platform/x86: int3472: Support multiple clock consumers

At present, the tps68470.c only supports a single clock consumer when
passing platform data to the clock driver. In some devices multiple
sensors depend on the clock provided by a single TPS68470 and so all
need to be able to acquire the clock. Support passing multiple
consumers as platform data.
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/clk/clk-tps68470.c

@@ -200,7 +200,9 @@ static int tps68470_clk_probe(struct platform_device *pdev)
 		.flags = CLK_SET_RATE_GATE,
 	};
 	struct tps68470_clkdata *tps68470_clkdata;
+	struct tps68470_clk_consumer *consumer;
 	int ret;
+	int i;
 
 	tps68470_clkdata = devm_kzalloc(&pdev->dev, sizeof(*tps68470_clkdata),
 					GFP_KERNEL);
@@ -223,10 +225,13 @@ static int tps68470_clk_probe(struct platform_device *pdev)
 		return ret;
 
 	if (pdata) {
-		ret = devm_clk_hw_register_clkdev(&pdev->dev,
-						  &tps68470_clkdata->clkout_hw,
-						  pdata->consumer_con_id,
-						  pdata->consumer_dev_name);
+		for (i = 0; i < pdata->n_consumers; i++) {
+			consumer = &pdata->consumers[i];
+			ret = devm_clk_hw_register_clkdev(&pdev->dev,
+							  &tps68470_clkdata->clkout_hw,
+							  consumer->consumer_con_id,
+							  consumer->consumer_dev_name);
+		}
 	}
 
 	return ret;

drivers/platform/x86/intel/int3472/tps68470.c

 // SPDX-License-Identifier: GPL-2.0
 /* Author: Dan Scally <djrscally@gmail.com> */
 
+#include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/mfd/core.h>
@@ -95,20 +96,64 @@ static int skl_int3472_tps68470_calc_type(struct acpi_device *adev)
 	return DESIGNED_FOR_WINDOWS;
 }
 
+/*
+ * Return the size of the flexible array member, because we'll need that later
+ * on to pass .pdata_size to cells.
+ */
+static int
+skl_int3472_fill_clk_pdata(struct device *dev, struct tps68470_clk_platform_data **clk_pdata)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct acpi_device *consumer;
+	unsigned int n_consumers = 0;
+	const char *sensor_name;
+	unsigned int i = 0;
+
+	for_each_acpi_consumer_dev(adev, consumer)
+		n_consumers++;
+
+	if (!n_consumers) {
+		dev_err(dev, "INT3472 seems to have no dependents\n");
+		return -ENODEV;
+	}
+
+	*clk_pdata = devm_kzalloc(dev, struct_size(*clk_pdata, consumers, n_consumers),
+				  GFP_KERNEL);
+	if (!*clk_pdata)
+		return -ENOMEM;
+
+	(*clk_pdata)->n_consumers = n_consumers;
+	i = 0;
+
+	for_each_acpi_consumer_dev(adev, consumer) {
+		sensor_name = devm_kasprintf(dev, GFP_KERNEL, I2C_DEV_NAME_FORMAT,
+					     acpi_dev_name(consumer));
+		if (!sensor_name)
+			return -ENOMEM;
+
+		(*clk_pdata)->consumers[i].consumer_dev_name = sensor_name;
+		i++;
+	}
+
+	acpi_dev_put(consumer);
+
+	return n_consumers;
+}
+
 static int skl_int3472_tps68470_probe(struct i2c_client *client)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 	const struct int3472_tps68470_board_data *board_data;
-	struct tps68470_clk_platform_data clk_pdata = {};
+	struct tps68470_clk_platform_data *clk_pdata;
 	struct mfd_cell *cells;
 	struct regmap *regmap;
+	int n_consumers;
 	int device_type;
 	int ret;
 
-	ret = skl_int3472_get_sensor_adev_and_name(&client->dev, NULL,
-						   &clk_pdata.consumer_dev_name);
-	if (ret)
-		return ret;
+	n_consumers = skl_int3472_fill_clk_pdata(&client->dev, &clk_pdata);
+	if (n_consumers < 0)
+		return n_consumers;
 
 	regmap = devm_regmap_init_i2c(client, &tps68470_regmap_config);
 	if (IS_ERR(regmap)) {
@@ -142,8 +187,8 @@ static int skl_int3472_tps68470_probe(struct i2c_client *client)
 		 * the clk + regulators must be ready when this happens.
 		 */
 		cells[0].name = "tps68470-clk";
-		cells[0].platform_data = &clk_pdata;
-		cells[0].pdata_size = sizeof(clk_pdata);
+		cells[0].platform_data = clk_pdata;
+		cells[0].pdata_size = struct_size(clk_pdata, consumers, n_consumers);
 		cells[1].name = "tps68470-regulator";
 		cells[1].platform_data = (void *)board_data->tps68470_regulator_pdata;
 		cells[1].pdata_size = sizeof(struct tps68470_regulator_platform_data);

include/linux/platform_data/tps68470.h

@@ -27,9 +27,14 @@ struct tps68470_regulator_platform_data {
 	const struct regulator_init_data *reg_init_data[TPS68470_NUM_REGULATORS];
 };
 
-struct tps68470_clk_platform_data {
+struct tps68470_clk_consumer {
 	const char *consumer_dev_name;
 	const char *consumer_con_id;
 };
 
+struct tps68470_clk_platform_data {
+	unsigned int n_consumers;
+	struct tps68470_clk_consumer consumers[];
+};
+
 #endif