Add Synopsys DesignWare xData IP driver. This driver enables/disables
the PCI traffic generator module pertain to the Synopsys DesignWare
prototype.

Signed-off-by: Gustavo Pimentel <gustavo.pimen...@synopsys.com>
---
 drivers/misc/dw-xdata-pcie.c | 401 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 401 insertions(+)
 create mode 100644 drivers/misc/dw-xdata-pcie.c

diff --git a/drivers/misc/dw-xdata-pcie.c b/drivers/misc/dw-xdata-pcie.c
new file mode 100644
index 00000000..43fdd35
--- /dev/null
+++ b/drivers/misc/dw-xdata-pcie.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare xData driver
+ *
+ * Author: Gustavo Pimentel <gustavo.pimen...@synopsys.com>
+ */
+
+#include <linux/miscdevice.h>
+#include <linux/bitfield.h>
+#include <linux/pci-epf.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+
+#define DW_XDATA_DRIVER_NAME           "dw-xdata-pcie"
+
+#define DW_XDATA_EP_MEM_OFFSET         0x8000000
+
+struct dw_xdata_pcie_data {
+       /* xData registers location */
+       enum pci_barno                  rg_bar;
+       off_t                           rg_off;
+       size_t                          rg_sz;
+};
+
+static const struct dw_xdata_pcie_data snps_edda_data = {
+       /* xData registers location */
+       .rg_bar                         = BAR_0,
+       .rg_off                         = 0x00000000,   /*   0 Kbytes */
+       .rg_sz                          = 0x0000012c,   /* 300  bytes */
+};
+
+#define STATUS_DONE                    BIT(0)
+
+#define CONTROL_DOORBELL               BIT(0)
+#define CONTROL_IS_WRITE               BIT(1)
+#define CONTROL_LENGTH(a)              FIELD_PREP(GENMASK(13, 2), a)
+#define CONTROL_PATTERN_INC            BIT(16)
+#define CONTROL_NO_ADDR_INC            BIT(18)
+
+#define XPERF_CONTROL_ENABLE           BIT(5)
+
+#define BURST_REPEAT                   BIT(31)
+#define BURST_VALUE                    0x1001
+
+#define PATTERN_VALUE                  0x0
+
+struct dw_xdata_regs {
+       u32 addr_lsb;                                   /* 0x000 */
+       u32 addr_msb;                                   /* 0x004 */
+       u32 burst_cnt;                                  /* 0x008 */
+       u32 control;                                    /* 0x00c */
+       u32 pattern;                                    /* 0x010 */
+       u32 status;                                     /* 0x014 */
+       u32 RAM_addr;                                   /* 0x018 */
+       u32 RAM_port;                                   /* 0x01c */
+       u32 _reserved0[14];                             /* 0x020..0x054 */
+       u32 perf_control;                               /* 0x058 */
+       u32 _reserved1[41];                             /* 0x05c..0x0fc */
+       u32 wr_cnt_lsb;                                 /* 0x100 */
+       u32 wr_cnt_msb;                                 /* 0x104 */
+       u32 rd_cnt_lsb;                                 /* 0x108 */
+       u32 rd_cnt_msb;                                 /* 0x10c */
+} __packed;
+
+struct dw_xdata_region {
+       phys_addr_t paddr;                              /* physical address */
+       void __iomem *vaddr;                            /* virtual address */
+       size_t sz;                                      /* size */
+};
+
+struct dw_xdata {
+       struct dw_xdata_region rg_region;               /* registers */
+       size_t max_wr_len;                              /* max wr xfer len */
+       size_t max_rd_len;                              /* max rd xfer len */
+       struct mutex mutex;
+       struct pci_dev *pdev;
+       struct device *dev;
+       struct miscdevice misc_dev;
+};
+
+static inline struct dw_xdata_regs __iomem *__dw_regs(struct dw_xdata *dw)
+{
+       return dw->rg_region.vaddr;
+}
+
+static void dw_xdata_stop(struct dw_xdata *dw)
+{
+       u32 burst;
+
+       mutex_lock(&dw->mutex);
+
+       burst = readl(&(__dw_regs(dw)->burst_cnt));
+
+       if (burst & BURST_REPEAT) {
+               burst &= ~(u32)BURST_REPEAT;
+               writel(burst, &(__dw_regs(dw)->burst_cnt));
+       }
+
+       mutex_unlock(&dw->mutex);
+}
+
+static void dw_xdata_start(struct dw_xdata *dw, bool write)
+{
+       u32 control, status;
+
+       /* Stop first if xfer in progress */
+       dw_xdata_stop(dw);
+
+       mutex_lock(&dw->mutex);
+
+       /* Clear status register */
+       writel(0x0, &(__dw_regs(dw)->status));
+
+       /* Burst count register set for continuous until stopped */
+       writel(BURST_REPEAT | BURST_VALUE, &(__dw_regs(dw)->burst_cnt));
+
+       /* Pattern register */
+       writel(PATTERN_VALUE, &(__dw_regs(dw)->pattern));
+
+       /* Control register */
+       control = CONTROL_DOORBELL | CONTROL_PATTERN_INC | CONTROL_NO_ADDR_INC;
+       if (write) {
+               control |= CONTROL_IS_WRITE;
+               control |= CONTROL_LENGTH(dw->max_wr_len);
+       } else {
+               control |= CONTROL_LENGTH(dw->max_rd_len);
+       }
+       writel(control, &(__dw_regs(dw)->control));
+
+       /*
+        * The xData HW block needs about 100 ms to initiate the traffic
+        * generation according this HW block datasheet.
+        */
+       usleep_range(100, 150);
+
+       status = readl(&(__dw_regs(dw)->status));
+
+       mutex_unlock(&dw->mutex);
+
+       if (!(status & STATUS_DONE))
+               pci_dbg(dw->pdev, "xData: started %s direction\n",
+                       write ? "write" : "read");
+}
+
+static void dw_xdata_perf_meas(struct dw_xdata *dw, u64 *data, bool write)
+{
+       if (write) {
+               *data = readl(&(__dw_regs(dw)->wr_cnt_msb));
+               *data <<= 32;
+               *data |= readl(&(__dw_regs(dw)->wr_cnt_lsb));
+       } else {
+               *data = readl(&(__dw_regs(dw)->rd_cnt_msb));
+               *data <<= 32;
+               *data |= readl(&(__dw_regs(dw)->rd_cnt_lsb));
+       }
+}
+
+static u64 dw_xdata_perf_diff(u64 *m1, u64 *m2, u64 time)
+{
+       u64 rate = (*m1 - *m2);
+
+       rate *= (1000 * 1000 * 1000);
+       rate >>= 20;
+       rate = DIV_ROUND_CLOSEST_ULL(rate, time);
+
+       return rate;
+}
+
+static void dw_xdata_perf(struct dw_xdata *dw, u64 *rate, bool write)
+{
+       u64 data[2], time[2], diff;
+
+       mutex_lock(&dw->mutex);
+
+       /* First acquisition of current count frames */
+       writel(0x0, &(__dw_regs(dw)->perf_control));
+       dw_xdata_perf_meas(dw, &data[0], write);
+       time[0] = jiffies;
+       writel((u32)XPERF_CONTROL_ENABLE, &(__dw_regs(dw)->perf_control));
+
+       /*
+        * Wait 100ms between the 1st count frame acquisition and the 2nd
+        * count frame acquisition, in order to calculate the speed later
+        */
+       mdelay(100);
+
+       /* Second acquisition of current count frames */
+       writel(0x0, &(__dw_regs(dw)->perf_control));
+       dw_xdata_perf_meas(dw, &data[1], write);
+       time[1] = jiffies;
+       writel((u32)XPERF_CONTROL_ENABLE, &(__dw_regs(dw)->perf_control));
+
+       /*
+        * Speed calculation
+        *
+        * rate = (2nd count frames - 1st count frames) / (time elapsed)
+        */
+       diff = jiffies_to_nsecs(time[1] - time[0]);
+       *rate = dw_xdata_perf_diff(&data[1], &data[0], diff);
+
+       mutex_unlock(&dw->mutex);
+
+       pci_dbg(dw->pdev, "xData: time=%llu us, %s=%llu MB/s\n",
+               diff, write ? "write" : "read", *rate);
+}
+
+static struct dw_xdata *misc_dev_to_dw(struct miscdevice *misc_dev)
+{
+       return container_of(misc_dev, struct dw_xdata, misc_dev);
+}
+
+static ssize_t write_show(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+       struct miscdevice *misc_dev = dev_get_drvdata(dev);
+       struct dw_xdata *dw = misc_dev_to_dw(misc_dev);
+       u64 rate;
+
+       dw_xdata_perf(dw, &rate, true);
+
+       return sysfs_emit(buf, "%llu\n", rate);
+}
+
+static ssize_t write_store(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t size)
+{
+       struct miscdevice *misc_dev = dev_get_drvdata(dev);
+       struct dw_xdata *dw = misc_dev_to_dw(misc_dev);
+
+       pci_dbg(dw->pdev, "xData: requested write transfer\n");
+
+       dw_xdata_start(dw, true);
+
+       return size;
+}
+
+static DEVICE_ATTR_RW(write);
+
+static ssize_t read_show(struct device *dev, struct device_attribute *attr,
+                        char *buf)
+{
+       struct miscdevice *misc_dev = dev_get_drvdata(dev);
+       struct dw_xdata *dw = misc_dev_to_dw(misc_dev);
+       u64 rate;
+
+       dw_xdata_perf(dw, &rate, false);
+
+       return sysfs_emit(buf, "%llu\n", rate);
+}
+
+static ssize_t read_store(struct device *dev, struct device_attribute *attr,
+                         const char *buf, size_t size)
+{
+       struct miscdevice *misc_dev = dev_get_drvdata(dev);
+       struct dw_xdata *dw = misc_dev_to_dw(misc_dev);
+
+       pci_dbg(dw->pdev, "xData: requested read transfer\n");
+
+       dw_xdata_start(dw, false);
+
+       return size;
+}
+
+static DEVICE_ATTR_RW(read);
+
+static ssize_t stop_store(struct device *dev, struct device_attribute *attr,
+                         const char *buf, size_t size)
+{
+       struct miscdevice *misc_dev = dev_get_drvdata(dev);
+       struct dw_xdata *dw = misc_dev_to_dw(misc_dev);
+
+       pci_dbg(dw->pdev, "xData: requested stop any transfer\n");
+
+       dw_xdata_stop(dw);
+
+       return size;
+}
+
+static DEVICE_ATTR_WO(stop);
+
+static struct attribute *xdata_attrs[] = {
+       &dev_attr_write.attr,
+       &dev_attr_read.attr,
+       &dev_attr_stop.attr,
+       NULL,
+};
+
+ATTRIBUTE_GROUPS(xdata);
+
+static int dw_xdata_pcie_probe(struct pci_dev *pdev,
+                              const struct pci_device_id *pid)
+{
+       const struct dw_xdata_pcie_data *pdata = (void *)pid->driver_data;
+       struct dw_xdata *dw;
+       u64 addr;
+       int err;
+
+       /* Enable PCI device */
+       err = pcim_enable_device(pdev);
+       if (err) {
+               pci_err(pdev, "enabling device failed\n");
+               return err;
+       }
+
+       /* Mapping PCI BAR regions */
+       err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar), pci_name(pdev));
+       if (err) {
+               pci_err(pdev, "xData BAR I/O remapping failed\n");
+               return err;
+       }
+
+       pci_set_master(pdev);
+
+       /* Allocate memory */
+       dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
+       if (!dw)
+               return -ENOMEM;
+
+       /* Data structure initialization */
+       mutex_init(&dw->mutex);
+
+       dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
+       if (!dw->rg_region.vaddr)
+               return -ENOMEM;
+
+       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->max_wr_len = pcie_get_mps(pdev);
+       dw->max_wr_len >>= 2;
+
+       dw->max_rd_len = pcie_get_readrq(pdev);
+       dw->max_rd_len >>= 2;
+
+       dw->pdev = pdev;
+       dw->dev = &pdev->dev;
+
+       dw->misc_dev.minor = MISC_DYNAMIC_MINOR;
+       dw->misc_dev.name = kstrdup(DW_XDATA_DRIVER_NAME, GFP_KERNEL);
+       dw->misc_dev.parent = &pdev->dev;
+       dw->misc_dev.groups = xdata_groups;
+
+       writel(0x0, &(__dw_regs(dw)->RAM_addr));
+       writel(0x0, &(__dw_regs(dw)->RAM_port));
+
+       addr = dw->rg_region.paddr + DW_XDATA_EP_MEM_OFFSET;
+       writel(lower_32_bits(addr), &(__dw_regs(dw)->addr_lsb));
+       writel(upper_32_bits(addr), &(__dw_regs(dw)->addr_msb));
+       pci_dbg(pdev, "xData: target address = 0x%.16llx\n", addr);
+
+       pci_dbg(pdev, "xData: wr_len = %zu, rd_len = %zu\n",
+               dw->max_wr_len * 4, dw->max_rd_len * 4);
+
+       /* Saving data structure reference */
+       pci_set_drvdata(pdev, dw);
+
+       /* Register misc device */
+       err = misc_register(&dw->misc_dev);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static void dw_xdata_pcie_remove(struct pci_dev *pdev)
+{
+       struct dw_xdata *dw = pci_get_drvdata(pdev);
+
+       if (dw) {
+               dw_xdata_stop(dw);
+               misc_deregister(&dw->misc_dev);
+       }
+}
+
+static const struct pci_device_id dw_xdata_pcie_id_table[] = {
+       { PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_data) },
+       { }
+};
+MODULE_DEVICE_TABLE(pci, dw_xdata_pcie_id_table);
+
+static struct pci_driver dw_xdata_pcie_driver = {
+       .name           = DW_XDATA_DRIVER_NAME,
+       .id_table       = dw_xdata_pcie_id_table,
+       .probe          = dw_xdata_pcie_probe,
+       .remove         = dw_xdata_pcie_remove,
+};
+
+module_pci_driver(dw_xdata_pcie_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Synopsys DesignWare xData PCIe driver");
+MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimen...@synopsys.com>");
+
-- 
2.7.4

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