regulator: qcom_spmi: Constify struct spmi_voltage_range

'struct spmi_voltage_range' are only modified at runtime to compile a
field, n_voltages, that could be computed at compile time.

So, simplify spmi_calculate_num_voltages() and compute n_voltages at
compile time within the SPMI_VOLTAGE_RANGE macro.

Constifying these structures moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
======
text data bss dec hex filename
85437 26776 512 112725 1b855 drivers/regulator/qcom_spmi-regulator.o

After:
=====
text data bss dec hex filename
86857 24760 512 112129 1b601 drivers/regulator/qcom_spmi-regulator.o

Signed-off-by: Christophe JAILLET <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Link: https://patch.msgid.link/ef2a4b6df6[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/qcom_spmi-regulator.c

···
  * so that range[i].set_point_max_uV < range[i+1].set_point_min_uV.
  */
 struct spmi_voltage_set_points {
-	struct spmi_voltage_range		*range;
+	const struct spmi_voltage_range		*range;
 	int					count;
 	unsigned				n_voltages;
 };
···
 		.set_point_max_uV	= _set_point_max_uV, \
 		.step_uV		= _step_uV, \
 		.range_sel		= _range_sel, \
+		.n_voltages		= (_set_point_max_uV != 0) ? \
+						((_set_point_max_uV - _set_point_min_uV) / _step_uV) + 1 : \
+						0, \
 	}
 
 #define DEFINE_SPMI_SET_POINTS(name) \
···
  * increasing and unique.  The set_voltage callback functions expect these
  * properties to hold.
  */
-static struct spmi_voltage_range pldo_ranges[] = {
+static const struct spmi_voltage_range pldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(2,  750000,  750000, 1537500, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(3, 1500000, 1550000, 3075000, 3075000, 25000),
 	SPMI_VOLTAGE_RANGE(4, 1750000, 3100000, 4900000, 4900000, 50000),
 };
 
-static struct spmi_voltage_range nldo1_ranges[] = {
+static const struct spmi_voltage_range nldo1_ranges[] = {
 	SPMI_VOLTAGE_RANGE(2,  750000,  750000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range nldo2_ranges[] = {
+static const struct spmi_voltage_range nldo2_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,       0,       0, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  375000,  375000,  768750,  768750,  6250),
 	SPMI_VOLTAGE_RANGE(2,  750000,  775000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range nldo3_ranges[] = {
+static const struct spmi_voltage_range nldo3_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1537500, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  375000,       0,       0, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(2,  750000,       0,       0, 1537500, 12500),
 };
 
-static struct spmi_voltage_range ln_ldo_ranges[] = {
+static const struct spmi_voltage_range ln_ldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(1,  690000,  690000, 1110000, 1110000, 60000),
 	SPMI_VOLTAGE_RANGE(0, 1380000, 1380000, 2220000, 2220000, 120000),
 };
 
-static struct spmi_voltage_range smps_ranges[] = {
+static const struct spmi_voltage_range smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1562500, 1562500, 12500),
 	SPMI_VOLTAGE_RANGE(1, 1550000, 1575000, 3125000, 3125000, 25000),
 };
 
-static struct spmi_voltage_range ftsmps_ranges[] = {
+static const struct spmi_voltage_range ftsmps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,       0,  350000, 1275000, 1275000,  5000),
 	SPMI_VOLTAGE_RANGE(1,       0, 1280000, 2040000, 2040000, 10000),
 };
 
-static struct spmi_voltage_range ftsmps2p5_ranges[] = {
+static const struct spmi_voltage_range ftsmps2p5_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,   80000,  350000, 1355000, 1355000,  5000),
 	SPMI_VOLTAGE_RANGE(1,  160000, 1360000, 2200000, 2200000, 10000),
 };
 
-static struct spmi_voltage_range ftsmps426_ranges[] = {
+static const struct spmi_voltage_range ftsmps426_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,       0,  320000, 1352000, 1352000,  4000),
 };
 
-static struct spmi_voltage_range boost_ranges[] = {
+static const struct spmi_voltage_range boost_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 4000000, 4000000, 5550000, 5550000, 50000),
 };
 
-static struct spmi_voltage_range boost_byp_ranges[] = {
+static const struct spmi_voltage_range boost_byp_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 2500000, 2500000, 5200000, 5650000, 50000),
 };
 
-static struct spmi_voltage_range ult_lo_smps_ranges[] = {
+static const struct spmi_voltage_range ult_lo_smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1562500, 1562500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  750000,       0,       0, 1525000, 25000),
 };
 
-static struct spmi_voltage_range ult_ho_smps_ranges[] = {
+static const struct spmi_voltage_range ult_ho_smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1550000, 1550000, 2325000, 2325000, 25000),
 };
 
-static struct spmi_voltage_range ult_nldo_ranges[] = {
+static const struct spmi_voltage_range ult_nldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range ult_pldo_ranges[] = {
+static const struct spmi_voltage_range ult_pldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1750000, 1750000, 3337500, 3337500, 12500),
 };
 
-static struct spmi_voltage_range pldo660_ranges[] = {
+static const struct spmi_voltage_range pldo660_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1504000, 1504000, 3544000, 3544000, 8000),
 };
 
-static struct spmi_voltage_range nldo660_ranges[] = {
+static const struct spmi_voltage_range nldo660_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  320000,  320000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range ht_lvpldo_ranges[] = {
+static const struct spmi_voltage_range ht_lvpldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1504000, 1504000, 2000000, 2000000, 8000),
 };
 
-static struct spmi_voltage_range ht_nldo_ranges[] = {
+static const struct spmi_voltage_range ht_nldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  312000,  312000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range hfs430_ranges[] = {
+static const struct spmi_voltage_range hfs430_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 320000, 320000, 2040000, 2040000, 8000),
 };
 
-static struct spmi_voltage_range ht_p150_ranges[] = {
+static const struct spmi_voltage_range ht_p150_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1616000, 1616000, 3304000, 3304000, 8000),
 };
 
-static struct spmi_voltage_range ht_p600_ranges[] = {
+static const struct spmi_voltage_range ht_p600_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1704000, 1704000, 1896000, 1896000, 8000),
 };
 
-static struct spmi_voltage_range nldo_510_ranges[] = {
+static const struct spmi_voltage_range nldo_510_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 320000, 320000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range ftsmps510_ranges[] = {
+static const struct spmi_voltage_range ftsmps510_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 300000, 300000, 1372000, 1372000, 4000),
 };
 
···
 
 static void spmi_calculate_num_voltages(struct spmi_voltage_set_points *points)
 {
-	unsigned int n;
-	struct spmi_voltage_range *range = points->range;
+	const struct spmi_voltage_range *range = points->range;
 
-	for (; range < points->range + points->count; range++) {
-		n = 0;
-		if (range->set_point_max_uV) {
-			n = range->set_point_max_uV - range->set_point_min_uV;
-			n = (n / range->step_uV) + 1;
-		}
-		range->n_voltages = n;
-		points->n_voltages += n;
-	}
+	for (; range < points->range + points->count; range++)
+		points->n_voltages += range->n_voltages;
 }
 
 static int spmi_regulator_match(struct spmi_regulator *vreg, u16 force_type)