[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/pnp/pnpbios/rsparser.c b/src/kernel/linux/v4.14/drivers/pnp/pnpbios/rsparser.c
new file mode 100644
index 0000000..2f31b21
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/pnp/pnpbios/rsparser.c
@@ -0,0 +1,810 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * rsparser.c - parses and encodes pnpbios resource data streams
+ */
+
+#include <linux/ctype.h>
+#include <linux/pnp.h>
+#include <linux/string.h>
+
+#ifdef CONFIG_PCI
+#include <linux/pci.h>
+#else
+inline void pcibios_penalize_isa_irq(int irq, int active)
+{
+}
+#endif /* CONFIG_PCI */
+
+#include "../base.h"
+#include "pnpbios.h"
+
+/* standard resource tags */
+#define SMALL_TAG_PNPVERNO 0x01
+#define SMALL_TAG_LOGDEVID 0x02
+#define SMALL_TAG_COMPATDEVID 0x03
+#define SMALL_TAG_IRQ 0x04
+#define SMALL_TAG_DMA 0x05
+#define SMALL_TAG_STARTDEP 0x06
+#define SMALL_TAG_ENDDEP 0x07
+#define SMALL_TAG_PORT 0x08
+#define SMALL_TAG_FIXEDPORT 0x09
+#define SMALL_TAG_VENDOR 0x0e
+#define SMALL_TAG_END 0x0f
+#define LARGE_TAG 0x80
+#define LARGE_TAG_MEM 0x81
+#define LARGE_TAG_ANSISTR 0x82
+#define LARGE_TAG_UNICODESTR 0x83
+#define LARGE_TAG_VENDOR 0x84
+#define LARGE_TAG_MEM32 0x85
+#define LARGE_TAG_FIXEDMEM32 0x86
+
+/*
+ * Resource Data Stream Format:
+ *
+ * Allocated Resources (required)
+ * end tag ->
+ * Resource Configuration Options (optional)
+ * end tag ->
+ * Compitable Device IDs (optional)
+ * final end tag ->
+ */
+
+/*
+ * Allocated Resources
+ */
+
+static void pnpbios_parse_allocated_ioresource(struct pnp_dev *dev,
+ int start, int len)
+{
+ int flags = 0;
+ int end = start + len - 1;
+
+ if (len <= 0 || end >= 0x10003)
+ flags |= IORESOURCE_DISABLED;
+
+ pnp_add_io_resource(dev, start, end, flags);
+}
+
+static void pnpbios_parse_allocated_memresource(struct pnp_dev *dev,
+ int start, int len)
+{
+ int flags = 0;
+ int end = start + len - 1;
+
+ if (len <= 0)
+ flags |= IORESOURCE_DISABLED;
+
+ pnp_add_mem_resource(dev, start, end, flags);
+}
+
+static unsigned char *pnpbios_parse_allocated_resource_data(struct pnp_dev *dev,
+ unsigned char *p,
+ unsigned char *end)
+{
+ unsigned int len, tag;
+ int io, size, mask, i, flags;
+
+ if (!p)
+ return NULL;
+
+ pnp_dbg(&dev->dev, "parse allocated resources\n");
+
+ pnp_init_resources(dev);
+
+ while ((char *)p < (char *)end) {
+
+ /* determine the type of tag */
+ if (p[0] & LARGE_TAG) { /* large tag */
+ len = (p[2] << 8) | p[1];
+ tag = p[0];
+ } else { /* small tag */
+ len = p[0] & 0x07;
+ tag = ((p[0] >> 3) & 0x0f);
+ }
+
+ switch (tag) {
+
+ case LARGE_TAG_MEM:
+ if (len != 9)
+ goto len_err;
+ io = *(short *)&p[4];
+ size = *(short *)&p[10];
+ pnpbios_parse_allocated_memresource(dev, io, size);
+ break;
+
+ case LARGE_TAG_ANSISTR:
+ /* ignore this for now */
+ break;
+
+ case LARGE_TAG_VENDOR:
+ /* do nothing */
+ break;
+
+ case LARGE_TAG_MEM32:
+ if (len != 17)
+ goto len_err;
+ io = *(int *)&p[4];
+ size = *(int *)&p[16];
+ pnpbios_parse_allocated_memresource(dev, io, size);
+ break;
+
+ case LARGE_TAG_FIXEDMEM32:
+ if (len != 9)
+ goto len_err;
+ io = *(int *)&p[4];
+ size = *(int *)&p[8];
+ pnpbios_parse_allocated_memresource(dev, io, size);
+ break;
+
+ case SMALL_TAG_IRQ:
+ if (len < 2 || len > 3)
+ goto len_err;
+ flags = 0;
+ io = -1;
+ mask = p[1] + p[2] * 256;
+ for (i = 0; i < 16; i++, mask = mask >> 1)
+ if (mask & 0x01)
+ io = i;
+ if (io != -1)
+ pcibios_penalize_isa_irq(io, 1);
+ else
+ flags = IORESOURCE_DISABLED;
+ pnp_add_irq_resource(dev, io, flags);
+ break;
+
+ case SMALL_TAG_DMA:
+ if (len != 2)
+ goto len_err;
+ flags = 0;
+ io = -1;
+ mask = p[1];
+ for (i = 0; i < 8; i++, mask = mask >> 1)
+ if (mask & 0x01)
+ io = i;
+ if (io == -1)
+ flags = IORESOURCE_DISABLED;
+ pnp_add_dma_resource(dev, io, flags);
+ break;
+
+ case SMALL_TAG_PORT:
+ if (len != 7)
+ goto len_err;
+ io = p[2] + p[3] * 256;
+ size = p[7];
+ pnpbios_parse_allocated_ioresource(dev, io, size);
+ break;
+
+ case SMALL_TAG_VENDOR:
+ /* do nothing */
+ break;
+
+ case SMALL_TAG_FIXEDPORT:
+ if (len != 3)
+ goto len_err;
+ io = p[1] + p[2] * 256;
+ size = p[3];
+ pnpbios_parse_allocated_ioresource(dev, io, size);
+ break;
+
+ case SMALL_TAG_END:
+ p = p + 2;
+ return (unsigned char *)p;
+ break;
+
+ default: /* an unknown tag */
+len_err:
+ dev_err(&dev->dev, "unknown tag %#x length %d\n",
+ tag, len);
+ break;
+ }
+
+ /* continue to the next tag */
+ if (p[0] & LARGE_TAG)
+ p += len + 3;
+ else
+ p += len + 1;
+ }
+
+ dev_err(&dev->dev, "no end tag in resource structure\n");
+
+ return NULL;
+}
+
+/*
+ * Resource Configuration Options
+ */
+
+static __init void pnpbios_parse_mem_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ resource_size_t min, max, align, len;
+ unsigned char flags;
+
+ min = ((p[5] << 8) | p[4]) << 8;
+ max = ((p[7] << 8) | p[6]) << 8;
+ align = (p[9] << 8) | p[8];
+ len = ((p[11] << 8) | p[10]) << 8;
+ flags = p[3];
+ pnp_register_mem_resource(dev, option_flags, min, max, align, len,
+ flags);
+}
+
+static __init void pnpbios_parse_mem32_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ resource_size_t min, max, align, len;
+ unsigned char flags;
+
+ min = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
+ max = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
+ align = (p[15] << 24) | (p[14] << 16) | (p[13] << 8) | p[12];
+ len = (p[19] << 24) | (p[18] << 16) | (p[17] << 8) | p[16];
+ flags = p[3];
+ pnp_register_mem_resource(dev, option_flags, min, max, align, len,
+ flags);
+}
+
+static __init void pnpbios_parse_fixed_mem32_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ resource_size_t base, len;
+ unsigned char flags;
+
+ base = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
+ len = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
+ flags = p[3];
+ pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
+}
+
+static __init void pnpbios_parse_irq_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ unsigned long bits;
+ pnp_irq_mask_t map;
+ unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;
+
+ bits = (p[2] << 8) | p[1];
+
+ bitmap_zero(map.bits, PNP_IRQ_NR);
+ bitmap_copy(map.bits, &bits, 16);
+
+ if (size > 2)
+ flags = p[3];
+
+ pnp_register_irq_resource(dev, option_flags, &map, flags);
+}
+
+static __init void pnpbios_parse_dma_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ pnp_register_dma_resource(dev, option_flags, p[1], p[2]);
+}
+
+static __init void pnpbios_parse_port_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ resource_size_t min, max, align, len;
+ unsigned char flags;
+
+ min = (p[3] << 8) | p[2];
+ max = (p[5] << 8) | p[4];
+ align = p[6];
+ len = p[7];
+ flags = p[1] ? IORESOURCE_IO_16BIT_ADDR : 0;
+ pnp_register_port_resource(dev, option_flags, min, max, align, len,
+ flags);
+}
+
+static __init void pnpbios_parse_fixed_port_option(struct pnp_dev *dev,
+ unsigned char *p, int size,
+ unsigned int option_flags)
+{
+ resource_size_t base, len;
+
+ base = (p[2] << 8) | p[1];
+ len = p[3];
+ pnp_register_port_resource(dev, option_flags, base, base, 0, len,
+ IORESOURCE_IO_FIXED);
+}
+
+static __init unsigned char *
+pnpbios_parse_resource_option_data(unsigned char *p, unsigned char *end,
+ struct pnp_dev *dev)
+{
+ unsigned int len, tag;
+ int priority;
+ unsigned int option_flags;
+
+ if (!p)
+ return NULL;
+
+ pnp_dbg(&dev->dev, "parse resource options\n");
+ option_flags = 0;
+ while ((char *)p < (char *)end) {
+
+ /* determine the type of tag */
+ if (p[0] & LARGE_TAG) { /* large tag */
+ len = (p[2] << 8) | p[1];
+ tag = p[0];
+ } else { /* small tag */
+ len = p[0] & 0x07;
+ tag = ((p[0] >> 3) & 0x0f);
+ }
+
+ switch (tag) {
+
+ case LARGE_TAG_MEM:
+ if (len != 9)
+ goto len_err;
+ pnpbios_parse_mem_option(dev, p, len, option_flags);
+ break;
+
+ case LARGE_TAG_MEM32:
+ if (len != 17)
+ goto len_err;
+ pnpbios_parse_mem32_option(dev, p, len, option_flags);
+ break;
+
+ case LARGE_TAG_FIXEDMEM32:
+ if (len != 9)
+ goto len_err;
+ pnpbios_parse_fixed_mem32_option(dev, p, len,
+ option_flags);
+ break;
+
+ case SMALL_TAG_IRQ:
+ if (len < 2 || len > 3)
+ goto len_err;
+ pnpbios_parse_irq_option(dev, p, len, option_flags);
+ break;
+
+ case SMALL_TAG_DMA:
+ if (len != 2)
+ goto len_err;
+ pnpbios_parse_dma_option(dev, p, len, option_flags);
+ break;
+
+ case SMALL_TAG_PORT:
+ if (len != 7)
+ goto len_err;
+ pnpbios_parse_port_option(dev, p, len, option_flags);
+ break;
+
+ case SMALL_TAG_VENDOR:
+ /* do nothing */
+ break;
+
+ case SMALL_TAG_FIXEDPORT:
+ if (len != 3)
+ goto len_err;
+ pnpbios_parse_fixed_port_option(dev, p, len,
+ option_flags);
+ break;
+
+ case SMALL_TAG_STARTDEP:
+ if (len > 1)
+ goto len_err;
+ priority = PNP_RES_PRIORITY_ACCEPTABLE;
+ if (len > 0)
+ priority = p[1];
+ option_flags = pnp_new_dependent_set(dev, priority);
+ break;
+
+ case SMALL_TAG_ENDDEP:
+ if (len != 0)
+ goto len_err;
+ option_flags = 0;
+ break;
+
+ case SMALL_TAG_END:
+ return p + 2;
+
+ default: /* an unknown tag */
+len_err:
+ dev_err(&dev->dev, "unknown tag %#x length %d\n",
+ tag, len);
+ break;
+ }
+
+ /* continue to the next tag */
+ if (p[0] & LARGE_TAG)
+ p += len + 3;
+ else
+ p += len + 1;
+ }
+
+ dev_err(&dev->dev, "no end tag in resource structure\n");
+
+ return NULL;
+}
+
+/*
+ * Compatible Device IDs
+ */
+
+static unsigned char *pnpbios_parse_compatible_ids(unsigned char *p,
+ unsigned char *end,
+ struct pnp_dev *dev)
+{
+ int len, tag;
+ u32 eisa_id;
+ char id[8];
+ struct pnp_id *dev_id;
+
+ if (!p)
+ return NULL;
+
+ while ((char *)p < (char *)end) {
+
+ /* determine the type of tag */
+ if (p[0] & LARGE_TAG) { /* large tag */
+ len = (p[2] << 8) | p[1];
+ tag = p[0];
+ } else { /* small tag */
+ len = p[0] & 0x07;
+ tag = ((p[0] >> 3) & 0x0f);
+ }
+
+ switch (tag) {
+
+ case LARGE_TAG_ANSISTR:
+ strncpy(dev->name, p + 3,
+ len >= PNP_NAME_LEN ? PNP_NAME_LEN - 2 : len);
+ dev->name[len >=
+ PNP_NAME_LEN ? PNP_NAME_LEN - 1 : len] = '\0';
+ break;
+
+ case SMALL_TAG_COMPATDEVID: /* compatible ID */
+ if (len != 4)
+ goto len_err;
+ eisa_id = p[1] | p[2] << 8 | p[3] << 16 | p[4] << 24;
+ pnp_eisa_id_to_string(eisa_id & PNP_EISA_ID_MASK, id);
+ dev_id = pnp_add_id(dev, id);
+ if (!dev_id)
+ return NULL;
+ break;
+
+ case SMALL_TAG_END:
+ p = p + 2;
+ return (unsigned char *)p;
+ break;
+
+ default: /* an unknown tag */
+len_err:
+ dev_err(&dev->dev, "unknown tag %#x length %d\n",
+ tag, len);
+ break;
+ }
+
+ /* continue to the next tag */
+ if (p[0] & LARGE_TAG)
+ p += len + 3;
+ else
+ p += len + 1;
+ }
+
+ dev_err(&dev->dev, "no end tag in resource structure\n");
+
+ return NULL;
+}
+
+/*
+ * Allocated Resource Encoding
+ */
+
+static void pnpbios_encode_mem(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long base;
+ unsigned long len;
+
+ if (pnp_resource_enabled(res)) {
+ base = res->start;
+ len = resource_size(res);
+ } else {
+ base = 0;
+ len = 0;
+ }
+
+ p[4] = (base >> 8) & 0xff;
+ p[5] = ((base >> 8) >> 8) & 0xff;
+ p[6] = (base >> 8) & 0xff;
+ p[7] = ((base >> 8) >> 8) & 0xff;
+ p[10] = (len >> 8) & 0xff;
+ p[11] = ((len >> 8) >> 8) & 0xff;
+
+ pnp_dbg(&dev->dev, " encode mem %#lx-%#lx\n", base, base + len - 1);
+}
+
+static void pnpbios_encode_mem32(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long base;
+ unsigned long len;
+
+ if (pnp_resource_enabled(res)) {
+ base = res->start;
+ len = resource_size(res);
+ } else {
+ base = 0;
+ len = 0;
+ }
+
+ p[4] = base & 0xff;
+ p[5] = (base >> 8) & 0xff;
+ p[6] = (base >> 16) & 0xff;
+ p[7] = (base >> 24) & 0xff;
+ p[8] = base & 0xff;
+ p[9] = (base >> 8) & 0xff;
+ p[10] = (base >> 16) & 0xff;
+ p[11] = (base >> 24) & 0xff;
+ p[16] = len & 0xff;
+ p[17] = (len >> 8) & 0xff;
+ p[18] = (len >> 16) & 0xff;
+ p[19] = (len >> 24) & 0xff;
+
+ pnp_dbg(&dev->dev, " encode mem32 %#lx-%#lx\n", base, base + len - 1);
+}
+
+static void pnpbios_encode_fixed_mem32(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long base;
+ unsigned long len;
+
+ if (pnp_resource_enabled(res)) {
+ base = res->start;
+ len = resource_size(res);
+ } else {
+ base = 0;
+ len = 0;
+ }
+
+ p[4] = base & 0xff;
+ p[5] = (base >> 8) & 0xff;
+ p[6] = (base >> 16) & 0xff;
+ p[7] = (base >> 24) & 0xff;
+ p[8] = len & 0xff;
+ p[9] = (len >> 8) & 0xff;
+ p[10] = (len >> 16) & 0xff;
+ p[11] = (len >> 24) & 0xff;
+
+ pnp_dbg(&dev->dev, " encode fixed_mem32 %#lx-%#lx\n", base,
+ base + len - 1);
+}
+
+static void pnpbios_encode_irq(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long map;
+
+ if (pnp_resource_enabled(res))
+ map = 1 << res->start;
+ else
+ map = 0;
+
+ p[1] = map & 0xff;
+ p[2] = (map >> 8) & 0xff;
+
+ pnp_dbg(&dev->dev, " encode irq mask %#lx\n", map);
+}
+
+static void pnpbios_encode_dma(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long map;
+
+ if (pnp_resource_enabled(res))
+ map = 1 << res->start;
+ else
+ map = 0;
+
+ p[1] = map & 0xff;
+
+ pnp_dbg(&dev->dev, " encode dma mask %#lx\n", map);
+}
+
+static void pnpbios_encode_port(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long base;
+ unsigned long len;
+
+ if (pnp_resource_enabled(res)) {
+ base = res->start;
+ len = resource_size(res);
+ } else {
+ base = 0;
+ len = 0;
+ }
+
+ p[2] = base & 0xff;
+ p[3] = (base >> 8) & 0xff;
+ p[4] = base & 0xff;
+ p[5] = (base >> 8) & 0xff;
+ p[7] = len & 0xff;
+
+ pnp_dbg(&dev->dev, " encode io %#lx-%#lx\n", base, base + len - 1);
+}
+
+static void pnpbios_encode_fixed_port(struct pnp_dev *dev, unsigned char *p,
+ struct resource *res)
+{
+ unsigned long base = res->start;
+ unsigned long len = resource_size(res);
+
+ if (pnp_resource_enabled(res)) {
+ base = res->start;
+ len = resource_size(res);
+ } else {
+ base = 0;
+ len = 0;
+ }
+
+ p[1] = base & 0xff;
+ p[2] = (base >> 8) & 0xff;
+ p[3] = len & 0xff;
+
+ pnp_dbg(&dev->dev, " encode fixed_io %#lx-%#lx\n", base,
+ base + len - 1);
+}
+
+static unsigned char *pnpbios_encode_allocated_resource_data(struct pnp_dev
+ *dev,
+ unsigned char *p,
+ unsigned char *end)
+{
+ unsigned int len, tag;
+ int port = 0, irq = 0, dma = 0, mem = 0;
+
+ if (!p)
+ return NULL;
+
+ while ((char *)p < (char *)end) {
+
+ /* determine the type of tag */
+ if (p[0] & LARGE_TAG) { /* large tag */
+ len = (p[2] << 8) | p[1];
+ tag = p[0];
+ } else { /* small tag */
+ len = p[0] & 0x07;
+ tag = ((p[0] >> 3) & 0x0f);
+ }
+
+ switch (tag) {
+
+ case LARGE_TAG_MEM:
+ if (len != 9)
+ goto len_err;
+ pnpbios_encode_mem(dev, p,
+ pnp_get_resource(dev, IORESOURCE_MEM, mem));
+ mem++;
+ break;
+
+ case LARGE_TAG_MEM32:
+ if (len != 17)
+ goto len_err;
+ pnpbios_encode_mem32(dev, p,
+ pnp_get_resource(dev, IORESOURCE_MEM, mem));
+ mem++;
+ break;
+
+ case LARGE_TAG_FIXEDMEM32:
+ if (len != 9)
+ goto len_err;
+ pnpbios_encode_fixed_mem32(dev, p,
+ pnp_get_resource(dev, IORESOURCE_MEM, mem));
+ mem++;
+ break;
+
+ case SMALL_TAG_IRQ:
+ if (len < 2 || len > 3)
+ goto len_err;
+ pnpbios_encode_irq(dev, p,
+ pnp_get_resource(dev, IORESOURCE_IRQ, irq));
+ irq++;
+ break;
+
+ case SMALL_TAG_DMA:
+ if (len != 2)
+ goto len_err;
+ pnpbios_encode_dma(dev, p,
+ pnp_get_resource(dev, IORESOURCE_DMA, dma));
+ dma++;
+ break;
+
+ case SMALL_TAG_PORT:
+ if (len != 7)
+ goto len_err;
+ pnpbios_encode_port(dev, p,
+ pnp_get_resource(dev, IORESOURCE_IO, port));
+ port++;
+ break;
+
+ case SMALL_TAG_VENDOR:
+ /* do nothing */
+ break;
+
+ case SMALL_TAG_FIXEDPORT:
+ if (len != 3)
+ goto len_err;
+ pnpbios_encode_fixed_port(dev, p,
+ pnp_get_resource(dev, IORESOURCE_IO, port));
+ port++;
+ break;
+
+ case SMALL_TAG_END:
+ p = p + 2;
+ return (unsigned char *)p;
+ break;
+
+ default: /* an unknown tag */
+len_err:
+ dev_err(&dev->dev, "unknown tag %#x length %d\n",
+ tag, len);
+ break;
+ }
+
+ /* continue to the next tag */
+ if (p[0] & LARGE_TAG)
+ p += len + 3;
+ else
+ p += len + 1;
+ }
+
+ dev_err(&dev->dev, "no end tag in resource structure\n");
+
+ return NULL;
+}
+
+/*
+ * Core Parsing Functions
+ */
+
+int __init pnpbios_parse_data_stream(struct pnp_dev *dev,
+ struct pnp_bios_node *node)
+{
+ unsigned char *p = (char *)node->data;
+ unsigned char *end = (char *)(node->data + node->size);
+
+ p = pnpbios_parse_allocated_resource_data(dev, p, end);
+ if (!p)
+ return -EIO;
+ p = pnpbios_parse_resource_option_data(p, end, dev);
+ if (!p)
+ return -EIO;
+ p = pnpbios_parse_compatible_ids(p, end, dev);
+ if (!p)
+ return -EIO;
+ return 0;
+}
+
+int pnpbios_read_resources_from_node(struct pnp_dev *dev,
+ struct pnp_bios_node *node)
+{
+ unsigned char *p = (char *)node->data;
+ unsigned char *end = (char *)(node->data + node->size);
+
+ p = pnpbios_parse_allocated_resource_data(dev, p, end);
+ if (!p)
+ return -EIO;
+ return 0;
+}
+
+int pnpbios_write_resources_to_node(struct pnp_dev *dev,
+ struct pnp_bios_node *node)
+{
+ unsigned char *p = (char *)node->data;
+ unsigned char *end = (char *)(node->data + node->size);
+
+ p = pnpbios_encode_allocated_resource_data(dev, p, end);
+ if (!p)
+ return -EIO;
+ return 0;
+}