[PATCH v2] dmaengine/ste_dma40: support pm in dma40

From: Narayanan G
Date: Thu Nov 17 2011 - 06:56:59 EST

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.

Change-Id: I4da140e5aca462c22490146b5c03cff72a7bd803
Signed-off-by: Narayanan G <narayanan.gopalakrishnan@xxxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/dma/ste_dma40.c | 267 ++++++++++++++++++++++++++++++++++++++++---
drivers/dma/ste_dma40_ll.h | 11 ++
2 files changed, 259 insertions(+), 19 deletions(-)

In this V2 version I have cleaned up the implementation, removing
the usage counters and managing using the pm_runtime_xxx() functions.

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 13259ca..909cf0d 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -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,
},
};

diff --git a/drivers/dma/ste_dma40_ll.h b/drivers/dma/ste_dma40_ll.h
index b44c4551..8d3d490 100644
--- a/drivers/dma/ste_dma40_ll.h
+++ b/drivers/dma/ste_dma40_ll.h
@@ -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
@@ -123,6 +125,15 @@

/* 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
--
1.7.4.3

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