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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-09 09:15:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-09 09:15:07 -0700
commitf7dbaef50558c08917a18f390c2609f253dc6659 (patch)
treec638428e9370117da5a2277e9fe3197ca091fc82 /drivers/i2c/i2c-stub.c
parent7b9828d44194b2d90595ed4bd5131cacbf29b201 (diff)
parentebba48b702ab11bbb76e357a7246bc2f19ad02bc (diff)
Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang: "Highlights: - class based instantiation finally dropped for most embedded drivers bringing boot up performance gains - removed two drivers (one outdated, one a duplicate) - ACPI has now operation region support (thanks to Lan Tianyu) - the i2c-stub driver got overhauled and gained new features to become more useful when writing i2c client drivers (thanks to Guenter Roeck and Jean Delvare) The rest is driver bugfixes, added bindings/ids, cleanups..." * 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (43 commits) i2c: mpc: delete unneeded test before of_node_put i2c: rk3x: fix interrupt handling issue i2c: imx: Fix format warning for dev_dbg i2c: qup: disable clks and return instead of just returning error i2c: exynos5: always enable HSI2C i2c: designware: add new bindings i2c: gpio: Drop dead code in i2c_gpio_remove i2c: pca954x: put the mux to disconnected state after resume i2c: st: Update i2c timings drivers/i2c/busses: use correct type for dma_map/unmap i2c: i2c-st: Use %pa to print 'resource_size_t' type i2c: s3c2410: resume the I2C controller earlier i2c: stub: Avoid an array overrun on I2C block transfers i2c: i801: Add device ID for Intel Wildcat Point PCH i2c: i801: Fix the alignment of the device table i2c: stub: Add support for banked register ranges i2c: stub: Remember the number of emulated chips i2c: stub: Add support for SMBus block commands i2c: efm32: correct namespacing of location property i2c: exynos5: remove extra line and fix an assignment ...
Diffstat (limited to 'drivers/i2c/i2c-stub.c')
-rw-r--r--drivers/i2c/i2c-stub.c237
1 files changed, 221 insertions, 16 deletions
diff --git a/drivers/i2c/i2c-stub.c b/drivers/i2c/i2c-stub.c
index 77e4849d2f2..d241aa295d9 100644
--- a/drivers/i2c/i2c-stub.c
+++ b/drivers/i2c/i2c-stub.c
@@ -2,7 +2,7 @@
i2c-stub.c - I2C/SMBus chip emulator
Copyright (c) 2004 Mark M. Hoffman <mhoffman@lightlink.com>
- Copyright (C) 2007, 2012 Jean Delvare <jdelvare@suse.de>
+ Copyright (C) 2007-2014 Jean Delvare <jdelvare@suse.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -27,28 +27,109 @@
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/i2c.h>
+#include <linux/list.h>
#define MAX_CHIPS 10
-#define STUB_FUNC (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | \
- I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | \
- I2C_FUNC_SMBUS_I2C_BLOCK)
+
+/*
+ * Support for I2C_FUNC_SMBUS_BLOCK_DATA is disabled by default and must
+ * be enabled explicitly by setting the I2C_FUNC_SMBUS_BLOCK_DATA bits
+ * in the 'functionality' module parameter.
+ */
+#define STUB_FUNC_DEFAULT \
+ (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | \
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | \
+ I2C_FUNC_SMBUS_I2C_BLOCK)
+
+#define STUB_FUNC_ALL \
+ (STUB_FUNC_DEFAULT | I2C_FUNC_SMBUS_BLOCK_DATA)
static unsigned short chip_addr[MAX_CHIPS];
module_param_array(chip_addr, ushort, NULL, S_IRUGO);
MODULE_PARM_DESC(chip_addr,
"Chip addresses (up to 10, between 0x03 and 0x77)");
-static unsigned long functionality = STUB_FUNC;
+static unsigned long functionality = STUB_FUNC_DEFAULT;
module_param(functionality, ulong, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(functionality, "Override functionality bitfield");
+/* Some chips have banked register ranges */
+
+static u8 bank_reg[MAX_CHIPS];
+module_param_array(bank_reg, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(bank_reg, "Bank register");
+
+static u8 bank_mask[MAX_CHIPS];
+module_param_array(bank_mask, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(bank_mask, "Bank value mask");
+
+static u8 bank_start[MAX_CHIPS];
+module_param_array(bank_start, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(bank_start, "First banked register");
+
+static u8 bank_end[MAX_CHIPS];
+module_param_array(bank_end, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(bank_end, "Last banked register");
+
+struct smbus_block_data {
+ struct list_head node;
+ u8 command;
+ u8 len;
+ u8 block[I2C_SMBUS_BLOCK_MAX];
+};
+
struct stub_chip {
u8 pointer;
u16 words[256]; /* Byte operations use the LSB as per SMBus
specification */
+ struct list_head smbus_blocks;
+
+ /* For chips with banks, extra registers are allocated dynamically */
+ u8 bank_reg;
+ u8 bank_shift;
+ u8 bank_mask;
+ u8 bank_sel; /* Currently selected bank */
+ u8 bank_start;
+ u8 bank_end;
+ u16 bank_size;
+ u16 *bank_words; /* Room for bank_mask * bank_size registers */
};
static struct stub_chip *stub_chips;
+static int stub_chips_nr;
+
+static struct smbus_block_data *stub_find_block(struct device *dev,
+ struct stub_chip *chip,
+ u8 command, bool create)
+{
+ struct smbus_block_data *b, *rb = NULL;
+
+ list_for_each_entry(b, &chip->smbus_blocks, node) {
+ if (b->command == command) {
+ rb = b;
+ break;
+ }
+ }
+ if (rb == NULL && create) {
+ rb = devm_kzalloc(dev, sizeof(*rb), GFP_KERNEL);
+ if (rb == NULL)
+ return rb;
+ rb->command = command;
+ list_add(&rb->node, &chip->smbus_blocks);
+ }
+ return rb;
+}
+
+static u16 *stub_get_wordp(struct stub_chip *chip, u8 offset)
+{
+ if (chip->bank_sel &&
+ offset >= chip->bank_start && offset <= chip->bank_end)
+ return chip->bank_words +
+ (chip->bank_sel - 1) * chip->bank_size +
+ offset - chip->bank_start;
+ else
+ return chip->words + offset;
+}
/* Return negative errno on error. */
static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
@@ -57,9 +138,11 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
s32 ret;
int i, len;
struct stub_chip *chip = NULL;
+ struct smbus_block_data *b;
+ u16 *wordp;
/* Search for the right chip */
- for (i = 0; i < MAX_CHIPS && chip_addr[i]; i++) {
+ for (i = 0; i < stub_chips_nr; i++) {
if (addr == chip_addr[i]) {
chip = stub_chips + i;
break;
@@ -82,7 +165,8 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
"smbus byte - addr 0x%02x, wrote 0x%02x.\n",
addr, command);
} else {
- data->byte = chip->words[chip->pointer++] & 0xff;
+ wordp = stub_get_wordp(chip, chip->pointer++);
+ data->byte = *wordp & 0xff;
dev_dbg(&adap->dev,
"smbus byte - addr 0x%02x, read 0x%02x.\n",
addr, data->byte);
@@ -92,14 +176,25 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
break;
case I2C_SMBUS_BYTE_DATA:
+ wordp = stub_get_wordp(chip, command);
if (read_write == I2C_SMBUS_WRITE) {
- chip->words[command] &= 0xff00;
- chip->words[command] |= data->byte;
+ *wordp &= 0xff00;
+ *wordp |= data->byte;
dev_dbg(&adap->dev,
"smbus byte data - addr 0x%02x, wrote 0x%02x at 0x%02x.\n",
addr, data->byte, command);
+
+ /* Set the bank as needed */
+ if (chip->bank_words && command == chip->bank_reg) {
+ chip->bank_sel =
+ (data->byte >> chip->bank_shift)
+ & chip->bank_mask;
+ dev_dbg(&adap->dev,
+ "switching to bank %u.\n",
+ chip->bank_sel);
+ }
} else {
- data->byte = chip->words[command] & 0xff;
+ data->byte = *wordp & 0xff;
dev_dbg(&adap->dev,
"smbus byte data - addr 0x%02x, read 0x%02x at 0x%02x.\n",
addr, data->byte, command);
@@ -110,13 +205,14 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
break;
case I2C_SMBUS_WORD_DATA:
+ wordp = stub_get_wordp(chip, command);
if (read_write == I2C_SMBUS_WRITE) {
- chip->words[command] = data->word;
+ *wordp = data->word;
dev_dbg(&adap->dev,
"smbus word data - addr 0x%02x, wrote 0x%04x at 0x%02x.\n",
addr, data->word, command);
} else {
- data->word = chip->words[command];
+ data->word = *wordp;
dev_dbg(&adap->dev,
"smbus word data - addr 0x%02x, read 0x%04x at 0x%02x.\n",
addr, data->word, command);
@@ -126,6 +222,12 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
+ /*
+ * We ignore banks here, because banked chips don't use I2C
+ * block transfers
+ */
+ if (data->block[0] > 256 - command) /* Avoid overrun */
+ data->block[0] = 256 - command;
len = data->block[0];
if (read_write == I2C_SMBUS_WRITE) {
for (i = 0; i < len; i++) {
@@ -148,6 +250,55 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
ret = 0;
break;
+ case I2C_SMBUS_BLOCK_DATA:
+ /*
+ * We ignore banks here, because chips typically don't use both
+ * banks and SMBus block transfers
+ */
+ b = stub_find_block(&adap->dev, chip, command, false);
+ if (read_write == I2C_SMBUS_WRITE) {
+ len = data->block[0];
+ if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) {
+ ret = -EINVAL;
+ break;
+ }
+ if (b == NULL) {
+ b = stub_find_block(&adap->dev, chip, command,
+ true);
+ if (b == NULL) {
+ ret = -ENOMEM;
+ break;
+ }
+ }
+ /* Largest write sets read block length */
+ if (len > b->len)
+ b->len = len;
+ for (i = 0; i < len; i++)
+ b->block[i] = data->block[i + 1];
+ /* update for byte and word commands */
+ chip->words[command] = (b->block[0] << 8) | b->len;
+ dev_dbg(&adap->dev,
+ "smbus block data - addr 0x%02x, wrote %d bytes at 0x%02x.\n",
+ addr, len, command);
+ } else {
+ if (b == NULL) {
+ dev_dbg(&adap->dev,
+ "SMBus block read command without prior block write not supported\n");
+ ret = -EOPNOTSUPP;
+ break;
+ }
+ len = b->len;
+ data->block[0] = len;
+ for (i = 0; i < len; i++)
+ data->block[i + 1] = b->block[i];
+ dev_dbg(&adap->dev,
+ "smbus block data - addr 0x%02x, read %d bytes at 0x%02x.\n",
+ addr, len, command);
+ }
+
+ ret = 0;
+ break;
+
default:
dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n");
ret = -EOPNOTSUPP;
@@ -159,7 +310,7 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
static u32 stub_func(struct i2c_adapter *adapter)
{
- return STUB_FUNC & functionality;
+ return STUB_FUNC_ALL & functionality;
}
static const struct i2c_algorithm smbus_algorithm = {
@@ -174,6 +325,43 @@ static struct i2c_adapter stub_adapter = {
.name = "SMBus stub driver",
};
+static int __init i2c_stub_allocate_banks(int i)
+{
+ struct stub_chip *chip = stub_chips + i;
+
+ chip->bank_reg = bank_reg[i];
+ chip->bank_start = bank_start[i];
+ chip->bank_end = bank_end[i];
+ chip->bank_size = bank_end[i] - bank_start[i] + 1;
+
+ /* We assume that all bits in the mask are contiguous */
+ chip->bank_mask = bank_mask[i];
+ while (!(chip->bank_mask & 1)) {
+ chip->bank_shift++;
+ chip->bank_mask >>= 1;
+ }
+
+ chip->bank_words = kzalloc(chip->bank_mask * chip->bank_size *
+ sizeof(u16), GFP_KERNEL);
+ if (!chip->bank_words)
+ return -ENOMEM;
+
+ pr_debug("i2c-stub: Allocated %u banks of %u words each (registers 0x%02x to 0x%02x)\n",
+ chip->bank_mask, chip->bank_size, chip->bank_start,
+ chip->bank_end);
+
+ return 0;
+}
+
+static void i2c_stub_free(void)
+{
+ int i;
+
+ for (i = 0; i < stub_chips_nr; i++)
+ kfree(stub_chips[i].bank_words);
+ kfree(stub_chips);
+}
+
static int __init i2c_stub_init(void)
{
int i, ret;
@@ -194,22 +382,39 @@ static int __init i2c_stub_init(void)
}
/* Allocate memory for all chips at once */
- stub_chips = kzalloc(i * sizeof(struct stub_chip), GFP_KERNEL);
+ stub_chips_nr = i;
+ stub_chips = kcalloc(stub_chips_nr, sizeof(struct stub_chip),
+ GFP_KERNEL);
if (!stub_chips) {
pr_err("i2c-stub: Out of memory\n");
return -ENOMEM;
}
+ for (i = 0; i < stub_chips_nr; i++) {
+ INIT_LIST_HEAD(&stub_chips[i].smbus_blocks);
+
+ /* Allocate extra memory for banked register ranges */
+ if (bank_mask[i]) {
+ ret = i2c_stub_allocate_banks(i);
+ if (ret)
+ goto fail_free;
+ }
+ }
ret = i2c_add_adapter(&stub_adapter);
if (ret)
- kfree(stub_chips);
+ goto fail_free;
+
+ return 0;
+
+ fail_free:
+ i2c_stub_free();
return ret;
}
static void __exit i2c_stub_exit(void)
{
i2c_del_adapter(&stub_adapter);
- kfree(stub_chips);
+ i2c_stub_free();
}
MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");