dmaengine/ste_dma40: support pm in dma40
authorNarayanan G <narayanan.gopalakrishnan@stericsson.com>
Thu, 17 Nov 2011 11:56:41 +0000 (17:26 +0530)
committerVinod Koul <vinod.koul@linux.intel.com>
Tue, 22 Nov 2011 04:16:06 +0000 (09:46 +0530)
This patch adds power management support to the dma40
driver. The DMA registers are backed up and restored,
during suspend/resume. Also flags to track the dma usage
have been introduced to facilitate this. Patch also includes
few other minor changes, related to formatting, comments.

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>
drivers/dma/ste_dma40.c
drivers/dma/ste_dma40_ll.h

index 15b311d54b740f58a098e615dd2874e1898054e9..c2cf8cfaf7d4e69ad6149bc46fd3058064d23dba 100644 (file)
@@ -14,6 +14,8 @@
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
 #include <linux/err.h>
 #include <linux/amba/bus.h>
 
@@ -32,6 +34,9 @@
 /* Maximum iterations taken before giving up suspending a channel */
 #define D40_SUSPEND_MAX_IT 500
 
+/* Milliseconds */
+#define DMA40_AUTOSUSPEND_DELAY        100
+
 /* Hardware requirement on LCLA alignment */
 #define LCLA_ALIGNMENT 0x40000
 
@@ -62,6 +67,55 @@ enum d40_command {
        D40_DMA_SUSPENDED       = 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.
+ */
+static u32 d40_backup_regs[] = {
+       D40_DREG_LCPA,
+       D40_DREG_LCLA,
+       D40_DREG_PRMSE,
+       D40_DREG_PRMSO,
+       D40_DREG_PRMOE,
+       D40_DREG_PRMOO,
+};
+
+#define BACKUP_REGS_SZ ARRAY_SIZE(d40_backup_regs)
+
+/* TODO: Check if all these registers have to be saved/restored on dma40 v3 */
+static u32 d40_backup_regs_v3[] = {
+       D40_DREG_PSEG1,
+       D40_DREG_PSEG2,
+       D40_DREG_PSEG3,
+       D40_DREG_PSEG4,
+       D40_DREG_PCEG1,
+       D40_DREG_PCEG2,
+       D40_DREG_PCEG3,
+       D40_DREG_PCEG4,
+       D40_DREG_RSEG1,
+       D40_DREG_RSEG2,
+       D40_DREG_RSEG3,
+       D40_DREG_RSEG4,
+       D40_DREG_RCEG1,
+       D40_DREG_RCEG2,
+       D40_DREG_RCEG3,
+       D40_DREG_RCEG4,
+};
+
+#define BACKUP_REGS_SZ_V3 ARRAY_SIZE(d40_backup_regs_v3)
+
+static u32 d40_backup_regs_chan[] = {
+       D40_CHAN_REG_SSCFG,
+       D40_CHAN_REG_SSELT,
+       D40_CHAN_REG_SSPTR,
+       D40_CHAN_REG_SSLNK,
+       D40_CHAN_REG_SDCFG,
+       D40_CHAN_REG_SDELT,
+       D40_CHAN_REG_SDPTR,
+       D40_CHAN_REG_SDLNK,
+};
+
 /**
  * struct d40_lli_pool - Structure for keeping LLIs in memory
  *
@@ -96,7 +150,7 @@ struct d40_lli_pool {
  * during a transfer.
  * @node: List entry.
  * @is_in_client_list: true if the client owns this descriptor.
- * the previous one.
+ * @cyclic: true if this is a cyclic job
  *
  * This descriptor is used for both logical and physical transfers.
  */
@@ -143,6 +197,7 @@ struct d40_lcla_pool {
  * channels.
  *
  * @lock: A lock protection this entity.
+ * @reserved: True if used by secure world or otherwise.
  * @num: The physical channel number of this entity.
  * @allocated_src: Bit mapped to show which src event line's are mapped to
  * this physical channel. Can also be free or physically allocated.
@@ -152,6 +207,7 @@ struct d40_lcla_pool {
  */
 struct d40_phy_res {
        spinlock_t lock;
+       bool       reserved;
        int        num;
        u32        allocated_src;
        u32        allocated_dst;
@@ -185,7 +241,6 @@ struct d40_base;
  * @src_def_cfg: Default cfg register setting for src.
  * @dst_def_cfg: Default cfg register setting for dst.
  * @log_def: Default logical channel settings.
- * @lcla: Space for one dst src pair for logical channel transfers.
  * @lcpa: Pointer to dst and src lcpa settings.
  * @runtime_addr: runtime configured address.
  * @runtime_direction: runtime configured direction.
@@ -241,6 +296,7 @@ struct d40_chan {
  * @dma_both: dma_device channels that can do both memcpy and slave transfers.
  * @dma_slave: dma_device channels that can do only do slave transfers.
  * @dma_memcpy: dma_device channels that can do only do memcpy transfers.
+ * @phy_chans: Room for all possible physical channels in system.
  * @log_chans: Room for all possible logical channels in system.
  * @lookup_log_chans: Used to map interrupt number to logical channel. Points
  * to log_chans entries.
@@ -254,6 +310,13 @@ struct d40_chan {
  * @phy_lcpa: The physical address of the LCPA.
  * @lcpa_size: The size of the LCPA area.
  * @desc_slab: cache for descriptors.
+ * @reg_val_backup: Here the values of some hardware registers are stored
+ * before the DMA is powered off. They are restored when the power is back on.
+ * @reg_val_backup_v3: Backup of registers that only exits on dma40 v3 and
+ * later.
+ * @reg_val_backup_chan: Backup data for standard channel parameter registers.
+ * @gcc_pwr_off_mask: Mask to maintain the channels that can be turned off.
+ * @initialized: true if the dma has been initialized
  */
 struct d40_base {
        spinlock_t                       interrupt_lock;
@@ -282,6 +345,11 @@ struct d40_base {
        dma_addr_t                        phy_lcpa;
        resource_size_t                   lcpa_size;
        struct kmem_cache                *desc_slab;
+       u32                               reg_val_backup[BACKUP_REGS_SZ];
+       u32                               reg_val_backup_v3[BACKUP_REGS_SZ_V3];
+       u32                              *reg_val_backup_chan;
+       u16                               gcc_pwr_off_mask;
+       bool                              initialized;
 };
 
 /**
@@ -479,13 +547,14 @@ static struct d40_desc *d40_desc_get(struct d40_chan *d40c)
                struct d40_desc *d;
                struct d40_desc *_d;
 
-               list_for_each_entry_safe(d, _d, &d40c->client, node)
+               list_for_each_entry_safe(d, _d, &d40c->client, node) {
                        if (async_tx_test_ack(&d->txd)) {
                                d40_desc_remove(d);
                                desc = d;
                                memset(desc, 0, sizeof(*desc));
                                break;
                        }
+               }
        }
 
        if (!desc)
@@ -740,7 +809,61 @@ static int d40_sg_2_dmalen(struct scatterlist *sgl, int sg_len,
        return len;
 }
 
-/* Support functions for logical channels */
+
+#ifdef CONFIG_PM
+static void dma40_backup(void __iomem *baseaddr, u32 *backup,
+                        u32 *regaddr, int num, bool save)
+{
+       int i;
+
+       for (i = 0; i < num; i++) {
+               void __iomem *addr = baseaddr + regaddr[i];
+
+               if (save)
+                       backup[i] = readl_relaxed(addr);
+               else
+                       writel_relaxed(backup[i], addr);
+       }
+}
+
+static void d40_save_restore_registers(struct d40_base *base, bool save)
+{
+       int i;
+
+       /* Save/Restore channel specific registers */
+       for (i = 0; i < base->num_phy_chans; i++) {
+               void __iomem *addr;
+               int idx;
+
+               if (base->phy_res[i].reserved)
+                       continue;
+
+               addr = base->virtbase + D40_DREG_PCBASE + i * D40_DREG_PCDELTA;
+               idx = i * ARRAY_SIZE(d40_backup_regs_chan);
+
+               dma40_backup(addr, &base->reg_val_backup_chan[idx],
+                            d40_backup_regs_chan,
+                            ARRAY_SIZE(d40_backup_regs_chan),
+                            save);
+       }
+
+       /* Save/Restore global registers */
+       dma40_backup(base->virtbase, base->reg_val_backup,
+                    d40_backup_regs, ARRAY_SIZE(d40_backup_regs),
+                    save);
+
+       /* Save/Restore registers only existing on dma40 v3 and later */
+       if (base->rev >= 3)
+               dma40_backup(base->virtbase, base->reg_val_backup_v3,
+                            d40_backup_regs_v3,
+                            ARRAY_SIZE(d40_backup_regs_v3),
+                            save);
+}
+#else
+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)
@@ -1013,6 +1136,7 @@ static int d40_pause(struct d40_chan *d40c)
        if (!d40c->busy)
                return 0;
 
+       pm_runtime_get_sync(d40c->base->dev);
        spin_lock_irqsave(&d40c->lock, flags);
 
        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
@@ -1025,7 +1149,8 @@ static int d40_pause(struct d40_chan *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);
        return res;
 }
@@ -1039,7 +1164,7 @@ static int d40_resume(struct d40_chan *d40c)
                return 0;
 
        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,
@@ -1057,6 +1182,8 @@ static int d40_resume(struct d40_chan *d40c)
        }
 
 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;
 }
@@ -1129,7 +1256,10 @@ static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
        d40d = d40_first_queued(d40c);
 
        if (d40d != NULL) {
-               d40c->busy = true;
+               if (!d40c->busy)
+                       d40c->busy = true;
+
+               pm_runtime_get_sync(d40c->base->dev);
 
                /* Remove from queue */
                d40_desc_remove(d40d);
@@ -1190,6 +1320,8 @@ static void dma_tc_handle(struct d40_chan *d40c)
 
                if (d40_queue_start(d40c) == NULL)
                        d40c->busy = false;
+               pm_runtime_mark_last_busy(d40c->base->dev);
+               pm_runtime_put_autosuspend(d40c->base->dev);
        }
 
        d40c->pending_tx++;
@@ -1643,10 +1775,11 @@ static int d40_free_dma(struct d40_chan *d40c)
                return -EINVAL;
        }
 
+       pm_runtime_get_sync(d40c->base->dev);
        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
        if (res) {
                chan_err(d40c, "suspend failed\n");
-               return res;
+               goto out;
        }
 
        if (chan_is_logical(d40c)) {
@@ -1664,13 +1797,11 @@ static int d40_free_dma(struct d40_chan *d40c)
                        if (d40_chan_has_events(d40c)) {
                                res = d40_channel_execute_command(d40c,
                                                                  D40_DMA_RUN);
-                               if (res) {
+                               if (res)
                                        chan_err(d40c,
                                                "Executing RUN command\n");
-                                       return res;
-                               }
                        }
-                       return 0;
+                       goto out;
                }
        } else {
                (void) d40_alloc_mask_free(phy, is_src, 0);
@@ -1680,13 +1811,23 @@ static int d40_free_dma(struct d40_chan *d40c)
        res = d40_channel_execute_command(d40c, D40_DMA_STOP);
        if (res) {
                chan_err(d40c, "Failed to stop channel\n");
-               return res;
+               goto out;
        }
+
+       if (d40c->busy) {
+               pm_runtime_mark_last_busy(d40c->base->dev);
+               pm_runtime_put_autosuspend(d40c->base->dev);
+       }
+
+       d40c->busy = false;
        d40c->phy_chan = NULL;
        d40c->configured = false;
        d40c->base->lookup_phy_chans[phy->num] = NULL;
+out:
 
-       return 0;
+       pm_runtime_mark_last_busy(d40c->base->dev);
+       pm_runtime_put_autosuspend(d40c->base->dev);
+       return res;
 }
 
 static bool d40_is_paused(struct d40_chan *d40c)
@@ -2016,9 +2157,11 @@ static int d40_alloc_chan_resources(struct dma_chan *chan)
        err = d40_allocate_channel(d40c);
        if (err) {
                chan_err(d40c, "Failed to allocate channel\n");
+               d40c->configured = false;
                goto fail;
        }
 
+       pm_runtime_get_sync(d40c->base->dev);
        /* Fill in basic CFG register values */
        d40_phy_cfg(&d40c->dma_cfg, &d40c->src_def_cfg,
                    &d40c->dst_def_cfg, chan_is_logical(d40c));
@@ -2046,6 +2189,8 @@ static int d40_alloc_chan_resources(struct dma_chan *chan)
        if (is_free_phy)
                d40_config_write(d40c);
 fail:
+       pm_runtime_mark_last_busy(d40c->base->dev);
+       pm_runtime_put_autosuspend(d40c->base->dev);
        spin_unlock_irqrestore(&d40c->lock, flags);
        return err;
 }
@@ -2519,6 +2664,55 @@ failure1:
        return err;
 }
 
+/* Suspend resume functionality */
+#ifdef CONFIG_PM
+static int dma40_pm_suspend(struct device *dev)
+{
+       if (!pm_runtime_suspended(dev))
+               return -EBUSY;
+
+       return 0;
+}
+
+static int dma40_runtime_suspend(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct d40_base *base = platform_get_drvdata(pdev);
+
+       d40_save_restore_registers(base, true);
+
+       /* Don't disable/enable clocks for v1 due to HW bugs */
+       if (base->rev != 1)
+               writel_relaxed(base->gcc_pwr_off_mask,
+                              base->virtbase + D40_DREG_GCC);
+
+       return 0;
+}
+
+static int dma40_runtime_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct d40_base *base = platform_get_drvdata(pdev);
+
+       if (base->initialized)
+               d40_save_restore_registers(base, false);
+
+       writel_relaxed(D40_DREG_GCC_ENABLE_ALL,
+                      base->virtbase + D40_DREG_GCC);
+       return 0;
+}
+
+
+static const struct dev_pm_ops dma40_pm_ops = {
+       .suspend                = dma40_pm_suspend,
+       .runtime_suspend        = dma40_runtime_suspend,
+       .runtime_resume         = dma40_runtime_resume,
+};
+#define DMA40_PM_OPS   (&dma40_pm_ops)
+#else
+#define DMA40_PM_OPS   NULL
+#endif
+
 /* Initialization functions. */
 
 static int __init d40_phy_res_init(struct d40_base *base)
@@ -2527,6 +2721,7 @@ static int __init d40_phy_res_init(struct d40_base *base)
        int num_phy_chans_avail = 0;
        u32 val[2];
        int odd_even_bit = -2;
+       int gcc = D40_DREG_GCC_ENA;
 
        val[0] = readl(base->virtbase + D40_DREG_PRSME);
        val[1] = readl(base->virtbase + D40_DREG_PRSMO);
@@ -2538,9 +2733,17 @@ static int __init d40_phy_res_init(struct d40_base *base)
                        /* Mark security only channels as occupied */
                        base->phy_res[i].allocated_src = D40_ALLOC_PHY;
                        base->phy_res[i].allocated_dst = D40_ALLOC_PHY;
+                       base->phy_res[i].reserved = true;
+                       gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(i),
+                                                      D40_DREG_GCC_SRC);
+                       gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(i),
+                                                      D40_DREG_GCC_DST);
+
+
                } else {
                        base->phy_res[i].allocated_src = D40_ALLOC_FREE;
                        base->phy_res[i].allocated_dst = D40_ALLOC_FREE;
+                       base->phy_res[i].reserved = false;
                        num_phy_chans_avail++;
                }
                spin_lock_init(&base->phy_res[i].lock);
@@ -2552,6 +2755,11 @@ static int __init d40_phy_res_init(struct d40_base *base)
 
                base->phy_res[chan].allocated_src = D40_ALLOC_PHY;
                base->phy_res[chan].allocated_dst = D40_ALLOC_PHY;
+               base->phy_res[chan].reserved = true;
+               gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(chan),
+                                              D40_DREG_GCC_SRC);
+               gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(chan),
+                                              D40_DREG_GCC_DST);
                num_phy_chans_avail--;
        }
 
@@ -2572,6 +2780,15 @@ static int __init d40_phy_res_init(struct d40_base *base)
                val[0] = val[0] >> 2;
        }
 
+       /*
+        * To keep things simple, Enable all clocks initially.
+        * The clocks will get managed later post channel allocation.
+        * The clocks for the event lines on which reserved channels exists
+        * are not managed here.
+        */
+       writel(D40_DREG_GCC_ENABLE_ALL, base->virtbase + D40_DREG_GCC);
+       base->gcc_pwr_off_mask = gcc;
+
        return num_phy_chans_avail;
 }
 
@@ -2699,10 +2916,15 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
                        goto failure;
        }
 
-       base->lcla_pool.alloc_map = kzalloc(num_phy_chans *
-                                           sizeof(struct d40_desc *) *
-                                           D40_LCLA_LINK_PER_EVENT_GRP,
+       base->reg_val_backup_chan = kmalloc(base->num_phy_chans *
+                                           sizeof(d40_backup_regs_chan),
                                            GFP_KERNEL);
+       if (!base->reg_val_backup_chan)
+               goto failure;
+
+       base->lcla_pool.alloc_map =
+               kzalloc(num_phy_chans * sizeof(struct d40_desc *)
+                       * D40_LCLA_LINK_PER_EVENT_GRP, GFP_KERNEL);
        if (!base->lcla_pool.alloc_map)
                goto failure;
 
@@ -2741,9 +2963,9 @@ failure:
 static void __init d40_hw_init(struct d40_base *base)
 {
 
-       static const struct d40_reg_val dma_init_reg[] = {
+       static struct d40_reg_val dma_init_reg[] = {
                /* Clock every part of the DMA block from start */
-               { .reg = D40_DREG_GCC,    .val = 0x0000ff01},
+               { .reg = D40_DREG_GCC,    .val = D40_DREG_GCC_ENABLE_ALL},
 
                /* Interrupts on all logical channels */
                { .reg = D40_DREG_LCMIS0, .val = 0xFFFFFFFF},
@@ -2960,6 +3182,12 @@ static int __init d40_probe(struct platform_device *pdev)
                goto failure;
        }
 
+       pm_runtime_irq_safe(base->dev);
+       pm_runtime_set_autosuspend_delay(base->dev, DMA40_AUTOSUSPEND_DELAY);
+       pm_runtime_use_autosuspend(base->dev);
+       pm_runtime_enable(base->dev);
+       pm_runtime_resume(base->dev);
+       base->initialized = true;
        err = d40_dmaengine_init(base, num_reserved_chans);
        if (err)
                goto failure;
@@ -3013,6 +3241,7 @@ static struct platform_driver d40_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name  = D40_NAME,
+               .pm = DMA40_PM_OPS,
        },
 };
 
index b44c455158de3461f31ee5a0b0594cb136b2ad6a..8d3d490968a3a8240b6f91e1631609a2425c3f4f 100644 (file)
@@ -16,6 +16,8 @@
 
 #define D40_TYPE_TO_GROUP(type) (type / 16)
 #define D40_TYPE_TO_EVENT(type) (type % 16)
+#define D40_GROUP_SIZE 8
+#define D40_PHYS_TO_GROUP(phys) ((phys & (D40_GROUP_SIZE - 1)) / 2)
 
 /* Most bits of the CFG register are the same in log as in phy mode */
 #define D40_SREG_CFG_MST_POS           15
 
 /* DMA Register Offsets */
 #define D40_DREG_GCC           0x000
+#define D40_DREG_GCC_ENA       0x1
+/* This assumes that there are only 4 event groups */
+#define D40_DREG_GCC_ENABLE_ALL        0xff01
+#define D40_DREG_GCC_EVTGRP_POS 8
+#define D40_DREG_GCC_SRC 0
+#define D40_DREG_GCC_DST 1
+#define D40_DREG_GCC_EVTGRP_ENA(x, y) \
+       (1 << (D40_DREG_GCC_EVTGRP_POS + 2 * x + y))
+
 #define D40_DREG_PRTYP         0x004
 #define D40_DREG_PRSME         0x008
 #define D40_DREG_PRSMO         0x00C