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Date: Sat, 9 Oct 2021 07:35:33 -0700 From: Guenter Roeck <linux@...ck-us.net> To: Oskar Senft <osk@...gle.com>, Jean Delvare <jdelvare@...e.com>, Rob Herring <robh+dt@...nel.org>, linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org, devicetree@...r.kernel.org Subject: Re: [PATCH v4 2/2] hwmon: (nct7802) Make temperature sensors configurable. On 10/8/21 7:58 PM, Oskar Senft wrote: > This change allows LTD and RTD inputs to be configured via > device tree bindings. If the DT bindings are not present, > the input configuration is not modified and left at HW > defaults. > > Signed-off-by: Oskar Senft <osk@...gle.com> > --- > drivers/hwmon/nct7802.c | 158 ++++++++++++++++++++++++++++++++++++---- > 1 file changed, 144 insertions(+), 14 deletions(-) > > diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c > index 604af2f6103a..5a7e38e8a188 100644 > --- a/drivers/hwmon/nct7802.c > +++ b/drivers/hwmon/nct7802.c > @@ -51,6 +51,23 @@ static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = { > #define REG_CHIP_ID 0xfe > #define REG_VERSION_ID 0xff > > +/* > + * Resistance temperature detector (RTD) modes according to 7.2.32 Mode > + * Selection Register > + */ > +#define RTD_MODE_CURRENT 0x1 > +#define RTD_MODE_THERMISTOR 0x2 > +#define RTD_MODE_VOLTAGE 0x3 > + > +#define MODE_RTD_MASK 0x3 > +#define MODE_LTD_EN 0x40 > + > +/* > + * Bit offset for sensors modes in REG_MODE. > + * Valid for index 0..2, indicating RTD1..3. > + */ > +#define MODE_BIT_OFFSET_RTD(index) ((index) * 2) > + > /* > * Data structures and manipulation thereof > */ > @@ -74,7 +91,9 @@ static ssize_t temp_type_show(struct device *dev, > if (ret < 0) > return ret; > > - return sprintf(buf, "%u\n", (mode >> (2 * sattr->index) & 3) + 2); > + return sprintf(buf, "%u\n", > + ((mode >> MODE_BIT_OFFSET_RTD(sattr->index)) & > + MODE_RTD_MASK) + 2); Please split into two patches to simplify review. The changes from constant to define are logically separate and should thus be in a separate patch. > } > > static ssize_t temp_type_store(struct device *dev, > @@ -94,7 +113,8 @@ static ssize_t temp_type_store(struct device *dev, > if (type < 3 || type > 4) > return -EINVAL; > err = regmap_update_bits(data->regmap, REG_MODE, > - 3 << 2 * sattr->index, (type - 2) << 2 * sattr->index); > + MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(sattr->index), > + (type - 2) << MODE_BIT_OFFSET_RTD(sattr->index)); > return err ? : count; > } > > @@ -682,24 +702,24 @@ static umode_t nct7802_temp_is_visible(struct kobject *kobj, > struct device *dev = kobj_to_dev(kobj); > struct nct7802_data *data = dev_get_drvdata(dev); > unsigned int reg; > + unsigned int rtd_mode; > int err; > > err = regmap_read(data->regmap, REG_MODE, ®); > if (err < 0) > return 0; > > - if (index < 10 && > - (reg & 03) != 0x01 && (reg & 0x03) != 0x02) /* RD1 */ > + rtd_mode = (reg >> MODE_BIT_OFFSET_RTD(index / 10)) & MODE_RTD_MASK; > + if (index >= 0 && index < 20 && /* RD1, RD 2*/ > + rtd_mode != 0x01 && rtd_mode != 0x02) > return 0; > > - if (index >= 10 && index < 20 && > - (reg & 0x0c) != 0x04 && (reg & 0x0c) != 0x08) /* RD2 */ > - return 0; > - if (index >= 20 && index < 30 && (reg & 0x30) != 0x20) /* RD3 */ > + if (index >= 20 && index < 30 && rtd_mode != 0x02) /* RD3 */ > return 0; > > - if (index >= 30 && index < 38) /* local */ > - return attr->mode; > + if (index >= 30 && index < 38 && /* local */ > + (reg & MODE_LTD_EN) != MODE_LTD_EN) This is just a single bit, so "!(reg & MODE_LTD_EN)" is sufficient. > + return 0; > > err = regmap_read(data->regmap, REG_PECI_ENABLE, ®); > if (err < 0) > @@ -1038,7 +1058,118 @@ static const struct regmap_config nct7802_regmap_config = { > .volatile_reg = nct7802_regmap_is_volatile, > }; > > -static int nct7802_init_chip(struct nct7802_data *data) > +static bool nct7802_get_input_config(struct device *dev, > + struct device_node *input, u8 *mode_mask, u8 *mode_val) Please align continuation lines with "(". The function should return an error code. > +{ > + u32 reg; > + const char *type_str, *md_str; > + u8 md; > + > + if (!input->name || of_node_cmp(input->name, "input")) > + return false; > + > + if (of_property_read_u32(input, "reg", ®)) { > + dev_err(dev, "Could not read reg value for '%s'\n", > + input->full_name); > + return false; > + } > + > + if (reg > 3) { > + dev_err(dev, > + "Invalid reg (%u) in '%s'\n", reg, input->full_name); > + return false; > + } > + > + if (reg == 0) { > + if (!of_device_is_available(input)) > + *mode_val &= ~MODE_LTD_EN; > + else > + *mode_val |= MODE_LTD_EN; > + *mode_mask |= MODE_LTD_EN; > + return true; > + } > + > + if (reg >= 1 && reg <= 3 && !of_device_is_available(input)) { reg will always be >=1 and <=3 here. > + *mode_val &= ~(MODE_RTD_MASK > + << MODE_BIT_OFFSET_RTD(reg-1)); space around '-' > + *mode_mask |= MODE_RTD_MASK > + << MODE_BIT_OFFSET_RTD(reg-1); Unnecessary continuation lines. There are several more of those; I won't comment on it further. Please only use continuation lines if the resulting line length is otherwise > 100 columns. > + return true; > + } > + > + if (of_property_read_string(input, "sensor-type", &type_str)) { > + dev_err(dev, "No type for '%s'\n", input->full_name); > + return false; > + } > + > + if (!strcmp(type_str, "voltage")) { > + *mode_val |= (RTD_MODE_VOLTAGE & MODE_RTD_MASK) > + << MODE_BIT_OFFSET_RTD(reg-1); > + *mode_mask |= MODE_RTD_MASK > + << MODE_BIT_OFFSET_RTD(reg-1); > + return true; > + } > + > + if (strcmp(type_str, "temperature")) { > + dev_err(dev, "Invalid type '%s' for '%s'\n", type_str, > + input->full_name); > + return false; > + } > + > + if (reg == 3) { > + /* RTD3 only supports thermistor mode */ > + md = RTD_MODE_THERMISTOR; > + } else { > + if (of_property_read_string(input, "temperature-mode", > + &md_str)) { > + dev_err(dev, "No mode for '%s'\n", input->full_name); > + return false; > + } > + > + if (!strcmp(md_str, "thermal-diode")) > + md = RTD_MODE_CURRENT; > + else if (!strcmp(md_str, "thermistor")) > + md = RTD_MODE_THERMISTOR; > + else { > + dev_err(dev, "Invalid mode '%s' for '%s'\n", md_str, > + input->full_name); > + return false; > + } > + } > + > + *mode_val |= (md & MODE_RTD_MASK) > + << MODE_BIT_OFFSET_RTD(reg-1); space before and after '-' > + *mode_mask |= MODE_RTD_MASK > + << MODE_BIT_OFFSET_RTD(reg-1); > + > + return true; > +} > + > +static int nct7802_configure_inputs(struct device *dev, > + struct nct7802_data *data) > +{ > + bool found_input_config = false; > + u8 mode_mask = 0, mode_val = 0; > + struct device_node *input; > + > + if (dev->of_node) { > + for_each_child_of_node(dev->of_node, input) { > + if (nct7802_get_input_config(dev, input, &mode_mask, > + &mode_val)) > + found_input_config = true; This is mixing errors with "dt configuration does not exist". nct7802_get_input_config() should return an actual error if the DT configuration is bad, and return that error to the calling code if that is the case. > + } > + } > + > + if (!found_input_config) { > + /* Enable local temperature sensor by default */ > + mode_val |= MODE_LTD_EN; > + mode_mask |= MODE_LTD_EN; > + } This can be set by default since nct7802_get_input_config() removes it if the channel is disabled, meaning found_input_config is really unnecessary. > + > + return regmap_update_bits(data->regmap, REG_MODE, mode_mask, mode_val); > +} > + > +static int nct7802_init_chip(struct device *dev, struct nct7802_data *data) > { > int err; > > @@ -1047,8 +1178,7 @@ static int nct7802_init_chip(struct nct7802_data *data) > if (err) > return err; > > - /* Enable local temperature sensor */ > - err = regmap_update_bits(data->regmap, REG_MODE, 0x40, 0x40); > + err = nct7802_configure_inputs(dev, data); > if (err) > return err; > > @@ -1074,7 +1204,7 @@ static int nct7802_probe(struct i2c_client *client) > mutex_init(&data->access_lock); > mutex_init(&data->in_alarm_lock); > > - ret = nct7802_init_chip(data); > + ret = nct7802_init_chip(dev, data); > if (ret < 0) > return ret; > >
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