Re: [PATCH 1/4] mfd: smsc: Add support for smsc gpio io/keypad driver

On Tue, Aug 21, 2012 at 04:15:37PM +0530, Sourav Poddar wrote:

+config MFD_SMSC
+       bool "Support for the SMSC ECE1099 series chips"
+       depends on I2C=y && MFD_CORE && REGMAP_I2C

This needs to select REGMAP_I2C not depend on it.  REGMAP_I2C will only
be enabled by being selected.

+int smsc_read(struct device *child, unsigned int reg,
+	unsigned int *dest)
+{
+	struct smsc     *smsc = dev_get_drvdata(child->parent);
+
+	return regmap_read(smsc->regmap, reg, dest);
+}
+EXPORT_SYMBOL_GPL(smsc_read);

I'd suggest making these static inlines in the header given that they're
so trivial.

+static struct regmap_config smsc_regmap_config = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.cache_type = REGCACHE_COMPRESSED,
+};

Indentation is weird here.  For the cache we should have at least
.max_register defined and given the functionality there must surely be
some volatile registers (I'm surprised this works at all as it is, the
cache should break things).

+	of_property_read_u32(node, "clock", &smsc->clk);
+

This is all unconditional, there should be a dependency on this in
Kconfig.

+	regmap_read(smsc->regmap, SMSC_DEV_ID, &ret);
+	dev_dbg(&i2c->dev, "SMSC Device ID: %d\n", ret);

I'd make these log messages dev_info() or something.

+err:
+	kfree(smsc);

Use devm_kzalloc() for this.

+static const struct i2c_device_id smsc_i2c_id[] = {
+	{ "smsc", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, smsc_i2c_id);

This should probably list the part name rather than "smsc" - that seems
far too generic a name to use, obviously smsc produce more than one
part!