dmaengine: dw: we do support Merrifield SoC in PCI mode

Intel Merrifield platform contains Intel integrated DMA (iDMA 32-bit) which has
a slightly different register mapping, e.g. some bits in CTL_* and CFG_*
channel registers, and has to use platform data since there is no
autoconfiguration.

The iDMA 32-bit specification is available in the publicly available
documentation for Intel Braswell and BayTrail SoCs as LPE Audio DMA.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/pci.c

@@ -15,6 +15,18 @@
 
 #include "internal.h"
 
+static struct dw_dma_platform_data mrfld_pdata = {
+	.nr_channels = 8,
+	.is_private = true,
+	.is_memcpy = true,
+	.is_idma32 = true,
+	.chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
+	.chan_priority = CHAN_PRIORITY_ASCENDING,
+	.block_size = 131071,
+	.nr_masters = 1,
+	.data_width = {4},
+};
+
 static int dw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *pid)
 {
 	const struct dw_dma_platform_data *pdata = (void *)pid->driver_data;
@@ -103,6 +115,9 @@ static const struct pci_device_id dw_pci_id_table[] = {
 	{ PCI_VDEVICE(INTEL, 0x0f06) },
 	{ PCI_VDEVICE(INTEL, 0x0f40) },
 
+	/* Merrifield iDMA 32-bit (GPDMA) */
+	{ PCI_VDEVICE(INTEL, 0x11a2), (kernel_ulong_t)&mrfld_pdata },
+
 	/* Braswell */
 	{ PCI_VDEVICE(INTEL, 0x2286) },
 	{ PCI_VDEVICE(INTEL, 0x22c0) },