regulator: pwm: Add support to have multiple instance of pwm regulator

Some of platforms like Nvidia's Tegra210 Jetson-TX1 platform has
multiple PMW based regulators. Add support to have multiple instances
of the driver by not changing any global data of pwm regulator and
if required, making instance specific copy and then making changes.

Signed-off-by: Laxman Dewangan <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/pwm-regulator.c

···
 
 	/* Voltage table */
 	struct pwm_voltages *duty_cycle_table;
+
+	/* regulator descriptor */
+	struct regulator_desc desc;
+
+	/* Regulator ops */
+	struct regulator_ops ops;
+
 	int state;
 
 	/* Continuous voltage */
···
 	}
 
 	drvdata->duty_cycle_table	= duty_cycle_table;
-	pwm_regulator_desc.ops		= &pwm_regulator_voltage_table_ops;
-	pwm_regulator_desc.n_voltages	= length / sizeof(*duty_cycle_table);
+	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
+	       sizeof(drvdata->ops));
+	drvdata->desc.ops = &drvdata->ops;
+	drvdata->desc.n_voltages	= length / sizeof(*duty_cycle_table);
 
 	return 0;
 }
···
 static int pwm_regulator_init_continuous(struct platform_device *pdev,
 					 struct pwm_regulator_data *drvdata)
 {
-	pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops;
-	pwm_regulator_desc.continuous_voltage_range = true;
+	memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops,
+	       sizeof(drvdata->ops));
+	drvdata->desc.ops = &drvdata->ops;
+	drvdata->desc.continuous_voltage_range = true;
 
 	return 0;
 }
···
 	if (!drvdata)
 		return -ENOMEM;
 
+	memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
+
 	if (of_find_property(np, "voltage-table", NULL))
 		ret = pwm_regulator_init_table(pdev, drvdata);
 	else
···
 		return ret;
 
 	init_data = of_get_regulator_init_data(&pdev->dev, np,
-					       &pwm_regulator_desc);
+					       &drvdata->desc);
 	if (!init_data)
 		return -ENOMEM;
 
···
 	}
 
 	regulator = devm_regulator_register(&pdev->dev,
-					    &pwm_regulator_desc, &config);
+					    &drvdata->desc, &config);
 	if (IS_ERR(regulator)) {
 		dev_err(&pdev->dev, "Failed to register regulator %s\n",
-			pwm_regulator_desc.name);
+			drvdata->desc.name);
 		return PTR_ERR(regulator);
 	}