| Message ID | e8b0dceb5995556214d03477662f4ff7caf734e1.1309259835.git.nicolas.ferre@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2011-06-28 at 13:17 +0200, Nicolas Ferre wrote: > Save/restore dma controller state across a suspend-resume sequence. > The prepare() function will wait for the non-cyclic channels to become idle. > It also deals with cyclic operations with the start at next period while > resuming. > > Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/dma/at_hdmac.c | 88 ++++++++++++++++++++++++++++++++++++++++++- > drivers/dma/at_hdmac_regs.h | 7 +++ > 2 files changed, 94 insertions(+), 1 deletions(-) > > diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c > index fd87b96..7096adb 100644 > --- a/drivers/dma/at_hdmac.c > +++ b/drivers/dma/at_hdmac.c > @@ -1385,27 +1385,113 @@ static void at_dma_shutdown(struct platform_device *pdev) > clk_disable(atdma->clk); > } > > +static int at_dma_prepare(struct device *dev) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct at_dma *atdma = platform_get_drvdata(pdev); > + struct dma_chan *chan, *_chan; > + > + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, > + device_node) { > + struct at_dma_chan *atchan = to_at_dma_chan(chan); > + /* wait for transaction completion (except in cyclic case) */ > + if (atc_chan_is_enabled(atchan) && > + !test_bit(ATC_IS_CYCLIC, &atchan->status)) > + return -EAGAIN; pls fix indent here > + } > + return 0; > +} > + > +static void atc_suspend_cyclic(struct at_dma_chan *atchan) > +{ > + struct dma_chan *chan = &atchan->chan_common; > + > + /* Channel should be paused by user > + * do it anyway even if it is not done already */ > + if (!test_bit(ATC_IS_PAUSED, &atchan->status)) { > + dev_warn(chan2dev(chan), > + "cyclic channel not paused, should be done by channel user\n"); > + atc_control(chan, DMA_PAUSE, 0); > + } > + > + /* now preserve additional data for cyclic operations */ > + /* next descriptor address in the cyclic list */ > + atchan->save_dscr = channel_readl(atchan, DSCR); > + > + vdbg_dump_regs(atchan); > +} > + > static int at_dma_suspend_noirq(struct device *dev) > { > struct platform_device *pdev = to_platform_device(dev); > struct at_dma *atdma = platform_get_drvdata(pdev); > + struct dma_chan *chan, *_chan; > > - at_dma_off(platform_get_drvdata(pdev)); > + /* preserve data */ > + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, > + device_node) { > + struct at_dma_chan *atchan = to_at_dma_chan(chan); > + > + if (test_bit(ATC_IS_CYCLIC, &atchan->status)) > + atc_suspend_cyclic(atchan); > + atchan->save_cfg = channel_readl(atchan, CFG); > + } > + atdma->save_imr = dma_readl(atdma, EBCIMR); > + > + /* disable DMA controller */ > + at_dma_off(atdma); > clk_disable(atdma->clk); > return 0; > } > > +static void atc_resume_cyclic(struct at_dma_chan *atchan) > +{ > + struct at_dma *atdma = to_at_dma(atchan->chan_common.device); > + > + /* restore channel status for cyclic descriptors list: > + * next descriptor in the cyclic list at the time of suspend */ > + channel_writel(atchan, SADDR, 0); > + channel_writel(atchan, DADDR, 0); > + channel_writel(atchan, CTRLA, 0); > + channel_writel(atchan, CTRLB, 0); > + channel_writel(atchan, DSCR, atchan->save_dscr); > + dma_writel(atdma, CHER, atchan->mask); > + > + /* channel pause status should be removed by channel user > + * We cannot take the initiative to do it here */ > + > + vdbg_dump_regs(atchan); > +} > + > static int at_dma_resume_noirq(struct device *dev) > { > struct platform_device *pdev = to_platform_device(dev); > struct at_dma *atdma = platform_get_drvdata(pdev); > + struct dma_chan *chan, *_chan; > > + /* bring back DMA controller */ > clk_enable(atdma->clk); > dma_writel(atdma, EN, AT_DMA_ENABLE); > + > + /* clear any pending interrupt */ > + while (dma_readl(atdma, EBCISR)) > + cpu_relax(); > + > + /* restore saved data */ > + dma_writel(atdma, EBCIER, atdma->save_imr); > + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, > + device_node) { > + struct at_dma_chan *atchan = to_at_dma_chan(chan); > + > + channel_writel(atchan, CFG, atchan->save_cfg); > + if (test_bit(ATC_IS_CYCLIC, &atchan->status)) > + atc_resume_cyclic(atchan); This testing on bits seems to be reused few times how about wrapping it up in a routine? > + } > return 0; > } > > static const struct dev_pm_ops at_dma_dev_pm_ops = { > + .prepare = at_dma_prepare, > .suspend_noirq = at_dma_suspend_noirq, > .resume_noirq = at_dma_resume_noirq, > }; > diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h > index 087dbf1..6f0c4a3 100644 > --- a/drivers/dma/at_hdmac_regs.h > +++ b/drivers/dma/at_hdmac_regs.h > @@ -204,6 +204,9 @@ enum atc_status { > * @status: transmit status information from irq/prep* functions > * to tasklet (use atomic operations) > * @tasklet: bottom half to finish transaction work > + * @save_cfg: configuration register that is saved on suspend/resume cycle > + * @save_dscr: for cyclic operations, preserve next descriptor address in > + * the cyclic list on suspend/resume cycle > * @lock: serializes enqueue/dequeue operations to descriptors lists > * @completed_cookie: identifier for the most recently completed operation > * @active_list: list of descriptors dmaengine is being running on > @@ -218,6 +221,8 @@ struct at_dma_chan { > u8 mask; > unsigned long status; > struct tasklet_struct tasklet; > + u32 save_cfg; > + u32 save_dscr; > > spinlock_t lock; > > @@ -248,6 +253,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan) > * @chan_common: common dmaengine dma_device object members > * @ch_regs: memory mapped register base > * @clk: dma controller clock > + * @save_imr: interrupt mask register that is saved on suspend/resume cycle > * @all_chan_mask: all channels availlable in a mask > * @dma_desc_pool: base of DMA descriptor region (DMA address) > * @chan: channels table to store at_dma_chan structures > @@ -256,6 +262,7 @@ struct at_dma { > struct dma_device dma_common; > void __iomem *regs; > struct clk *clk; > + u32 save_imr; > > u8 all_chan_mask; >
On 07/07/2011 04:20 AM, Vinod Koul wrote: > On Tue, 2011-06-28 at 13:17 +0200, Nicolas Ferre wrote: >> Save/restore dma controller state across a suspend-resume sequence. >> The prepare() function will wait for the non-cyclic channels to become idle. >> It also deals with cyclic operations with the start at next period while >> resuming. >> >> Signed-off-by: Nicolas Ferre<nicolas.ferre@atmel.com> >> Signed-off-by: Uwe Kleine-König<u.kleine-koenig@pengutronix.de> >> --- >> drivers/dma/at_hdmac.c | 88 ++++++++++++++++++++++++++++++++++++++++++- >> drivers/dma/at_hdmac_regs.h | 7 +++ >> 2 files changed, 94 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c >> index fd87b96..7096adb 100644 >> --- a/drivers/dma/at_hdmac.c >> +++ b/drivers/dma/at_hdmac.c >> @@ -1385,27 +1385,113 @@ static void at_dma_shutdown(struct platform_device *pdev) >> clk_disable(atdma->clk); >> } >> >> +static int at_dma_prepare(struct device *dev) >> +{ >> + struct platform_device *pdev = to_platform_device(dev); >> + struct at_dma *atdma = platform_get_drvdata(pdev); >> + struct dma_chan *chan, *_chan; >> + >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, >> + device_node) { >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); >> + /* wait for transaction completion (except in cyclic case) */ >> + if (atc_chan_is_enabled(atchan)&& >> + !test_bit(ATC_IS_CYCLIC,&atchan->status)) >> + return -EAGAIN; > pls fix indent here Fixed by replacement of test_bit() with a wrapper in a patch to come (as you suggest hereafter). >> + } >> + return 0; >> +} >> + >> +static void atc_suspend_cyclic(struct at_dma_chan *atchan) >> +{ >> + struct dma_chan *chan =&atchan->chan_common; >> + >> + /* Channel should be paused by user >> + * do it anyway even if it is not done already */ >> + if (!test_bit(ATC_IS_PAUSED,&atchan->status)) { >> + dev_warn(chan2dev(chan), >> + "cyclic channel not paused, should be done by channel user\n"); >> + atc_control(chan, DMA_PAUSE, 0); >> + } >> + >> + /* now preserve additional data for cyclic operations */ >> + /* next descriptor address in the cyclic list */ >> + atchan->save_dscr = channel_readl(atchan, DSCR); >> + >> + vdbg_dump_regs(atchan); >> +} >> + >> static int at_dma_suspend_noirq(struct device *dev) >> { >> struct platform_device *pdev = to_platform_device(dev); >> struct at_dma *atdma = platform_get_drvdata(pdev); >> + struct dma_chan *chan, *_chan; >> >> - at_dma_off(platform_get_drvdata(pdev)); >> + /* preserve data */ >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, >> + device_node) { >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); >> + >> + if (test_bit(ATC_IS_CYCLIC,&atchan->status)) >> + atc_suspend_cyclic(atchan); >> + atchan->save_cfg = channel_readl(atchan, CFG); >> + } >> + atdma->save_imr = dma_readl(atdma, EBCIMR); >> + >> + /* disable DMA controller */ >> + at_dma_off(atdma); >> clk_disable(atdma->clk); >> return 0; >> } >> >> +static void atc_resume_cyclic(struct at_dma_chan *atchan) >> +{ >> + struct at_dma *atdma = to_at_dma(atchan->chan_common.device); >> + >> + /* restore channel status for cyclic descriptors list: >> + * next descriptor in the cyclic list at the time of suspend */ >> + channel_writel(atchan, SADDR, 0); >> + channel_writel(atchan, DADDR, 0); >> + channel_writel(atchan, CTRLA, 0); >> + channel_writel(atchan, CTRLB, 0); >> + channel_writel(atchan, DSCR, atchan->save_dscr); >> + dma_writel(atdma, CHER, atchan->mask); >> + >> + /* channel pause status should be removed by channel user >> + * We cannot take the initiative to do it here */ >> + >> + vdbg_dump_regs(atchan); >> +} >> + >> static int at_dma_resume_noirq(struct device *dev) >> { >> struct platform_device *pdev = to_platform_device(dev); >> struct at_dma *atdma = platform_get_drvdata(pdev); >> + struct dma_chan *chan, *_chan; >> >> + /* bring back DMA controller */ >> clk_enable(atdma->clk); >> dma_writel(atdma, EN, AT_DMA_ENABLE); >> + >> + /* clear any pending interrupt */ >> + while (dma_readl(atdma, EBCISR)) >> + cpu_relax(); >> + >> + /* restore saved data */ >> + dma_writel(atdma, EBCIER, atdma->save_imr); >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, >> + device_node) { >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); >> + >> + channel_writel(atchan, CFG, atchan->save_cfg); >> + if (test_bit(ATC_IS_CYCLIC,&atchan->status)) >> + atc_resume_cyclic(atchan); > This testing on bits seems to be reused few times how about wrapping it > up in a routine? True: I write a little patch for this and the "PAUSE" state. I send a patch for this now: dmaengine: at_hdmac: add wrappers for testing channel state So can you: 1/ queue 1/3 and 2/3 of this patch series 2/ queue the following patch named "dmaengine: at_hdmac: add wrappers for testing channel state" on top of that 3/ drop the patch 3/3 of this series: it certainly have to be reworked with all slave config infrastructure implementation in the at_hdmac driver. >> + } >> return 0; >> } >> >> static const struct dev_pm_ops at_dma_dev_pm_ops = { >> + .prepare = at_dma_prepare, >> .suspend_noirq = at_dma_suspend_noirq, >> .resume_noirq = at_dma_resume_noirq, >> }; >> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h >> index 087dbf1..6f0c4a3 100644 >> --- a/drivers/dma/at_hdmac_regs.h >> +++ b/drivers/dma/at_hdmac_regs.h >> @@ -204,6 +204,9 @@ enum atc_status { >> * @status: transmit status information from irq/prep* functions >> * to tasklet (use atomic operations) >> * @tasklet: bottom half to finish transaction work >> + * @save_cfg: configuration register that is saved on suspend/resume cycle >> + * @save_dscr: for cyclic operations, preserve next descriptor address in >> + * the cyclic list on suspend/resume cycle >> * @lock: serializes enqueue/dequeue operations to descriptors lists >> * @completed_cookie: identifier for the most recently completed operation >> * @active_list: list of descriptors dmaengine is being running on >> @@ -218,6 +221,8 @@ struct at_dma_chan { >> u8 mask; >> unsigned long status; >> struct tasklet_struct tasklet; >> + u32 save_cfg; >> + u32 save_dscr; >> >> spinlock_t lock; >> >> @@ -248,6 +253,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan) >> * @chan_common: common dmaengine dma_device object members >> * @ch_regs: memory mapped register base >> * @clk: dma controller clock >> + * @save_imr: interrupt mask register that is saved on suspend/resume cycle >> * @all_chan_mask: all channels availlable in a mask >> * @dma_desc_pool: base of DMA descriptor region (DMA address) >> * @chan: channels table to store at_dma_chan structures >> @@ -256,6 +262,7 @@ struct at_dma { >> struct dma_device dma_common; >> void __iomem *regs; >> struct clk *clk; >> + u32 save_imr; >> >> u8 all_chan_mask;
On Mon, 2011-07-25 at 23:06 +0200, Nicolas Ferre wrote: > On 07/07/2011 04:20 AM, Vinod Koul wrote: > > On Tue, 2011-06-28 at 13:17 +0200, Nicolas Ferre wrote: > >> Save/restore dma controller state across a suspend-resume sequence. > >> The prepare() function will wait for the non-cyclic channels to become idle. > >> It also deals with cyclic operations with the start at next period while > >> resuming. > >> > >> Signed-off-by: Nicolas Ferre<nicolas.ferre@atmel.com> > >> Signed-off-by: Uwe Kleine-König<u.kleine-koenig@pengutronix.de> > >> --- > >> drivers/dma/at_hdmac.c | 88 ++++++++++++++++++++++++++++++++++++++++++- > >> drivers/dma/at_hdmac_regs.h | 7 +++ > >> 2 files changed, 94 insertions(+), 1 deletions(-) > >> > >> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c > >> index fd87b96..7096adb 100644 > >> --- a/drivers/dma/at_hdmac.c > >> +++ b/drivers/dma/at_hdmac.c > >> @@ -1385,27 +1385,113 @@ static void at_dma_shutdown(struct platform_device *pdev) > >> clk_disable(atdma->clk); > >> } > >> > >> +static int at_dma_prepare(struct device *dev) > >> +{ > >> + struct platform_device *pdev = to_platform_device(dev); > >> + struct at_dma *atdma = platform_get_drvdata(pdev); > >> + struct dma_chan *chan, *_chan; > >> + > >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, > >> + device_node) { > >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); > >> + /* wait for transaction completion (except in cyclic case) */ > >> + if (atc_chan_is_enabled(atchan)&& > >> + !test_bit(ATC_IS_CYCLIC,&atchan->status)) > >> + return -EAGAIN; > > pls fix indent here > > Fixed by replacement of test_bit() with a wrapper in a patch to come (as > you suggest hereafter). > > >> + } > >> + return 0; > >> +} > >> + > >> +static void atc_suspend_cyclic(struct at_dma_chan *atchan) > >> +{ > >> + struct dma_chan *chan =&atchan->chan_common; > >> + > >> + /* Channel should be paused by user > >> + * do it anyway even if it is not done already */ > >> + if (!test_bit(ATC_IS_PAUSED,&atchan->status)) { > >> + dev_warn(chan2dev(chan), > >> + "cyclic channel not paused, should be done by channel user\n"); > >> + atc_control(chan, DMA_PAUSE, 0); > >> + } > >> + > >> + /* now preserve additional data for cyclic operations */ > >> + /* next descriptor address in the cyclic list */ > >> + atchan->save_dscr = channel_readl(atchan, DSCR); > >> + > >> + vdbg_dump_regs(atchan); > >> +} > >> + > >> static int at_dma_suspend_noirq(struct device *dev) > >> { > >> struct platform_device *pdev = to_platform_device(dev); > >> struct at_dma *atdma = platform_get_drvdata(pdev); > >> + struct dma_chan *chan, *_chan; > >> > >> - at_dma_off(platform_get_drvdata(pdev)); > >> + /* preserve data */ > >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, > >> + device_node) { > >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); > >> + > >> + if (test_bit(ATC_IS_CYCLIC,&atchan->status)) > >> + atc_suspend_cyclic(atchan); > >> + atchan->save_cfg = channel_readl(atchan, CFG); > >> + } > >> + atdma->save_imr = dma_readl(atdma, EBCIMR); > >> + > >> + /* disable DMA controller */ > >> + at_dma_off(atdma); > >> clk_disable(atdma->clk); > >> return 0; > >> } > >> > >> +static void atc_resume_cyclic(struct at_dma_chan *atchan) > >> +{ > >> + struct at_dma *atdma = to_at_dma(atchan->chan_common.device); > >> + > >> + /* restore channel status for cyclic descriptors list: > >> + * next descriptor in the cyclic list at the time of suspend */ > >> + channel_writel(atchan, SADDR, 0); > >> + channel_writel(atchan, DADDR, 0); > >> + channel_writel(atchan, CTRLA, 0); > >> + channel_writel(atchan, CTRLB, 0); > >> + channel_writel(atchan, DSCR, atchan->save_dscr); > >> + dma_writel(atdma, CHER, atchan->mask); > >> + > >> + /* channel pause status should be removed by channel user > >> + * We cannot take the initiative to do it here */ > >> + > >> + vdbg_dump_regs(atchan); > >> +} > >> + > >> static int at_dma_resume_noirq(struct device *dev) > >> { > >> struct platform_device *pdev = to_platform_device(dev); > >> struct at_dma *atdma = platform_get_drvdata(pdev); > >> + struct dma_chan *chan, *_chan; > >> > >> + /* bring back DMA controller */ > >> clk_enable(atdma->clk); > >> dma_writel(atdma, EN, AT_DMA_ENABLE); > >> + > >> + /* clear any pending interrupt */ > >> + while (dma_readl(atdma, EBCISR)) > >> + cpu_relax(); > >> + > >> + /* restore saved data */ > >> + dma_writel(atdma, EBCIER, atdma->save_imr); > >> + list_for_each_entry_safe(chan, _chan,&atdma->dma_common.channels, > >> + device_node) { > >> + struct at_dma_chan *atchan = to_at_dma_chan(chan); > >> + > >> + channel_writel(atchan, CFG, atchan->save_cfg); > >> + if (test_bit(ATC_IS_CYCLIC,&atchan->status)) > >> + atc_resume_cyclic(atchan); > > This testing on bits seems to be reused few times how about wrapping it > > up in a routine? > > True: I write a little patch for this and the "PAUSE" state. I send a > patch for this now: > dmaengine: at_hdmac: add wrappers for testing channel state > So can you: > 1/ queue 1/3 and 2/3 of this patch series > 2/ queue the following patch named > "dmaengine: at_hdmac: add wrappers for testing channel state" > on top of that > > 3/ drop the patch 3/3 of this series: it certainly have to be reworked > with all slave config infrastructure implementation in the at_hdmac driver. The indent needs to be fixed before I can apply this one, sorry but error introduced in one patch cannot be fixed in next, it is not supposed to work that way
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index fd87b96..7096adb 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1385,27 +1385,113 @@ static void at_dma_shutdown(struct platform_device *pdev) clk_disable(atdma->clk); } +static int at_dma_prepare(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct at_dma *atdma = platform_get_drvdata(pdev); + struct dma_chan *chan, *_chan; + + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + /* wait for transaction completion (except in cyclic case) */ + if (atc_chan_is_enabled(atchan) && + !test_bit(ATC_IS_CYCLIC, &atchan->status)) + return -EAGAIN; + } + return 0; +} + +static void atc_suspend_cyclic(struct at_dma_chan *atchan) +{ + struct dma_chan *chan = &atchan->chan_common; + + /* Channel should be paused by user + * do it anyway even if it is not done already */ + if (!test_bit(ATC_IS_PAUSED, &atchan->status)) { + dev_warn(chan2dev(chan), + "cyclic channel not paused, should be done by channel user\n"); + atc_control(chan, DMA_PAUSE, 0); + } + + /* now preserve additional data for cyclic operations */ + /* next descriptor address in the cyclic list */ + atchan->save_dscr = channel_readl(atchan, DSCR); + + vdbg_dump_regs(atchan); +} + static int at_dma_suspend_noirq(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct at_dma *atdma = platform_get_drvdata(pdev); + struct dma_chan *chan, *_chan; - at_dma_off(platform_get_drvdata(pdev)); + /* preserve data */ + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + if (test_bit(ATC_IS_CYCLIC, &atchan->status)) + atc_suspend_cyclic(atchan); + atchan->save_cfg = channel_readl(atchan, CFG); + } + atdma->save_imr = dma_readl(atdma, EBCIMR); + + /* disable DMA controller */ + at_dma_off(atdma); clk_disable(atdma->clk); return 0; } +static void atc_resume_cyclic(struct at_dma_chan *atchan) +{ + struct at_dma *atdma = to_at_dma(atchan->chan_common.device); + + /* restore channel status for cyclic descriptors list: + * next descriptor in the cyclic list at the time of suspend */ + channel_writel(atchan, SADDR, 0); + channel_writel(atchan, DADDR, 0); + channel_writel(atchan, CTRLA, 0); + channel_writel(atchan, CTRLB, 0); + channel_writel(atchan, DSCR, atchan->save_dscr); + dma_writel(atdma, CHER, atchan->mask); + + /* channel pause status should be removed by channel user + * We cannot take the initiative to do it here */ + + vdbg_dump_regs(atchan); +} + static int at_dma_resume_noirq(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct at_dma *atdma = platform_get_drvdata(pdev); + struct dma_chan *chan, *_chan; + /* bring back DMA controller */ clk_enable(atdma->clk); dma_writel(atdma, EN, AT_DMA_ENABLE); + + /* clear any pending interrupt */ + while (dma_readl(atdma, EBCISR)) + cpu_relax(); + + /* restore saved data */ + dma_writel(atdma, EBCIER, atdma->save_imr); + list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + channel_writel(atchan, CFG, atchan->save_cfg); + if (test_bit(ATC_IS_CYCLIC, &atchan->status)) + atc_resume_cyclic(atchan); + } return 0; } static const struct dev_pm_ops at_dma_dev_pm_ops = { + .prepare = at_dma_prepare, .suspend_noirq = at_dma_suspend_noirq, .resume_noirq = at_dma_resume_noirq, }; diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h index 087dbf1..6f0c4a3 100644 --- a/drivers/dma/at_hdmac_regs.h +++ b/drivers/dma/at_hdmac_regs.h @@ -204,6 +204,9 @@ enum atc_status { * @status: transmit status information from irq/prep* functions * to tasklet (use atomic operations) * @tasklet: bottom half to finish transaction work + * @save_cfg: configuration register that is saved on suspend/resume cycle + * @save_dscr: for cyclic operations, preserve next descriptor address in + * the cyclic list on suspend/resume cycle * @lock: serializes enqueue/dequeue operations to descriptors lists * @completed_cookie: identifier for the most recently completed operation * @active_list: list of descriptors dmaengine is being running on @@ -218,6 +221,8 @@ struct at_dma_chan { u8 mask; unsigned long status; struct tasklet_struct tasklet; + u32 save_cfg; + u32 save_dscr; spinlock_t lock; @@ -248,6 +253,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan) * @chan_common: common dmaengine dma_device object members * @ch_regs: memory mapped register base * @clk: dma controller clock + * @save_imr: interrupt mask register that is saved on suspend/resume cycle * @all_chan_mask: all channels availlable in a mask * @dma_desc_pool: base of DMA descriptor region (DMA address) * @chan: channels table to store at_dma_chan structures @@ -256,6 +262,7 @@ struct at_dma { struct dma_device dma_common; void __iomem *regs; struct clk *clk; + u32 save_imr; u8 all_chan_mask;