On Wed, Nov 09, 2016 at 11:32:06AM -0800, Guenter Roeck wrote: > On Wed, Nov 09, 2016 at 06:16:13PM +0100, Clemens Gruber wrote: > > Support setting the reference voltage from the device tree. > > > > Signed-off-by: Clemens Gruber <clemens.gruber@xxxxxxxxxxxx> > > --- > > drivers/hwmon/mcp3021.c | 46 ++++++++++++++++++++++++++++++++++++---------- > > 1 file changed, 36 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/hwmon/mcp3021.c b/drivers/hwmon/mcp3021.c > > index 972444a..81f4b7f 100644 > > --- a/drivers/hwmon/mcp3021.c > > +++ b/drivers/hwmon/mcp3021.c > > @@ -4,6 +4,7 @@ > > * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc. > > * Author: Mingkai Hu <Mingkai.hu@xxxxxxxxxxxxx> > > * Reworked by Sven Schuchmann <schuchmann@xxxxxxxxxxxxxxxxx> > > + * Copyright (C) 2016 Clemens Gruber <clemens.gruber@xxxxxxxxxxxx> > > Sorry, I can't accept that for such a minor change. Feel free to add > something like "devicetree support added by ...", if you like. I understand, no problem. I'll use your suggestion then. > > > * > > * This driver export the value of analog input voltage to sysfs, the > > * voltage unit is mV. Through the sysfs interface, lm-sensors tool > > @@ -22,11 +23,13 @@ > > #include <linux/i2c.h> > > #include <linux/err.h> > > #include <linux/device.h> > > +#include <linux/of.h> > > +#include <linux/of_device.h> > > > > -/* Vdd info */ > > +/* Vdd / reference voltage in millivolt */ > > #define MCP3021_VDD_MAX 5500 > > #define MCP3021_VDD_MIN 2700 > > -#define MCP3021_VDD_REF 3300 > > +#define MCP3021_VDD_DEFAULT 3300 > > I don't really see the value of changing this, but if it makes you > feel better at least make it MCP3021_VDD_REF_DEFAULT. I changed it because all three defines are about the reference voltage, not only the last one, which is just the default value. Only changing the last one to MCP3021_VDD_REF_DEFAULT would not make it less confusing. Maybe replace MCP3021_VDD_ with MCP3021_VDD_REF_ for all three? > > > > > /* output format */ > > #define MCP3021_SAR_SHIFT 2 > > @@ -47,7 +50,7 @@ enum chips { > > */ > > struct mcp3021_data { > > struct device *hwmon_dev; > > - u32 vdd; /* device power supply */ > > + u32 vdd; /* supply and reference voltage in millivolt */ > > u16 sar_shift; > > u16 sar_mask; > > u8 output_res; > > @@ -106,6 +109,7 @@ static int mcp3021_probe(struct i2c_client *client, > > { > > int err; > > struct mcp3021_data *data = NULL; > > + struct device_node *np = client->dev.of_node; > > > > if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > > return -ENODEV; > > @@ -117,6 +121,21 @@ static int mcp3021_probe(struct i2c_client *client, > > > > i2c_set_clientdata(client, data); > > > > + if (np) { > > + if (of_property_read_u32(np, "reference-voltage-microvolt", > > + &data->vdd)) > > + data->vdd = MCP3021_VDD_DEFAULT; > > + else > > + data->vdd /= 1000; > > It would be slightly better to reverse the logic here to make the code easier > to read. > > if (!of_property_read_u32(np, "reference-voltage-microvolt", > &data->vdd)) > data->vdd /= 1000; > else > data->vdd = MCP3021_VDD_DEFAULT; Yes, I'll change it. > > Not worth arguing about it, though, so feel free to keep it as is. > > > + } else { > > + u32 *pdata = dev_get_platdata(&client->dev); > > + > > + if (pdata) > > + data->vdd = *pdata; > > + else > > + data->vdd = MCP3021_VDD_DEFAULT; > > + } > > + > > switch (id->driver_data) { > > case mcp3021: > > data->sar_shift = MCP3021_SAR_SHIFT; > > @@ -129,15 +148,12 @@ static int mcp3021_probe(struct i2c_client *client, > > data->sar_mask = MCP3221_SAR_MASK; > > data->output_res = MCP3221_OUTPUT_RES; > > break; > > + default: > > + return -ENODEV; > > Hmm ... that is really an unrelated change (nor is it really needed > unless there is a bug in the code). Not worth arguing about it either, > but please keep in mind that this is one of the things making life > hard for maintainers. I see, I'll remove it then. Thank you for your feedback! Clemens -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html