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Message-ID: <20190807135359.GB11447@roeck-us.net>
Date: Wed, 7 Aug 2019 06:53:59 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Iker Perez <iker.perez@...ethink.co.uk>
Cc: linux-hwmon@...r.kernel.org, jdelvare@...e.com,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] hwmon: (lm75) Create structure to save all the
configuration parameters.
On Tue, Aug 06, 2019 at 10:11:04AM +0100, Iker Perez wrote:
> From: Iker Perez del Palomar Sustatxa <iker.perez@...ethink.co.uk>
>
> * Add to lm75_data kind field to store the kind of device the driver is
> working with.
> * Add an structure to store the configuration parameters of all the
> supported devices.
> * Delete resolution_limits from lm75_data and include them in the structure
> described above.
> * Add a pointer to the configuration parameters structure to be used as a
> reference to obtain the parameters.
> * Delete switch-case approach to get the device configuration parameters.
> * The structure is cleaner and easier to maintain.
>
> Signed-off-by: Iker Perez del Palomar Sustatxa <iker.perez@...ethink.co.uk>
> ---
> drivers/hwmon/lm75.c | 275 +++++++++++++++++++++++++++++++--------------------
> 1 file changed, 169 insertions(+), 106 deletions(-)
>
> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> index a2d3f2ce3e1d..1c012301b6ca 100644
> --- a/drivers/hwmon/lm75.c
> +++ b/drivers/hwmon/lm75.c
> @@ -18,7 +18,6 @@
> #include <linux/regmap.h>
> #include "lm75.h"
>
> -
> /*
> * This driver handles the LM75 and compatible digital temperature sensors.
> */
> @@ -51,6 +50,25 @@ enum lm75_type { /* keep sorted in alphabetical order */
> tmp75c,
> };
>
> +/**
> + * struct lm75_params - lm75 configuration parameters.
> + * @set_mask: Bits to set in cofiguration register when configuring
> + * the chip.
> + * @clr_mask: Bits to clear in configuration register when configuring
> + * the chip.
> + * @resolution: Number of bits to represent the temperatue value.
> + * @resolution_limits: Resolution range.
I had to look this up to remember. Turns out this isn't the resolution range.
Please replace the description with something like:
Limit register resolution.
Optional. Should be set if the resolution of
limit registers does not match the resolution
of the temperature register.
> + * default_sample_time: Sample time to be set by default.
> + */
> +
> +struct lm75_params {
> + u8 set_mask;
> + u8 clr_mask;
> + u8 default_resolution;
> + u8 resolution_limits;
> + unsigned int default_sample_time;
> +};
> +
> /* Addresses scanned */
> static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
> 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
> @@ -63,15 +81,147 @@ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
>
> /* Each client has this additional data */
> struct lm75_data {
> - struct i2c_client *client;
> - struct regmap *regmap;
> - u8 orig_conf;
> - u8 resolution; /* In bits, between 9 and 16 */
> - u8 resolution_limits;
> - unsigned int sample_time; /* In ms */
> + struct i2c_client *client;
> + struct regmap *regmap;
> + u8 orig_conf;
> + u8 current_conf;
> + u8 resolution; /* In bits, 9 to 16 */
> + unsigned int sample_time; /* In ms */
> + enum lm75_type kind;
> + const struct lm75_params *params;
> };
>
> /*-----------------------------------------------------------------------*/
> +/* The structure below stores the configuration values of the supported devices.
> + * In case of being supported multiple configurations, the default one must
> + * always be the first element of the array
> + */
> +static const struct lm75_params device_params[] = {
> + [adt75] = {
> + .clr_mask = 1 << 5, /* not one-shot mode */
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 8,
> + },
> + [ds1775] = {
> + .clr_mask = 3 << 5,
> + .set_mask = 2 << 5, /* 11-bit mode */
> + .default_resolution = 11,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [ds75] = {
> + .clr_mask = 3 << 5,
> + .set_mask = 2 << 5, /* 11-bit mode */
> + .default_resolution = 11,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [stds75] = {
> + .clr_mask = 3 << 5,
> + .set_mask = 2 << 5, /* 11-bit mode */
> + .default_resolution = 11,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [stlm75] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 5,
> + },
> + [ds7505] = {
> + .set_mask = 3 << 5, /* 12-bit mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + },
> + [g751] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [lm75] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [lm75a] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [lm75b] = {
> + .default_resolution = 11,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + },
> + [max6625] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + },
> + [max6626] = {
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + .resolution_limits = 9,
> + },
> + [max31725] = {
> + .default_resolution = 16,
> + .default_sample_time = MSEC_PER_SEC / 8,
> + },
> + [tcn75] = {
> + .default_resolution = 9,
> + .default_sample_time = MSEC_PER_SEC / 8,
> + },
> + [mcp980x] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode */
> + .default_resolution = 12,
> + .resolution_limits = 9,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [tmp100] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode */
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [tmp101] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode */
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC,
> + },
> + [tmp112] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* no one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + },
> + [tmp105] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [tmp175] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [tmp275] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [tmp75] = {
> + .set_mask = 3 << 5, /* 12-bit mode */
> + .clr_mask = 1 << 7, /* not one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 2,
> + },
> + [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */
> + .clr_mask = 1 << 7 | 3 << 5,
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 37,
> + },
> + [tmp75c] = {
> + .clr_mask = 1 << 5, /*not one-shot mode*/
> + .default_resolution = 12,
> + .default_sample_time = MSEC_PER_SEC / 4,
> + }
> +};
>
> static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
> {
> @@ -146,8 +296,8 @@ static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
> * Resolution of limit registers is assumed to be the same as the
> * temperature input register resolution unless given explicitly.
> */
> - if (data->resolution_limits)
> - resolution = data->resolution_limits;
> + if (data->params->resolution_limits)
> + resolution = data->params->resolution_limits;
> else
> resolution = data->resolution;
>
> @@ -239,7 +389,6 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> struct device *hwmon_dev;
> struct lm75_data *data;
> int status, err;
> - u8 set_mask, clr_mask;
> int new;
> enum lm75_type kind;
>
> @@ -257,6 +406,7 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> return -ENOMEM;
>
> data->client = client;
> + data->kind = kind;
>
> data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
> if (IS_ERR(data->regmap))
> @@ -265,109 +415,22 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
> * Then tweak to be more precise when appropriate.
> */
> - set_mask = 0;
> - clr_mask = LM75_SHUTDOWN; /* continuous conversions */
> -
> - switch (kind) {
> - case adt75:
> - clr_mask |= 1 << 5; /* not one-shot mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 8;
> - break;
> - case ds1775:
> - case ds75:
> - case stds75:
> - clr_mask |= 3 << 5;
> - set_mask |= 2 << 5; /* 11-bit mode */
> - data->resolution = 11;
> - data->sample_time = MSEC_PER_SEC;
> - break;
> - case stlm75:
> - data->resolution = 9;
> - data->sample_time = MSEC_PER_SEC / 5;
> - break;
> - case ds7505:
> - set_mask |= 3 << 5; /* 12-bit mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - case g751:
> - case lm75:
> - case lm75a:
> - data->resolution = 9;
> - data->sample_time = MSEC_PER_SEC / 2;
> - break;
> - case lm75b:
> - data->resolution = 11;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - case max6625:
> - data->resolution = 9;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - case max6626:
> - data->resolution = 12;
> - data->resolution_limits = 9;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - case max31725:
> - data->resolution = 16;
> - data->sample_time = MSEC_PER_SEC / 8;
> - break;
> - case tcn75:
> - data->resolution = 9;
> - data->sample_time = MSEC_PER_SEC / 8;
> - break;
> - case pct2075:
> - data->resolution = 11;
> - data->sample_time = MSEC_PER_SEC / 10;
> - break;
> - case mcp980x:
> - data->resolution_limits = 9;
> - /* fall through */
> - case tmp100:
> - case tmp101:
> - set_mask |= 3 << 5; /* 12-bit mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC;
> - clr_mask |= 1 << 7; /* not one-shot mode */
> - break;
> - case tmp112:
> - set_mask |= 3 << 5; /* 12-bit mode */
> - clr_mask |= 1 << 7; /* not one-shot mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - case tmp105:
> - case tmp175:
> - case tmp275:
> - case tmp75:
> - set_mask |= 3 << 5; /* 12-bit mode */
> - clr_mask |= 1 << 7; /* not one-shot mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 2;
> - break;
> - case tmp75b: /* not one-shot mode, Conversion rate 37Hz */
> - clr_mask |= 1 << 7 | 0x3 << 5;
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 37;
> - break;
> - case tmp75c:
> - clr_mask |= 1 << 5; /* not one-shot mode */
> - data->resolution = 12;
> - data->sample_time = MSEC_PER_SEC / 4;
> - break;
> - }
>
> - /* configure as specified */
> + data->params = &device_params[data->kind];
> +
> + /* Save default sample time and resolution*/
> + data->sample_time = data->params->default_sample_time;
> + data->resolution = data->params->default_resolution;
> +
> + /* Cache original configuration */
> status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
> if (status < 0) {
> dev_dbg(dev, "Can't read config? %d\n", status);
> return status;
> }
> data->orig_conf = status;
> - new = status & ~clr_mask;
> - new |= set_mask;
> + new = status & ~(data->params->clr_mask | LM75_SHUTDOWN);
> + new |= data->params->set_mask;
> if (status != new)
> i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
>
> --
> 2.11.0
>
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