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-rw-r--r--Documentation/i2c/i2c-stub11
-rw-r--r--drivers/i2c/i2c-stub.c131
2 files changed, 128 insertions, 14 deletions
diff --git a/Documentation/i2c/i2c-stub b/Documentation/i2c/i2c-stub
index a0fe7a04a3bd..a16924fbd289 100644
--- a/Documentation/i2c/i2c-stub
+++ b/Documentation/i2c/i2c-stub
@@ -47,15 +47,18 @@ unsigned long functionality:
value 0x1f0000 would only enable the quick, byte and byte data
commands.
+u8 bank_reg[10]
+u8 bank_mask[10]
+u8 bank_start[10]
+u8 bank_end[10]:
+ Optional bank settings. They tell which bits in which register
+ select the active bank, as well as the range of banked registers.
+
CAVEATS:
If your target driver polls some byte or word waiting for it to change, the
stub could lock it up. Use i2cset to unlock it.
-If the hardware for your driver has banked registers (e.g. Winbond sensors
-chips) this module will not work well - although it could be extended to
-support that pretty easily.
-
If you spam it hard enough, printk can be lossy. This module really wants
something like relayfs.
diff --git a/drivers/i2c/i2c-stub.c b/drivers/i2c/i2c-stub.c
index ad52f0701198..e815c6067ff3 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
@@ -53,6 +53,24 @@ 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;
@@ -65,6 +83,16 @@ struct stub_chip {
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;
@@ -92,6 +120,17 @@ static struct smbus_block_data *stub_find_block(struct device *dev,
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,
char read_write, u8 command, int size, union i2c_smbus_data *data)
@@ -100,6 +139,7 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
int i, len;
struct stub_chip *chip = NULL;
struct smbus_block_data *b;
+ u16 *wordp;
/* Search for the right chip */
for (i = 0; i < stub_chips_nr; i++) {
@@ -125,7 +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);
@@ -135,14 +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);
@@ -153,13 +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);
@@ -169,6 +222,10 @@ 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
+ */
len = data->block[0];
if (read_write == I2C_SMBUS_WRITE) {
for (i = 0; i < len; i++) {
@@ -192,6 +249,10 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
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];
@@ -262,6 +323,43 @@ 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;
@@ -289,19 +387,32 @@ static int __init i2c_stub_init(void)
pr_err("i2c-stub: Out of memory\n");
return -ENOMEM;
}
- for (i = 0; i < stub_chips_nr; i++)
+ 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>");
generated by cgit (git 2.34.1) at 2024-05-10 07:32:46 +0000