diff options
Diffstat (limited to 'drivers/i2c/i2c-stub.c')
| -rw-r--r-- | drivers/i2c/i2c-stub.c | 237 |
1 files changed, 221 insertions, 16 deletions
diff --git a/drivers/i2c/i2c-stub.c b/drivers/i2c/i2c-stub.c index 77e4849d2f2a..d241aa295d96 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>"); |