Merge tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This time very little driver changes but lots of core changes.

  We have some interesting cooperative work for ARM and Intel alike,
  making the GPIO subsystem more and more suitable for industrial
  systems and the like, in addition to the in-kernel users.

  We touch driver core (device properties) and lib/* by adding one
  simple string array free function, these are authored by Andy
  Shevchenko who is a well known and recognized core helpers maintainers
  so this should be fine.

  We also see some Android GKI-related modularization in the MXC
  drivers.

  Core changes:

   - The big core change is the updated (v2) userspace character device
     API.

     This corrects badly designed 64-bit alignment around the line
     events. We also add the debounce request feature. This echoes the
     often quotes passage from Frederick Brooks "The mythical man-month"
     to always throw one away, which we have seen before in things such
     as V4L2. So we put in a new one and deprecate and obsolete the old
     one.

   - All example tools in tools/gpio/* are migrated to the new API to
     set a good example. The libgpiod userspace library has been
     augmented to use this new API pretty much from day 1.

   - Some misc API hardening by using strn* function calls has been
     added as well.

   - Use the simpler IDA interface for GPIO chip instance enumeration.

   - Add device core function for counting string arrays in device
     properties.

   - Provide a generic library function kfree_strarray() that can be
     used throughout the kernel.

  Driver enhancements:

   - The DesignWare dwapb-gpio driver has been enhanced and now uses the
     IRQ handling in the gpiolib core.

   - The mockup and aggregator drivers have seen some substantial code
     clean-up and now use more of the core kernel inftrastructure.

   - Misc cleanups using dev_err_probe().

   - The MXC drivers (Freescale/NXP) can now be built modularized, which
     makes modularized GKI Android kernels happy"

* tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
  gpiolib: Update header block in gpiolib-cdev.h
  gpiolib: cdev: switch from kstrdup() to kstrndup()
  docs: gpio: add a new document to its index.rst
  gpio: pca953x: Add support for the NXP PCAL9554B/C
  tools: gpio: add debounce support to gpio-event-mon
  tools: gpio: add multi-line monitoring to gpio-event-mon
  tools: gpio: port gpio-event-mon to v2 uAPI
  tools: gpio: port gpio-hammer to v2 uAPI
  tools: gpio: rename nlines to num_lines
  tools: gpio: port gpio-watch to v2 uAPI
  tools: gpio: port lsgpio to v2 uAPI
  gpio: uapi: document uAPI v1 as deprecated
  gpiolib: cdev: support setting debounce
  gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
  gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
  gpiolib: cdev: support edge detection for uAPI v2
  gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
  gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
  gpiolib: add build option for CDEV v1 ABI
  gpiolib: make cdev a build option
  ...

1 files changed, 321 insertions, 13 deletions

diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 9c27cecf406f..07865c601099 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -11,9 +11,17 @@
 #ifndef _UAPI_GPIO_H_
 #define _UAPI_GPIO_H_
 
+#include <linux/const.h>
 #include <linux/ioctl.h>
 #include <linux/types.h>
 
+/*
+ * The maximum size of name and label arrays.
+ *
+ * Must be a multiple of 8 to ensure 32/64-bit alignment of structs.
+ */
+#define GPIO_MAX_NAME_SIZE 32
+
 /**
  * struct gpiochip_info - Information about a certain GPIO chip
  * @name: the Linux kernel name of this GPIO chip
@@ -22,11 +30,273 @@
  * @lines: number of GPIO lines on this chip
  */
 struct gpiochip_info {
-	char name[32];
-	char label[32];
+	char name[GPIO_MAX_NAME_SIZE];
+	char label[GPIO_MAX_NAME_SIZE];
 	__u32 lines;
 };
 
+/*
+ * Maximum number of requested lines.
+ *
+ * Must be no greater than 64, as bitmaps are restricted here to 64-bits
+ * for simplicity, and a multiple of 2 to ensure 32/64-bit alignment of
+ * structs.
+ */
+#define GPIO_V2_LINES_MAX 64
+
+/*
+ * The maximum number of configuration attributes associated with a line
+ * request.
+ */
+#define GPIO_V2_LINE_NUM_ATTRS_MAX 10
+
+/**
+ * enum gpio_v2_line_flag - &struct gpio_v2_line_attribute.flags values
+ * @GPIO_V2_LINE_FLAG_USED: line is not available for request
+ * @GPIO_V2_LINE_FLAG_ACTIVE_LOW: line active state is physical low
+ * @GPIO_V2_LINE_FLAG_INPUT: line is an input
+ * @GPIO_V2_LINE_FLAG_OUTPUT: line is an output
+ * @GPIO_V2_LINE_FLAG_EDGE_RISING: line detects rising (inactive to active)
+ * edges
+ * @GPIO_V2_LINE_FLAG_EDGE_FALLING: line detects falling (active to
+ * inactive) edges
+ * @GPIO_V2_LINE_FLAG_OPEN_DRAIN: line is an open drain output
+ * @GPIO_V2_LINE_FLAG_OPEN_SOURCE: line is an open source output
+ * @GPIO_V2_LINE_FLAG_BIAS_PULL_UP: line has pull-up bias enabled
+ * @GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN: line has pull-down bias enabled
+ * @GPIO_V2_LINE_FLAG_BIAS_DISABLED: line has bias disabled
+ */
+enum gpio_v2_line_flag {
+	GPIO_V2_LINE_FLAG_USED			= _BITULL(0),
+	GPIO_V2_LINE_FLAG_ACTIVE_LOW		= _BITULL(1),
+	GPIO_V2_LINE_FLAG_INPUT			= _BITULL(2),
+	GPIO_V2_LINE_FLAG_OUTPUT		= _BITULL(3),
+	GPIO_V2_LINE_FLAG_EDGE_RISING		= _BITULL(4),
+	GPIO_V2_LINE_FLAG_EDGE_FALLING		= _BITULL(5),
+	GPIO_V2_LINE_FLAG_OPEN_DRAIN		= _BITULL(6),
+	GPIO_V2_LINE_FLAG_OPEN_SOURCE		= _BITULL(7),
+	GPIO_V2_LINE_FLAG_BIAS_PULL_UP		= _BITULL(8),
+	GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN	= _BITULL(9),
+	GPIO_V2_LINE_FLAG_BIAS_DISABLED		= _BITULL(10),
+};
+
+/**
+ * struct gpio_v2_line_values - Values of GPIO lines
+ * @bits: a bitmap containing the value of the lines, set to 1 for active
+ * and 0 for inactive.
+ * @mask: a bitmap identifying the lines to get or set, with each bit
+ * number corresponding to the index into &struct
+ * gpio_v2_line_request.offsets.
+ */
+struct gpio_v2_line_values {
+	__aligned_u64 bits;
+	__aligned_u64 mask;
+};
+
+/**
+ * enum gpio_v2_line_attr_id - &struct gpio_v2_line_attribute.id values
+ * identifying which field of the attribute union is in use.
+ * @GPIO_V2_LINE_ATTR_ID_FLAGS: flags field is in use
+ * @GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES: values field is in use
+ * @GPIO_V2_LINE_ATTR_ID_DEBOUNCE: debounce_period_us is in use
+ */
+enum gpio_v2_line_attr_id {
+	GPIO_V2_LINE_ATTR_ID_FLAGS		= 1,
+	GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES	= 2,
+	GPIO_V2_LINE_ATTR_ID_DEBOUNCE		= 3,
+};
+
+/**
+ * struct gpio_v2_line_attribute - a configurable attribute of a line
+ * @id: attribute identifier with value from &enum gpio_v2_line_attr_id
+ * @padding: reserved for future use and must be zero filled
+ * @flags: if id is GPIO_V2_LINE_ATTR_ID_FLAGS, the flags for the GPIO
+ * line, with values from enum gpio_v2_line_flag, such as
+ * GPIO_V2_LINE_FLAG_ACTIVE_LOW, GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed
+ * together.  This overrides the default flags contained in the &struct
+ * gpio_v2_line_config for the associated line.
+ * @values: if id is GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES, a bitmap
+ * containing the values to which the lines will be set, with each bit
+ * number corresponding to the index into &struct
+ * gpio_v2_line_request.offsets.
+ * @debounce_period_us: if id is GPIO_V2_LINE_ATTR_ID_DEBOUNCE, the desired
+ * debounce period, in microseconds
+ */
+struct gpio_v2_line_attribute {
+	__u32 id;
+	__u32 padding;
+	union {
+		__aligned_u64 flags;
+		__aligned_u64 values;
+		__u32 debounce_period_us;
+	};
+};
+
+/**
+ * struct gpio_v2_line_config_attribute - a configuration attribute
+ * associated with one or more of the requested lines.
+ * @attr: the configurable attribute
+ * @mask: a bitmap identifying the lines to which the attribute applies,
+ * with each bit number corresponding to the index into &struct
+ * gpio_v2_line_request.offsets.
+ */
+struct gpio_v2_line_config_attribute {
+	struct gpio_v2_line_attribute attr;
+	__aligned_u64 mask;
+};
+
+/**
+ * struct gpio_v2_line_config - Configuration for GPIO lines
+ * @flags: flags for the GPIO lines, with values from enum
+ * gpio_v2_line_flag, such as GPIO_V2_LINE_FLAG_ACTIVE_LOW,
+ * GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed together.  This is the default for
+ * all requested lines but may be overridden for particular lines using
+ * attrs.
+ * @num_attrs: the number of attributes in attrs
+ * @padding: reserved for future use and must be zero filled
+ * @attrs: the configuration attributes associated with the requested
+ * lines.  Any attribute should only be associated with a particular line
+ * once.  If an attribute is associated with a line multiple times then the
+ * first occurrence (i.e. lowest index) has precedence.
+ */
+struct gpio_v2_line_config {
+	__aligned_u64 flags;
+	__u32 num_attrs;
+	/* Pad to fill implicit padding and reserve space for future use. */
+	__u32 padding[5];
+	struct gpio_v2_line_config_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
+};
+
+/**
+ * struct gpio_v2_line_request - Information about a request for GPIO lines
+ * @offsets: an array of desired lines, specified by offset index for the
+ * associated GPIO chip
+ * @consumer: a desired consumer label for the selected GPIO lines such as
+ * "my-bitbanged-relay"
+ * @config: requested configuration for the lines.
+ * @num_lines: number of lines requested in this request, i.e. the number
+ * of valid fields in the GPIO_V2_LINES_MAX sized arrays, set to 1 to
+ * request a single line
+ * @event_buffer_size: a suggested minimum number of line events that the
+ * kernel should buffer.  This is only relevant if edge detection is
+ * enabled in the configuration. Note that this is only a suggested value
+ * and the kernel may allocate a larger buffer or cap the size of the
+ * buffer. If this field is zero then the buffer size defaults to a minimum
+ * of num_lines*16.
+ * @padding: reserved for future use and must be zero filled
+ * @fd: if successful this field will contain a valid anonymous file handle
+ * after a GPIO_GET_LINE_IOCTL operation, zero or negative value means
+ * error
+ */
+struct gpio_v2_line_request {
+	__u32 offsets[GPIO_V2_LINES_MAX];
+	char consumer[GPIO_MAX_NAME_SIZE];
+	struct gpio_v2_line_config config;
+	__u32 num_lines;
+	__u32 event_buffer_size;
+	/* Pad to fill implicit padding and reserve space for future use. */
+	__u32 padding[5];
+	__s32 fd;
+};
+
+/**
+ * struct gpio_v2_line_info - Information about a certain GPIO line
+ * @name: the name of this GPIO line, such as the output pin of the line on
+ * the chip, a rail or a pin header name on a board, as specified by the
+ * GPIO chip, may be empty
+ * @consumer: a functional name for the consumer of this GPIO line as set
+ * by whatever is using it, will be empty if there is no current user but
+ * may also be empty if the consumer doesn't set this up
+ * @flags: flags for the GPIO line, such as GPIO_V2_LINE_FLAG_ACTIVE_LOW,
+ * GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed together
+ * @offset: the local offset on this GPIO chip, fill this in when
+ * requesting the line information from the kernel
+ * @num_attrs: the number of attributes in attrs
+ * @attrs: the configuration attributes associated with the line
+ * @padding: reserved for future use
+ */
+struct gpio_v2_line_info {
+	char name[GPIO_MAX_NAME_SIZE];
+	char consumer[GPIO_MAX_NAME_SIZE];
+	__u32 offset;
+	__u32 num_attrs;
+	__aligned_u64 flags;
+	struct gpio_v2_line_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
+	/* Space reserved for future use. */
+	__u32 padding[4];
+};
+
+/**
+ * enum gpio_v2_line_changed_type - &struct gpio_v2_line_changed.event_type
+ * values
+ * @GPIO_V2_LINE_CHANGED_REQUESTED: line has been requested
+ * @GPIO_V2_LINE_CHANGED_RELEASED: line has been released
+ * @GPIO_V2_LINE_CHANGED_CONFIG: line has been reconfigured
+ */
+enum gpio_v2_line_changed_type {
+	GPIO_V2_LINE_CHANGED_REQUESTED	= 1,
+	GPIO_V2_LINE_CHANGED_RELEASED	= 2,
+	GPIO_V2_LINE_CHANGED_CONFIG	= 3,
+};
+
+/**
+ * struct gpio_v2_line_info_changed - Information about a change in status
+ * of a GPIO line
+ * @info: updated line information
+ * @timestamp_ns: estimate of time of status change occurrence, in nanoseconds
+ * @event_type: the type of change with a value from enum
+ * gpio_v2_line_changed_type
+ * @padding: reserved for future use
+ */
+struct gpio_v2_line_info_changed {
+	struct gpio_v2_line_info info;
+	__aligned_u64 timestamp_ns;
+	__u32 event_type;
+	/* Pad struct to 64-bit boundary and reserve space for future use. */
+	__u32 padding[5];
+};
+
+/**
+ * enum gpio_v2_line_event_id - &struct gpio_v2_line_event.id values
+ * @GPIO_V2_LINE_EVENT_RISING_EDGE: event triggered by a rising edge
+ * @GPIO_V2_LINE_EVENT_FALLING_EDGE: event triggered by a falling edge
+ */
+enum gpio_v2_line_event_id {
+	GPIO_V2_LINE_EVENT_RISING_EDGE	= 1,
+	GPIO_V2_LINE_EVENT_FALLING_EDGE	= 2,
+};
+
+/**
+ * struct gpio_v2_line_event - The actual event being pushed to userspace
+ * @timestamp_ns: best estimate of time of event occurrence, in nanoseconds.
+ * The timestamp_ns is read from CLOCK_MONOTONIC and is intended to allow the
+ * accurate measurement of the time between events.  It does not provide
+ * the wall-clock time.
+ * @id: event identifier with value from enum gpio_v2_line_event_id
+ * @offset: the offset of the line that triggered the event
+ * @seqno: the sequence number for this event in the sequence of events for
+ * all the lines in this line request
+ * @line_seqno: the sequence number for this event in the sequence of
+ * events on this particular line
+ * @padding: reserved for future use
+ */
+struct gpio_v2_line_event {
+	__aligned_u64 timestamp_ns;
+	__u32 id;
+	__u32 offset;
+	__u32 seqno;
+	__u32 line_seqno;
+	/* Space reserved for future use. */
+	__u32 padding[6];
+};
+
+/*
+ *  ABI v1
+ *
+ * This version of the ABI is deprecated.
+ * Use the latest version of the ABI, defined above, instead.
+ */
+
 /* Informational flags */
 #define GPIOLINE_FLAG_KERNEL		(1UL << 0) /* Line used by the kernel */
 #define GPIOLINE_FLAG_IS_OUT		(1UL << 1)
@@ -48,12 +318,15 @@ struct gpiochip_info {
  * @consumer: a functional name for the consumer of this GPIO line as set by
  * whatever is using it, will be empty if there is no current user but may
  * also be empty if the consumer doesn't set this up
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_info instead.
  */
 struct gpioline_info {
 	__u32 line_offset;
 	__u32 flags;
-	char name[32];
-	char consumer[32];
+	char name[GPIO_MAX_NAME_SIZE];
+	char consumer[GPIO_MAX_NAME_SIZE];
 };
 
 /* Maximum number of requested handles */
@@ -79,6 +352,9 @@ enum {
  * guarantee there are no implicit holes between it and subsequent members.
  * The 20-byte padding at the end makes sure we don't add any implicit padding
  * at the end of the structure on 64-bit architectures.
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_info_changed instead.
  */
 struct gpioline_info_changed {
 	struct gpioline_info info;
@@ -118,12 +394,15 @@ struct gpioline_info_changed {
  * @fd: if successful this field will contain a valid anonymous file handle
  * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value
  * means error
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_request instead.
  */
 struct gpiohandle_request {
 	__u32 lineoffsets[GPIOHANDLES_MAX];
 	__u32 flags;
 	__u8 default_values[GPIOHANDLES_MAX];
-	char consumer_label[32];
+	char consumer_label[GPIO_MAX_NAME_SIZE];
 	__u32 lines;
 	int fd;
 };
@@ -137,6 +416,9 @@ struct gpiohandle_request {
  * this specifies the default output value, should be 0 (low) or
  * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
  * @padding: reserved for future use and should be zero filled
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_config instead.
  */
 struct gpiohandle_config {
 	__u32 flags;
@@ -144,21 +426,19 @@ struct gpiohandle_config {
 	__u32 padding[4]; /* padding for future use */
 };
 
-#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config)
-
 /**
  * struct gpiohandle_data - Information of values on a GPIO handle
  * @values: when getting the state of lines this contains the current
  * state of a line, when setting the state of lines these should contain
  * the desired target state
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_values instead.
  */
 struct gpiohandle_data {
 	__u8 values[GPIOHANDLES_MAX];
 };
 
-#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
-#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
-
 /* Eventrequest flags */
 #define GPIOEVENT_REQUEST_RISING_EDGE	(1UL << 0)
 #define GPIOEVENT_REQUEST_FALLING_EDGE	(1UL << 1)
@@ -177,12 +457,15 @@ struct gpiohandle_data {
  * @fd: if successful this field will contain a valid anonymous file handle
  * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value
  * means error
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_request instead.
  */
 struct gpioevent_request {
 	__u32 lineoffset;
 	__u32 handleflags;
 	__u32 eventflags;
-	char consumer_label[32];
+	char consumer_label[GPIO_MAX_NAME_SIZE];
 	int fd;
 };
 
@@ -196,17 +479,42 @@ struct gpioevent_request {
  * struct gpioevent_data - The actual event being pushed to userspace
  * @timestamp: best estimate of time of event occurrence, in nanoseconds
  * @id: event identifier
+ *
+ * This struct is part of ABI v1 and is deprecated.
+ * Use struct gpio_v2_line_event instead.
  */
 struct gpioevent_data {
 	__u64 timestamp;
 	__u32 id;
 };
 
+/*
+ * v1 and v2 ioctl()s
+ */
 #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
+#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0C, __u32)
+
+/*
+ * v2 ioctl()s
+ */
+#define GPIO_V2_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x05, struct gpio_v2_line_info)
+#define GPIO_V2_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x06, struct gpio_v2_line_info)
+#define GPIO_V2_GET_LINE_IOCTL _IOWR(0xB4, 0x07, struct gpio_v2_line_request)
+#define GPIO_V2_LINE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0D, struct gpio_v2_line_config)
+#define GPIO_V2_LINE_GET_VALUES_IOCTL _IOWR(0xB4, 0x0E, struct gpio_v2_line_values)
+#define GPIO_V2_LINE_SET_VALUES_IOCTL _IOWR(0xB4, 0x0F, struct gpio_v2_line_values)
+
+/*
+ * v1 ioctl()s
+ *
+ * These ioctl()s are deprecated.  Use the v2 equivalent instead.
+ */
 #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
-#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0b, struct gpioline_info)
-#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0c, __u32)
 #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
 #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)
+#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
+#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
+#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0A, struct gpiohandle_config)
+#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0B, struct gpioline_info)
 
 #endif /* _UAPI_GPIO_H_ */