Synopsys eDMA IP is normally distributed along with Synopsys PCIe
EndPoint IP (depends of the use and licensing agreement).
This IP requires some basic configurations, such as:
- eDMA registers BAR
- eDMA registers offset
- eDMA registers size
- eDMA linked list memory BAR
- eDMA linked list memory offset
- eDMA linked list memory sze
- eDMA data memory BAR
- eDMA data memory offset
- eDMA data memory size
- eDMA version
- eDMA mode
- IRQs available for eDMA
As a working example, PCIe glue-logic will attach to a Synopsys PCIe
EndPoint IP prototype kit (Vendor ID = 0x16c3, Device ID = 0xedda),
which has built-in an eDMA IP with this default configuration:
- eDMA registers BAR = 0
- eDMA registers offset = 0x00001000 (4 Kbytes)
- eDMA registers size = 0x00002000 (8 Kbytes)
- eDMA linked list memory BAR = 2
- eDMA linked list memory offset = 0x00000000 (0 Kbytes)
- eDMA linked list memory size = 0x00800000 (8 Mbytes)
- eDMA data memory BAR = 2
- eDMA data memory offset = 0x00800000 (8 Mbytes)
- eDMA data memory size = 0x03800000 (56 Mbytes)
- eDMA version = 0
- eDMA mode = EDMA_MODE_UNROLL
- IRQs = 1
This driver can be compile as built-in or external module in kernel.
To enable this driver just select DW_EDMA_PCIE option in kernel
configuration, however it requires and selects automatically DW_EDMA
option too.
Changes:
RFC v1->RFC v2:
- Replace comments // (C99 style) by /**/
- Merge two pcim_iomap_regions() calls into just one call
- Remove pci_try_set_mwi() call
- Replace some dev_info() by dev_dbg() to reduce *noise*
- Remove pci_name(pdev) call after being call dw_edma_remove()
- Remove all power management support
- Fix the headers of the .c and .h files according to the most recent
convention
- Fix errors and checks pointed out by checkpatch with --strict option
- Replace patch small description tag from dma by dmaengine
RFC v2->RFC v3:
- Fix printk variable of phys_addr_t type
- Fix missing variable initialization (chan->configured)
- Change linked list size to 512 Kbytes
- Add data memory information
- Add register size information
- Add comments or improve existing ones
- Add possibility to work with multiple IRQs feature
- Replace MSI and MSI-X enable condition by pci_dev_msi_enabled()
- Replace code to acquire MSI(-X) address and data by
get_cached_msi_msg()
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Eugeniy Paltsev <paltsev@xxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Cc: Niklas Cassel <niklas.cassel@xxxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Joao Pinto <jpinto@xxxxxxxxxxxx>
Cc: Jose Abreu <jose.abreu@xxxxxxxxxxxx>
Cc: Luis Oliveira <lolivei@xxxxxxxxxxxx>
Cc: Vitor Soares <vitor.soares@xxxxxxxxxxxx>
Cc: Nelson Costa <nelson.costa@xxxxxxxxxxxx>
Cc: Pedro Sousa <pedrom.sousa@xxxxxxxxxxxx>
---
drivers/dma/dw-edma/Kconfig | 9 ++
drivers/dma/dw-edma/Makefile | 1 +
drivers/dma/dw-edma/dw-edma-pcie.c | 254 +++++++++++++++++++++++++++++++++++++
3 files changed, 264 insertions(+)
create mode 100644 drivers/dma/dw-edma/dw-edma-pcie.c
diff --git a/drivers/dma/dw-edma/Kconfig b/drivers/dma/dw-edma/Kconfig
index 3016bed..c0838ce 100644
--- a/drivers/dma/dw-edma/Kconfig
+++ b/drivers/dma/dw-edma/Kconfig
@@ -7,3 +7,12 @@ config DW_EDMA
help
Support the Synopsys DesignWare eDMA controller, normally
implemented on endpoints SoCs.
+
+config DW_EDMA_PCIE
+ tristate "Synopsys DesignWare eDMA PCIe driver"
+ depends on PCI && PCI_MSI
+ select DW_EDMA
+ help
+ Provides a glue-logic between the Synopsys DesignWare
+ eDMA controller and an endpoint PCIe device. This also serves
+ as a reference design to whom desires to use this IP.
diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile
index 0c53033..8d45c0d 100644
--- a/drivers/dma/dw-edma/Makefile
+++ b/drivers/dma/dw-edma/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DW_EDMA) += dw-edma.o
dw-edma-$(CONFIG_DEBUG_FS) := dw-edma-v0-debugfs.o
dw-edma-objs := dw-edma-core.o \
dw-edma-v0-core.o $(dw-edma-y)
+obj-$(CONFIG_DW_EDMA_PCIE) += dw-edma-pcie.o
diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
new file mode 100644
index 0000000..b96b3c4
--- /dev/null
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare eDMA PCIe driver
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/device.h>
+#include <linux/dma/edma.h>
+#include <linux/msi.h>
+
+#include "dw-edma-core.h"
+
+enum dw_edma_pcie_bar {
+ BAR_0,
+ BAR_1,
+ BAR_2,
+ BAR_3,
+ BAR_4,
+ BAR_5
+};
+
+struct dw_edma_pcie_data {
+ /* eDMA registers location */
+ enum dw_edma_pcie_bar rg_bar;
+ off_t rg_off;
+ size_t rg_sz;
+ /* eDMA memory linked list location */
+ enum dw_edma_pcie_bar ll_bar;
+ off_t ll_off;
+ size_t ll_sz;
+ /* eDMA memory data location */
+ enum dw_edma_pcie_bar dt_bar;
+ off_t dt_off;
+ size_t dt_sz;
+ /* Other */
+ u32 version;
+ enum dw_edma_mode mode;
+ u8 irqs_cnt;
+};
+
+static const struct dw_edma_pcie_data snps_edda_data = {
+ /* eDMA registers location */
+ .rg_bar = BAR_0,
+ .rg_off = 0x00001000, /* 4 Kbytes */
+ .rg_sz = 0x00002000, /* 8 Kbytes */
+ /* eDMA memory linked list location */
+ .ll_bar = BAR_2,
+ .ll_off = 0x00000000, /* 0 Kbytes */
+ .ll_sz = 0x00800000, /* 8 Mbytes */
+ /* eDMA memory data location */
+ .dt_bar = BAR_2,
+ .dt_off = 0x00800000, /* 8 Mbytes */
+ .dt_sz = 0x03800000, /* 56 Mbytes */
+ /* Other */
+ .version = 0,
+ .mode = EDMA_MODE_UNROLL,
+ .irqs_cnt = 1,
+};
+
+static bool disable_msix;
+module_param(disable_msix, bool, 0644);
+MODULE_PARM_DESC(disable_msix, "Disable MSI-X interrupts");
+
+static int dw_edma_pcie_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pid)
+{
+ const struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+ struct device *dev = &pdev->dev;
+ struct dw_edma_chip *chip;
+ struct dw_edma *dw;
+ unsigned int irq_flags = PCI_IRQ_MSI;
+ int err, nr_irqs, i;
+
+ if (!pdata) {
+ dev_err(dev, "%s missing data structure\n", pci_name(pdev));
+ return -EFAULT;
+ }
+
+ /* Enable PCI device */
+ err = pcim_enable_device(pdev);
+ if (err) {
+ dev_err(dev, "%s enabling device failed\n", pci_name(pdev));
+ return err;
+ }
+
+ /* Mapping PCI BAR regions */
+ err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar) |
+ BIT(pdata->ll_bar) |
+ BIT(pdata->dt_bar),
+ pci_name(pdev));
+ if (err) {
+ dev_err(dev, "%s eDMA BAR I/O remapping failed\n",
+ pci_name(pdev));
+ return err;
+ }
+
+ pci_set_master(pdev);
+
+ /* DMA configuration */
+ err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (err) {
+ dev_err(dev, "%s DMA mask set failed\n", pci_name(pdev));
+ return err;
+ }
+
+ err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (err) {
+ dev_err(dev, "%s consistent DMA mask set failed\n",
+ pci_name(pdev));
+ return err;
+ }
+
+ /* Data structure allocation */
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ dw = devm_kzalloc(dev, sizeof(*dw), GFP_KERNEL);
+ if (!dw)
+ return -ENOMEM;
+
+ /* IRQs allocation */
+ if (!disable_msix)
+ irq_flags |= PCI_IRQ_MSIX;
+
+ nr_irqs = pci_alloc_irq_vectors(pdev, 1, pdata->irqs_cnt, irq_flags);
+ if (nr_irqs < 1) {
+ dev_err(dev, "%s failed to alloc IRQ vector (Number of IRQs=%u)\n",
+ pci_name(pdev), nr_irqs);
+ return -EPERM;
+ }
+
+ /* Data structure initialization */
+ chip->dw = dw;
+ chip->dev = dev;
+ chip->id = pdev->devfn;
+ chip->irq = pdev->irq;
+
+ if (!pcim_iomap_table(pdev))
+ return -EACCES;
+
+ dw->rg_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->rg_bar];
+ dw->rg_region.vaddr += pdata->rg_off;
+ dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
+ dw->rg_region.paddr += pdata->rg_off;
+ dw->rg_region.sz = pdata->rg_sz;
+
+ dw->ll_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->ll_bar];
+ dw->ll_region.vaddr += pdata->ll_off;
+ dw->ll_region.paddr = pdev->resource[pdata->ll_bar].start;
+ dw->ll_region.paddr += pdata->ll_off;
+ dw->ll_region.sz = pdata->ll_sz;
+
+ dw->dt_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->dt_bar];
+ dw->dt_region.vaddr += pdata->dt_off;
+ dw->dt_region.paddr = pdev->resource[pdata->dt_bar].start;
+ dw->dt_region.paddr += pdata->dt_off;
+ dw->dt_region.sz = pdata->dt_sz;
+
+ dw->version = pdata->version;
+ dw->mode = pdata->mode;
+ dw->nr_irqs = nr_irqs;
+
+ /* Debug info */
+ dev_dbg(dev, "Version:\t%u\n", dw->version);
+
+ dev_dbg(dev, "Mode:\t%s\n",
+ dw->mode == EDMA_MODE_LEGACY ? "Legacy" : "Unroll");
+
+ dev_dbg(dev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
+ pdata->rg_bar, pdata->rg_off, pdata->rg_sz,
+ &dw->rg_region.vaddr, &dw->rg_region.paddr);
+
+ dev_dbg(dev, "L. List:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
+ pdata->ll_bar, pdata->ll_off, pdata->ll_sz,
+ &dw->ll_region.vaddr, &dw->ll_region.paddr);
+
+ dev_dbg(dev, "Data:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
+ pdata->dt_bar, pdata->dt_off, pdata->dt_sz,
+ &dw->dt_region.vaddr, &dw->dt_region.paddr);
+
+ dev_dbg(dev, "Nr. IRQs:\t%u\n", dw->nr_irqs);
+
+ /* Validating if PCI interrupts were enabled */
+ if (!pci_dev_msi_enabled(pdev)) {
+ dev_err(dev, "%s enable interrupt failed\n", pci_name(pdev));
+ return -EPERM;
+ }
+
+ /*
+ * Acquiring PCI MSI(-X) configuration (address and data) for
+ * setting it later on eDMA interrupt registers
+ */
+ dw->msi = devm_kcalloc(dev, nr_irqs, sizeof(*dw->msi), GFP_KERNEL);
+ if (!dw->msi)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_irqs; i++)
+ get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), i),
+ &dw->msi[i]);
+
+ /* Starting eDMA driver */
+ err = dw_edma_probe(chip);
+ if (err) {
+ dev_err(dev, "%s eDMA probe failed\n", pci_name(pdev));
+ return err;
+ }
+
+ /* Saving data structure reference */
+ pci_set_drvdata(pdev, chip);
+
+ dev_info(dev, "DesignWare eDMA PCIe driver loaded completely\n");
+
+ return 0;
+}
+
+static void dw_edma_pcie_remove(struct pci_dev *pdev)
+{
+ struct dw_edma_chip *chip = pci_get_drvdata(pdev);
+ struct device *dev = &pdev->dev;
+ int err;
+
+ /* Stopping eDMA driver */
+ err = dw_edma_remove(chip);
+ if (err)
+ dev_warn(dev, "can't remove device properly: %d\n", err);
+
+ /* Freeing IRQs */
+ pci_free_irq_vectors(pdev);
+
+ dev_info(dev, "DesignWare eDMA PCIe driver unloaded completely\n");
+}
+
+static const struct pci_device_id dw_edma_pcie_id_table[] = {
+ { PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_data) },
+ { }
+};
+MODULE_DEVICE_TABLE(pci, dw_edma_pcie_id_table);
+
+static struct pci_driver dw_edma_pcie_driver = {
+ .name = "dw-edma-pcie",
+ .id_table = dw_edma_pcie_id_table,
+ .probe = dw_edma_pcie_probe,
+ .remove = dw_edma_pcie_remove,
+};
+
+module_pci_driver(dw_edma_pcie_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Synopsys DesignWare eDMA PCIe driver");
+MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>");
--
2.7.4
