_dma_data             data;
         bool                            enabled;
@@ -391,6 +406,8 @@ struct sdma_engine {
         u32                             spba_start_addr;
         u32                             spba_end_addr;
         unsigned int                    irq;
+        dma_addr_t                      bd0_phys;
+        struct sdma_buffer_descriptor   *bd0;
 };
 
 static struct sdma_driver_data sdma_imx31 = {
@@ -625,7 +642,7 @@ static int sdma_run_channel0(struct sdma_engine *sdma)
 static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
                 u32 address)
 {
-        struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
+        struct sdma_buffer_descriptor *bd0 = sdma->bd0;
         void *buf_virt;
         dma_addr_t buf_phys;
         int ret;
@@ -700,7 +717,9 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac)
          * call callback function.
          */
         while (1) {
-                bd = &sdmac->bd[sdmac->buf_tail];
+                struct sdma_desc *desc = sdmac->desc;
+
+                bd = &desc->bd[desc->buf_tail];
 
                 if (bd->mode.status & BD_DONE)
                         break;
@@ -716,11 +735,11 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac)
                 * the number of bytes present in the current buffer descriptor.
                 */
 
-                sdmac->chn_real_count = bd->mode.count;
+                desc->chn_real_count = bd->mode.count;
                 bd->mode.status |= BD_DONE;
-                bd->mode.count = sdmac->period_len;
-                sdmac->buf_ptail = sdmac->buf_tail;
-                sdmac->buf_tail = (sdmac->buf_tail + 1) % sdmac->num_bd;
+                bd->mode.count = desc->period_len;
+                desc->buf_ptail = desc->buf_tail;
+                desc->buf_tail = (desc->buf_tail + 1) % desc->num_bd;
 
                 /*
                  * The callback is called from the interrupt context in order
@@ -729,7 +748,7 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac)
                  * executed.
                  */
 
-                dmaengine_desc_get_callback_invoke(&sdmac->desc, NULL);
+                dmaengine_desc_get_callback_invoke(&sdmac->txdesc, NULL);
 
                 if (error)
                         sdmac->status = old_status;
@@ -742,17 +761,17 @@ static void mxc_sdma_handle_channel_normal(unsigned long data)
         struct sdma_buffer_descriptor *bd;
         int i, error = 0;
 
-        sdmac->chn_real_count = 0;
+        sdmac->desc->chn_real_count = 0;
         /*
          * non loop mode. Iterate over all descriptors, collect
          * errors and call callback function
          */
-        for (i = 0; i < sdmac->num_bd; i++) {
-                bd = &sdmac->bd[i];
+        for (i = 0; i < sdmac->desc->num_bd; i++) {
+                bd = &sdmac->desc->bd[i];
 
                  if (bd->mode.status & (BD_DONE | BD_RROR))
                         error = -EIO;
-                 sdmac->chn_real_count += bd->mode.count;
+                 sdmac->desc->chn_real_count += bd->mode.count;
         }
 
         if (error)
@@ -760,9 +779,9 @@ static void mxc_sdma_handle_channel_normal(unsigned long data)
         else
                 sdmac->status = DMA_COMPLETE;
 
-        dma_cookie_complete(&sdmac->desc);
+        dma_cookie_complete(&sdmac->txdesc);
 
-        dmaengine_desc_get_callback_invoke(&sdmac->desc, NULL);
+        dmaengine_desc_get_callback_invoke(&sdmac->txdesc, NULL);
 }
 
 static irqreturn_t sdma_int_handler(int irq, void *dev_id)
@@ -890,7 +909,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
         int channel = sdmac->channel;
         int load_address;
         struct sdma_context_data *context = sdma->context;
-        struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
+        struct sdma_buffer_descriptor *bd0 = sdma->bd0;
         int ret;
         unsigned long flags;
 
@@ -1093,18 +1112,22 @@ static int sdma_set_channel_priority(struct sdma_channel *sdmac,
 static int sdma_request_channel(struct sdma_channel *sdmac)
 {
         struct sdma_engine *sdma = sdmac->sdma;
+        struct sdma_desc *desc;
         int channel = sdmac->channel;
         int ret = -EBUSY;
 
-        sdmac->bd = dma_zalloc_coherent(NULL, PAGE_SIZE, &sdmac->bd_phys,
+        sdmac->desc = &sdmac->_desc;
+        desc = sdmac->desc;
+
+        desc->bd = dma_zalloc_coherent(NULL, PAGE_SIZE, &desc->bd_phys,
                                         GFP_KERNEL);
-        if (!sdmac->bd) {
+        if (!desc->bd) {
                 ret = -ENOMEM;
                 goto out;
         }
 
-        sdma->channel_control[channel].base_bd_ptr = sdmac->bd_phys;
-        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+        sdma->channel_control[channel].base_bd_ptr = desc->bd_phys;
+        sdma->channel_control[channel].current_bd_ptr = desc->bd_phys;
 
         sdma_set_channel_priority(sdmac, MXC_SDMA_DEFAULT_PRIORITY);
         return 0;
@@ -1169,10 +1192,10 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan)
         if (ret)
                 goto disable_clk_ahb;
 
-        dma_async_tx_descriptor_init(&sdmac->desc, chan);
-        sdmac->desc.tx_submit = sdma_tx_submit;
+        dma_async_tx_descriptor_init(&sdmac->txdesc, chan);
+        sdmac->txdesc.tx_submit = sdma_tx_submit;
         /* txd.flags will be overwritten in prep funcs */
-        sdmac->desc.flags = DMA_CTRL_ACK;
+        sdmac->txdesc.flags = DMA_CTRL_ACK;
 
         return 0;
 
@@ -1187,6 +1210,7 @@ static void sdma_free_chan_resources(struct dma_chan *chan)
 {
         struct sdma_channel *sdmac = to_sdma_chan(chan);
         struct sdma_engine *sdma = sdmac->sdma;
+        struct sdma_desc *desc = sdmac->desc;
 
         sdma_disable_channel(chan);
 
@@ -1200,7 +1224,7 @@ static void sdma_free_chan_resources(struct dma_chan *chan)
 
         sdma_set_channel_priority(sdmac, 0);
 
-        dma_free_coherent(NULL, PAGE_SIZE, sdmac->bd, sdmac->bd_phys);
+        dma_free_coherent(NULL, PAGE_SIZE, desc->bd, desc->bd_phys);
 
         clk_disable(sdma->clk_ipg);
         clk_disable(sdma->clk_ahb);
@@ -1216,6 +1240,7 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
         int ret, i, count;
         int channel = sdmac->channel;
         struct scatterlist *sg;
+        struct sdma_desc *desc = sdmac->desc;
 
         if (sdmac->status == DMA_IN_PROGRESS)
                 return NULL;
@@ -1223,9 +1248,9 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
 
         sdmac->flags = 0;
 
-        sdmac->buf_tail = 0;
-        sdmac->buf_ptail = 0;
-        sdmac->chn_real_count = 0;
+        desc->buf_tail = 0;
+        desc->buf_ptail = 0;
+        desc->chn_real_count = 0;
 
         dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
                         sg_len, channel);
@@ -1242,9 +1267,9 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                 goto err_out;
         }
 
-        sdmac->chn_count = 0;
+        desc->chn_count = 0;
         for_each_sg(sgl, sg, sg_len, i) {
-                struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
+                struct sdma_buffer_descriptor *bd = &desc->bd[i];
                 int param;
 
                 bd->buffer_addr = sg->dma_address;
@@ -1259,7 +1284,7 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                 }
 
                 bd->mode.count = count;
-                sdmac->chn_count += count;
+                desc->chn_count += count;
 
                 if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) {
                         ret =  -EINVAL;
@@ -1300,10 +1325,10 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                 bd->mode.status = param;
         }
 
-        sdmac->num_bd = sg_len;
-        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+        desc->num_bd = sg_len;
+        sdma->channel_control[channel].current_bd_ptr = desc->bd_phys;
 
-        return &sdmac->desc;
+        return &sdmac->txdesc;
 err_out:
         sdmac->status = DMA_ERROR;
         return NULL;
@@ -1319,6 +1344,7 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
         int num_periods = buf_len / period_len;
         int channel = sdmac->channel;
         int ret, i = 0, buf = 0;
+        struct sdma_desc *desc = sdmac->desc;
 
         dev_dbg(sdma->dev, "%s channel: %d\n", __func__, channel);
 
@@ -1327,10 +1353,10 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
 
         sdmac->status = DMA_IN_PROGRESS;
 
-        sdmac->buf_tail = 0;
-        sdmac->buf_ptail = 0;
-        sdmac->chn_real_count = 0;
-        sdmac->period_len = period_len;
+        desc->buf_tail = 0;
+        desc->buf_ptail = 0;
+        desc->chn_real_count = 0;
+        desc->period_len = period_len;
 
         sdmac->flags |= IMX_DMA_SG_LOOP;
         sdmac->direction = direction;
@@ -1351,7 +1377,7 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
         }
 
         while (buf < buf_len) {
-                struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
+                struct sdma_buffer_descriptor *bd = &desc->bd[i];
                 int param;
 
                 bd->buffer_addr = dma_addr;
@@ -1382,10 +1408,10 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
                 i++;
         }
 
-        sdmac->num_bd = num_periods;
-        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+        desc->num_bd = num_periods;
+        sdma->channel_control[channel].current_bd_ptr = desc->bd_phys;
 
-        return &sdmac->desc;
+        return &sdmac->txdesc;
 err_out:
         sdmac->status = DMA_ERROR;
         return NULL;
@@ -1424,13 +1450,14 @@ static enum dma_status sdma_tx_status(struct dma_chan *chan,
                                       struct dma_tx_state *txstate)
 {
         struct sdma_channel *sdmac = to_sdma_chan(chan);
+        struct sdma_desc *desc = sdmac->desc;
         u32 residue;
 
         if (sdmac->flags & IMX_DMA_SG_LOOP)
-                residue = (sdmac->num_bd - sdmac->buf_ptail) *
-                           sdmac->period_len - sdmac->chn_real_count;
+                residue = (desc->num_bd - desc->buf_ptail) *
+                           desc->period_len - desc->chn_real_count;
         else
-                residue = sdmac->chn_count - sdmac->chn_real_count;
+                residue = desc->chn_count - desc->chn_real_count;
 
         dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
                          residue);
@@ -1654,6 +1681,8 @@ static int sdma_init(struct sdma_engine *sdma)
         if (ret)
                 goto err_dma_alloc;
 
+        sdma->bd0 = sdma->channel[0].desc->bd;
+
         sdma_config_ownership(&sdma->channel[0], false, true, false);
 
         /* Set Command Channel (Channel Zero) */