staging: iio: tsl2583: move from a global to a per device lux table

The driver contains a global lux table that can be updated via sysfs.
Change this to a per device lux table so that multiple devices can be
hooked up to the same system with different lux tables.

There are 10 entries, plus 1 for the termination segment, set aside for
the entries in the lux table. When updating the lux table via sysfs,
only 9 entries, plus the terminator, could be added. This changes
the code to allow for the 10 entries, plus the terminator.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/light/tsl2583.c

@@ -70,11 +70,34 @@ struct tsl2583_als_info {
 	u16 lux;
 };
 
+struct tsl2583_lux {
+	unsigned int ratio;
+	unsigned int ch0;
+	unsigned int ch1;
+};
+
+static const struct tsl2583_lux tsl2583_default_lux[] = {
+	{  9830,  8520, 15729 },
+	{ 12452, 10807, 23344 },
+	{ 14746,  6383, 11705 },
+	{ 17695,  4063,  6554 },
+	{     0,     0,     0 }  /* Termination segment */
+};
+
+#define TSL2583_MAX_LUX_TABLE_ENTRIES 11
+
 struct tsl2583_settings {
 	int als_time;
 	int als_gain;
 	int als_gain_trim;
 	int als_cal_target;
+
+	/*
+	 * This structure is intentionally large to accommodate updates via
+	 * sysfs. Sized to 11 = max 10 segments + 1 termination segment.
+	 * Assumption is that one and only one type of glass used.
+	 */
+	struct tsl2583_lux als_device_lux[TSL2583_MAX_LUX_TABLE_ENTRIES];
 };
 
 struct tsl2583_chip {
@@ -87,24 +110,6 @@ struct tsl2583_chip {
 	bool suspended;
 };
 
-struct tsl2583_lux {
-	unsigned int ratio;
-	unsigned int ch0;
-	unsigned int ch1;
-};
-
-/*
- * This structure is intentionally large to accommodate updates via sysfs.
- * Sized to 11 = max 10 segments + 1 termination segment. Assumption is that
- * one and only one type of glass used.
- */
-static struct tsl2583_lux tsl2583_device_lux[11] = {
-	{  9830,  8520, 15729 },
-	{ 12452, 10807, 23344 },
-	{ 14746,  6383, 11705 },
-	{ 17695,  4063,  6554 },
-};
-
 struct gainadj {
 	s16 ch0;
 	s16 ch1;
@@ -142,6 +147,10 @@ static void tsl2583_defaults(struct tsl2583_chip *chip)
 
 	/* Known external ALS reading used for calibration */
 	chip->als_settings.als_cal_target = 130;
+
+	/* Default lux table. */
+	memcpy(chip->als_settings.als_device_lux, tsl2583_default_lux,
+	       sizeof(tsl2583_default_lux));
 }
 
 /*
@@ -151,7 +160,7 @@ static void tsl2583_defaults(struct tsl2583_chip *chip)
  * Time scale factor array values are adjusted based on the integration time.
  * The raw values are multiplied by a scale factor, and device gain is obtained
  * using gain index. Limit checks are done next, then the ratio of a multiple
- * of ch1 value, to the ch0 value, is calculated. The array tsl2583_device_lux[]
+ * of ch1 value, to the ch0 value, is calculated. The array als_device_lux[]
  * declared above is then scanned to find the first ratio value that is just
  * above the ratio we just calculated. The ch0 and ch1 multiplier constants in
  * the array are then used along with the time scale factor array values, to
@@ -233,7 +242,7 @@ static int tsl2583_get_lux(struct iio_dev *indio_dev)
 	ratio = (ch1 << 15) / ch0;
 
 	/* convert to unscaled lux using the pointer to the table */
-	for (p = (struct tsl2583_lux *)tsl2583_device_lux;
+	for (p = (struct tsl2583_lux *)chip->als_settings.als_device_lux;
 	     p->ratio != 0 && p->ratio < ratio; p++)
 		;
 
@@ -270,7 +279,7 @@ static int tsl2583_get_lux(struct iio_dev *indio_dev)
 
 	/*
 	 * Adjust for active gain scale.
-	 * The tsl2583_device_lux tables above have a factor of 8192 built in,
+	 * The tsl2583_default_lux tables above have a factor of 8192 built in,
 	 * so we need to shift right.
 	 * User-specified gain provides a multiplier.
 	 * Apply user-specified gain before shifting right to retain precision.
@@ -522,15 +531,17 @@ static ssize_t in_illuminance_lux_table_show(struct device *dev,
 					     struct device_attribute *attr,
 					     char *buf)
 {
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct tsl2583_chip *chip = iio_priv(indio_dev);
 	unsigned int i;
 	int offset = 0;
 
-	for (i = 0; i < ARRAY_SIZE(tsl2583_device_lux); i++) {
+	for (i = 0; i < ARRAY_SIZE(chip->als_settings.als_device_lux); i++) {
 		offset += sprintf(buf + offset, "%u,%u,%u,",
-				  tsl2583_device_lux[i].ratio,
-				  tsl2583_device_lux[i].ch0,
-				  tsl2583_device_lux[i].ch1);
-		if (tsl2583_device_lux[i].ratio == 0) {
+				  chip->als_settings.als_device_lux[i].ratio,
+				  chip->als_settings.als_device_lux[i].ch0,
+				  chip->als_settings.als_device_lux[i].ch1);
+		if (chip->als_settings.als_device_lux[i].ratio == 0) {
 			/*
 			 * We just printed the first "0" entry.
 			 * Now get rid of the extra "," and break.
@@ -545,15 +556,14 @@ static ssize_t in_illuminance_lux_table_show(struct device *dev,
 	return offset;
 }
 
-#define TSL2583_MAX_LUX_INTS ((ARRAY_SIZE(tsl2583_device_lux) - 1) * 3)
-
 static ssize_t in_illuminance_lux_table_store(struct device *dev,
 					      struct device_attribute *attr,
 					      const char *buf, size_t len)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct tsl2583_chip *chip = iio_priv(indio_dev);
-	int value[ARRAY_SIZE(tsl2583_device_lux) * 3 + 1];
+	const unsigned int max_ints = TSL2583_MAX_LUX_TABLE_ENTRIES * 3;
+	int value[TSL2583_MAX_LUX_TABLE_ENTRIES * 3];
 	int ret = -EINVAL;
 	unsigned int n;
 
@@ -568,10 +578,10 @@ static ssize_t in_illuminance_lux_table_store(struct device *dev,
 	 * and the last table entry is all 0.
 	 */
 	n = value[0];
-	if ((n % 3) || n < 6 || n > TSL2583_MAX_LUX_INTS) {
+	if ((n % 3) || n < 6 || n > max_ints) {
 		dev_err(dev,
-			"%s: The number of entries in the lux table must be a multiple of 3 and within the range [6, %zu]\n",
-			__func__, TSL2583_MAX_LUX_INTS);
+			"%s: The number of entries in the lux table must be a multiple of 3 and within the range [6, %d]\n",
+			__func__, max_ints);
 		goto done;
 	}
 	if ((value[n - 2] | value[n - 1] | value[n]) != 0) {
@@ -581,8 +591,10 @@ static ssize_t in_illuminance_lux_table_store(struct device *dev,
 	}
 
 	/* Zero out the table */
-	memset(tsl2583_device_lux, 0, sizeof(tsl2583_device_lux));
-	memcpy(tsl2583_device_lux, &value[1], value[0] * sizeof(value[1]));
+	memset(chip->als_settings.als_device_lux, 0,
+	       sizeof(chip->als_settings.als_device_lux));
+	memcpy(chip->als_settings.als_device_lux, &value[1],
+	       value[0] * sizeof(value[1]));
 
 	ret = len;