Messages in this thread Patch in this message | | | From | Narayanan G <> | Subject | [PATCH] dmaengine/ste_dma40: support pm in dma40 | Date | Wed, 16 Nov 2011 12:00:03 +0530 |
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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, grammar.
Signed-off-by: Narayanan G <narayanan.gopalakrishnan@stericsson.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/dma/ste_dma40.c | 398 +++++++++++++++++++++++++++++++++++++++----- drivers/dma/ste_dma40_ll.h | 11 ++ 2 files changed, 366 insertions(+), 43 deletions(-)
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index 13259ca..fd5cb0f 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. + * @usage_lock: lock for usage count. + * @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. + * @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; + spinlock_t usage_lock; + u32 reg_val_backup[BACKUP_REGS_SZ]; + u32 reg_val_backup_v3[BACKUP_REGS_SZ_V3]; + u32 *reg_val_backup_chan; + 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)); + memset(desc, 0, sizeof(struct d40_desc)); break; } + } } if (!desc) @@ -740,8 +809,166 @@ 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; + + /* Enable all clocks -- revisit after HW bug is fixed */ + if (!save) + writel_relaxed(D40_DREG_GCC_ENABLE_ALL, + base->virtbase + D40_DREG_GCC); + + /* 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 void d40_power_off(struct d40_base *base, int phy_num) +{ + u32 gcc; + int i; + int j; + int p; + + /* + * Disable the rest of the code for v1, because of GCC register HW bugs + * which are not worth working around. + */ + if (base->rev == 1) + return; + + /* + * Power off event group related to physical channel, if + * the other physical channels that belong to the same + * event group are not in use + */ + + for (j = 0; j < base->num_phy_chans; j += D40_GROUP_SIZE) { + + for (i = 0; i < 2; i++) { + p = (((phy_num & (base->num_phy_chans - 1)) + + ((phy_num & 1) ? - i : i)) + & (D40_GROUP_SIZE - 1)) + j; + if (p == phy_num) + continue; + /* + * If another physical channel in the same group is + * allocated or reserved just return. + */ + if (base->phy_res[p].allocated_dst != D40_ALLOC_FREE || + base->phy_res[p].allocated_src != D40_ALLOC_FREE || + base->phy_res[p].reserved == true) { + return; + } + } + } + + /* The GCC register is protected via the usage_lock */ + gcc = readl(base->virtbase + D40_DREG_GCC); + + gcc &= ~D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(phy_num), + D40_DREG_GCC_SRC); + gcc &= ~D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(phy_num), + D40_DREG_GCC_DST); + + writel(gcc, base->virtbase + D40_DREG_GCC); +} + +static void d40_power_on(struct d40_base *base, int phy_num) +{ + u32 gcc; + + /* + * Disable the rest of the code for v1, because of GCC register HW bugs + * which are not worth working around. + */ + if (base->rev == 1) + return; + + /* The GCC register is protected via the usage_lock */ + gcc = readl(base->virtbase + D40_DREG_GCC); + + gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(phy_num), + D40_DREG_GCC_SRC); + gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(phy_num), + D40_DREG_GCC_DST); + + writel(gcc, base->virtbase + D40_DREG_GCC); +} + +static void d40_usage_inc(struct d40_chan *d40c) +{ + unsigned long flags; + + spin_lock_irqsave(&d40c->base->usage_lock, flags); + + pm_runtime_get_sync(d40c->base->dev); + + d40_power_on(d40c->base, d40c->phy_chan->num); + + spin_unlock_irqrestore(&d40c->base->usage_lock, flags); +} + +static void d40_usage_dec(struct d40_chan *d40c) +{ + unsigned long flags; + + spin_lock_irqsave(&d40c->base->usage_lock, flags); + + d40_power_off(d40c->base, d40c->phy_chan->num); + + pm_runtime_mark_last_busy(d40c->base->dev); + pm_runtime_put_autosuspend(d40c->base->dev); + + spin_unlock_irqrestore(&d40c->base->usage_lock, flags); +} static int d40_channel_execute_command(struct d40_chan *d40c, enum d40_command command) { @@ -1013,6 +1240,7 @@ static int d40_pause(struct d40_chan *d40c) if (!d40c->busy) return 0; + d40_usage_inc(d40c); spin_lock_irqsave(&d40c->lock, flags); res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ); @@ -1025,7 +1253,7 @@ static int d40_pause(struct d40_chan *d40c) D40_DMA_RUN); } } - + d40_usage_dec(d40c); spin_unlock_irqrestore(&d40c->lock, flags); return res; } @@ -1039,7 +1267,7 @@ static int d40_resume(struct d40_chan *d40c) return 0; spin_lock_irqsave(&d40c->lock, flags); - + d40_usage_inc(d40c); if (d40c->base->rev == 0) if (chan_is_logical(d40c)) { res = d40_channel_execute_command(d40c, @@ -1057,6 +1285,7 @@ static int d40_resume(struct d40_chan *d40c) } no_suspend: + d40_usage_dec(d40c); spin_unlock_irqrestore(&d40c->lock, flags); return res; } @@ -1129,7 +1358,10 @@ 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) { + d40_usage_inc(d40c); + d40c->busy = true; + } /* Remove from queue */ d40_desc_remove(d40d); @@ -1190,6 +1422,7 @@ static void dma_tc_handle(struct d40_chan *d40c) if (d40_queue_start(d40c) == NULL) d40c->busy = false; + d40_usage_dec(d40c); } d40c->pending_tx++; @@ -1643,6 +1876,7 @@ static int d40_free_dma(struct d40_chan *d40c) return -EINVAL; } + d40_usage_inc(d40c); res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ); if (res) { chan_err(d40c, "suspend failed\n"); @@ -1680,8 +1914,14 @@ 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"); + d40_usage_dec(d40c); return res; } + d40_usage_dec(d40c); + if (d40c->busy) + d40_usage_dec(d40c); + d40c->busy = false; + d40c->phy_chan = NULL; d40c->configured = false; d40c->base->lookup_phy_chans[phy->num] = NULL; @@ -1999,6 +2239,8 @@ static int d40_alloc_chan_resources(struct dma_chan *chan) struct d40_chan *d40c = container_of(chan, struct d40_chan, chan); bool is_free_phy; + + spin_lock_irqsave(&d40c->lock, flags); d40c->completed = chan->cookie = 1; @@ -2016,9 +2258,11 @@ 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; } + d40_usage_inc(d40c); /* 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 +2290,7 @@ static int d40_alloc_chan_resources(struct dma_chan *chan) if (is_free_phy) d40_config_write(d40c); fail: + d40_usage_dec(d40c); spin_unlock_irqrestore(&d40c->lock, flags); return err; } @@ -2117,36 +2362,6 @@ static struct dma_async_tx_descriptor *d40_prep_slave_sg(struct dma_chan *chan, return d40_prep_sg(chan, sgl, sgl, sg_len, direction, dma_flags); } -static struct dma_async_tx_descriptor * -dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr, - size_t buf_len, size_t period_len, - enum dma_data_direction direction) -{ - unsigned int periods = buf_len / period_len; - struct dma_async_tx_descriptor *txd; - struct scatterlist *sg; - int i; - - sg = kcalloc(periods + 1, sizeof(struct scatterlist), GFP_NOWAIT); - for (i = 0; i < periods; i++) { - sg_dma_address(&sg[i]) = dma_addr; - sg_dma_len(&sg[i]) = period_len; - dma_addr += period_len; - } - - sg[periods].offset = 0; - sg[periods].length = 0; - sg[periods].page_link = - ((unsigned long)sg | 0x01) & ~0x02; - - txd = d40_prep_sg(chan, sg, sg, periods, direction, - DMA_PREP_INTERRUPT); - - kfree(sg); - - return txd; -} - static enum dma_status d40_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) @@ -2392,6 +2607,36 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, return -ENXIO; } +static struct dma_async_tx_descriptor * +dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr, + size_t buf_len, size_t period_len, + enum dma_data_direction direction) +{ + unsigned int periods = buf_len / period_len; + struct dma_async_tx_descriptor *txd; + struct scatterlist *sg; + int i; + + sg = kcalloc(periods + 1, sizeof(struct scatterlist), GFP_ATOMIC); + for (i = 0; i < periods; i++) { + sg_dma_address(&sg[i]) = dma_addr; + sg_dma_len(&sg[i]) = period_len; + dma_addr += period_len; + } + + sg[periods].offset = 0; + sg[periods].length = 0; + sg[periods].page_link = + ((unsigned long)sg | 0x01) & ~0x02; + + txd = d40_prep_sg(chan, sg, sg, periods, direction, + DMA_PREP_INTERRUPT); + + kfree(sg); + + return txd; +} + /* Initialization functions */ static void __init d40_chan_init(struct d40_base *base, struct dma_device *dma, @@ -2519,6 +2764,48 @@ 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); + + 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); + + 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) @@ -2538,9 +2825,12 @@ 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; + } 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 +2842,7 @@ 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; num_phy_chans_avail--; } @@ -2572,6 +2863,14 @@ 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); + return num_phy_chans_avail; } @@ -2699,10 +2998,15 @@ 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 +3045,9 @@ 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}, @@ -2908,6 +3212,7 @@ static int __init d40_probe(struct platform_device *pdev) spin_lock_init(&base->interrupt_lock); spin_lock_init(&base->execmd_lock); + spin_lock_init(&base->usage_lock); /* Get IO for logical channel parameter address */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "lcpa"); @@ -2960,6 +3265,12 @@ 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 +3324,7 @@ 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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