[PATCH 2/2] dmaengine: tegra210-adma: Add support for ADMA virtualization

[Sameer Pujar]

From: Mohan Kumar <mkumard@xxxxxxxxxx>

Tegra ADMA HW supports multiple PAGES for virtualization, to
support virtualization support reg-names property has been added
to DT binding to know the hypervisor mode. Also in hypervisor
mode the ADMA global registers are not accessed by guest OS.

Signed-off-by: Mohan Kumar <mkumard@xxxxxxxxxx>
Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
---
 drivers/dma/tegra210-adma.c | 44 ++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index 24ad7077c53b..92f1c0c949dd 100644
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -160,6 +160,8 @@ struct tegra_adma {
 	/* Used to store global command register state when suspending */
 	unsigned int			global_cmd;
 
+	bool is_virtualized;
+
 	const struct tegra_adma_chip_data *cdata;
 
 	/* Last member of the structure */
@@ -222,8 +224,15 @@ static int tegra_adma_init(struct tegra_adma *tdma)
 	u32 status;
 	int ret;
 
-	/* Clear any interrupts */
-	tdma_write(tdma, tdma->cdata->ch_base_offset + tdma->cdata->global_int_clear, 0x1);
+	if (!tdma->is_virtualized) {
+		/* Clear any interrupts */
+		tdma_write(tdma, tdma->cdata->ch_base_offset + tdma->cdata->global_int_clear, 0x1);
+	} else {
+		/* For virtualized mode, ADMA global registers are not accessed */
+		tdma_write(tdma, tdma->cdata->global_int_clear, 0x1);
+		tdma->global_cmd = 1;
+		return 0;
+	}
 
 	/* Assert soft reset */
 	tdma_write(tdma, ADMA_GLOBAL_SOFT_RESET, 0x1);
@@ -736,7 +745,9 @@ static int __maybe_unused tegra_adma_runtime_suspend(struct device *dev)
 	struct tegra_adma_chan *tdc;
 	int i;
 
-	tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
+	if (!tdma->is_virtualized)
+		tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
+
 	if (!tdma->global_cmd)
 		goto clk_disable;
 
@@ -777,7 +788,9 @@ static int __maybe_unused tegra_adma_runtime_resume(struct device *dev)
 		dev_err(dev, "ahub clk_enable failed: %d\n", ret);
 		return ret;
 	}
-	tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);
+
+	if (!tdma->is_virtualized)
+		tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);
 
 	if (!tdma->global_cmd)
 		return 0;
@@ -846,6 +859,8 @@ static int tegra_adma_probe(struct platform_device *pdev)
 {
 	const struct tegra_adma_chip_data *cdata;
 	struct tegra_adma *tdma;
+	unsigned int ch_base_offset;
+	struct resource *res;
 	int ret, i;
 
 	cdata = of_device_get_match_data(&pdev->dev);
@@ -865,9 +880,22 @@ static int tegra_adma_probe(struct platform_device *pdev)
 	tdma->nr_channels = cdata->nr_channels;
 	platform_set_drvdata(pdev, tdma);
 
-	tdma->base_addr = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(tdma->base_addr))
-		return PTR_ERR(tdma->base_addr);
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vm");
+	if (res) {
+		tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(tdma->base_addr))
+			return PTR_ERR(tdma->base_addr);
+
+		tdma->is_virtualized = true;
+		ch_base_offset = 0;
+	} else {
+		tdma->base_addr = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(tdma->base_addr))
+			return PTR_ERR(tdma->base_addr);
+
+		tdma->is_virtualized = false;
+		ch_base_offset = cdata->ch_base_offset;
+	}
 
 	tdma->ahub_clk = devm_clk_get(&pdev->dev, "d_audio");
 	if (IS_ERR(tdma->ahub_clk)) {
@@ -900,7 +928,7 @@ static int tegra_adma_probe(struct platform_device *pdev)
 		if (!test_bit(i, tdma->dma_chan_mask))
 			continue;
 
-		tdc->chan_addr = tdma->base_addr + cdata->ch_base_offset
+		tdc->chan_addr = tdma->base_addr + ch_base_offset
 				 + (cdata->ch_reg_size * i);
 
 		tdc->irq = of_irq_get(pdev->dev.of_node, i);
-- 
2.45.1