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>");