[RFC PATCH 3/3] usb: host: ohci-tmio: init genalloc for local memory

[laurentiu . tudor]

From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

In preparation for dropping the existing "coherent" dma mem declaration
APIs, replace the current dma_declare_coherent_memory() based mechanism
with the creation of a genalloc pool that will be used in the OHCI
subsystem as replacement for the DMA APIs.

For context, see thread here: https://lkml.org/lkml/2019/4/22/357

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
---
 drivers/usb/host/ohci-tmio.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/host/ohci-tmio.c b/drivers/usb/host/ohci-tmio.c
index f88a0370659f..16ff99b56fd3 100644
--- a/drivers/usb/host/ohci-tmio.c
+++ b/drivers/usb/host/ohci-tmio.c
@@ -30,6 +30,7 @@
 #include <linux/mfd/core.h>
 #include <linux/mfd/tmio.h>
 #include <linux/dma-mapping.h>
+#include <linux/genalloc.h>
 
 /*-------------------------------------------------------------------------*/
 
@@ -224,11 +225,6 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev)
 		goto err_ioremap_regs;
 	}
 
-	ret = dma_declare_coherent_memory(&dev->dev, sram->start, sram->start,
-				resource_size(sram));
-	if (ret)
-		goto err_dma_declare;
-
 	if (cell->enable) {
 		ret = cell->enable(dev);
 		if (ret)
@@ -239,6 +235,20 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev)
 	ohci = hcd_to_ohci(hcd);
 	ohci_hcd_init(ohci);
 
+	ohci->localmem_pool = devm_gen_pool_create(&dev->dev, PAGE_SHIFT,
+						   dev_to_node(&dev->dev),
+						   "ohci-sm501");
+	if (IS_ERR(ohci->localmem_pool)) {
+		ret = PTR_ERR(ohci->localmem_pool);
+		goto err_enable;
+	}
+	ret = gen_pool_add_virt(ohci->localmem_pool, sram->start, sram->start,
+				resource_size(sram), dev_to_node(&dev->dev));
+	if (ret < 0) {
+		dev_err(&dev->dev, "failed to add to pool: %d\n", ret);
+		goto err_enable;
+	}
+
 	ret = usb_add_hcd(hcd, irq, 0);
 	if (ret)
 		goto err_add_hcd;
@@ -254,8 +264,6 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev)
 	if (cell->disable)
 		cell->disable(dev);
 err_enable:
-	dma_release_declared_memory(&dev->dev);
-err_dma_declare:
 	iounmap(hcd->regs);
 err_ioremap_regs:
 	iounmap(tmio->ccr);
@@ -276,7 +284,6 @@ static int ohci_hcd_tmio_drv_remove(struct platform_device *dev)
 	tmio_stop_hc(dev);
 	if (cell->disable)
 		cell->disable(dev);
-	dma_release_declared_memory(&dev->dev);
 	iounmap(hcd->regs);
 	iounmap(tmio->ccr);
 	usb_put_hcd(hcd);
-- 
2.17.1