On some platforms the clock can be fixed rate, always running one and
there is no need to do anything with it.

In order to support those platforms, switch to use optional clock.

Fixes: f8d9ddbc2851 ("dmaengine: dw: platform: Enable iDMA 32-bit on Intel Elkhart Lake")
Depends-on: 60b8f0ddf1a9 ("clk: Add (devm_)clk_get_optional() functions")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20190924085116.83683-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

For better maintenance split OF helpers to the separate module.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

For better maintenance split ACPI helpers to the separate module.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Move ACPI handle check to the dw_dma_acpi_controller_register().

While here, convert it to has_acpi_companion() which is recommended way.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-9-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

There is a possibility to have registered ACPI DMA controller
while it has been gone already.

To avoid the potential crash, move to non-managed
acpi_dma_controller_register().

Fixes: 42c91ee71d6d ("dw_dmac: add ACPI support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Intel® PSE (Programmable Services Engine) provides few DMA controllers
to the host on Intel Elkhart Lake. Enable them in the ACPI glue driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Now, when we have a generic structure for the chip and platform data,
use it in the platform glue driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

We are expecting some devices can be enumerated either as PCI or ACPI.
Nevertheless, they will share same information, thus, provide a generic
struct dw_dma_chip_pdata for all glue drivers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Intel Elkhart Lake Offload Service Engine (OSE) will be called as
Intel(R) Programmable Services Engine (Intel(R) PSE) in documentation.

Update the comment here accordingly.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20190813080602.15376-1-jarkko.nikula@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>