[PATCH v2 1/4] hwmon: (lm75) Create structure to save all the configuration parameters.

[Iker Perez <iker.perez@codethink.co.uk>]

From: Iker Perez del Palomar Sustatxa <iker.perez@codethink.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@codethink.co.uk>
---

Changes since v1:
- In the lm75_params structure documentation there have been the next changes:
        - @resolution has been corrected to @default_resolution.
        - @resolution_limits description has been corrected.
- pct2075 device's parameters has been included in device_params structure.

 drivers/hwmon/lm75.c | 282 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 176 insertions(+), 106 deletions(-)

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index a2d3f2ce3e1d..65a1131bfa7e 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 +50,28 @@ enum lm75_type {		/* keep sorted in alphabetical order */
 	tmp75c,
 };
 
+/**
+ * struct lm75_params - lm75 configuration parameters.
+ * @set_mask:		Bits to set in configuration register when configuring
+ *			the chip.
+ * @clr_mask:		Bits to clear in configuration register when configuring
+ *			the chip.
+ * @default_resolution:	Default number of bits to represent the temperature
+ *			value.
+ * @resolution_limits:	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 +84,151 @@ 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,
+	},
+	[pct2075] = {
+		.default_resolution = 11,
+		.default_sample_time = MSEC_PER_SEC / 10,
+	},
+	[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 +303,8 @@ 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 +396,6 @@ 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 +413,7 @@ 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 +422,22 @@ 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