dm: sandbox: Add a emulated PCI device as an example

This device sits on the sandbox PCI bus and provides a case-swapping
service for sandbox. It illustrates the use of both PCI I/O and PCI
memory accesses.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/misc/swap_case.c b/drivers/misc/swap_case.c
new file mode 100644 (file)
index 0000000..f6028ba
--- /dev/null
+++ b/drivers/misc/swap_case.c
@@ -0,0 +1,285 @@
+/*
+ * PCI emulation device which swaps the case of text
+ *
+ * Copyright (c) 2014 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <pci.h>
+#include <asm/test.h>
+#include <linux/ctype.h>
+
+/**
+ * struct swap_case_platdata - platform data for this device
+ *
+ * @command:   Current PCI command value
+ * @bar:       Current base address values
+ */
+struct swap_case_platdata {
+       u16 command;
+       u32 bar[2];
+};
+
+#define offset_to_barnum(offset)       \
+               (((offset) - PCI_BASE_ADDRESS_0) / sizeof(u32))
+
+enum {
+       MEM_TEXT_SIZE   = 0x100,
+};
+
+enum swap_case_op {
+       OP_TO_LOWER,
+       OP_TO_UPPER,
+       OP_SWAP,
+};
+
+static struct pci_bar {
+       int type;
+       u32 size;
+} barinfo[] = {
+       { PCI_BASE_ADDRESS_SPACE_IO, 1 },
+       { PCI_BASE_ADDRESS_MEM_TYPE_32, MEM_TEXT_SIZE },
+       { 0, 0 },
+       { 0, 0 },
+       { 0, 0 },
+       { 0, 0 },
+};
+
+struct swap_case_priv {
+       enum swap_case_op op;
+       char mem_text[MEM_TEXT_SIZE];
+};
+
+static int sandbox_swap_case_get_devfn(struct udevice *dev)
+{
+       struct pci_child_platdata *plat = dev_get_parent_platdata(dev);
+
+       return plat->devfn;
+}
+
+static int sandbox_swap_case_read_config(struct udevice *emul, uint offset,
+                                        ulong *valuep, enum pci_size_t size)
+{
+       struct swap_case_platdata *plat = dev_get_platdata(emul);
+
+       switch (offset) {
+       case PCI_COMMAND:
+               *valuep = plat->command;
+               break;
+       case PCI_HEADER_TYPE:
+               *valuep = 0;
+               break;
+       case PCI_VENDOR_ID:
+               *valuep = SANDBOX_PCI_VENDOR_ID;
+               break;
+       case PCI_DEVICE_ID:
+               *valuep = SANDBOX_PCI_DEVICE_ID;
+               break;
+       case PCI_CLASS_DEVICE:
+               if (size == PCI_SIZE_8) {
+                       *valuep = SANDBOX_PCI_CLASS_SUB_CODE;
+               } else {
+                       *valuep = (SANDBOX_PCI_CLASS_CODE << 8) |
+                                       SANDBOX_PCI_CLASS_SUB_CODE;
+               }
+               break;
+       case PCI_CLASS_CODE:
+               *valuep = SANDBOX_PCI_CLASS_CODE;
+               break;
+       case PCI_BASE_ADDRESS_0:
+       case PCI_BASE_ADDRESS_1:
+       case PCI_BASE_ADDRESS_2:
+       case PCI_BASE_ADDRESS_3:
+       case PCI_BASE_ADDRESS_4:
+       case PCI_BASE_ADDRESS_5: {
+               int barnum;
+               u32 *bar, result;
+
+               barnum = offset_to_barnum(offset);
+               bar = &plat->bar[barnum];
+
+               result = *bar;
+               if (*bar == 0xffffffff) {
+                       if (barinfo[barnum].type) {
+                               result = (~(barinfo[barnum].size - 1) &
+                                       PCI_BASE_ADDRESS_IO_MASK) |
+                                       PCI_BASE_ADDRESS_SPACE_IO;
+                       } else {
+                               result = (~(barinfo[barnum].size - 1) &
+                                       PCI_BASE_ADDRESS_MEM_MASK) |
+                                       PCI_BASE_ADDRESS_MEM_TYPE_32;
+                       }
+               }
+               debug("r bar %d=%x\n", barnum, result);
+               *valuep = result;
+               break;
+       }
+       }
+
+       return 0;
+}
+
+static int sandbox_swap_case_write_config(struct udevice *emul, uint offset,
+                                         ulong value, enum pci_size_t size)
+{
+       struct swap_case_platdata *plat = dev_get_platdata(emul);
+
+       switch (offset) {
+       case PCI_COMMAND:
+               plat->command = value;
+               break;
+       case PCI_BASE_ADDRESS_0:
+       case PCI_BASE_ADDRESS_1: {
+               int barnum;
+               u32 *bar;
+
+               barnum = offset_to_barnum(offset);
+               bar = &plat->bar[barnum];
+
+               debug("w bar %d=%lx\n", barnum, value);
+               *bar = value;
+               break;
+       }
+       }
+
+       return 0;
+}
+
+static int sandbox_swap_case_find_bar(struct udevice *emul, unsigned int addr,
+                                     int *barnump, unsigned int *offsetp)
+{
+       struct swap_case_platdata *plat = dev_get_platdata(emul);
+       int barnum;
+
+       for (barnum = 0; barnum < ARRAY_SIZE(barinfo); barnum++) {
+               unsigned int size = barinfo[barnum].size;
+
+               if (addr >= plat->bar[barnum] &&
+                   addr < plat->bar[barnum] + size) {
+                       *barnump = barnum;
+                       *offsetp = addr - plat->bar[barnum];
+                       return 0;
+               }
+       }
+       *barnump = -1;
+
+       return -ENOENT;
+}
+
+static void sandbox_swap_case_do_op(enum swap_case_op op, char *str, int len)
+{
+       for (; len > 0; len--, str++) {
+               switch (op) {
+               case OP_TO_UPPER:
+                       *str = toupper(*str);
+                       break;
+               case OP_TO_LOWER:
+                       *str = tolower(*str);
+                       break;
+               case OP_SWAP:
+                       if (isupper(*str))
+                               *str = tolower(*str);
+                       else
+                               *str = toupper(*str);
+                       break;
+               }
+       }
+}
+
+int sandbox_swap_case_read_io(struct udevice *dev, unsigned int addr,
+                             ulong *valuep, enum pci_size_t size)
+{
+       struct swap_case_priv *priv = dev_get_priv(dev);
+       unsigned int offset;
+       int barnum;
+       int ret;
+
+       ret = sandbox_swap_case_find_bar(dev, addr, &barnum, &offset);
+       if (ret)
+               return ret;
+
+       if (barnum == 0 && offset == 0)
+               *valuep = (*valuep & ~0xff) | priv->op;
+
+       return 0;
+}
+
+int sandbox_swap_case_write_io(struct udevice *dev, unsigned int addr,
+                              ulong value, enum pci_size_t size)
+{
+       struct swap_case_priv *priv = dev_get_priv(dev);
+       unsigned int offset;
+       int barnum;
+       int ret;
+
+       ret = sandbox_swap_case_find_bar(dev, addr, &barnum, &offset);
+       if (ret)
+               return ret;
+       if (barnum == 0 && offset == 0)
+               priv->op = value;
+
+       return 0;
+}
+
+static int sandbox_swap_case_map_physmem(struct udevice *dev,
+               phys_addr_t addr, unsigned long *lenp, void **ptrp)
+{
+       struct swap_case_priv *priv = dev_get_priv(dev);
+       unsigned int offset, avail;
+       int barnum;
+       int ret;
+
+       ret = sandbox_swap_case_find_bar(dev, addr, &barnum, &offset);
+       if (ret)
+               return ret;
+       if (barnum == 1) {
+               *ptrp = priv->mem_text + offset;
+               avail = barinfo[1].size - offset;
+               if (avail > barinfo[1].size)
+                       *lenp = 0;
+               else
+                       *lenp = min(*lenp, (ulong)avail);
+
+               return 0;
+       }
+
+       return -ENOENT;
+}
+
+static int sandbox_swap_case_unmap_physmem(struct udevice *dev,
+                                          const void *vaddr, unsigned long len)
+{
+       struct swap_case_priv *priv = dev_get_priv(dev);
+
+       sandbox_swap_case_do_op(priv->op, (void *)vaddr, len);
+
+       return 0;
+}
+
+struct dm_pci_emul_ops sandbox_swap_case_emul_ops = {
+       .get_devfn = sandbox_swap_case_get_devfn,
+       .read_config = sandbox_swap_case_read_config,
+       .write_config = sandbox_swap_case_write_config,
+       .read_io = sandbox_swap_case_read_io,
+       .write_io = sandbox_swap_case_write_io,
+       .map_physmem = sandbox_swap_case_map_physmem,
+       .unmap_physmem = sandbox_swap_case_unmap_physmem,
+};
+
+static const struct udevice_id sandbox_swap_case_ids[] = {
+       { .compatible = "sandbox,swap-case" },
+       { }
+};
+
+U_BOOT_DRIVER(sandbox_swap_case_emul) = {
+       .name           = "sandbox_swap_case_emul",
+       .id             = UCLASS_PCI_EMUL,
+       .of_match       = sandbox_swap_case_ids,
+       .ops            = &sandbox_swap_case_emul_ops,
+       .priv_auto_alloc_size = sizeof(struct swap_case_priv),
+       .platdata_auto_alloc_size = sizeof(struct swap_case_platdata),
+};