Messages in this thread | | | Subject | Re: [PATCH v4 1/2] hwmon: (adt7475) Added attenuator bypass support | From | Guenter Roeck <> | Date | Wed, 22 Jan 2020 07:03:55 -0800 |
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On 1/19/20 4:17 PM, Logan Shaw wrote: > Added support for reading DTS properties to set attenuators on > device probe for the ADT7473, ADT7475, ADT7476, and ADT7490. > > Signed-off-by: Logan Shaw <logan.shaw@alliedtelesis.co.nz> > --- > --- > drivers/hwmon/adt7475.c | 76 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > > diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c > index 6c64d50c9aae..2bb787acb363 100644 > --- a/drivers/hwmon/adt7475.c > +++ b/drivers/hwmon/adt7475.c > @@ -19,6 +19,7 @@ > #include <linux/hwmon-vid.h> > #include <linux/err.h> > #include <linux/jiffies.h> > +#include <linux/of.h> > #include <linux/util_macros.h> > > /* Indexes for the sysfs hooks */ > @@ -1457,6 +1458,76 @@ static int adt7475_update_limits(struct i2c_client *client) > return 0; > } > > +/**
I don't see the point of adding this private comment into the documentation.
> + * Attempts to read a u32 property from the DTS, if there is no error and > + * the properties value is zero then the bit given by parameter bit_index > + * is cleared in the parameter config. If the value is non-zero then the bit > + * is set. > + * > + * If reading the dts property returned an error code then it is returned and > + * the config parameter is not modified. > + */ > +static int modify_config_from_dts_prop(const struct i2c_client *client, > + char *dts_property, u8 *config, u8 bit_index) {
Alignment is far off. Please run "checkpatch --strict" and fix all problems it reports.
total: 6 errors, 12 warnings, 9 checks, 94 lines checked
is a bit much.
modify_config_from_dts_prop and dts_property are unnecessary long and result in multi-line code. Please use shorter function/parameter names.
> + u32 is_attenuator_bypassed = 0; > + int ret = of_property_read_u32(client->dev.of_node, dts_property, > + &is_attenuator_bypassed); > + > + if (! ret) { > + if (is_attenuator_bypassed) > + *config |= (1 << bit_index); > + else > + *config &= ~(1 << bit_index); > + } > + > + return ret;
This return value is never used. Please drop it.
> +} > + > +/** > + * Reads all individual voltage input bypass attenuator properties from the > + * DTS, and if the property is present the corresponding bit is set in the > + * register. > + > + * Properties are in the form of "bypass-attenuator-inx", where x is an > + * integer from the set {0, 1, 3, 4} (can not bypass in2 attenuator). > +.* > + * The adt7473 and adt7475 only support bypassing in1. > + * > + * Returns a negative error code if there was an error writing to the register. > + */ > +static int load_all_bypass_attenuators(const struct i2c_client *client, > + int chip, u8 *config2, u8 *config4) > +{ > + u8 config2_copy = *config2; > + u8 config4_copy = *config4; > + Two "copy" variables are unnecessary, as only one is ever used.
> + if (chip == adt7476 || chip == adt7490) { > + modify_config_from_dts_prop(client, "bypass-attenuator-in0", > + &config4_copy, 4); > + modify_config_from_dts_prop(client, "bypass-attenuator-in1", > + &config4_copy, 5); > + modify_config_from_dts_prop(client, "bypass-attenuator-in3", > + &config4_copy, 6); > + modify_config_from_dts_prop(client, "bypass-attenuator-in4", > + &config4_copy, 7); > + > + if (i2c_smbus_write_byte_data(client, REG_CONFIG4, config4_copy) < 0) > + return -EREMOTEIO; > + > + *config4 = config4_copy; > + } else if (chip == adt7473 || chip == adt7475) { > + modify_config_from_dts_prop(client, "bypass-attenuator-in1", > + &config2_copy, 5); > + > + if (i2c_smbus_write_byte_data(client, REG_CONFIG2, config2_copy) < 0) > + return -EREMOTEIO;
Please do not override error codes.
> + > + *config2 = config2_copy; > + } > + > + return 0; > +} > + > static int adt7475_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -1546,6 +1617,11 @@ static int adt7475_probe(struct i2c_client *client, > > /* Voltage attenuators can be bypassed, globally or individually */ > config2 = adt7475_read(REG_CONFIG2); > + if (load_all_bypass_attenuators(client, chip, > + &config2, &(data->config4)) < 0) > + dev_warn(&client->dev, > + "Error setting bypass attenuator bits\n"); > + > if (config2 & CONFIG2_ATTN) { > data->bypass_attn = (0x3 << 3) | 0x3; > } else { >
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