| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <0674a2d0-f0a2-d6bc-33e3-483614602bae@roeck-us.net>
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;
>
>
Powered by blists - more mailing lists