hwmon: (lm70) Add support for ACPI

This commit adds support for lm70 commpatible drivers with systems that
use ACPI.
Signed-off-by: Andrej Picej <andpicej@gmail.com>
[groeck: Fix various issues seen if CONFIG_ACPI=n]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/lm70.c

@@ -25,7 +25,7 @@
 #include <linux/spi/spi.h>
 #include <linux/slab.h>
 #include <linux/of_device.h>
-
+#include <linux/acpi.h>
 
 #define DRVNAME		"lm70"
 
@@ -148,18 +148,50 @@ static const struct of_device_id lm70_of_ids[] = {
 MODULE_DEVICE_TABLE(of, lm70_of_ids);
 #endif
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id lm70_acpi_ids[] = {
+	{
+		.id = "LM000070",
+		.driver_data = LM70_CHIP_LM70,
+	},
+	{
+		.id = "TMP00121",
+		.driver_data = LM70_CHIP_TMP121,
+	},
+	{
+		.id = "LM000071",
+		.driver_data = LM70_CHIP_LM71,
+	},
+	{
+		.id = "LM000074",
+		.driver_data = LM70_CHIP_LM74,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, lm70_acpi_ids);
+#endif
+
 static int lm70_probe(struct spi_device *spi)
 {
-	const struct of_device_id *match;
+	const struct of_device_id *of_match;
 	struct device *hwmon_dev;
 	struct lm70 *p_lm70;
 	int chip;
 
-	match = of_match_device(lm70_of_ids, &spi->dev);
-	if (match)
-		chip = (int)(uintptr_t)match->data;
+	of_match = of_match_device(lm70_of_ids, &spi->dev);
+	if (of_match)
+		chip = (int)(uintptr_t)of_match->data;
+	else {
+#ifdef CONFIG_ACPI
+		const struct acpi_device_id *acpi_match;
+
+		acpi_match = acpi_match_device(lm70_acpi_ids, &spi->dev);
+		if (acpi_match)
+			chip = (int)(uintptr_t)acpi_match->driver_data;
 		else
+#endif
 			chip = spi_get_device_id(spi)->driver_data;
+	}
 
 	/* signaling is SPI_MODE_0 */
 	if (spi->mode & (SPI_CPOL | SPI_CPHA))
@@ -195,6 +227,7 @@ static struct spi_driver lm70_driver = {
 	.driver = {
 		.name	= "lm70",
 		.of_match_table	= of_match_ptr(lm70_of_ids),
+		.acpi_match_table = ACPI_PTR(lm70_acpi_ids),
 	},
 	.id_table = lm70_ids,
 	.probe	= lm70_probe,