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>

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),
+};