Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote:
> > > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > > NULL) instead of (i2c_imx->use_dma == true) please ?
> >
> > But there are two judge conditions. But only the "i2c_imx->dma", but also
> > whether "i2c_imx_dma_request" success.
> >
> > "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> > !i2c_imx_dma_request()"
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(>dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(>dev,
> + "can't allocate dma struct faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(>dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
>
> OK, looking at this one more time, why don't you wrap the allocation of
> i2c_imx-
> >dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a
> >local
> variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only
> at
> the end of the i2c_imx_dma_request() function , at the point where you are
> sure
> nothing failed. Then you can check i2c_imx->dma != NULL throughout the code
> to
> check if the DMA is available, no ?
>
> Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
I'm with you, Marek.
Shawn
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Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote:
I think we disconnected here, sorry. Why can you not use (i2c_imx-dma !=
NULL) instead of (i2c_imx-use_dma == true) please ?
But there are two judge conditions. But only the i2c_imx-dma, but also
whether i2c_imx_dma_request success.
i2c_imx-use_dma == true be equivalent to i2c_imx-dma != NULL
!i2c_imx_dma_request()
+ /* Init DMA config if support*/
+ i2c_imx-dma = devm_kzalloc(pdev-dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx-dma) {
+ dev_info(pdev-dev,
+ can't allocate dma struct faild use dma.\n);
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of
i2c_imx-
dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a
local
variable in i2c_imx_dma_request() and then assign it into i2c_imx-dma only
at
the end of the i2c_imx_dma_request() function , at the point where you are
sure
nothing failed. Then you can check i2c_imx-dma != NULL throughout the code
to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
I'm with you, Marek.
Shawn
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Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 08:08:28 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > > >
> > > > [...]
> > > >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > > +(dma_addr_t)phy_addr))
> > > >
> > > > {
> > > >
> > > > > > > + dev_info(>dev,
> > > > > > > + "can't request dma chan, faild use dma.
> >
> > \n");
> >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else {
> > > > > > > + i2c_imx->use_dma = true;
> > > > > > > + }
> > > > > >
> > > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > > >
> > > > pointer ?
> > > >
> > > > > > Then you won't need a separate variable, for this purpose ...
> >
> > right ?
> >
> > > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > > Then for the second question, maybe there are some other ways, But
> > > > > I think it is more tidy and easier understanding for using a
> > > > > separate variable, for this purpose.
> > > >
> > > > You are just wasting space and duplicating data, unless I am wrong.
> > >
> > > Well, Do you have a better idea? Although I think it's necessary.
> >
> > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > NULL) instead of (i2c_imx->use_dma == true) please ?
>
> But there are two judge conditions. But only the "i2c_imx->dma", but also
> whether "i2c_imx_dma_request" success.
>
> "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> !i2c_imx_dma_request()"
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(>dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(>dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(>dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
>dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
the end of the i2c_imx_dma_request() function , at the point where you are sure
nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
Best regards,
Marek Vasut
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RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > >
> > > [...]
> > >
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > +(dma_addr_t)phy_addr))
> > >
> > > {
> > >
> > > > > > + dev_info(>dev,
> > > > > > + "can't request dma chan, faild use dma.
> \n");
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else {
> > > > > > + i2c_imx->use_dma = true;
> > > > > > + }
> > > > >
> > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > >
> > > pointer ?
> > >
> > > > > Then you won't need a separate variable, for this purpose ...
> right ?
> > > >
> > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > Then for the second question, maybe there are some other ways, But
> > > > I think it is more tidy and easier understanding for using a
> > > > separate variable, for this purpose.
> > >
> > > You are just wasting space and duplicating data, unless I am wrong.
> >
> > Well, Do you have a better idea? Although I think it's necessary.
>
> I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> NULL) instead of (i2c_imx->use_dma == true) please ?
>
But there are two judge conditions. But only the "i2c_imx->dma", but also
whether "i2c_imx_dma_request" success.
"i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
!i2c_imx_dma_request()"
Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> >
> > [...]
> >
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> >
> > {
> >
> > > > > + dev_info(>dev,
> > > > > + "can't request dma chan, faild use dma.
\n");
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else {
> > > > > + i2c_imx->use_dma = true;
> > > > > + }
> > > >
> > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> >
> > pointer ?
> >
> > > > Then you won't need a separate variable, for this purpose ... right ?
> > >
> > > Sorry and I think what I know is just to check whether it is NULL.
> > > Then for the second question, maybe there are some other ways, But I
> > > think it is more tidy and easier understanding for using a separate
> > > variable, for this purpose.
> >
> > You are just wasting space and duplicating data, unless I am wrong.
>
> Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx->dma != NULL)
instead of (i2c_imx->use_dma == true) please ?
Best regards,
Marek Vasut
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Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
{
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.
\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
Can you not just check if i2c_imx-dma is valid pointer or NULL
pointer ?
Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I
think it is more tidy and easier understanding for using a separate
variable, for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx-dma != NULL)
instead of (i2c_imx-use_dma == true) please ?
Best regards,
Marek Vasut
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
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RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx,
+(dma_addr_t)phy_addr))
{
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.
\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
Can you not just check if i2c_imx-dma is valid pointer or NULL
pointer ?
Then you won't need a separate variable, for this purpose ...
right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But
I think it is more tidy and easier understanding for using a
separate variable, for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx-dma !=
NULL) instead of (i2c_imx-use_dma == true) please ?
But there are two judge conditions. But only the i2c_imx-dma, but also
whether i2c_imx_dma_request success.
i2c_imx-use_dma == true be equivalent to i2c_imx-dma != NULL
!i2c_imx_dma_request()
Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 08:08:28 AM, Yao Yuan wrote:
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx,
+(dma_addr_t)phy_addr))
{
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.
\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
Can you not just check if i2c_imx-dma is valid pointer or NULL
pointer ?
Then you won't need a separate variable, for this purpose ...
right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But
I think it is more tidy and easier understanding for using a
separate variable, for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx-dma !=
NULL) instead of (i2c_imx-use_dma == true) please ?
But there are two judge conditions. But only the i2c_imx-dma, but also
whether i2c_imx_dma_request success.
i2c_imx-use_dma == true be equivalent to i2c_imx-dma != NULL
!i2c_imx_dma_request()
+ /* Init DMA config if support*/
+ i2c_imx-dma = devm_kzalloc(pdev-dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx-dma) {
+ dev_info(pdev-dev,
+ can't allocate dma struct faild use dma.\n);
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
variable in i2c_imx_dma_request() and then assign it into i2c_imx-dma only at
the end of the i2c_imx_dma_request() function , at the point where you are sure
nothing failed. Then you can check i2c_imx-dma != NULL throughout the code to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
Best regards,
Marek Vasut
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
>
> [...]
>
> > > > + i2c_imx->use_dma = false;
> > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> {
> > > > + dev_info(>dev,
> > > > + "can't request dma chan, faild use
> > > > dma.\n");
> > > > + i2c_imx->use_dma = false;
> > > > + } else {
> > > > + i2c_imx->use_dma = true;
> > > > + }
> > >
> > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> pointer ?
> > > Then you won't need a separate variable, for this purpose ... right ?
> >
> > Sorry and I think what I know is just to check whether it is NULL.
> > Then for the second question, maybe there are some other ways, But I
> > think it is more tidy and easier understanding for using a separate
> > variable, for this purpose.
>
> You are just wasting space and duplicating data, unless I am wrong.
>
Well, Do you have a better idea? Although I think it's necessary.
Best regards,
Yuan Yao
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Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
> > > + i2c_imx->use_dma = false;
> > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > > + dev_info(>dev,
> > > + "can't request dma chan, faild use dma.\n");
> > > + i2c_imx->use_dma = false;
> > > + } else {
> > > + i2c_imx->use_dma = true;
> > > + }
> >
> > Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> > Then you won't need a separate variable, for this purpose ... right ?
>
> Sorry and I think what I know is just to check whether it is NULL.
> Then for the second question, maybe there are some other ways, But I think
> it is more tidy and easier understanding for using a separate variable,
> for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Best regards,
Marek Vasut
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Sunday, March 23, 2014 @ 11:50:00 AM, Marek Vasut wrote:
> On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> > Add dma support for i2c. This function depend on DMA driver.
> > You can turn on it by write both the dmas and dma-name properties in
> > dts node.
> >
> > Signed-off-by: Yuan Yao
> > ---
> > drivers/i2c/busses/i2c-imx.c | 354
> > +-- 1 file changed, 306
> > insertions(+), 48 deletions(-)
>
> Changelog is missing.
Sorry for this, Maybe the changelog is in the junk box. It's named "[PATCH v3
0/2] i2c: add DMA support for freescale i2c driver".
> [...]
>
> > +/* Functions for DMA support */
> > +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> > + dma_addr_t phy_addr)
> > +{
> > + struct imx_i2c_dma *dma = i2c_imx->dma;
> > + struct dma_slave_config dma_sconfig;
> > + struct device *dev = _imx->adapter.dev;
> > + int ret;
> > +
> > + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> > + if (!dma->chan_tx) {
> > + dev_err(dev, "Dma tx channel request failed!\n");
>
> DMA is written in all caps, it's an abbrev. for Direct Memory Access .
> Please fix globally.
>
Ok, I will fix it globally.
> [...]
>
> > static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct
> > i2c_msg
> > *msgs) {
>
> [...]
>
> > - /* write data */
> > - for (i = 0; i < msgs->len; i++) {
> > - dev_dbg(_imx->adapter.dev,
> > - "<%s> write byte: B%d=0x%X\n",
> > - __func__, i, msgs->buf[i]);
> > - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp |= I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = wait_for_completion_interruptible_timeout(
> > + _imx->dma->cmd_complete,
> > + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> > + if (result <= 0) {
> > + dmaengine_terminate_all(dma->chan_using);
> > + if (result)
> > + return result;
> > + else
> > + return -ETIMEDOUT;
> > + }
> > +
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Do you ever check if this really timed out and handle such case at all ?
> I don't see it , but I might be wrong ...
>
Oh, It's a bug, Thank you very much.
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp &= ~I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write the last byte */
> > + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> > + i2c_imx, IMX_I2C_I2DR);
> > result = i2c_imx_trx_complete(i2c_imx);
> > if (result)
> > return result;
> > +
> > result = i2c_imx_acked(i2c_imx);
> > if (result)
> > return result;
> > + } else {
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + dev_dbg(_imx->adapter.dev, "<%s> write data\n", __func__);
> > +
> > + /* write data */
> > + for (i = 0; i < msgs->len; i++) {
> > + dev_dbg(_imx->adapter.dev,
> > + "<%s> write byte: B%d=0x%X\n",
> > + __func__, i, msgs->buf[i]);
>
> Can you not just have a variable $dev here and avoid having such a long
> noodle in the dev_dbg() call ?
>
Ok, And I don't think the dev_dbg() is very helpful here now.
> > + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > + }
> > }
> > return 0;
> > }
> [...]
>
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
>
RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Sunday, March 23, 2014 @ 11:50:00 AM, Marek Vasut wrote:
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in
dts node.
Signed-off-by: Yuan Yao yao.y...@freescale.com
---
drivers/i2c/busses/i2c-imx.c | 354
+-- 1 file changed, 306
insertions(+), 48 deletions(-)
Changelog is missing.
Sorry for this, Maybe the changelog is in the junk box. It's named [PATCH v3
0/2] i2c: add DMA support for freescale i2c driver.
[...]
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx-dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = i2c_imx-adapter.dev;
+ int ret;
+
+ dma-chan_tx = dma_request_slave_channel(dev, tx);
+ if (!dma-chan_tx) {
+ dev_err(dev, Dma tx channel request failed!\n);
DMA is written in all caps, it's an abbrev. for Direct Memory Access .
Please fix globally.
Ok, I will fix it globally.
[...]
static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct
i2c_msg
*msgs) {
[...]
- /* write data */
- for (i = 0; i msgs-len; i++) {
- dev_dbg(i2c_imx-adapter.dev,
- %s write byte: B%d=0x%X\n,
- __func__, i, msgs-buf[i]);
- imx_i2c_write_reg(msgs-buf[i], i2c_imx, IMX_I2C_I2DR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write slave address */
+ imx_i2c_write_reg(msgs-addr 1, i2c_imx, IMX_I2C_I2DR);
+ result = wait_for_completion_interruptible_timeout(
+ i2c_imx-dma-cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result = 0) {
+ dmaengine_terminate_all(dma-chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp I2SR_ICF)
+ break;
+ udelay(10);
+ }
Do you ever check if this really timed out and handle such case at all ?
I don't see it , but I might be wrong ...
Oh, It's a bug, Thank you very much.
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp = ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write the last byte */
+ imx_i2c_write_reg(msgs-buf[msgs-len-1],
+ i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
if (result)
return result;
+
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
+ } else {
+ /* write slave address */
+ imx_i2c_write_reg(msgs-addr 1, i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+
+ dev_dbg(i2c_imx-adapter.dev, %s write data\n, __func__);
+
+ /* write data */
+ for (i = 0; i msgs-len; i++) {
+ dev_dbg(i2c_imx-adapter.dev,
+ %s write byte: B%d=0x%X\n,
+ __func__, i, msgs-buf[i]);
Can you not just have a variable $dev here and avoid having such a long
noodle in the dev_dbg() call ?
Ok, And I don't think the dev_dbg() is very helpful here now.
+ imx_i2c_write_reg(msgs-buf[i], i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+ }
}
return 0;
}
[...]
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp I2SR_ICF)
+ break;
+ udelay(10);
+ }
Timeout handling here as well ...
[...]
@@ -696,6 +936,21 @@ static int i2c_imx_probe(struct
Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(pdev-dev,
+ can't request dma chan, faild use dma.\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
Can you not just check if i2c_imx-dma is valid pointer or NULL pointer ?
Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I think
it is more tidy and easier understanding for using a separate variable,
for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Best regards,
Marek Vasut
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RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
+ i2c_imx-use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
{
+ dev_info(pdev-dev,
+ can't request dma chan, faild use
dma.\n);
+ i2c_imx-use_dma = false;
+ } else {
+ i2c_imx-use_dma = true;
+ }
Can you not just check if i2c_imx-dma is valid pointer or NULL
pointer ?
Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I
think it is more tidy and easier understanding for using a separate
variable, for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Well, Do you have a better idea? Although I think it's necessary.
Best regards,
Yuan Yao
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Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> Add dma support for i2c. This function depend on DMA driver.
> You can turn on it by write both the dmas and dma-name properties in dts
> node.
>
> Signed-off-by: Yuan Yao
> ---
> drivers/i2c/busses/i2c-imx.c | 354
> +-- 1 file changed, 306
> insertions(+), 48 deletions(-)
Changelog is missing.
[...]
> +/* Functions for DMA support */
> +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> + dma_addr_t phy_addr)
> +{
> + struct imx_i2c_dma *dma = i2c_imx->dma;
> + struct dma_slave_config dma_sconfig;
> + struct device *dev = _imx->adapter.dev;
> + int ret;
> +
> + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> + if (!dma->chan_tx) {
> + dev_err(dev, "Dma tx channel request failed!\n");
DMA is written in all caps, it's an abbrev. for Direct Memory Access . Please
fix globally.
[...]
> static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
> *msgs) {
[...]
> - /* write data */
> - for (i = 0; i < msgs->len; i++) {
> - dev_dbg(_imx->adapter.dev,
> - "<%s> write byte: B%d=0x%X\n",
> - __func__, i, msgs->buf[i]);
> - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp |= I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = wait_for_completion_interruptible_timeout(
> + _imx->dma->cmd_complete,
> + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> + if (result <= 0) {
> + dmaengine_terminate_all(dma->chan_using);
> + if (result)
> + return result;
> + else
> + return -ETIMEDOUT;
> + }
> +
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Do you ever check if this really timed out and handle such case at all ? I
don't
see it , but I might be wrong ...
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp &= ~I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write the last byte */
> + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> + i2c_imx, IMX_I2C_I2DR);
> result = i2c_imx_trx_complete(i2c_imx);
> if (result)
> return result;
> +
> result = i2c_imx_acked(i2c_imx);
> if (result)
> return result;
> + } else {
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> +
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> +
> + dev_dbg(_imx->adapter.dev, "<%s> write data\n", __func__);
> +
> + /* write data */
> + for (i = 0; i < msgs->len; i++) {
> + dev_dbg(_imx->adapter.dev,
> + "<%s> write byte: B%d=0x%X\n",
> + __func__, i, msgs->buf[i]);
Can you not just have a variable $dev here and avoid having such a long noodle
in the dev_dbg() call ?
> + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> + }
> }
> return 0;
> }
[...]
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Timeout handling here as well ...
[...]
> @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
> i2c_imx->adapter.name);
> dev_info(_imx->adapter.dev, "IMX I2C adapter registered\n");
>
> + /* Init DMA config if support*/
> +
Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts
node.
Signed-off-by: Yuan Yao yao.y...@freescale.com
---
drivers/i2c/busses/i2c-imx.c | 354
+-- 1 file changed, 306
insertions(+), 48 deletions(-)
Changelog is missing.
[...]
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx-dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = i2c_imx-adapter.dev;
+ int ret;
+
+ dma-chan_tx = dma_request_slave_channel(dev, tx);
+ if (!dma-chan_tx) {
+ dev_err(dev, Dma tx channel request failed!\n);
DMA is written in all caps, it's an abbrev. for Direct Memory Access . Please
fix globally.
[...]
static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
*msgs) {
[...]
- /* write data */
- for (i = 0; i msgs-len; i++) {
- dev_dbg(i2c_imx-adapter.dev,
- %s write byte: B%d=0x%X\n,
- __func__, i, msgs-buf[i]);
- imx_i2c_write_reg(msgs-buf[i], i2c_imx, IMX_I2C_I2DR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write slave address */
+ imx_i2c_write_reg(msgs-addr 1, i2c_imx, IMX_I2C_I2DR);
+ result = wait_for_completion_interruptible_timeout(
+ i2c_imx-dma-cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result = 0) {
+ dmaengine_terminate_all(dma-chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp I2SR_ICF)
+ break;
+ udelay(10);
+ }
Do you ever check if this really timed out and handle such case at all ? I
don't
see it , but I might be wrong ...
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp = ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write the last byte */
+ imx_i2c_write_reg(msgs-buf[msgs-len-1],
+ i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
if (result)
return result;
+
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
+ } else {
+ /* write slave address */
+ imx_i2c_write_reg(msgs-addr 1, i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+
+ dev_dbg(i2c_imx-adapter.dev, %s write data\n, __func__);
+
+ /* write data */
+ for (i = 0; i msgs-len; i++) {
+ dev_dbg(i2c_imx-adapter.dev,
+ %s write byte: B%d=0x%X\n,
+ __func__, i, msgs-buf[i]);
Can you not just have a variable $dev here and avoid having such a long noodle
in the dev_dbg() call ?
+ imx_i2c_write_reg(msgs-buf[i], i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+ }
}
return 0;
}
[...]
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp I2SR_ICF)
+ break;
+ udelay(10);
+ }
Timeout handling here as well ...
[...]
@@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
i2c_imx-adapter.name);
dev_info(i2c_imx-adapter.dev, IMX I2C adapter registered\n);
+ /* Init DMA config if support*/
+ i2c_imx-dma = devm_kzalloc(pdev-dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+
[PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: Yuan Yao
---
drivers/i2c/busses/i2c-imx.c | 354 +--
1 file changed, 306 insertions(+), 48 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index db895fb..6bfe23c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -37,22 +37,27 @@
/** Includes
***
***/
-#include
-#include
-#include
+#include
+#include
+#include
+#include
+#include
+#include
#include
#include
#include
-#include
#include
+#include
#include
-#include
-#include
-#include
-#include
+#include
+#include
#include
#include
+#include
#include
+#include
+#include
+#include
/** Defines
***/
@@ -63,6 +68,10 @@
/* Default value */
#define IMX_I2C_BIT_RATE 10 /* 100kHz */
+/* enable DMA if transfer byte size is bigger than this threshold */
+#define IMX_I2C_DMA_THRESHOLD 16
+#define IMX_I2C_DMA_TIMEOUT1000
+
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provid support for all these chips, split the
@@ -88,6 +97,7 @@
#define I2SR_IBB 0x20
#define I2SR_IAAS 0x40
#define I2SR_ICF 0x80
+#define I2CR_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
@@ -174,6 +184,17 @@ struct imx_i2c_hwdata {
unsignedi2cr_ien_opcode;
};
+struct imx_i2c_dma {
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_using;
+ struct completion cmd_complete;
+ dma_addr_t dma_buf;
+ unsigned intdma_len;
+ unsigned intdma_transfer_dir;
+ unsigned intdma_data_dir;
+};
+
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
@@ -184,6 +205,9 @@ struct imx_i2c_struct {
int stopped;
unsigned intifdr; /* IMX_I2C_IFDR */
const struct imx_i2c_hwdata *hwdata;
+
+ struct imx_i2c_dma *dma;
+ booluse_dma;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -254,9 +278,121 @@ static inline unsigned char imx_i2c_read_reg(struct
imx_i2c_struct *i2c_imx,
return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = _imx->adapter.dev;
+ int ret;
+
+ dma->chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!dma->chan_tx) {
+ dev_err(dev, "Dma tx channel request failed!\n");
+ return -ENODEV;
+ }
+
+ dma_sconfig.dst_addr = phy_addr +
+ (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.dst_maxburst = 1;
+ dma_sconfig.direction = DMA_MEM_TO_DEV;
+ ret = dmaengine_slave_config(dma->chan_tx, _sconfig);
+ if (ret < 0) {
+ dev_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_tx;
+ }
+
+ dma->chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!dma->chan_rx) {
+ dev_err(dev, "Dma rx channel request failed!\n");
+ ret = -ENODEV;
+ goto fail_tx;
+ }
+
+ dma_sconfig.src_addr = phy_addr +
+ (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.src_maxburst = 1;
+ dma_sconfig.direction = DMA_DEV_TO_MEM;
+ ret = dmaengine_slave_config(dma->chan_rx, _sconfig);
+ if (ret < 0) {
+ dev_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_rx;
+ }
+
+ init_completion(>cmd_complete);
+
+ return 0;
+
+fail_rx:
+ dma_release_channel(dma->chan_rx);
+fail_tx:
+ dma_release_channel(dma->chan_tx);
+ return ret;
+}
+
+static void i2c_imx_dma_callback(void *arg)
+{
+ struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+
+ dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
+
[PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: Yuan Yao yao.y...@freescale.com
---
drivers/i2c/busses/i2c-imx.c | 354 +--
1 file changed, 306 insertions(+), 48 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index db895fb..6bfe23c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -37,22 +37,27 @@
/** Includes
***
***/
-#include linux/init.h
-#include linux/kernel.h
-#include linux/module.h
+#include linux/clk.h
+#include linux/completion.h
+#include linux/delay.h
+#include linux/dma-mapping.h
+#include linux/dmaengine.h
+#include linux/dmapool.h
#include linux/errno.h
#include linux/err.h
#include linux/interrupt.h
-#include linux/delay.h
#include linux/i2c.h
+#include linux/init.h
#include linux/io.h
-#include linux/sched.h
-#include linux/platform_device.h
-#include linux/clk.h
-#include linux/slab.h
+#include linux/kernel.h
+#include linux/module.h
#include linux/of.h
#include linux/of_device.h
+#include linux/of_dma.h
#include linux/platform_data/i2c-imx.h
+#include linux/platform_device.h
+#include linux/sched.h
+#include linux/slab.h
/** Defines
***/
@@ -63,6 +68,10 @@
/* Default value */
#define IMX_I2C_BIT_RATE 10 /* 100kHz */
+/* enable DMA if transfer byte size is bigger than this threshold */
+#define IMX_I2C_DMA_THRESHOLD 16
+#define IMX_I2C_DMA_TIMEOUT1000
+
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provid support for all these chips, split the
@@ -88,6 +97,7 @@
#define I2SR_IBB 0x20
#define I2SR_IAAS 0x40
#define I2SR_ICF 0x80
+#define I2CR_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
@@ -174,6 +184,17 @@ struct imx_i2c_hwdata {
unsignedi2cr_ien_opcode;
};
+struct imx_i2c_dma {
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_using;
+ struct completion cmd_complete;
+ dma_addr_t dma_buf;
+ unsigned intdma_len;
+ unsigned intdma_transfer_dir;
+ unsigned intdma_data_dir;
+};
+
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
@@ -184,6 +205,9 @@ struct imx_i2c_struct {
int stopped;
unsigned intifdr; /* IMX_I2C_IFDR */
const struct imx_i2c_hwdata *hwdata;
+
+ struct imx_i2c_dma *dma;
+ booluse_dma;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -254,9 +278,121 @@ static inline unsigned char imx_i2c_read_reg(struct
imx_i2c_struct *i2c_imx,
return readb(i2c_imx-base + (reg i2c_imx-hwdata-regshift));
}
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx-dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = i2c_imx-adapter.dev;
+ int ret;
+
+ dma-chan_tx = dma_request_slave_channel(dev, tx);
+ if (!dma-chan_tx) {
+ dev_err(dev, Dma tx channel request failed!\n);
+ return -ENODEV;
+ }
+
+ dma_sconfig.dst_addr = phy_addr +
+ (IMX_I2C_I2DR i2c_imx-hwdata-regshift);
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.dst_maxburst = 1;
+ dma_sconfig.direction = DMA_MEM_TO_DEV;
+ ret = dmaengine_slave_config(dma-chan_tx, dma_sconfig);
+ if (ret 0) {
+ dev_err(dev, Dma slave config failed, err = %d\n, ret);
+ goto fail_tx;
+ }
+
+ dma-chan_rx = dma_request_slave_channel(dev, rx);
+ if (!dma-chan_rx) {
+ dev_err(dev, Dma rx channel request failed!\n);
+ ret = -ENODEV;
+ goto fail_tx;
+ }
+
+ dma_sconfig.src_addr = phy_addr +
+ (IMX_I2C_I2DR i2c_imx-hwdata-regshift);
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.src_maxburst = 1;
+ dma_sconfig.direction = DMA_DEV_TO_MEM;
+ ret = dmaengine_slave_config(dma-chan_rx, dma_sconfig);
+ if (ret 0) {
+ dev_err(dev, Dma slave config failed, err = %d\n, ret);
+ goto fail_rx;
+ }
+
+
