Currently, if DMA information isn't passed from platform data, then DMA
will not be used. This patch allows DMA information obtained though Device
Tree to be used as well.
Cc: Russell King <[email protected]>
Cc: Chris Ball <[email protected]>
Cc: [email protected]
Signed-off-by: Lee Jones <[email protected]>
---
drivers/mmc/host/mmci.c | 43 +++++++++++++++++++++++++++++++------------
1 file changed, 31 insertions(+), 12 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 372e921..42e8fec 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -298,15 +298,32 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
* no custom DMA interfaces are supported.
*/
#ifdef CONFIG_DMA_ENGINE
-static void mmci_dma_setup(struct mmci_host *host)
+static void mmci_dma_setup(struct amba_device *dev,
+ struct mmci_host *host)
{
+ struct device_node *np = dev->dev.of_node;
struct mmci_platform_data *plat = host->plat;
const char *rxname, *txname;
dma_cap_mask_t mask;
+ const char *chan_name;
+ int count, i;
+ bool do_tx = false, do_rx = false;
if (!plat || !plat->dma_filter) {
- dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
- return;
+ if (np) {
+ count = of_property_count_strings(np, "dma-names");
+ for (i = 0; i < count; i++) {
+ of_property_read_string_index(np, "dma-names",
+ i, &chan_name);
+ if (strcmp(chan_name, "tx"))
+ do_tx = true;
+ else if (strcmp(chan_name, "rx"))
+ do_rx = true;
+ }
+ } else {
+ dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+ return;
+ }
}
/* initialize pre request cookie */
@@ -321,19 +338,21 @@ static void mmci_dma_setup(struct mmci_host *host)
* attempt to use it bidirectionally, however if it is
* is specified but cannot be located, DMA will be disabled.
*/
- if (plat->dma_rx_param) {
- host->dma_rx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_rx_param);
+ if (plat->dma_rx_param || do_rx) {
+ host->dma_rx_channel = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_rx_param : NULL,
+ &dev->dev, "rx");
/* E.g if no DMA hardware is present */
if (!host->dma_rx_channel)
dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
}
- if (plat->dma_tx_param) {
- host->dma_tx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_tx_param);
+ if (plat->dma_tx_param || do_tx) {
+ host->dma_tx_channel = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_tx_param : NULL,
+ &dev->dev, "tx");
if (!host->dma_tx_channel)
dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
} else {
@@ -1538,7 +1557,7 @@ static int mmci_probe(struct amba_device *dev,
amba_rev(dev), (unsigned long long)dev->res.start,
dev->irq[0], dev->irq[1]);
- mmci_dma_setup(host);
+ mmci_dma_setup(dev, host);
pm_runtime_set_autosuspend_delay(&dev->dev, 50);
pm_runtime_use_autosuspend(&dev->dev);
--
1.7.10.4
On Wednesday 17 April 2013, Lee Jones wrote:
> #ifdef CONFIG_DMA_ENGINE
> -static void mmci_dma_setup(struct mmci_host *host)
> +static void mmci_dma_setup(struct amba_device *dev,
> + struct mmci_host *host)
> {
> + struct device_node *np = dev->dev.of_node;
> struct mmci_platform_data *plat = host->plat;
> const char *rxname, *txname;
> dma_cap_mask_t mask;
> + const char *chan_name;
> + int count, i;
> + bool do_tx = false, do_rx = false;
>
> if (!plat || !plat->dma_filter) {
> - dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
> - return;
> + if (np) {
> + count = of_property_count_strings(np, "dma-names");
> + for (i = 0; i < count; i++) {
> + of_property_read_string_index(np, "dma-names",
> + i, &chan_name);
> + if (strcmp(chan_name, "tx"))
> + do_tx = true;
> + else if (strcmp(chan_name, "rx"))
> + do_rx = true;
> + }
> + } else {
> + dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
> + return;
> + }
> }
This looks unnecessarily complex.
> /* initialize pre request cookie */
> @@ -321,19 +338,21 @@ static void mmci_dma_setup(struct mmci_host *host)
> * attempt to use it bidirectionally, however if it is
> * is specified but cannot be located, DMA will be disabled.
> */
> - if (plat->dma_rx_param) {
> - host->dma_rx_channel = dma_request_channel(mask,
> - plat->dma_filter,
> - plat->dma_rx_param);
> + if (plat->dma_rx_param || do_rx) {
> + host->dma_rx_channel = dma_request_slave_channel_compat(mask,
> + (plat) ? plat->dma_filter : NULL,
> + (plat) ? plat->dma_rx_param : NULL,
> + &dev->dev, "rx");
> /* E.g if no DMA hardware is present */
> if (!host->dma_rx_channel)
> dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
> }
Why not just do dma_request_slave_channel_compat() unconditionally here?
It's not an error for MMCI if that fails. If you want to keep the warning
in the case dma_rx_channel is provided by not working, you can do it like
host->dma_rx_channel = dma_request_slave_channel(dev, "rx");
if (!host->dma_rx_channel && plat->dma_rx_param) {
host->dma_rx_channel = dma_request_channel(mask,
plat->dma_filter,
plat->dma_rx_param);
...
}
Arnd
> This looks unnecessarily complex.
That thought did cross my mind.
> Why not just do dma_request_slave_channel_compat() unconditionally here?
So how about something like this instead, as it keeps the current
semantics, and only differs in the case of DT.
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 372e921..1fd212a 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -298,14 +298,16 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
* no custom DMA interfaces are supported.
*/
#ifdef CONFIG_DMA_ENGINE
-static void mmci_dma_setup(struct mmci_host *host)
+static void mmci_dma_setup(struct amba_device *dev,
+ struct mmci_host *host)
{
+ struct device_node *np = dev->dev.of_node;
struct mmci_platform_data *plat = host->plat;
const char *rxname, *txname;
dma_cap_mask_t mask;
- if (!plat || !plat->dma_filter) {
- dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+ if (!(plat && plat->dma_filter) && !np) {
+ dev_info(mmc_dev(host->mmc), "no DMA platform data or DT\n");
return;
}
@@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
* attempt to use it bidirectionally, however if it is
* is specified but cannot be located, DMA will be disabled.
*/
- if (plat->dma_rx_param) {
- host->dma_rx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_rx_param);
+ if ((plat && plat->dma_rx_param) || np) {
+ host->dma_rx_channel = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_rx_param : NULL,
+ &dev->dev, "rx");
/* E.g if no DMA hardware is present */
if (!host->dma_rx_channel)
dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
}
- if (plat->dma_tx_param) {
- host->dma_tx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_tx_param);
+ if ((plat && plat->dma_tx_param) || np) {
+ host->dma_tx_channel = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_tx_param : NULL,
+ &dev->dev, "tx");
if (!host->dma_tx_channel)
dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
} else {
@@ -1538,7 +1542,7 @@ static int mmci_probe(struct amba_device *dev,
amba_rev(dev), (unsigned long long)dev->res.start,
dev->irq[0], dev->irq[1]);
- mmci_dma_setup(host);
+ mmci_dma_setup(dev, host);
pm_runtime_set_autosuspend_delay(&dev->dev, 50);
pm_runtime_use_autosuspend(&dev->dev);
--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
On Wednesday 17 April 2013, Lee Jones wrote:
> > This looks unnecessarily complex.
>
> That thought did cross my mind.
>
> > Why not just do dma_request_slave_channel_compat() unconditionally here?
>
> So how about something like this instead, as it keeps the current
> semantics, and only differs in the case of DT.
Yes, looks better.
> @@ -298,14 +298,16 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
> * no custom DMA interfaces are supported.
> */
> #ifdef CONFIG_DMA_ENGINE
> -static void mmci_dma_setup(struct mmci_host *host)
> +static void mmci_dma_setup(struct amba_device *dev,
> + struct mmci_host *host)
> {
> + struct device_node *np = dev->dev.of_node;
> struct mmci_platform_data *plat = host->plat;
> const char *rxname, *txname;
> dma_cap_mask_t mask;
>
> - if (!plat || !plat->dma_filter) {
> - dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
> + if (!(plat && plat->dma_filter) && !np) {
> + dev_info(mmc_dev(host->mmc), "no DMA platform data or DT\n");
> return;
> }
I think you can further simplify this, given that in the DT case we always
allocate a zeroed mmci_platform_data for host->plat, so !plat cannot happen
when we get here.
> @@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
> * attempt to use it bidirectionally, however if it is
> * is specified but cannot be located, DMA will be disabled.
> */
> - if (plat->dma_rx_param) {
> - host->dma_rx_channel = dma_request_channel(mask,
> - plat->dma_filter,
> - plat->dma_rx_param);
> + if ((plat && plat->dma_rx_param) || np) {
> + host->dma_rx_channel = dma_request_slave_channel_compat(mask,
> + (plat) ? plat->dma_filter : NULL,
> + (plat) ? plat->dma_rx_param : NULL,
> + &dev->dev, "rx");
> /* E.g if no DMA hardware is present */
> if (!host->dma_rx_channel)
> dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
And based on that, you can unconditionally pass plat->dma_filter and
plat->dma_rx_param here. In case of DT, they will be NULL, and they
will not be used either.
Arnd
> I think you can further simplify this, given that in the DT case we always
> allocate a zeroed mmci_platform_data for host->plat, so !plat cannot happen
> when we get here.
Okay, third time lucky. :)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 372e921..3260ab4 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -298,14 +298,16 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
* no custom DMA interfaces are supported.
*/
#ifdef CONFIG_DMA_ENGINE
-static void mmci_dma_setup(struct mmci_host *host)
+static void mmci_dma_setup(struct amba_device *dev,
+ struct mmci_host *host)
{
+ struct device_node *np = dev->dev.of_node;
struct mmci_platform_data *plat = host->plat;
const char *rxname, *txname;
dma_cap_mask_t mask;
- if (!plat || !plat->dma_filter) {
- dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+ if (!(plat->dma_filter || np)) {
+ dev_info(mmc_dev(host->mmc), "no DMA platform data or DT\n");
return;
}
@@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
* attempt to use it bidirectionally, however if it is
* is specified but cannot be located, DMA will be disabled.
*/
- if (plat->dma_rx_param) {
- host->dma_rx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_rx_param);
+ if (plat->dma_rx_param || np) {
+ host->dma_rx_channel = dma_request_slave_channel_compat(mask,
+ plat->dma_filter,
+ plat->dma_rx_param,
+ &dev->dev, "rx");
/* E.g if no DMA hardware is present */
if (!host->dma_rx_channel)
dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
}
- if (plat->dma_tx_param) {
- host->dma_tx_channel = dma_request_channel(mask,
- plat->dma_filter,
- plat->dma_tx_param);
+ if (plat->dma_tx_param || np) {
+ host->dma_tx_channel = dma_request_slave_channel_compat(mask,
+ plat->dma_filter,
+ plat->dma_tx_param,
+ &dev->dev, "tx");
if (!host->dma_tx_channel)
dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
} else {
@@ -1538,7 +1542,7 @@ static int mmci_probe(struct amba_device *dev,
amba_rev(dev), (unsigned long long)dev->res.start,
dev->irq[0], dev->irq[1]);
- mmci_dma_setup(host);
+ mmci_dma_setup(dev, host);
pm_runtime_set_autosuspend_delay(&dev->dev, 50);
pm_runtime_use_autosuspend(&dev->dev);
--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
On Thu, Apr 18, 2013 at 09:02:38AM +0100, Lee Jones wrote:
> @@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
> * attempt to use it bidirectionally, however if it is
> * is specified but cannot be located, DMA will be disabled.
> */
> - if (plat->dma_rx_param) {
> - host->dma_rx_channel = dma_request_channel(mask,
> - plat->dma_filter,
> - plat->dma_rx_param);
> + if (plat->dma_rx_param || np) {
> + host->dma_rx_channel = dma_request_slave_channel_compat(mask,
> + plat->dma_filter,
> + plat->dma_rx_param,
> + &dev->dev, "rx");
> /* E.g if no DMA hardware is present */
> if (!host->dma_rx_channel)
> dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
I don't think this is right - I think Arnd has been leading you up the
garden path saying that this can be simplified. Why?
If you look at what this code does, the DMA channels are optional. If
they're not provided, then you don't get an error or a warning printk from
the code. However, after your conversion, if you use DT and avoid giving
the DMA information (which you have to avoid on the majority of ARM
platforms) then "np" will be non-NULL, and
dma_request_slave_channel_compat() will return NULL, causing the error
and/or warning to be printed.
So, we really need to know whether the DMA channel information has been
provided in DT in the upper level "if" statement, and _not_ use
dma_request_slave_channel_compat().
On 18 April 2013 10:02, Lee Jones <[email protected]> wrote:
>> I think you can further simplify this, given that in the DT case we always
>> allocate a zeroed mmci_platform_data for host->plat, so !plat cannot happen
>> when we get here.
>
> Okay, third time lucky. :)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index 372e921..3260ab4 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -298,14 +298,16 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
> * no custom DMA interfaces are supported.
> */
> #ifdef CONFIG_DMA_ENGINE
> -static void mmci_dma_setup(struct mmci_host *host)
> +static void mmci_dma_setup(struct amba_device *dev,
> + struct mmci_host *host)
Hi Lee,
You don't need to pass the amba_device, this can be fetched from the
mmci_host. Check how other functions converts the mmci host it in this
driver.
Kind regards
Ulf Hansson
> {
> + struct device_node *np = dev->dev.of_node;
> struct mmci_platform_data *plat = host->plat;
> const char *rxname, *txname;
> dma_cap_mask_t mask;
>
> - if (!plat || !plat->dma_filter) {
> - dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
> + if (!(plat->dma_filter || np)) {
> + dev_info(mmc_dev(host->mmc), "no DMA platform data or DT\n");
> return;
> }
>
> @@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
> * attempt to use it bidirectionally, however if it is
> * is specified but cannot be located, DMA will be disabled.
> */
> - if (plat->dma_rx_param) {
> - host->dma_rx_channel = dma_request_channel(mask,
> - plat->dma_filter,
> - plat->dma_rx_param);
> + if (plat->dma_rx_param || np) {
> + host->dma_rx_channel = dma_request_slave_channel_compat(mask,
> + plat->dma_filter,
> + plat->dma_rx_param,
> + &dev->dev, "rx");
> /* E.g if no DMA hardware is present */
> if (!host->dma_rx_channel)
> dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
> }
>
> - if (plat->dma_tx_param) {
> - host->dma_tx_channel = dma_request_channel(mask,
> - plat->dma_filter,
> - plat->dma_tx_param);
> + if (plat->dma_tx_param || np) {
> + host->dma_tx_channel = dma_request_slave_channel_compat(mask,
> + plat->dma_filter,
> + plat->dma_tx_param,
> + &dev->dev, "tx");
> if (!host->dma_tx_channel)
> dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
> } else {
> @@ -1538,7 +1542,7 @@ static int mmci_probe(struct amba_device *dev,
> amba_rev(dev), (unsigned long long)dev->res.start,
> dev->irq[0], dev->irq[1]);
>
> - mmci_dma_setup(host);
> + mmci_dma_setup(dev, host);
>
> pm_runtime_set_autosuspend_delay(&dev->dev, 50);
> pm_runtime_use_autosuspend(&dev->dev);
>
> --
> Lee Jones
> Linaro ST-Ericsson Landing Team Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday 18 April 2013, Russell King - ARM Linux wrote:
> On Thu, Apr 18, 2013 at 09:02:38AM +0100, Lee Jones wrote:
> > @@ -321,19 +323,21 @@ static void mmci_dma_setup(struct mmci_host *host)
> > * attempt to use it bidirectionally, however if it is
> > * is specified but cannot be located, DMA will be disabled.
> > */
> > - if (plat->dma_rx_param) {
> > - host->dma_rx_channel = dma_request_channel(mask,
> > - plat->dma_filter,
> > - plat->dma_rx_param);
> > + if (plat->dma_rx_param || np) {
> > + host->dma_rx_channel = dma_request_slave_channel_compat(mask,
> > + plat->dma_filter,
> > + plat->dma_rx_param,
> > + &dev->dev, "rx");
> > /* E.g if no DMA hardware is present */
> > if (!host->dma_rx_channel)
> > dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
>
> I don't think this is right - I think Arnd has been leading you up the
> garden path saying that this can be simplified. Why?
>
> If you look at what this code does, the DMA channels are optional. If
> they're not provided, then you don't get an error or a warning printk from
> the code. However, after your conversion, if you use DT and avoid giving
> the DMA information (which you have to avoid on the majority of ARM
> platforms) then "np" will be non-NULL, and
> dma_request_slave_channel_compat() will return NULL, causing the error
> and/or warning to be printed.
Right, so I guess we should print the warning only if plat->dma_filter
is non-NULL, or we don't use dma_request_slave_channel_compat, which
does not actually simplify the code here.
Arnd
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 375c109..c97bc92 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -298,20 +298,11 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
* no custom DMA interfaces are supported.
*/
#ifdef CONFIG_DMA_ENGINE
-static void mmci_dma_setup(struct mmci_host *host)
+static int mmci_dma_plat_setup(struct mmci_host *host)
{
struct mmci_platform_data *plat = host->plat;
- const char *rxname, *txname;
dma_cap_mask_t mask;
- if (!plat || !plat->dma_filter) {
- dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
- return;
- }
-
- /* initialize pre request cookie */
- host->next_data.cookie = 1;
-
/* Try to acquire a generic DMA engine slave channel */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
@@ -339,6 +330,25 @@ static void mmci_dma_setup(struct mmci_host *host)
} else {
host->dma_tx_channel = host->dma_rx_channel;
}
+}
+
+static void mmci_dma_setup(struct device *dev, struct mmci_host *host)
+{
+ const char *rxname, *txname;
+
+ host->dma_rx_channel = dma_request_slave_channel(dev, "rx");
+ host->dma_tx_channel = dma_request_slave_channel(dev, "tx");
+
+ if (!host->dma_rx_channel && !host->dma_tx_channel) {
+ if (host->plat && host->plat->dma_filter)
+ mmci_dma_plat_setup(host);
+ else
+ dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+ return;
+ }
+
+ /* initialize pre request cookie */
+ host->next_data.cookie = 1;
if (host->dma_rx_channel)
rxname = dma_chan_name(host->dma_rx_channel);
On Thu, Apr 18, 2013 at 11:25:44AM +0200, Arnd Bergmann wrote:
> +static void mmci_dma_setup(struct device *dev, struct mmci_host *host)
> +{
> + const char *rxname, *txname;
> +
> + host->dma_rx_channel = dma_request_slave_channel(dev, "rx");
> + host->dma_tx_channel = dma_request_slave_channel(dev, "tx");
> +
> + if (!host->dma_rx_channel && !host->dma_tx_channel) {
> + if (host->plat && host->plat->dma_filter)
> + mmci_dma_plat_setup(host);
> + else
> + dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
> + return;
You may like to fix the sillies in this patch... but yes, the above
would be better.