1 files changed, 128 insertions, 16 deletions

diff --git a/drivers/mtd/hyperbus/hbmc-am654.c b/drivers/mtd/hyperbus/hbmc-am654.c
index e0e33f6bf513..a3439b791eeb 100644
--- a/drivers/mtd/hyperbus/hbmc-am654.c
+++ b/drivers/mtd/hyperbus/hbmc-am654.c
@@ -3,6 +3,10 @@
 // Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
 // Author: Vignesh Raghavendra <vigneshr@ti.com>
 
+#include <linux/completion.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -13,11 +17,18 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
-#include <linux/pm_runtime.h>
+#include <linux/sched/task_stack.h>
 #include <linux/types.h>
 
 #define AM654_HBMC_CALIB_COUNT 25
 
+struct am654_hbmc_device_priv {
+	struct completion rx_dma_complete;
+	phys_addr_t device_base;
+	struct hyperbus_ctlr *ctlr;
+	struct dma_chan *rx_chan;
+};
+
 struct am654_hbmc_priv {
 	struct hyperbus_ctlr ctlr;
 	struct hyperbus_device hbdev;
@@ -52,13 +63,103 @@ static int am654_hbmc_calibrate(struct hyperbus_device *hbdev)
 	return ret;
 }
 
+static void am654_hbmc_dma_callback(void *param)
+{
+	struct am654_hbmc_device_priv *priv = param;
+
+	complete(&priv->rx_dma_complete);
+}
+
+static int am654_hbmc_dma_read(struct am654_hbmc_device_priv *priv, void *to,
+			       unsigned long from, ssize_t len)
+
+{
+	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
+	struct dma_chan *rx_chan = priv->rx_chan;
+	struct dma_async_tx_descriptor *tx;
+	dma_addr_t dma_dst, dma_src;
+	dma_cookie_t cookie;
+	int ret;
+
+	if (!priv->rx_chan || !virt_addr_valid(to) || object_is_on_stack(to))
+		return -EINVAL;
+
+	dma_dst = dma_map_single(rx_chan->device->dev, to, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(rx_chan->device->dev, dma_dst)) {
+		dev_dbg(priv->ctlr->dev, "DMA mapping failed\n");
+		return -EIO;
+	}
+
+	dma_src = priv->device_base + from;
+	tx = dmaengine_prep_dma_memcpy(rx_chan, dma_dst, dma_src, len, flags);
+	if (!tx) {
+		dev_err(priv->ctlr->dev, "device_prep_dma_memcpy error\n");
+		ret = -EIO;
+		goto unmap_dma;
+	}
+
+	reinit_completion(&priv->rx_dma_complete);
+	tx->callback = am654_hbmc_dma_callback;
+	tx->callback_param = priv;
+	cookie = dmaengine_submit(tx);
+
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(priv->ctlr->dev, "dma_submit_error %d\n", cookie);
+		goto unmap_dma;
+	}
+
+	dma_async_issue_pending(rx_chan);
+	if (!wait_for_completion_timeout(&priv->rx_dma_complete,  msecs_to_jiffies(len + 1000))) {
+		dmaengine_terminate_sync(rx_chan);
+		dev_err(priv->ctlr->dev, "DMA wait_for_completion_timeout\n");
+		ret = -ETIMEDOUT;
+	}
+
+unmap_dma:
+	dma_unmap_single(rx_chan->device->dev, dma_dst, len, DMA_FROM_DEVICE);
+	return ret;
+}
+
+static void am654_hbmc_read(struct hyperbus_device *hbdev, void *to,
+			    unsigned long from, ssize_t len)
+{
+	struct am654_hbmc_device_priv *priv = hbdev->priv;
+
+	if (len < SZ_1K || am654_hbmc_dma_read(priv, to, from, len))
+		memcpy_fromio(to, hbdev->map.virt + from, len);
+}
+
 static const struct hyperbus_ops am654_hbmc_ops = {
 	.calibrate = am654_hbmc_calibrate,
+	.copy_from = am654_hbmc_read,
 };
 
+static int am654_hbmc_request_mmap_dma(struct am654_hbmc_device_priv *priv)
+{
+	struct dma_chan *rx_chan;
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+
+	rx_chan = dma_request_chan_by_mask(&mask);
+	if (IS_ERR(rx_chan)) {
+		if (PTR_ERR(rx_chan) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		dev_dbg(priv->ctlr->dev, "No DMA channel available\n");
+		return 0;
+	}
+	priv->rx_chan = rx_chan;
+	init_completion(&priv->rx_dma_complete);
+
+	return 0;
+}
+
 static int am654_hbmc_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
+	struct am654_hbmc_device_priv *dev_priv;
 	struct device *dev = &pdev->dev;
 	struct am654_hbmc_priv *priv;
 	struct resource res;
@@ -70,7 +171,8 @@ static int am654_hbmc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
-	ret = of_address_to_resource(np, 0, &res);
+	priv->hbdev.np = of_get_next_child(np, NULL);
+	ret = of_address_to_resource(priv->hbdev.np, 0, &res);
 	if (ret)
 		return ret;
 
@@ -88,13 +190,6 @@ static int am654_hbmc_probe(struct platform_device *pdev)
 		priv->mux_ctrl = control;
 	}
 
-	pm_runtime_enable(dev);
-	ret = pm_runtime_get_sync(dev);
-	if (ret < 0) {
-		pm_runtime_put_noidle(dev);
-		goto disable_pm;
-	}
-
 	priv->hbdev.map.size = resource_size(&res);
 	priv->hbdev.map.virt = devm_ioremap_resource(dev, &res);
 	if (IS_ERR(priv->hbdev.map.virt))
@@ -103,17 +198,32 @@ static int am654_hbmc_probe(struct platform_device *pdev)
 	priv->ctlr.dev = dev;
 	priv->ctlr.ops = &am654_hbmc_ops;
 	priv->hbdev.ctlr = &priv->ctlr;
-	priv->hbdev.np = of_get_next_child(dev->of_node, NULL);
+
+	dev_priv = devm_kzalloc(dev, sizeof(*dev_priv), GFP_KERNEL);
+	if (!dev_priv) {
+		ret = -ENOMEM;
+		goto disable_mux;
+	}
+
+	priv->hbdev.priv = dev_priv;
+	dev_priv->device_base = res.start;
+	dev_priv->ctlr = &priv->ctlr;
+
+	ret = am654_hbmc_request_mmap_dma(dev_priv);
+	if (ret)
+		goto disable_mux;
+
 	ret = hyperbus_register_device(&priv->hbdev);
 	if (ret) {
 		dev_err(dev, "failed to register controller\n");
-		pm_runtime_put_sync(&pdev->dev);
-		goto disable_pm;
+		goto release_dma;
 	}
 
 	return 0;
-disable_pm:
-	pm_runtime_disable(dev);
+release_dma:
+	if (dev_priv->rx_chan)
+		dma_release_channel(dev_priv->rx_chan);
+disable_mux:
 	if (priv->mux_ctrl)
 		mux_control_deselect(priv->mux_ctrl);
 	return ret;
@@ -122,13 +232,15 @@ disable_pm:
 static int am654_hbmc_remove(struct platform_device *pdev)
 {
 	struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
+	struct am654_hbmc_device_priv *dev_priv = priv->hbdev.priv;
 	int ret;
 
 	ret = hyperbus_unregister_device(&priv->hbdev);
 	if (priv->mux_ctrl)
 		mux_control_deselect(priv->mux_ctrl);
-	pm_runtime_put_sync(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
+
+	if (dev_priv->rx_chan)
+		dma_release_channel(dev_priv->rx_chan);
 
 	return ret;
 }