i2c: Add a generic driver to generate ACPI info

Many I2C devices produce roughly the same ACPI data with just things like
the GPIO/interrupt information being different.

This can be handled by a generic driver along with some information in the
device tree.

Add a generic i2c driver for this purpose.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>

2 files changed, 78 insertions, 0 deletions

diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index a5b1221782..1b838fcb85 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -10,7 +10,9 @@
 #define __ACPI_DEVICE_H
 
 #include <i2c.h>
+#include <irq.h>
 #include <spi.h>
+#include <asm-generic/gpio.h>
 #include <linux/bitops.h>
 
 struct acpi_ctx;
@@ -236,6 +238,59 @@ struct acpi_spi {
 };
 
 /**
+ * struct acpi_i2c_priv - Information read from device tree
+ *
+ * This is used by devices which want to specify various pieces of ACPI
+ * information, including power control. It allows a generic function to
+ * generate the information for ACPI, based on device-tree properties.
+ *
+ * @disable_gpio_export_in_crs: Don't export GPIOs in the CRS
+ * @reset_gpio: GPIO used to assert reset to the device
+ * @enable_gpio: GPIO used to enable the device
+ * @stop_gpio: GPIO used to stop the device
+ * @irq_gpio: GPIO used for interrupt (if @irq is not used)
+ * @irq: IRQ used for interrupt (if @irq_gpio is not used)
+ * @hid: _HID value for device (required)
+ * @uid: _UID value for device
+ * @desc: _DDN value for device
+ * @wake: Wake event, e.g. GPE0_DW1_15; 0 if none
+ * @property_count: Number of other DSD properties (currently always 0)
+ * @probed: true set set 'linux,probed' property
+ * @compat_string: Device tree compatible string to report through ACPI
+ * @has_power_resource: true if this device has a power resource
+ * @reset_delay_ms: Delay after de-asserting reset, in ms
+ * @reset_off_delay_ms: Delay after asserting reset (during power off)
+ * @enable_delay_ms: Delay after asserting enable
+ * @enable_off_delay_ms: Delay after de-asserting enable (during power off)
+ * @stop_delay_ms: Delay after de-aserting stop
+ * @stop_off_delay_ms: Delay after asserting stop (during power off)
+ * @hid_desc_reg_offset: HID register offset (for Human Interface Devices)
+ */
+struct acpi_i2c_priv {
+	bool disable_gpio_export_in_crs;
+	struct gpio_desc reset_gpio;
+	struct gpio_desc enable_gpio;
+	struct gpio_desc irq_gpio;
+	struct gpio_desc stop_gpio;
+	struct irq irq;
+	const char *hid;
+	u32 uid;
+	const char *desc;
+	u32 wake;
+	u32 property_count;
+	bool probed;
+	const char *compat_string;
+	bool has_power_resource;
+	u32 reset_delay_ms;
+	u32 reset_off_delay_ms;
+	u32 enable_delay_ms;
+	u32 enable_off_delay_ms;
+	u32 stop_delay_ms;
+	u32 stop_off_delay_ms;
+	u32 hid_desc_reg_offset;
+};
+
+/**
  * acpi_device_path() - Get the full path to an ACPI device
  *
  * This gets the full path in the form XXXX.YYYY.ZZZZ where XXXX is the root
diff --git a/include/i2c.h b/include/i2c.h
index 1d792db454..880aa8032b 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -58,6 +58,12 @@ enum i2c_address_mode {
 	I2C_MODE_10_BIT
 };
 
+/** enum i2c_device_t - Types of I2C devices, used for compatible strings */
+enum i2c_device_t {
+	I2C_DEVICE_GENERIC,
+	I2C_DEVICE_HID_OVER_I2C,
+};
+
 struct udevice;
 /**
  * struct dm_i2c_chip - information about an i2c chip
@@ -558,6 +564,23 @@ int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
  */
 struct udevice *i2c_emul_get_device(struct udevice *emul);
 
+/* ACPI operations for generic I2C devices */
+extern struct acpi_ops i2c_acpi_ops;
+
+/**
+ * acpi_i2c_ofdata_to_platdata() - Read properties intended for ACPI
+ *
+ * This reads the generic I2C properties from the device tree, so that these
+ * can be used to create ACPI information for the device.
+ *
+ * See the i2c/generic-acpi.txt binding file for information about the
+ * properties.
+ *
+ * @dev: I2C device to process
+ * @return 0 if OK, -EINVAL if acpi,hid is not present
+ */
+int acpi_i2c_ofdata_to_platdata(struct udevice *dev);
+
 #ifndef CONFIG_DM_I2C
 
 /*