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Subject[PATCH 4/4] dmaengine: xlldma OF bus driver
Date
Open Firmware bus attachment for the Xilinx MPMC Soft Direct Memory
Access Controller DMA engine.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
---
diff -uprN a/drivers/dma/xlldma_of.c b/drivers/dma/xlldma_of.c
--- a/drivers/dma/xlldma_of.c 1969-12-31 18:00:00.000000000 -0600
+++ b/drivers/dma/xlldma_of.c 2010-03-17 11:11:16.000000000 -0500
@@ -0,0 +1,252 @@
+/*
+ * Xilinx Multi-Port Memory Controller (MPMC) DMA Engine support
+ *
+ * Copyright (C) 2010 Digital Design Corporation. All rights reserved.
+ *
+ * Author:
+ * Steve Magnani <steve@digidescorp.com>, Mar 2010
+ *
+ * Description:
+ * OpenFirmware bus attachment for the Xilinx MPMC Soft Direct Memory
+ * Access Controller DMA engine.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/of_platform.h>
+#include <linux/module.h>
+
+#include "xlldma.h"
+
+static int __devinit xlldma_of_chan_probe(struct xlldma_device *xdev,
+ struct device_node *node,
+ const char *compatible)
+{
+ struct xlldma_chan *chan;
+ int err;
+#ifdef CONFIG_PPC_DCR_NATIVE
+ unsigned int dcrs;
+#endif
+
+ /* alloc channel */
+ chan = kzalloc(sizeof(struct xlldma_chan), GFP_KERNEL);
+ if (!chan) {
+ dev_err(xdev->dev, "No free memory for allocating "
+ "dma channels!\n");
+ return -ENOMEM;
+ }
+
+ /* get dma channel register base */
+#ifdef CONFIG_PPC_DCR_NATIVE
+ dcrs = dcr_resource_start(node, 0);
+ if (dcrs == 0) {
+ dev_err(xdev->dev, "could not get DMA register address\n");
+ goto err_no_reg;
+ }
+ chan->dcr_c = dcr_resource_len(node, 0);
+ chan->reg_dcrs = dcr_map(node, dcrs, dcr_c);
+ dev_dbg(xdev->dev, "DCR base: %x\n", dcrs);
+#else
+ chan->reg_base = NULL;
+
+ err = of_address_to_resource(node, 0, &chan->reg);
+ if (err) {
+ dev_err(xdev->dev, "Can't get %s property 'reg'\n",
+ node->full_name);
+ goto err_no_reg;
+ }
+
+ chan->reg_base = of_iomap(node, 0);
+ if (chan->reg_base) {
+ dev_dbg(xdev->dev, "MEM base: %p\n", chan->reg_base);
+ } else {
+ dev_err(xdev->dev, "unable to map DMA registers\n");
+ goto err_no_reg;
+ }
+#endif
+
+ chan->xdev = xdev;
+
+ chan->id = xdev->common.chancnt;
+ if (chan->id >= XLLDMA_MAX_CHANS_PER_DEVICE) {
+ dev_err(xdev->dev, "There is no %d channel!\n",
+ chan->id);
+ err = -EINVAL;
+ goto err_no_chan;
+ }
+ xdev->chan[chan->id] = chan;
+ tasklet_init(&chan->tasklet, xlldma_cleanup_tasklet,
+ (unsigned long)chan);
+
+ spin_lock_init(&chan->desc_lock);
+ INIT_LIST_HEAD(&chan->desc_queue);
+ INIT_LIST_HEAD(&chan->pending_free);
+
+ chan->common.device = &xdev->common;
+
+ /* Add the channel to DMA device channel list */
+ list_add_tail(&chan->common.device_node, &xdev->common.channels);
+ xdev->common.chancnt++;
+
+ /* RX interrupt is required, and first */
+ chan->rx_irq = irq_of_parse_and_map(node, 0);
+ if (chan->rx_irq == NO_IRQ) {
+ err = -ENXIO;
+ goto err_no_irq;
+ }
+
+ err = request_irq(chan->rx_irq,
+ &xlldma_chan_rx_interrupt, IRQF_SHARED,
+ "xlldma-rx", chan);
+ if (err) {
+ dev_err(xdev->dev, "DMA channel %s request_irq error "
+ "with return %d\n", node->full_name, err);
+ goto err_no_irq;
+ }
+
+ /* TX interrupt is optional, and second */
+ chan->tx_irq = irq_of_parse_and_map(node, 1);
+ if (chan->tx_irq != NO_IRQ) {
+ err = request_irq(chan->tx_irq,
+ &xlldma_chan_tx_interrupt, IRQF_SHARED,
+ "xlldma-tx", chan);
+ if (err) {
+ dev_err(xdev->dev, "DMA channel %s request_irq error "
+ "with return %d\n", node->full_name, err);
+ goto err_rx_irq;
+ }
+ }
+
+ dev_info(xdev->dev, "#%d (%s), tx irq %d, rx irq %d\n", chan->id,
+ compatible, chan->tx_irq, chan->rx_irq);
+
+ return 0;
+err_rx_irq:
+ free_irq(chan->rx_irq, chan);
+err_no_irq:
+ list_del(&chan->common.device_node);
+err_no_chan:
+#ifdef CONFIG_PPC_DCR_NATIVE
+ dcr_unmap(chan->reg_dcrs, chan->dcr_c);
+#else
+ iounmap(chan->reg_base);
+#endif
+err_no_reg:
+ kfree(chan);
+ return err;
+}
+
+static int __devinit xlldma_probe_channels(struct device *dev)
+{
+ struct of_device *odev = to_of_device(dev);
+ struct xlldma_device *xdev = dev_get_drvdata(dev);
+ struct device_node *child;
+ int rc = 0;
+
+ /* We cannot use of_platform_bus_probe() because there is no
+ * of_platform_bus_remove. Instead, we manually instantiate every DMA
+ * channel object.
+ */
+ for_each_child_of_node(odev->node, child) {
+ if (of_device_is_compatible(child, "xlnx,ll-dma-channel")) {
+ rc = xlldma_of_chan_probe(xdev, child,
+ "xlnx,ll-dma-channel");
+ if (rc)
+ break;
+ }
+ }
+
+ return rc;
+}
+
+static int __devinit xlldma_of_probe(struct of_device *dev,
+ const struct of_device_id *match)
+{
+ struct xlldma_device *xdev;
+ int i, rc;
+
+ dev_info(&dev->dev,
+ "Probe the Xilinx DMA driver for %s controller...\n",
+ match->compatible);
+
+
+ xdev = kzalloc(sizeof(struct xlldma_device), GFP_KERNEL);
+ if (!xdev) {
+ dev_err(&dev->dev, "Not enough memory for 'priv'\n");
+ rc = -ENOMEM;
+ goto fail_alloc;
+ }
+ xdev->dev = &dev->dev;
+ INIT_LIST_HEAD(&xdev->common.channels);
+
+ xdev->common.dev = &dev->dev;
+ dev_set_drvdata(&dev->dev, xdev);
+
+ rc = xlldma_probe_channels(xdev->dev);
+ if (xdev->common.chancnt == 0)
+ goto fail_nochan;
+
+ rc = xlldma_device_setup(xdev->dev);
+ if (rc == 0)
+ return 0;
+
+/* fail: */
+ for (i = 0; i < XLLDMA_MAX_CHANS_PER_DEVICE; i++) {
+ if (xdev->chan[i])
+ xlldma_chan_remove(xdev->chan[i]);
+ }
+fail_nochan:
+ dev_set_drvdata(&dev->dev, NULL);
+ kfree(xdev);
+
+fail_alloc:
+ return rc;
+}
+
+static int __devexit xlldma_of_remove(struct of_device *op)
+{
+ return xlldma_device_teardown(&op->dev);
+}
+
+static const struct of_device_id xlldma_of_ids[] = {
+ { .compatible = "xlnx,ll-dma-1.00.a", },
+ { .compatible = "xlnx,ll-dma-1.00.b", },
+ { .compatible = "xlnx,ll-dma-1.01.a", },
+ {}
+};
+
+static struct of_platform_driver xlldma_of_driver = {
+ .name = "xlldma",
+ .match_table = xlldma_of_ids,
+ .probe = xlldma_of_probe,
+ .remove = __devexit_p(xlldma_of_remove),
+};
+
+static __init int xlldma_of_init(void)
+{
+ int ret;
+
+ pr_info("Xilinx LocalLink DMA driver\n");
+
+ ret = of_register_platform_driver(&xlldma_of_driver);
+ if (ret)
+ pr_err("xlldma: failed to register platform driver\n");
+
+ return ret;
+}
+
+static void __exit xlldma_of_exit(void)
+{
+ of_unregister_platform_driver(&xlldma_of_driver);
+}
+
+module_init(xlldma_of_init);
+module_exit(xlldma_of_exit);
+
+MODULE_AUTHOR("Digital Design Corporation");
+MODULE_DESCRIPTION("Xilinx LocalLink DMA OpenFirmware driver");
+MODULE_LICENSE("GPL");



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