From 9ed030d728f3bd03b6e869357da02725afda19a7 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 17 Nov 2010 13:00:48 +0100 Subject: misc/at24: parse device tree data Information about the pagesize and read-only-status may also come from the devicetree. Parse this data, too, and act accordingly. While we are here, change the initialization printout a bit. write_max is useful to know to detect performance bottlenecks, the rest is superfluous. Signed-off-by: Wolfram Sang Signed-off-by: Grant Likely --- drivers/misc/eeprom/at24.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 559b0b3c16c3..3a53efc28821 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -457,6 +458,27 @@ static ssize_t at24_macc_write(struct memory_accessor *macc, const char *buf, /*-------------------------------------------------------------------------*/ +#ifdef CONFIG_OF +static void at24_get_ofdata(struct i2c_client *client, + struct at24_platform_data *chip) +{ + const __be32 *val; + struct device_node *node = client->dev.of_node; + + if (node) { + if (of_get_property(node, "read-only", NULL)) + chip->flags |= AT24_FLAG_READONLY; + val = of_get_property(node, "pagesize", NULL); + if (val) + chip->page_size = be32_to_cpup(val); + } +} +#else +static void at24_get_ofdata(struct i2c_client *client, + struct at24_platform_data *chip) +{ } +#endif /* CONFIG_OF */ + static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct at24_platform_data chip; @@ -485,6 +507,9 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) */ chip.page_size = 1; + /* update chipdata if OF is present */ + at24_get_ofdata(client, &chip); + chip.setup = NULL; chip.context = NULL; } @@ -597,19 +622,15 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) i2c_set_clientdata(client, at24); - dev_info(&client->dev, "%zu byte %s EEPROM %s\n", + dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n", at24->bin.size, client->name, - writable ? "(writable)" : "(read-only)"); + writable ? "writable" : "read-only", at24->write_max); if (use_smbus == I2C_SMBUS_WORD_DATA || use_smbus == I2C_SMBUS_BYTE_DATA) { dev_notice(&client->dev, "Falling back to %s reads, " "performance will suffer\n", use_smbus == I2C_SMBUS_WORD_DATA ? "word" : "byte"); } - dev_dbg(&client->dev, - "page_size %d, num_addresses %d, write_max %d, use_smbus %d\n", - chip.page_size, num_addresses, - at24->write_max, use_smbus); /* export data to kernel code */ if (chip.setup) -- cgit v1.2.1 From 45efe847971e6274a04eea75a0745d8015b54d37 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 17 Nov 2010 13:00:49 +0100 Subject: misc/at24: add more sanity checks for parameters Side-effects happen when passing 0 to either io_limit or page_size. Give an error in case of this misconfiguration. Signed-off-by: Wolfram Sang Signed-off-by: Grant Likely --- drivers/misc/eeprom/at24.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/misc') diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 3a53efc28821..ab1ad41786d1 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -517,6 +517,11 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) if (!is_power_of_2(chip.byte_len)) dev_warn(&client->dev, "byte_len looks suspicious (no power of 2)!\n"); + if (!chip.page_size) { + dev_err(&client->dev, "page_size must not be 0!\n"); + err = -EINVAL; + goto err_out; + } if (!is_power_of_2(chip.page_size)) dev_warn(&client->dev, "page_size looks suspicious (no power of 2)!\n"); @@ -681,6 +686,11 @@ static struct i2c_driver at24_driver = { static int __init at24_init(void) { + if (!io_limit) { + pr_err("at24: io_limit must not be 0!\n"); + return -EINVAL; + } + io_limit = rounddown_pow_of_two(io_limit); return i2c_add_driver(&at24_driver); } -- cgit v1.2.1