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path: root/drivers/mtd/hyperbus/hbmc-am654.c
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Diffstat (limited to 'drivers/mtd/hyperbus/hbmc-am654.c')
-rw-r--r--drivers/mtd/hyperbus/hbmc-am654.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/mtd/hyperbus/hbmc-am654.c b/drivers/mtd/hyperbus/hbmc-am654.c
new file mode 100644
index 0000000000..a6161ce340
--- /dev/null
+++ b/drivers/mtd/hyperbus/hbmc-am654.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// 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>
+#include <linux/mtd/cfi.h>
+#include <linux/mtd/hyperbus.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mux/consumer.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.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;
+ struct mux_control *mux_ctrl;
+};
+
+static int am654_hbmc_calibrate(struct hyperbus_device *hbdev)
+{
+ struct map_info *map = &hbdev->map;
+ struct cfi_private cfi;
+ int count = AM654_HBMC_CALIB_COUNT;
+ int pass_count = 0;
+ int ret;
+
+ cfi.interleave = 1;
+ cfi.device_type = CFI_DEVICETYPE_X16;
+ cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
+ cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
+
+ while (count--) {
+ ret = cfi_qry_present(map, 0, &cfi);
+ if (ret)
+ pass_count++;
+ else
+ pass_count = 0;
+ if (pass_count == 5)
+ break;
+ }
+
+ cfi_qry_mode_off(0, map, &cfi);
+
+ 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;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, priv);
+
+ priv->hbdev.np = of_get_next_child(np, NULL);
+ ret = of_address_to_resource(priv->hbdev.np, 0, &res);
+ if (ret)
+ return ret;
+
+ if (of_property_read_bool(dev->of_node, "mux-controls")) {
+ struct mux_control *control = devm_mux_control_get(dev, NULL);
+
+ if (IS_ERR(control))
+ return PTR_ERR(control);
+
+ ret = mux_control_select(control, 1);
+ if (ret) {
+ dev_err(dev, "Failed to select HBMC mux\n");
+ return ret;
+ }
+ priv->mux_ctrl = control;
+ }
+
+ priv->hbdev.map.size = resource_size(&res);
+ priv->hbdev.map.virt = devm_ioremap_resource(dev, &res);
+ if (IS_ERR(priv->hbdev.map.virt))
+ return PTR_ERR(priv->hbdev.map.virt);
+
+ priv->ctlr.dev = dev;
+ priv->ctlr.ops = &am654_hbmc_ops;
+ priv->hbdev.ctlr = &priv->ctlr;
+
+ 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");
+ goto release_dma;
+ }
+
+ return 0;
+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;
+}
+
+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;
+
+ hyperbus_unregister_device(&priv->hbdev);
+
+ if (priv->mux_ctrl)
+ mux_control_deselect(priv->mux_ctrl);
+
+ if (dev_priv->rx_chan)
+ dma_release_channel(dev_priv->rx_chan);
+
+ return 0;
+}
+
+static const struct of_device_id am654_hbmc_dt_ids[] = {
+ {
+ .compatible = "ti,am654-hbmc",
+ },
+ { /* end of table */ }
+};
+
+MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
+
+static struct platform_driver am654_hbmc_platform_driver = {
+ .probe = am654_hbmc_probe,
+ .remove = am654_hbmc_remove,
+ .driver = {
+ .name = "hbmc-am654",
+ .of_match_table = am654_hbmc_dt_ids,
+ },
+};
+
+module_platform_driver(am654_hbmc_platform_driver);
+
+MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:hbmc-am654");
+MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");