Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1211636 > unrolled thread

Re: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA

Started byVinod Koul <vinod.koul@intel.com>
First post2015-08-23 16:40 +0200
Last post2015-08-24 11:30 +0200
Articles 3 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA Vinod Koul <vinod.koul@intel.com> - 2015-08-23 16:40 +0200
    Re: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA Jon Hunter <jonathanh@nvidia.com> - 2015-08-24 11:00 +0200
      Re: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA Vinod Koul <vinod.koul@intel.com> - 2015-08-24 11:30 +0200

#1211636 — Re: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA

FromVinod Koul <vinod.koul@intel.com>
Date2015-08-23 16:40 +0200
SubjectRe: [RFC PATCH 7/7] DMA: tegra-adma: Add support for Tegra210 ADMA
Message-ID<q0EBc-3yk-23@gated-at.bofh.it>
On Tue, Aug 18, 2015 at 02:49:15PM +0100, Jon Hunter wrote:
> +#define AHUB_TO_MEMORY						2
> +#define MEMORY_TO_AHUB						4

namespace this aptly as well

> +static void tegra_adma_stop(struct tegra_dma_channel *tdc)
> +{
> +	u32 status;
> +
> +	/* TODO: Do we need to disable interrupts here? */

when?

> +static void tegra_adma_start(struct tegra_dma_channel *tdc,
> +		struct tegra_dma_sg_req *sg_req)
> +{
> +	struct tegra_adma_chan_regs *ch_regs = &sg_req->adma_ch_regs;
> +
> +	/* Update transfer done count for position calculation */
> +	tdc->adma_ch_regs.tc = ch_regs->tc;
> +	tdc_write(tdc, ADMA_CH_TC, ch_regs->tc);
> +	tdc_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);
> +	tdc_write(tdc, ADMA_CH_LOWER_SOURCE_ADDR, ch_regs->src_ptr);
> +	tdc_write(tdc, ADMA_CH_LOWER_TARGET_ADDR, ch_regs->tgt_ptr);
> +	tdc_write(tdc, ADMA_CH_AHUB_FIFO_CTRL, ch_regs->ahub_fifo_ctrl);
> +	tdc_write(tdc, ADMA_CH_CONFIG, ch_regs->config);
empty line here please

> +static int tegra_adma_get_xfer_params(struct tegra_dma_channel *tdc,
> +				      struct tegra_adma_chan_regs *ch_regs,
> +				      enum dma_transfer_direction direction)
> +{
> +	u32 burst_size, ctrl, ctrl_mask, slave_id, fifo_mask, fifo_shift;
> +
> +	ch_regs->ahub_fifo_ctrl = tdc_read(tdc, ADMA_CH_AHUB_FIFO_CTRL);
> +	ch_regs->config = tdc_read(tdc, ADMA_CH_CONFIG);
> +	ch_regs->ctrl = tdc_read(tdc, ADMA_CH_CTRL);
> +	slave_id = tdc->dma_sconfig.slave_id;
> +
> +	switch (direction) {
> +	case DMA_MEM_TO_DEV:
> +		burst_size = fls(tdc->dma_sconfig.dst_maxburst);
> +		ctrl_mask = ADMA_CH_CTRL_TX_REQUEST_SELECT_MASK;
> +		ctrl = MEMORY_TO_AHUB << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
> +		ctrl |= slave_id << ADMA_CH_CTRL_TX_REQUEST_SELECT_SHIFT;
> +		fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_MASK;
> +		fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_SHIFT;
> +		break;
Empty line here pls

> +	case DMA_DEV_TO_MEM:
> +		burst_size = fls(tdc->dma_sconfig.src_maxburst);
> +		ctrl_mask = ADMA_CH_CTRL_RX_REQUEST_SELECT_MASK;
> +		ctrl = AHUB_TO_MEMORY << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
> +		ctrl |= slave_id << ADMA_CH_CTRL_RX_REQUEST_SELECT_SHIFT;
> +		fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_RX_FIFO_SIZE_MASK;
> +		fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_RX_FIFO_SIZE_SHIFT;
> +		break;

here too...

> +	default:
> +		dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!burst_size || burst_size > ADMA_BURSTSIZE_16)
> +		burst_size = ADMA_BURSTSIZE_16;
> +
> +	ch_regs->ahub_fifo_ctrl &= ~fifo_mask;
> +	ch_regs->ahub_fifo_ctrl |= ADMA_FIFO_DEFAULT_SIZE << fifo_shift;
> +	ch_regs->config &= ~ADMA_CH_CONFIG_BURST_SIZE_MASK;
> +	ch_regs->config |= burst_size << ADMA_CH_CONFIG_BURST_SIZE_SHIFT;
> +	ch_regs->ctrl &= ~(ctrl_mask | ADMA_CH_CTRL_TRANSFER_DIRECTION_MASK);
> +	ch_regs->ctrl |= ctrl;
> +
> +	return -EINVAL;
??

> +static int tegra_adma_pm_suspend(struct device *dev)
> +{
> +	struct tegra_dma *tdma = dev_get_drvdata(dev);
> +	int i;
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(dev);
why is this required :)

> +static int tegra_adma_pm_resume(struct device *dev)
> +{
> +	struct tegra_dma *tdma = dev_get_drvdata(dev);
> +	int i;
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(dev);
and this

-- 
~Vinod
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]


#1211925

FromJon Hunter <jonathanh@nvidia.com>
Date2015-08-24 11:00 +0200
Message-ID<q0VLH-2M2-1@gated-at.bofh.it>
In reply to#1211636
On 23/08/15 15:33, Vinod Koul wrote:
> On Tue, Aug 18, 2015 at 02:49:15PM +0100, Jon Hunter wrote:
>> +#define AHUB_TO_MEMORY						2
>> +#define MEMORY_TO_AHUB						4
> 
> namespace this aptly as well
> 
>> +static void tegra_adma_stop(struct tegra_dma_channel *tdc)
>> +{
>> +	u32 status;
>> +
>> +	/* TODO: Do we need to disable interrupts here? */
> 
> when?

Once everyone is happy with the RFC in general.

>> +static void tegra_adma_start(struct tegra_dma_channel *tdc,
>> +		struct tegra_dma_sg_req *sg_req)
>> +{
>> +	struct tegra_adma_chan_regs *ch_regs = &sg_req->adma_ch_regs;
>> +
>> +	/* Update transfer done count for position calculation */
>> +	tdc->adma_ch_regs.tc = ch_regs->tc;
>> +	tdc_write(tdc, ADMA_CH_TC, ch_regs->tc);
>> +	tdc_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);
>> +	tdc_write(tdc, ADMA_CH_LOWER_SOURCE_ADDR, ch_regs->src_ptr);
>> +	tdc_write(tdc, ADMA_CH_LOWER_TARGET_ADDR, ch_regs->tgt_ptr);
>> +	tdc_write(tdc, ADMA_CH_AHUB_FIFO_CTRL, ch_regs->ahub_fifo_ctrl);
>> +	tdc_write(tdc, ADMA_CH_CONFIG, ch_regs->config);
> empty line here please

Ok.

>> +static int tegra_adma_get_xfer_params(struct tegra_dma_channel *tdc,
>> +				      struct tegra_adma_chan_regs *ch_regs,
>> +				      enum dma_transfer_direction direction)
>> +{
>> +	u32 burst_size, ctrl, ctrl_mask, slave_id, fifo_mask, fifo_shift;
>> +
>> +	ch_regs->ahub_fifo_ctrl = tdc_read(tdc, ADMA_CH_AHUB_FIFO_CTRL);
>> +	ch_regs->config = tdc_read(tdc, ADMA_CH_CONFIG);
>> +	ch_regs->ctrl = tdc_read(tdc, ADMA_CH_CTRL);
>> +	slave_id = tdc->dma_sconfig.slave_id;
>> +
>> +	switch (direction) {
>> +	case DMA_MEM_TO_DEV:
>> +		burst_size = fls(tdc->dma_sconfig.dst_maxburst);
>> +		ctrl_mask = ADMA_CH_CTRL_TX_REQUEST_SELECT_MASK;
>> +		ctrl = MEMORY_TO_AHUB << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
>> +		ctrl |= slave_id << ADMA_CH_CTRL_TX_REQUEST_SELECT_SHIFT;
>> +		fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_MASK;
>> +		fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_SHIFT;
>> +		break;
> Empty line here pls

Ok, any reason why? Other dma drivers don't appear to do this.

>> +	case DMA_DEV_TO_MEM:
>> +		burst_size = fls(tdc->dma_sconfig.src_maxburst);
>> +		ctrl_mask = ADMA_CH_CTRL_RX_REQUEST_SELECT_MASK;
>> +		ctrl = AHUB_TO_MEMORY << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
>> +		ctrl |= slave_id << ADMA_CH_CTRL_RX_REQUEST_SELECT_SHIFT;
>> +		fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_RX_FIFO_SIZE_MASK;
>> +		fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_RX_FIFO_SIZE_SHIFT;
>> +		break;
> 
> here too...
> 
>> +	default:
>> +		dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (!burst_size || burst_size > ADMA_BURSTSIZE_16)
>> +		burst_size = ADMA_BURSTSIZE_16;
>> +
>> +	ch_regs->ahub_fifo_ctrl &= ~fifo_mask;
>> +	ch_regs->ahub_fifo_ctrl |= ADMA_FIFO_DEFAULT_SIZE << fifo_shift;
>> +	ch_regs->config &= ~ADMA_CH_CONFIG_BURST_SIZE_MASK;
>> +	ch_regs->config |= burst_size << ADMA_CH_CONFIG_BURST_SIZE_SHIFT;
>> +	ch_regs->ctrl &= ~(ctrl_mask | ADMA_CH_CTRL_TRANSFER_DIRECTION_MASK);
>> +	ch_regs->ctrl |= ctrl;
>> +
>> +	return -EINVAL;
> ??

Thanks. That's an error. Will fix.

>> +static int tegra_adma_pm_suspend(struct device *dev)
>> +{
>> +	struct tegra_dma *tdma = dev_get_drvdata(dev);
>> +	int i;
>> +	int ret;
>> +
>> +	ret = pm_runtime_get_sync(dev);
> why is this required :)

To ensure that the clocks are enabled before the registers are read.
This function saves the dma context before suspend, in case the hardware
state is lost.

>> +static int tegra_adma_pm_resume(struct device *dev)
>> +{
>> +	struct tegra_dma *tdma = dev_get_drvdata(dev);
>> +	int i;
>> +	int ret;
>> +
>> +	ret = pm_runtime_get_sync(dev);
> and this

Same here.

Cheers
Jon
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]


#1211996

FromVinod Koul <vinod.koul@intel.com>
Date2015-08-24 11:30 +0200
Message-ID<q0WeM-3A1-65@gated-at.bofh.it>
In reply to#1211925
On Mon, Aug 24, 2015 at 09:55:03AM +0100, Jon Hunter wrote:
> >> +static int tegra_adma_get_xfer_params(struct tegra_dma_channel *tdc,
> >> +				      struct tegra_adma_chan_regs *ch_regs,
> >> +				      enum dma_transfer_direction direction)
> >> +{
> >> +	u32 burst_size, ctrl, ctrl_mask, slave_id, fifo_mask, fifo_shift;
> >> +
> >> +	ch_regs->ahub_fifo_ctrl = tdc_read(tdc, ADMA_CH_AHUB_FIFO_CTRL);
> >> +	ch_regs->config = tdc_read(tdc, ADMA_CH_CONFIG);
> >> +	ch_regs->ctrl = tdc_read(tdc, ADMA_CH_CTRL);
> >> +	slave_id = tdc->dma_sconfig.slave_id;
> >> +
> >> +	switch (direction) {
> >> +	case DMA_MEM_TO_DEV:
> >> +		burst_size = fls(tdc->dma_sconfig.dst_maxburst);
> >> +		ctrl_mask = ADMA_CH_CTRL_TX_REQUEST_SELECT_MASK;
> >> +		ctrl = MEMORY_TO_AHUB << ADMA_CH_CTRL_TRANSFER_DIRECTION_SHIFT;
> >> +		ctrl |= slave_id << ADMA_CH_CTRL_TX_REQUEST_SELECT_SHIFT;
> >> +		fifo_mask = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_MASK;
> >> +		fifo_shift = ADMA_CH_AHUB_FIFO_CTRL_TX_FIFO_SIZE_SHIFT;
> >> +		break;
> > Empty line here pls
> 
> Ok, any reason why? Other dma drivers don't appear to do this.

This improves readablity. It is a good idea to sprinkle empty lines between
logial blocks

> >> +static int tegra_adma_pm_suspend(struct device *dev)
> >> +{
> >> +	struct tegra_dma *tdma = dev_get_drvdata(dev);
> >> +	int i;
> >> +	int ret;
> >> +
> >> +	ret = pm_runtime_get_sync(dev);
> > why is this required :)
> 
> To ensure that the clocks are enabled before the registers are read.
> This function saves the dma context before suspend, in case the hardware
> state is lost.
I think same reason here too, so based on my other argument, this may not be
required!

-- 
~Vinod
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web