staging: kpc2000: add initial set of Daktronics drivers

These drivers have been outside of the kernel tree since the 2.x days,
and it's time to bring them into the tree so they can get properly
cleaned up.

This first dump of drivers is based on a tarball Matt gave to me, minus
an odd "dma" driver that I could not get to build at all.  I renamed a
few files, added the proper SPDX lines to it, added Kconfig entries and
tied it into the kernel build.  I also fixed up a number of initial
obvious kernel build warnings, but left the odd bitfield warning that
gcc is spitting out, as I'm not quite sure what to do about that.

There's loads of low-hanging coding style cleanups in here for people to
start attacking, as well as the more obvious logic and api cleanups as
well.

Cc: Matt Sickler <Matt.Sickler@daktronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

20 files changed, 2793 insertions, 0 deletions

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index ca944a2db9bc..b770c8c535f4 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -122,4 +122,6 @@ source "drivers/staging/erofs/Kconfig"
 
 source "drivers/staging/fieldbus/Kconfig"
 
+source "drivers/staging/kpc2000/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index f5b60efb1a0b..0640bd632851 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -51,3 +51,4 @@ obj-$(CONFIG_STAGING_GASKET_FRAMEWORK)	+= gasket/
 obj-$(CONFIG_XIL_AXIS_FIFO)	+= axis-fifo/
 obj-$(CONFIG_EROFS_FS)		+= erofs/
 obj-$(CONFIG_FIELDBUS_DEV)     += fieldbus/
+obj-$(CONFIG_KPC2000)		+= kpc2000/
diff --git a/drivers/staging/kpc2000/Kconfig b/drivers/staging/kpc2000/Kconfig
new file mode 100644
index 000000000000..926e770d6e0e
--- /dev/null
+++ b/drivers/staging/kpc2000/Kconfig
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config KPC2000
+	bool "Daktronics KPC Device support"
+	depends on PCI
+	help
+	  Select this if you wish to use the Daktronics KPC PCI devices
+
+	  If unsure, say N.
+
+config KPC2000_CORE
+	tristate "Daktronics KPC PCI UIO device"
+	depends on KPC2000
+	help
+	  Say Y here if you wish to support the Daktronics KPC PCI
+	  device in UIO mode.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called kpc2000
+
+	  If unsure, say N.
+
+config KPC2000_SPI
+	tristate "Kaktronics KPC SPI device"
+	depends on KPC2000 && SPI
+	help
+	  Say Y here if you wish to support the Daktronics KPC PCI
+	  device in SPI mode.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called kpc2000_spi
+
+	  If unsure, say N.
+
+config KPC2000_I2C
+	tristate "Kaktronics KPC I2C device"
+	depends on KPC2000 && I2C
+	help
+	  Say Y here if you wish to support the Daktronics KPC PCI
+	  device in I2C mode.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called kpc2000_i2c
+
+	  If unsure, say N.
+
diff --git a/drivers/staging/kpc2000/Makefile b/drivers/staging/kpc2000/Makefile
new file mode 100644
index 000000000000..6fcb2ee7b27d
--- /dev/null
+++ b/drivers/staging/kpc2000/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_KPC2000) += kpc2000/
+obj-$(CONFIG_KPC2000_I2C) += kpc_i2c/
+obj-$(CONFIG_KPC2000_SPI) += kpc_spi/
diff --git a/drivers/staging/kpc2000/TODO b/drivers/staging/kpc2000/TODO
new file mode 100644
index 000000000000..8c7af29fefae
--- /dev/null
+++ b/drivers/staging/kpc2000/TODO
@@ -0,0 +1,8 @@
+- the kpc_spi driver doesn't seem to let multiple transactions (to different instances of the core) happen in parallel...
+- The kpc_i2c driver is a hot mess, it should probably be cleaned up a ton.  It functions against current hardware though.
+- pcard->card_num in kp2000_pcie_probe() is a global variable and needs atomic / locking / something better.
+- probe_core_uio() probably needs error handling
+- the loop in kp2000_probe_cores() that uses probe_core_uio() also probably needs error handling
+- would be nice if the AIO fileops in kpc_dma could be made to work
+    - probably want to add a CONFIG_ option to control compilation of the AIO functions
+- if the AIO fileops in kpc_dma start working, next would be making iov_count > 1 work too
diff --git a/drivers/staging/kpc2000/kpc.h b/drivers/staging/kpc2000/kpc.h
new file mode 100644
index 000000000000..a3fc9c9221aa
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef KPC_H_
+#define KPC_H_
+
+/* *****  Driver Names  ***** */
+#define KP_DRIVER_NAME_KP2000           "kp2000"
+#define KP_DRIVER_NAME_INVALID          "kpc_invalid"
+#define KP_DRIVER_NAME_DMA_CONTROLLER   "kpc_nwl_dma"
+#define KP_DRIVER_NAME_UIO              "uio_pdrv_genirq"
+#define KP_DRIVER_NAME_I2C              "kpc_i2c"
+#define KP_DRIVER_NAME_SPI              "kpc_spi"
+
+struct kpc_core_device_platdata {
+	u32 card_id;
+	u32 build_version;
+	u32 hardware_revision;
+	u64 ssid;
+	u64 ddna;
+};
+
+#define PCI_DEVICE_ID_DAKTRONICS_KADOKA_P2KR0           0x4b03
+
+#endif /* KPC_H_ */
diff --git a/drivers/staging/kpc2000/kpc2000/Makefile b/drivers/staging/kpc2000/kpc2000/Makefile
new file mode 100644
index 000000000000..28ab1e185f9f
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc2000/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-m := kpc2000.o
+kpc2000-objs += kp2000_module.o  core.o  cell_probe.o  fileops.o
diff --git a/drivers/staging/kpc2000/kpc2000/cell_probe.c b/drivers/staging/kpc2000/kpc2000/cell_probe.c
new file mode 100644
index 000000000000..ad2cc0a3bfa1
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc2000/cell_probe.c
@@ -0,0 +1,466 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <linux/io.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/uio_driver.h>
+#include "pcie.h"
+
+/*  Core (Resource) Table Layout:
+ *      one Resource per record (8 bytes)
+ *                 6         5         4         3         2         1         0
+ *              3210987654321098765432109876543210987654321098765432109876543210
+ *              IIIIIIIIIIII                                                        Core Type    [up to 4095 types]
+ *                          D                                                       S2C DMA Present
+ *                           DDD                                                    S2C DMA Channel Number    [up to 8 channels]
+ *                              LLLLLLLLLLLLLLLL                                    Register Count (64-bit registers)    [up to 65535 registers]
+ *                                              OOOOOOOOOOOOOOOO                    Core Offset (in 4kB blocks)    [up to 65535 cores]
+ *                                                              D                   C2S DMA Present
+ *                                                               DDD                C2S DMA Channel Number    [up to 8 channels]
+ *                                                                  II              IRQ Count [0 to 3 IRQs per core]
+                                                                      1111111000
+ *                                                                    IIIIIII       IRQ Base Number [up to 128 IRQs per card]
+ *                                                                           ___    Spare
+ *
+ */
+
+#define KPC_OLD_DMA_CH_NUM(present, channel)   ((present) ? (0x8 | ((channel) & 0x7)) : 0)
+#define KPC_OLD_S2C_DMA_CH_NUM(cte)   KPC_OLD_DMA_CH_NUM(cte.s2c_dma_present, cte.s2c_dma_channel_num)
+#define KPC_OLD_C2S_DMA_CH_NUM(cte)   KPC_OLD_DMA_CH_NUM(cte.c2s_dma_present, cte.c2s_dma_channel_num)
+
+#define KP_CORE_ID_INVALID      0
+#define KP_CORE_ID_I2C          3
+#define KP_CORE_ID_SPI          5
+
+struct core_table_entry {
+    u16     type;
+    u32     offset;
+    u32     length;
+    bool    s2c_dma_present;
+    u8      s2c_dma_channel_num;
+    bool    c2s_dma_present;
+    u8      c2s_dma_channel_num;
+    u8      irq_count;
+    u8      irq_base_num;
+};
+
+static
+void  parse_core_table_entry_v0(struct core_table_entry *cte, const u64 read_val)
+{
+    cte->type                = ((read_val & 0xFFF0000000000000) >> 52);
+    cte->offset              = ((read_val & 0x00000000FFFF0000) >> 16) * 4096;
+    cte->length              = ((read_val & 0x0000FFFF00000000) >> 32) * 8;
+    cte->s2c_dma_present     = ((read_val & 0x0008000000000000) >> 51);
+    cte->s2c_dma_channel_num = ((read_val & 0x0007000000000000) >> 48);
+    cte->c2s_dma_present     = ((read_val & 0x0000000000008000) >> 15);
+    cte->c2s_dma_channel_num = ((read_val & 0x0000000000007000) >> 12);
+    cte->irq_count           = ((read_val & 0x0000000000000C00) >> 10);
+    cte->irq_base_num        = ((read_val & 0x00000000000003F8) >>  3);
+}
+
+static
+void dbg_cte(struct kp2000_device *pcard, struct core_table_entry *cte)
+{
+    dev_dbg(&pcard->pdev->dev, "CTE: type:%3d  offset:%3d (%3d)  length:%3d (%3d)  s2c:%d  c2s:%d  irq_count:%d  base_irq:%d\n",
+        cte->type,
+        cte->offset,
+        cte->offset / 4096,
+        cte->length,
+        cte->length / 8,
+        (cte->s2c_dma_present ? cte->s2c_dma_channel_num : -1),
+        (cte->c2s_dma_present ? cte->c2s_dma_channel_num : -1),
+        cte->irq_count,
+        cte->irq_base_num
+    );
+}
+
+static
+void parse_core_table_entry(struct core_table_entry *cte, const u64 read_val, const u8 entry_rev)
+{
+	switch (entry_rev) {
+	case 0: parse_core_table_entry_v0(cte, read_val); break;
+	default: cte->type = 0; break;
+	}
+}
+
+
+int  probe_core_basic(unsigned int core_num, struct kp2000_device *pcard, char *name, const struct core_table_entry cte)
+{
+    struct mfd_cell  cell = {0};
+    struct resource  resources[2] = {0};
+    
+    struct kpc_core_device_platdata  core_pdata = {
+        .card_id           = pcard->card_id,
+        .build_version     = pcard->build_version,
+        .hardware_revision = pcard->hardware_revision,
+        .ssid              = pcard->ssid,
+        .ddna              = pcard->ddna,
+    };
+
+    dev_dbg(&pcard->pdev->dev, "Found Basic core: type = %02d  dma = %02x / %02x  offset = 0x%x  length = 0x%x (%d regs)\n", cte.type, KPC_OLD_S2C_DMA_CH_NUM(cte), KPC_OLD_C2S_DMA_CH_NUM(cte), cte.offset, cte.length, cte.length / 8);
+    
+    
+    cell.platform_data = &core_pdata;
+    cell.pdata_size = sizeof(struct kpc_core_device_platdata);
+    cell.name = name;
+    cell.id = core_num;
+    cell.num_resources = 2;
+    
+    resources[0].start = cte.offset;
+    resources[0].end   = cte.offset + (cte.length - 1);
+    resources[0].flags = IORESOURCE_MEM;
+    
+    resources[1].start = pcard->pdev->irq;
+    resources[1].end   = pcard->pdev->irq;
+    resources[1].flags = IORESOURCE_IRQ;
+    
+    cell.resources = resources;
+    
+    return mfd_add_devices(
+        PCARD_TO_DEV(pcard),    // parent
+        pcard->card_num * 100,  // id
+        &cell,                  // struct mfd_cell *
+        1,                      // ndevs
+        &pcard->regs_base_resource,
+        0,                      // irq_base
+        NULL                    // struct irq_domain *
+    );
+}
+
+
+struct kpc_uio_device {
+    struct list_head list;
+    struct kp2000_device *pcard;
+    struct device  *dev;
+    struct uio_info uioinfo;
+    struct core_table_entry cte;
+    u16 core_num;
+};
+
+static ssize_t  show_attr(struct device *dev, struct device_attribute *attr, char *buf)
+{
+    struct kpc_uio_device *kudev = dev_get_drvdata(dev);
+    
+    #define ATTR_NAME_CMP(v)  (strcmp(v, attr->attr.name) == 0)
+    if ATTR_NAME_CMP("offset"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.offset);
+    } else if ATTR_NAME_CMP("size"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.length);
+    } else if ATTR_NAME_CMP("type"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.type);
+    }
+    else if ATTR_NAME_CMP("s2c_dma"){
+        if (kudev->cte.s2c_dma_present){
+            return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.s2c_dma_channel_num);
+        } else {
+            return scnprintf(buf, PAGE_SIZE, "not present\n");
+        }
+    } else if ATTR_NAME_CMP("c2s_dma"){
+        if (kudev->cte.c2s_dma_present){
+            return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.c2s_dma_channel_num);
+        } else {
+            return scnprintf(buf, PAGE_SIZE, "not present\n");
+        }
+    }
+    else if ATTR_NAME_CMP("irq_count"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.irq_count);
+    } else if ATTR_NAME_CMP("irq_base_num"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->cte.irq_base_num);
+    } else if ATTR_NAME_CMP("core_num"){
+        return scnprintf(buf, PAGE_SIZE, "%u\n", kudev->core_num);
+    } else {
+        return 0;
+    }
+    #undef ATTR_NAME_CMP
+}
+
+
+DEVICE_ATTR(offset,  0444, show_attr, NULL);
+DEVICE_ATTR(size,    0444, show_attr, NULL);
+DEVICE_ATTR(type,    0444, show_attr, NULL);
+DEVICE_ATTR(s2c_dma_ch, 0444, show_attr, NULL);
+DEVICE_ATTR(c2s_dma_ch, 0444, show_attr, NULL);
+DEVICE_ATTR(s2c_dma, 0444, show_attr, NULL);
+DEVICE_ATTR(c2s_dma, 0444, show_attr, NULL);
+DEVICE_ATTR(irq_count, 0444, show_attr, NULL);
+DEVICE_ATTR(irq_base_num, 0444, show_attr, NULL);
+DEVICE_ATTR(core_num, 0444, show_attr, NULL);
+struct attribute * kpc_uio_class_attrs[] = {
+	&dev_attr_offset.attr,
+	&dev_attr_size.attr,
+	&dev_attr_type.attr,
+	&dev_attr_s2c_dma_ch.attr,
+	&dev_attr_c2s_dma_ch.attr,
+	&dev_attr_s2c_dma.attr,
+	&dev_attr_c2s_dma.attr,
+	&dev_attr_irq_count.attr,
+	&dev_attr_irq_base_num.attr,
+	&dev_attr_core_num.attr,
+	NULL,
+};
+
+
+static
+int  kp2000_check_uio_irq(struct kp2000_device *pcard, u32 irq_num)
+{
+    u64 interrupt_active   =  readq(pcard->sysinfo_regs_base + REG_INTERRUPT_ACTIVE);
+    u64 interrupt_mask_inv = ~readq(pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
+    u64 irq_check_mask = (1 << irq_num);
+    if (interrupt_active & irq_check_mask){ // if it's active (interrupt pending)
+        if (interrupt_mask_inv & irq_check_mask){    // and if it's not masked off
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static
+irqreturn_t  kuio_handler(int irq, struct uio_info *uioinfo)
+{
+    struct kpc_uio_device *kudev = uioinfo->priv;
+    if (irq != kudev->pcard->pdev->irq)
+        return IRQ_NONE;
+    
+    if (kp2000_check_uio_irq(kudev->pcard, kudev->cte.irq_base_num)){
+        writeq((1 << kudev->cte.irq_base_num), kudev->pcard->sysinfo_regs_base + REG_INTERRUPT_ACTIVE); // Clear the active flag
+        return IRQ_HANDLED;
+    }
+    return IRQ_NONE;
+}
+
+static
+int kuio_irqcontrol(struct uio_info *uioinfo, s32 irq_on)
+{
+    struct kpc_uio_device *kudev = uioinfo->priv;
+    struct kp2000_device *pcard = kudev->pcard;
+    u64 mask;
+    
+    lock_card(pcard);
+    mask = readq(pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
+    if (irq_on){
+        mask &= ~(1 << (kudev->cte.irq_base_num));
+    } else {
+        mask |= (1 << (kudev->cte.irq_base_num));
+    }
+    writeq(mask, pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
+    unlock_card(pcard);
+    
+    return 0;
+}
+
+int  probe_core_uio(unsigned int core_num, struct kp2000_device *pcard, char *name, const struct core_table_entry cte)
+{
+    struct kpc_uio_device  *kudev;
+    int rv;
+
+    dev_dbg(&pcard->pdev->dev, "Found UIO core:   type = %02d  dma = %02x / %02x  offset = 0x%x  length = 0x%x (%d regs)\n", cte.type, KPC_OLD_S2C_DMA_CH_NUM(cte), KPC_OLD_C2S_DMA_CH_NUM(cte), cte.offset, cte.length, cte.length / 8);
+    
+    kudev = kzalloc(sizeof(struct kpc_uio_device), GFP_KERNEL);
+    if (!kudev){
+        dev_err(&pcard->pdev->dev, "probe_core_uio: failed to kzalloc kpc_uio_device\n");
+        return -ENOMEM;
+    }
+    
+    INIT_LIST_HEAD(&kudev->list);
+    kudev->pcard = pcard;
+    kudev->cte = cte;
+    kudev->core_num = core_num;
+    
+    kudev->uioinfo.priv = kudev;
+    kudev->uioinfo.name = name;
+    kudev->uioinfo.version = "0.0";
+    if (cte.irq_count > 0){
+        kudev->uioinfo.irq_flags = IRQF_SHARED;
+        kudev->uioinfo.irq = pcard->pdev->irq;
+        kudev->uioinfo.handler = kuio_handler;
+        kudev->uioinfo.irqcontrol = kuio_irqcontrol;
+    } else {
+        kudev->uioinfo.irq = 0;
+    }
+
+    kudev->uioinfo.mem[0].name = "uiomap";
+    kudev->uioinfo.mem[0].addr = pci_resource_start(pcard->pdev, REG_BAR) + cte.offset;
+    kudev->uioinfo.mem[0].size = (cte.length + PAGE_SIZE-1) & ~(PAGE_SIZE-1); // Round up to nearest PAGE_SIZE boundary
+    kudev->uioinfo.mem[0].memtype = UIO_MEM_PHYS;
+    
+    kudev->dev = device_create(kpc_uio_class, &pcard->pdev->dev, MKDEV(0,0), kudev, "%s.%d.%d.%d", kudev->uioinfo.name, pcard->card_num, cte.type, kudev->core_num);
+    if (IS_ERR(kudev->dev)) {
+        dev_err(&pcard->pdev->dev, "probe_core_uio device_create failed!\n");
+        return -ENODEV;
+    }
+    dev_set_drvdata(kudev->dev, kudev);
+    
+    rv = uio_register_device(kudev->dev, &kudev->uioinfo);
+    if (rv){
+        dev_err(&pcard->pdev->dev, "probe_core_uio failed uio_register_device: %d\n", rv);
+        return rv;
+    }
+    
+    list_add_tail(&kudev->list, &pcard->uio_devices_list);
+    
+    return 0;
+}
+
+
+static int  create_dma_engine_core(struct kp2000_device *pcard, size_t engine_regs_offset, int engine_num, int irq_num)
+{
+    struct mfd_cell  cell = {0};
+    struct resource  resources[2] = {0};
+    
+    dev_dbg(&pcard->pdev->dev, "create_dma_core(pcard = [%p], engine_regs_offset = %zx, engine_num = %d)\n", pcard, engine_regs_offset, engine_num);
+    
+    cell.platform_data = NULL;
+    cell.pdata_size = 0;
+    cell.id = engine_num;
+    cell.name = KP_DRIVER_NAME_DMA_CONTROLLER;
+    cell.num_resources = 2;
+    
+    resources[0].start = engine_regs_offset;
+    resources[0].end   = engine_regs_offset + (KPC_DMA_ENGINE_SIZE - 1);
+    resources[0].flags = IORESOURCE_MEM;
+    
+    resources[1].start = irq_num;
+    resources[1].end   = irq_num;
+    resources[1].flags = IORESOURCE_IRQ;
+    
+    cell.resources = resources;
+    
+    return mfd_add_devices(
+        PCARD_TO_DEV(pcard),    // parent
+        pcard->card_num * 100,  // id
+        &cell,                  // struct mfd_cell *
+        1,                      // ndevs
+        &pcard->dma_base_resource,
+        0,                      // irq_base
+        NULL                    // struct irq_domain *
+    );
+}
+
+static int  kp2000_setup_dma_controller(struct kp2000_device *pcard)
+{
+    int err;
+    unsigned int i;
+    u64 capabilities_reg;
+    
+    // S2C Engines
+    for (i = 0 ; i < 32 ; i++){
+        capabilities_reg = readq( pcard->dma_bar_base + KPC_DMA_S2C_BASE_OFFSET + (KPC_DMA_ENGINE_SIZE * i) );
+        if (capabilities_reg & ENGINE_CAP_PRESENT_MASK){
+            err = create_dma_engine_core(pcard, (KPC_DMA_S2C_BASE_OFFSET + (KPC_DMA_ENGINE_SIZE * i)), i,  pcard->pdev->irq);
+            if (err) goto err_out;
+        }
+    }
+    // C2S Engines
+    for (i = 0 ; i < 32 ; i++){
+        capabilities_reg = readq( pcard->dma_bar_base + KPC_DMA_C2S_BASE_OFFSET + (KPC_DMA_ENGINE_SIZE * i) );
+        if (capabilities_reg & ENGINE_CAP_PRESENT_MASK){
+            err = create_dma_engine_core(pcard, (KPC_DMA_C2S_BASE_OFFSET + (KPC_DMA_ENGINE_SIZE * i)), 32+i,  pcard->pdev->irq);
+            if (err) goto err_out;
+        }
+    }
+    
+    return 0;
+    
+err_out:
+    dev_err(&pcard->pdev->dev, "kp2000_setup_dma_controller: failed to add a DMA Engine: %d\n", err);
+    return err;
+}
+
+int  kp2000_probe_cores(struct kp2000_device *pcard)
+{
+    int err = 0;
+    int i;
+    int current_type_id;
+    u64 read_val;
+    unsigned int highest_core_id = 0;
+    struct core_table_entry cte;
+
+    dev_dbg(&pcard->pdev->dev, "kp2000_probe_cores(pcard = %p / %d)\n", pcard, pcard->card_num);
+    
+    err = kp2000_setup_dma_controller(pcard);
+    if (err) return err;
+    
+    INIT_LIST_HEAD(&pcard->uio_devices_list);
+    
+    // First, iterate the core table looking for the highest CORE_ID
+    for (i = 0 ; i < pcard->core_table_length ; i++){
+        read_val = readq(pcard->sysinfo_regs_base + ((pcard->core_table_offset + i) * 8));
+        parse_core_table_entry(&cte, read_val, pcard->core_table_rev);
+        dbg_cte(pcard, &cte);
+        if (cte.type > highest_core_id){
+            highest_core_id = cte.type;
+        }
+        if (cte.type == KP_CORE_ID_INVALID){
+            dev_info(&pcard->pdev->dev, "Found Invalid core: %016llx\n", read_val);
+        }
+    }
+    // Then, iterate over the possible core types.
+    for (current_type_id = 1 ; current_type_id <= highest_core_id ; current_type_id++){
+        unsigned int core_num = 0;
+        // Foreach core type, iterate the whole table and instantiate subdevices for each core.
+        // Yes, this is O(n*m) but the actual runtime is small enough that it's an acceptable tradeoff.
+        for (i = 0 ; i < pcard->core_table_length ; i++){
+            read_val = readq(pcard->sysinfo_regs_base + ((pcard->core_table_offset + i) * 8));
+            parse_core_table_entry(&cte, read_val, pcard->core_table_rev);
+            
+            if (cte.type == current_type_id){
+                switch (cte.type){
+                    case KP_CORE_ID_I2C:
+                        err = probe_core_basic(core_num, pcard, KP_DRIVER_NAME_I2C, cte);
+                        break;
+                    
+                    case KP_CORE_ID_SPI:
+                        err = probe_core_basic(core_num, pcard, KP_DRIVER_NAME_SPI, cte);
+                        break;
+                    
+                    default:
+                        err = probe_core_uio(core_num, pcard, "kpc_uio", cte);
+                        break;
+                }
+                if (err){
+                    dev_err(&pcard->pdev->dev, "kp2000_probe_cores: failed to add core %d: %d\n", i, err);
+                    return err;
+                }
+                core_num++;
+            }
+        }
+    }
+    
+    // Finally, instantiate a UIO device for the core_table.
+    cte.type                = 0; // CORE_ID_BOARD_INFO
+    cte.offset              = 0; // board info is always at the beginning
+    cte.length              = 512*8;
+    cte.s2c_dma_present     = false;
+    cte.s2c_dma_channel_num = 0;
+    cte.c2s_dma_present     = false;
+    cte.c2s_dma_channel_num = 0;
+    cte.irq_count           = 0;
+    cte.irq_base_num        = 0;
+    err = probe_core_uio(0, pcard, "kpc_uio", cte);
+    if (err){
+        dev_err(&pcard->pdev->dev, "kp2000_probe_cores: failed to add board_info core: %d\n", err);
+        return err;
+    }
+    
+    return 0;
+}
+
+void  kp2000_remove_cores(struct kp2000_device *pcard)
+{
+    struct list_head *ptr;
+    struct list_head *next;
+    list_for_each_safe(ptr, next, &pcard->uio_devices_list){
+        struct kpc_uio_device *kudev = list_entry(ptr, struct kpc_uio_device, list);
+        uio_unregister_device(&kudev->uioinfo);
+        device_unregister(kudev->dev);
+        list_del(&kudev->list);
+        kfree(kudev);
+    }
+}
+
diff --git a/drivers/staging/kpc2000/kpc2000/core.c b/drivers/staging/kpc2000/kpc2000/core.c
new file mode 100644
index 000000000000..35b87cdc4fb0
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc2000/core.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <linux/io.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/jiffies.h>
+#include "pcie.h"
+
+
+/*******************************************************
+  * SysFS Attributes
+  ******************************************************/
+static ssize_t  show_attr(struct device *dev, struct device_attribute *attr, char *buf)
+{
+    struct pci_dev *pdev = to_pci_dev(dev);
+    struct kp2000_device *pcard;
+
+    if (!pdev)  return -ENXIO;
+    pcard = pci_get_drvdata(pdev);
+    if (!pcard)  return -ENXIO;
+    
+    if (strcmp("ssid", attr->attr.name) == 0){         return scnprintf(buf, PAGE_SIZE, "%016llx\n", pcard->ssid);  } else
+    if (strcmp("ddna", attr->attr.name) == 0){         return scnprintf(buf, PAGE_SIZE, "%016llx\n", pcard->ddna);  } else
+    if (strcmp("card_id", attr->attr.name) == 0){      return scnprintf(buf, PAGE_SIZE, "%08x\n", pcard->card_id);  } else
+    if (strcmp("hw_rev", attr->attr.name) == 0){       return scnprintf(buf, PAGE_SIZE, "%08x\n", pcard->hardware_revision);  } else
+    if (strcmp("build", attr->attr.name) == 0){        return scnprintf(buf, PAGE_SIZE, "%08x\n", pcard->build_version);  } else
+    if (strcmp("build_date", attr->attr.name) == 0){   return scnprintf(buf, PAGE_SIZE, "%08x\n", pcard->build_datestamp);  } else
+    if (strcmp("build_time", attr->attr.name) == 0){   return scnprintf(buf, PAGE_SIZE, "%08x\n", pcard->build_timestamp);  } else
+    { return -ENXIO; }
+}
+
+static ssize_t  show_cpld_config_reg(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct kp2000_device *pcard;
+	u64 val;
+
+	if (!pdev)
+		return -ENXIO;
+
+	pcard = pci_get_drvdata(pdev);
+	if (!pcard)
+		return -ENXIO;
+
+	val = readq(pcard->sysinfo_regs_base + REG_CPLD_CONFIG);
+	return scnprintf(buf, PAGE_SIZE, "%016llx\n", val);
+}
+static ssize_t cpld_reconfigure(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+    struct pci_dev *pdev = to_pci_dev(dev);
+    long wr_val;
+    struct kp2000_device *pcard;
+    int rv;
+
+    if (!pdev)  return -ENXIO;
+    pcard = pci_get_drvdata(pdev);
+    if (!pcard)  return -ENXIO;
+    
+    rv = kstrtol(buf, 0, &wr_val);
+    if (rv < 0)  return rv;
+    if (wr_val > 7)  return -EINVAL;
+    
+    wr_val = wr_val << 8;
+    wr_val |= 0x1; // Set the "Configure Go" bit
+    writeq(wr_val, pcard->sysinfo_regs_base + REG_CPLD_CONFIG);
+    return count;
+}
+
+
+DEVICE_ATTR(ssid,       0444, show_attr, NULL);
+DEVICE_ATTR(ddna,       0444, show_attr, NULL);
+DEVICE_ATTR(card_id,    0444, show_attr, NULL);
+DEVICE_ATTR(hw_rev,     0444, show_attr, NULL);
+DEVICE_ATTR(build,      0444, show_attr, NULL);
+DEVICE_ATTR(build_date, 0444, show_attr, NULL);
+DEVICE_ATTR(build_time, 0444, show_attr, NULL);
+DEVICE_ATTR(cpld_reg,   0444, show_cpld_config_reg, NULL);
+DEVICE_ATTR(cpld_reconfigure,   0220, NULL, cpld_reconfigure);
+
+static const struct attribute *  kp_attr_list[] = {
+    &dev_attr_ssid.attr,
+    &dev_attr_ddna.attr,
+    &dev_attr_card_id.attr,
+    &dev_attr_hw_rev.attr,
+    &dev_attr_build.attr,
+    &dev_attr_build_date.attr,
+    &dev_attr_build_time.attr,
+    &dev_attr_cpld_reg.attr,
+    &dev_attr_cpld_reconfigure.attr,
+    NULL,
+};
+
+
+/*******************************************************
+  * Functions
+  ******************************************************/
+
+static void wait_and_read_ssid(struct kp2000_device *pcard)
+{
+    u64 read_val = readq(pcard->sysinfo_regs_base + REG_FPGA_SSID);
+    unsigned long timeout;
+    
+    if (read_val & 0x8000000000000000){
+        pcard->ssid = read_val;
+        return;
+    }
+    
+    timeout = jiffies + (HZ * 2);
+    do {
+        read_val = readq(pcard->sysinfo_regs_base + REG_FPGA_SSID);
+        if (read_val & 0x8000000000000000){
+            pcard->ssid = read_val;
+            return;
+        }
+        cpu_relax();
+        //schedule();
+    } while (time_before(jiffies, timeout));
+    
+    dev_notice(&pcard->pdev->dev, "SSID didn't show up!\n");
+    
+    #if 0
+    // Timed out waiting for the SSID to show up, just use the DDNA instead?
+    read_val = readq(pcard->sysinfo_regs_base + REG_FPGA_DDNA);
+    pcard->ssid = read_val;
+    #else
+    // Timed out waiting for the SSID to show up, stick all zeros in the value
+    pcard->ssid = 0;
+    #endif
+}
+
+static int  read_system_regs(struct kp2000_device *pcard)
+{
+    u64 read_val;
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_MAGIC_NUMBER);
+    if (read_val != KP2000_MAGIC_VALUE){
+        dev_err(&pcard->pdev->dev, "Invalid magic!  Got: 0x%016llx  Want: 0x%016lx\n", read_val, KP2000_MAGIC_VALUE);
+        return -EILSEQ;
+    }
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_CARD_ID_AND_BUILD);
+    pcard->card_id = (read_val & 0xFFFFFFFF00000000) >> 32;
+    pcard->build_version = (read_val & 0x00000000FFFFFFFF) >> 0;
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_DATE_AND_TIME_STAMPS);
+    pcard->build_datestamp = (read_val & 0xFFFFFFFF00000000) >> 32;
+    pcard->build_timestamp = (read_val & 0x00000000FFFFFFFF) >> 0;
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_CORE_TABLE_OFFSET);
+    pcard->core_table_length = (read_val & 0xFFFFFFFF00000000) >> 32;
+    pcard->core_table_offset = (read_val & 0x00000000FFFFFFFF) >> 0;
+    
+    wait_and_read_ssid(pcard);
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_FPGA_HW_ID);
+    pcard->core_table_rev    = (read_val & 0x0000000000000F00) >> 8;
+    pcard->hardware_revision = (read_val & 0x000000000000001F);
+    
+    read_val = readq(pcard->sysinfo_regs_base + REG_FPGA_DDNA);
+    pcard->ddna = read_val;
+    
+    dev_info(&pcard->pdev->dev, "system_regs: %08x %08x %08x %08x  %02x  %d %d  %016llx  %016llx\n",
+        pcard->card_id,
+        pcard->build_version,
+        pcard->build_datestamp,
+        pcard->build_timestamp,
+        pcard->hardware_revision,
+        pcard->core_table_rev,
+        pcard->core_table_length,
+        pcard->ssid,
+        pcard->ddna
+    );
+    
+    if (pcard->core_table_rev > 1){
+        dev_err(&pcard->pdev->dev, "core table entry revision is higher than we can deal with, cannot continue with this card!\n");
+        return 1;
+    }
+    
+    return 0;
+}
+
+irqreturn_t  kp2000_irq_handler(int irq, void *dev_id)
+{
+    struct kp2000_device  *pcard = (struct kp2000_device*)dev_id;
+    SetBackEndControl(pcard->dma_common_regs, KPC_DMA_CARD_IRQ_ENABLE | KPC_DMA_CARD_USER_INTERRUPT_MODE | KPC_DMA_CARD_USER_INTERRUPT_ACTIVE);
+    return IRQ_HANDLED;
+}
+
+int  kp2000_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+    int err = 0;