dma40: Improve the logic of stopping logical chan

can be directly stopped by issuing a SUSPEND_REQ on the EE
bits. There is no need to suspend the physical channel and
restart it.

Also, the support for pre-V2 hw is discontinued.

EE bits for writing:

00: disable only if AS=11 or AS=00
01: enable
10: suspend_req only if AS=01 & EE=01 or EE=11
11: round / no change for writing

Signed-off-by: Narayanan G <narayanan.gopalakrishnan@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

2 files changed, 199 insertions, 123 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index bdd41d4bfa8d..c5f26cc2c277 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -69,6 +69,22 @@ enum d40_command {
 };
 
 /*
+ * enum d40_events - The different Event Enables for the event lines.
+ *
+ * @D40_DEACTIVATE_EVENTLINE: De-activate Event line, stopping the logical chan.
+ * @D40_ACTIVATE_EVENTLINE: Activate the Event line, to start a logical chan.
+ * @D40_SUSPEND_REQ_EVENTLINE: Requesting for suspending a event line.
+ * @D40_ROUND_EVENTLINE: Status check for event line.
+ */
+
+enum d40_events {
+        D40_DEACTIVATE_EVENTLINE        = 0,
+        D40_ACTIVATE_EVENTLINE          = 1,
+        D40_SUSPEND_REQ_EVENTLINE       = 2,
+        D40_ROUND_EVENTLINE             = 3
+};
+
+/*
  * These are the registers that has to be saved and later restored
  * when the DMA hw is powered off.
  * TODO: Add save/restore of D40_DREG_GCC on dma40 v3 or later, if that works.
@@ -870,8 +886,8 @@ static void d40_save_restore_registers(struct d40_base *base, bool save)
 }
 #endif
 
-static int d40_channel_execute_command(struct d40_chan *d40c,
-                                       enum d40_command command)
+static int __d40_execute_command_phy(struct d40_chan *d40c,
+                                     enum d40_command command)
 {
         u32 status;
         int i;
@@ -880,6 +896,12 @@ static int d40_channel_execute_command(struct d40_chan *d40c,
         unsigned long flags;
         u32 wmask;
 
+        if (command == D40_DMA_STOP) {
+                ret = __d40_execute_command_phy(d40c, D40_DMA_SUSPEND_REQ);
+                if (ret)
+                        return ret;
+        }
+
         spin_lock_irqsave(&d40c->base->execmd_lock, flags);
 
         if (d40c->phy_chan->num % 2 == 0)
@@ -973,67 +995,109 @@ static void d40_term_all(struct d40_chan *d40c)
                 }
 
         d40c->pending_tx = 0;
-        d40c->busy = false;
 }
 
-static void __d40_config_set_event(struct d40_chan *d40c, bool enable,
-                                   u32 event, int reg)
+static void __d40_config_set_event(struct d40_chan *d40c,
+                                   enum d40_events event_type, u32 event,
+                                   int reg)
 {
         void __iomem *addr = chan_base(d40c) + reg;
         int tries;
+        u32 status;
+
+        switch (event_type) {
+
+        case D40_DEACTIVATE_EVENTLINE:
 
-        if (!enable) {
                 writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
                        | ~D40_EVENTLINE_MASK(event), addr);
-                return;
-        }
+                break;
+
+        case D40_SUSPEND_REQ_EVENTLINE:
+                status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+                          D40_EVENTLINE_POS(event);
+
+                if (status == D40_DEACTIVATE_EVENTLINE ||
+                    status == D40_SUSPEND_REQ_EVENTLINE)
+                        break;
 
+                writel((D40_SUSPEND_REQ_EVENTLINE << D40_EVENTLINE_POS(event))
+                       | ~D40_EVENTLINE_MASK(event), addr);
+
+                for (tries = 0 ; tries < D40_SUSPEND_MAX_IT; tries++) {
+
+                        status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+                                  D40_EVENTLINE_POS(event);
+
+                        cpu_relax();
+                        /*
+                         * Reduce the number of bus accesses while
+                         * waiting for the DMA to suspend.
+                         */
+                        udelay(3);
+
+                        if (status == D40_DEACTIVATE_EVENTLINE)
+                                break;
+                }
+
+                if (tries == D40_SUSPEND_MAX_IT) {
+                        chan_err(d40c,
+                                "unable to stop the event_line chl %d (log: %d)"
+                                "status %x\n", d40c->phy_chan->num,
+                                 d40c->log_num, status);
+                }
+                break;
+
+        case D40_ACTIVATE_EVENTLINE:
         /*
          * The hardware sometimes doesn't register the enable when src and dst
          * event lines are active on the same logical channel.  Retry to ensure
          * it does.  Usually only one retry is sufficient.
          */
-        tries = 100;
-        while (--tries) {
-                writel((D40_ACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
-                       | ~D40_EVENTLINE_MASK(event), addr);
+                tries = 100;
+                while (--tries) {
+                        writel((D40_ACTIVATE_EVENTLINE <<
+                                D40_EVENTLINE_POS(event)) |
+                                ~D40_EVENTLINE_MASK(event), addr);
 
-                if (readl(addr) & D40_EVENTLINE_MASK(event))
-                        break;
-        }
+                        if (readl(addr) & D40_EVENTLINE_MASK(event))
+                                break;
+                }
 
-        if (tries != 99)
-                dev_dbg(chan2dev(d40c),
-                        "[%s] workaround enable S%cLNK (%d tries)\n",
-                        __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
-                        100 - tries);
+                if (tries != 99)
+                        dev_dbg(chan2dev(d40c),
+                                "[%s] workaround enable S%cLNK (%d tries)\n",
+                                __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
+                                100 - tries);
 
-        WARN_ON(!tries);
-}
+                WARN_ON(!tries);
+                break;
 
-static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
-{
-        unsigned long flags;
+        case D40_ROUND_EVENTLINE:
+                BUG();
+                break;
 
-        spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+        }
+}
 
+static void d40_config_set_event(struct d40_chan *d40c,
+                                 enum d40_events event_type)
+{
         /* Enable event line connected to device (or memcpy) */
         if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
             (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH)) {
                 u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
 
-                __d40_config_set_event(d40c, do_enable, event,
+                __d40_config_set_event(d40c, event_type, event,
                                        D40_CHAN_REG_SSLNK);
         }
 
         if (d40c->dma_cfg.dir !=  STEDMA40_PERIPH_TO_MEM) {
                 u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
 
-                __d40_config_set_event(d40c, do_enable, event,
+                __d40_config_set_event(d40c, event_type, event,
                                        D40_CHAN_REG_SDLNK);
         }
-
-        spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
 }
 
 static u32 d40_chan_has_events(struct d40_chan *d40c)
@@ -1047,6 +1111,64 @@ static u32 d40_chan_has_events(struct d40_chan *d40c)
         return val;
 }
 
+static int
+__d40_execute_command_log(struct d40_chan *d40c, enum d40_command command)
+{
+        unsigned long flags;
+        int ret = 0;
+        u32 active_status;
+        void __iomem *active_reg;
+
+        if (d40c->phy_chan->num % 2 == 0)
+                active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
+        else
+                active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;
+
+
+        spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+
+        switch (command) {
+        case D40_DMA_STOP:
+        case D40_DMA_SUSPEND_REQ:
+
+                active_status = (readl(active_reg) &
+                                 D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
+                                 D40_CHAN_POS(d40c->phy_chan->num);
+
+                if (active_status == D40_DMA_RUN)
+                        d40_config_set_event(d40c, D40_SUSPEND_REQ_EVENTLINE);
+                else
+                        d40_config_set_event(d40c, D40_DEACTIVATE_EVENTLINE);
+
+                if (!d40_chan_has_events(d40c) && (command == D40_DMA_STOP))
+                        ret = __d40_execute_command_phy(d40c, command);
+
+                break;
+
+        case D40_DMA_RUN:
+
+                d40_config_set_event(d40c, D40_ACTIVATE_EVENTLINE);
+                ret = __d40_execute_command_phy(d40c, command);
+                break;
+
+        case D40_DMA_SUSPENDED:
+                BUG();
+                break;
+        }
+
+        spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
+        return ret;
+}
+
+static int d40_channel_execute_command(struct d40_chan *d40c,
+                                       enum d40_command command)
+{
+        if (chan_is_logical(d40c))
+                return __d40_execute_command_log(d40c, command);
+        else
+                return __d40_execute_command_phy(d40c, command);
+}
+
 static u32 d40_get_prmo(struct d40_chan *d40c)
 {
         static const unsigned int phy_map[] = {
@@ -1149,15 +1271,7 @@ static int d40_pause(struct d40_chan *d40c)
         spin_lock_irqsave(&d40c->lock, flags);
 
         res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
-        if (res == 0) {
-                if (chan_is_logical(d40c)) {
-                        d40_config_set_event(d40c, false);
-                        /* Resume the other logical channels if any */
-                        if (d40_chan_has_events(d40c))
-                                res = d40_channel_execute_command(d40c,
-                                                                  D40_DMA_RUN);
-                }
-        }
+
         pm_runtime_mark_last_busy(d40c->base->dev);
         pm_runtime_put_autosuspend(d40c->base->dev);
         spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1174,45 +1288,17 @@ static int d40_resume(struct d40_chan *d40c)
 
         spin_lock_irqsave(&d40c->lock, flags);
         pm_runtime_get_sync(d40c->base->dev);
-        if (d40c->base->rev == 0)
-                if (chan_is_logical(d40c)) {
-                        res = d40_channel_execute_command(d40c,
-                                                          D40_DMA_SUSPEND_REQ);
-                        goto no_suspend;
-                }
 
         /* If bytes left to transfer or linked tx resume job */
-        if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
-
-                if (chan_is_logical(d40c))
-                        d40_config_set_event(d40c, true);
-
+        if (d40_residue(d40c) || d40_tx_is_linked(d40c))
                 res = d40_channel_execute_command(d40c, D40_DMA_RUN);
-        }
 
-no_suspend:
         pm_runtime_mark_last_busy(d40c->base->dev);
         pm_runtime_put_autosuspend(d40c->base->dev);
         spin_unlock_irqrestore(&d40c->lock, flags);
         return res;
 }
 
-static int d40_terminate_all(struct d40_chan *chan)
-{
-        unsigned long flags;
-        int ret = 0;
-
-        ret = d40_pause(chan);
-        if (!ret && chan_is_physical(chan))
-                ret = d40_channel_execute_command(chan, D40_DMA_STOP);
-
-        spin_lock_irqsave(&chan->lock, flags);
-        d40_term_all(chan);
-        spin_unlock_irqrestore(&chan->lock, flags);
-
-        return ret;
-}
-
 static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 {
         struct d40_chan *d40c = container_of(tx->chan,
@@ -1232,20 +1318,6 @@ static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 
 static int d40_start(struct d40_chan *d40c)
 {
-        if (d40c->base->rev == 0) {
-                int err;
-
-                if (chan_is_logical(d40c)) {
-                        err = d40_channel_execute_command(d40c,
-                                                          D40_DMA_SUSPEND_REQ);
-                        if (err)
-                                return err;
-                }
-        }
-
-        if (chan_is_logical(d40c))
-                d40_config_set_event(d40c, true);
-
         return d40_channel_execute_command(d40c, D40_DMA_RUN);
 }
 
@@ -1258,10 +1330,10 @@ static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
         d40d = d40_first_queued(d40c);
 
         if (d40d != NULL) {
-                if (!d40c->busy)
+                if (!d40c->busy) {
                         d40c->busy = true;
-
-                pm_runtime_get_sync(d40c->base->dev);
+                        pm_runtime_get_sync(d40c->base->dev);
+                }
 
                 /* Remove from queue */
                 d40_desc_remove(d40d);
@@ -1388,8 +1460,8 @@ static void dma_tasklet(unsigned long data)
 
         return;
 
- err:
-        /* Rescue manoeuvre if receiving double interrupts */
+err:
+        /* Rescue manouver if receiving double interrupts */
         if (d40c->pending_tx > 0)
                 d40c->pending_tx--;
         spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1770,7 +1842,6 @@ static int d40_config_memcpy(struct d40_chan *d40c)
         return 0;
 }
 
-
 static int d40_free_dma(struct d40_chan *d40c)
 {
 
@@ -1806,43 +1877,18 @@ static int d40_free_dma(struct d40_chan *d40c)
         }
 
         pm_runtime_get_sync(d40c->base->dev);
-        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
+        res = d40_channel_execute_command(d40c, D40_DMA_STOP);
         if (res) {
-                chan_err(d40c, "suspend failed\n");
+                chan_err(d40c, "stop failed\n");
                 goto out;
         }
 
-        if (chan_is_logical(d40c)) {
-                /* Release logical channel, deactivate the event line */
+        d40_alloc_mask_free(phy, is_src, chan_is_logical(d40c) ? event : 0);
 
-                d40_config_set_event(d40c, false);
+        if (chan_is_logical(d40c))
                 d40c->base->lookup_log_chans[d40c->log_num] = NULL;
-
-                /*
-                 * Check if there are more logical allocation
-                 * on this phy channel.
-                 */
-                if (!d40_alloc_mask_free(phy, is_src, event)) {
-                        /* Resume the other logical channels if any */
-                        if (d40_chan_has_events(d40c)) {
-                                res = d40_channel_execute_command(d40c,
-                                                                  D40_DMA_RUN);
-                                if (res)
-                                        chan_err(d40c,
-                                                "Executing RUN command\n");
-                        }
-                        goto out;
-                }
-        } else {
-                (void) d40_alloc_mask_free(phy, is_src, 0);
-        }
-
-        /* Release physical channel */
-        res = d40_channel_execute_command(d40c, D40_DMA_STOP);
-        if (res) {
-                chan_err(d40c, "Failed to stop channel\n");
-                goto out;
-        }
+        else
+                d40c->base->lookup_phy_chans[phy->num] = NULL;
 
         if (d40c->busy) {
                 pm_runtime_mark_last_busy(d40c->base->dev);
@@ -1852,7 +1898,6 @@ static int d40_free_dma(struct d40_chan *d40c)
         d40c->busy = false;
         d40c->phy_chan = NULL;
         d40c->configured = false;
-        d40c->base->lookup_phy_chans[phy->num] = NULL;
 out:
 
         pm_runtime_mark_last_busy(d40c->base->dev);
@@ -2371,6 +2416,31 @@ static void d40_issue_pending(struct dma_chan *chan)
         spin_unlock_irqrestore(&d40c->lock, flags);
 }
 
+static void d40_terminate_all(struct dma_chan *chan)
+{
+        unsigned long flags;
+        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
+        int ret;
+
+        spin_lock_irqsave(&d40c->lock, flags);
+
+        pm_runtime_get_sync(d40c->base->dev);
+        ret = d40_channel_execute_command(d40c, D40_DMA_STOP);
+        if (ret)
+                chan_err(d40c, "Failed to stop channel\n");
+
+        d40_term_all(d40c);
+        pm_runtime_mark_last_busy(d40c->base->dev);
+        pm_runtime_put_autosuspend(d40c->base->dev);
+        if (d40c->busy) {
+                pm_runtime_mark_last_busy(d40c->base->dev);
+                pm_runtime_put_autosuspend(d40c->base->dev);
+        }
+        d40c->busy = false;
+
+        spin_unlock_irqrestore(&d40c->lock, flags);
+}
+
 static int
 dma40_config_to_halfchannel(struct d40_chan *d40c,
                             struct stedma40_half_channel_info *info,
@@ -2551,7 +2621,8 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 
         switch (cmd) {
         case DMA_TERMINATE_ALL:
-                return d40_terminate_all(d40c);
+                d40_terminate_all(chan);
+                return 0;
         case DMA_PAUSE:
                 return d40_pause(d40c);
         case DMA_RESUME:
@@ -2908,6 +2979,12 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
         dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
                  rev, res->start);
 
+        if (rev < 2) {
+                d40_err(&pdev->dev, "hardware revision: %d is not supported",
+                        rev);
+                goto failure;
+        }
+
         plat_data = pdev->dev.platform_data;
 
         /* Count the number of logical channels in use */
@@ -2998,6 +3075,7 @@ failure:
 
         if (base) {
                 kfree(base->lcla_pool.alloc_map);
+                kfree(base->reg_val_backup_chan);
                 kfree(base->lookup_log_chans);
                 kfree(base->lookup_phy_chans);
                 kfree(base->phy_res);
diff --git a/drivers/dma/ste_dma40_ll.h b/drivers/dma/ste_dma40_ll.h
index 8d3d490968a3..51e8e5396e9b 100644
--- a/drivers/dma/ste_dma40_ll.h
+++ b/drivers/dma/ste_dma40_ll.h
@@ -62,8 +62,6 @@
 #define D40_SREG_ELEM_LOG_LIDX_MASK     (0xFF << D40_SREG_ELEM_LOG_LIDX_POS)
 
 /* Link register */
-#define D40_DEACTIVATE_EVENTLINE        0x0
-#define D40_ACTIVATE_EVENTLINE          0x1
 #define D40_EVENTLINE_POS(i)            (2 * i)
 #define D40_EVENTLINE_MASK(i)           (0x3 << D40_EVENTLINE_POS(i))