DM: virtio-gpio: gpio initialization.

Add gpio initializaiton and gpio usage implementation

gpio usage:
-s <slot>,virtio-gpio,<gpio resources>

<gpio resources format>
<@chip_name{offset|name[=vname]:offset|name[=vname]:...}
[@chip_name{offset|name[=vname]:offset|name[=vname]:...}]
[@chip_name{offset|name[=vname]:offset|name[=vname]:...}]
...>

Tracked-On: #2512
Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

devicemodel/hw/pci/virtio/virtio_gpio.c

@@ -107,13 +107,93 @@ struct virtio_gpio_config {
 	uint16_t	ngpio;	/* number of gpios */
 } __attribute__((packed));
 
+struct gpio_line {
+	char	name[32];		/* native gpio name */
+	char	vname[32];		/* virtual gpio name */
+	int	offset;			/* offset in real chip */
+	int	voffset;		/* offset in virtual chip */
+	int	fd;			/* native gpio line fd */
+	int	dir;			/* gpio direction */
+	bool	busy;			/* gpio line request by kernel */
+	struct native_gpio_chip	*chip;	/* parent gpio chip */
+};
+
+struct native_gpio_chip {
+	char	name[32];		/* gpio chip name */
+	char	label[32];		/* gpio chip label name */
+	char	dev_name[32];		/* device node name */
+	int	fd;			/* native gpio chip fd */
+	uint32_t		ngpio;	/* gpio line numbers */
+	struct gpio_line	*lines;	/* gpio lines in the chip */
+};
+
 struct virtio_gpio {
 	pthread_mutex_t	mtx;
 	struct virtio_base	base;
 	struct virtio_vq_info	queues[VIRTIO_GPIO_MAXQ];
+	struct native_gpio_chip	chips[VIRTIO_GPIO_MAX_CHIPS];
+	uint32_t		nchip;
+	struct gpio_line	*vlines[VIRTIO_GPIO_MAX_VLINES];
+	uint32_t		nvline;
 	struct virtio_gpio_config	config;
 };
 
+static void
+native_gpio_update_line_info(struct gpio_line *line)
+{
+	struct gpioline_info info;
+	int rc;
+
+	memset(&info, 0, sizeof(info));
+	info.line_offset = line->offset;
+	rc = ioctl(line->chip->fd, GPIO_GET_LINEINFO_IOCTL, &info);
+	if (rc) {
+		DPRINTF("ioctl GPIO_GET_LINEINFO_IOCTL error %s\n",
+				strerror(errno));
+		return;
+	}
+
+	line->busy = info.flags & GPIOLINE_FLAG_KERNEL;
+
+	/*
+	 * if it is already used by virtio gpio model,
+	 * it is not set to busy state
+	 */
+	if (line->fd > 0)
+		line->busy = false;
+
+	/* 0 means output, 1 means input */
+	line->dir = info.flags & GPIOLINE_FLAG_IS_OUT ? 0 : 1;
+	strncpy(line->name, info.name, sizeof(line->name) - 1);
+}
+
+static int
+native_gpio_open_line(struct gpio_line *line, unsigned int flags,
+		unsigned int value)
+{
+	struct gpiohandle_request req;
+	int rc;
+
+	memset(&req, 0, sizeof(req));
+	req.lineoffsets[0] = line->offset;
+	req.lines = 1;
+	strncpy(req.consumer_label, "acrn_dm", sizeof(req.consumer_label) - 1);
+	if (flags) {
+		req.flags = flags;
+		if (flags & GPIOHANDLE_REQUEST_OUTPUT)
+			req.default_values[0] = value;
+	}
+	rc = ioctl(line->chip->fd, GPIO_GET_LINEHANDLE_IOCTL, &req);
+	if (rc < 0) {
+		DPRINTF("ioctl GPIO_GET_LINEHANDLE_IOCTL error %s\n",
+				strerror(errno));
+		return -1;
+	}
+
+	line->fd = req.fd;
+	return 0;
+}
+
 static void virtio_gpio_reset(void *vdev)
 {
 	struct virtio_gpio *gpio;
@@ -176,12 +256,229 @@ virtio_gpio_notify(void *vdev, struct virtio_vq_info *vq)
 	}
 }
 
+static int
+native_gpio_open_chip(struct native_gpio_chip *chip, const char *name)
+{
+	struct gpiochip_info info;
+	struct gpio_line *line;
+	char path[64] = {0};
+	int fd, rc, i;
+
+	snprintf(path, sizeof(path), "/dev/%s", name);
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		DPRINTF("Can't open gpio device: %s, error %s\n",
+				path, strerror(errno));
+		return -1;
+	}
+
+	memset(&info, 0, sizeof(info));
+	rc = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info);
+	if (rc < 0) {
+		DPRINTF("Can't ioctl gpio device: %s, error %s\n",
+				path, strerror(errno));
+		goto fail;
+	}
+
+	chip->lines = calloc(1, info.lines * sizeof(*chip->lines));
+	if (!chip->lines) {
+		DPRINTF("Alloc chip lines error, %s:%d, error %s\n",
+				path, chip->ngpio, strerror(errno));
+		goto fail;
+	}
+	chip->fd = fd;
+	chip->ngpio = info.lines;
+	strncpy(chip->name, info.name, sizeof(chip->name) - 1);
+	strncpy(chip->label, info.label, sizeof(chip->label) - 1);
+	strncpy(chip->dev_name, name, sizeof(chip->dev_name) - 1);
+
+	/* initialize all lines of the chip */
+	for (i = 0; i < chip->ngpio; i++) {
+		line = &chip->lines[i];
+		line->offset = i;
+		line->chip = chip;
+
+		/*
+		 * The line's fd and voffset will be initialized
+		 * when virtual gpio line connects to the real line.
+		 */
+		line->fd = -1;
+		line->voffset = -1;
+
+		/* Set line state and name via ioctl*/
+		native_gpio_update_line_info(line);
+	}
+
+	return 0;
+
+fail:
+	if (fd > 0)
+		close(fd);
+	chip->fd = -1;
+	chip->ngpio = 0;
+	return -1;
+}
+
+static void
+native_gpio_close_chip(struct native_gpio_chip *chip)
+{
+	if (chip) {
+		memset(chip->name, 0, sizeof(chip->name));
+		memset(chip->label, 0, sizeof(chip->label));
+		memset(chip->dev_name, 0, sizeof(chip->dev_name));
+		if (chip->fd > 0) {
+			close(chip->fd);
+			chip->fd = -1;
+		}
+		if (chip->lines) {
+			free(chip->lines);
+			chip->lines = NULL;
+		}
+		chip->ngpio = 0;
+	}
+}
+
+static int
+native_gpio_get_offset(struct native_gpio_chip *chip, char *name)
+{
+	int rc;
+	int i;
+
+	/* try to find a gpio index by offset or name */
+	if (isalpha(name[0])) {
+		for (i = 0; i < chip->ngpio; i++) {
+			if (!strcmp(chip->lines[i].name, name))
+				return i;
+		}
+	} else if (isdigit(name[0])) {
+		rc = dm_strtoi(name, NULL, 10, &i);
+		if (rc == 0 && i < chip->ngpio)
+			return i;
+	}
+	return -1;
+}
+
+static struct gpio_line *
+native_gpio_find_line(struct native_gpio_chip *chip, const char *name)
+{
+	int offset;
+	char *b, *o, *c;
+	struct gpio_line *line = NULL;
+
+	b = o = strdup(name);
+	c = strsep(&o, "=");
+
+	/* find the line's offset in the chip by name or number */
+	offset = native_gpio_get_offset(chip, c);
+	if (offset < 0) {
+		DPRINTF("the %s line has not been found in %s chip\n",
+				c, chip->dev_name);
+		goto out;
+	}
+
+	line = &chip->lines[offset];
+	if (line->busy || native_gpio_open_line(line, 0, 0) < 0) {
+		line = NULL;
+		goto out;
+	}
+
+	/* If the user sets the name of the GPIO, copy it to vname */
+	if (o)
+		strncpy(line->vname, o, sizeof(line->vname) - 1);
+
+out:
+	free(b);
+	return line;
+}
+
+
+static int
+native_gpio_init(struct virtio_gpio *gpio, char *opts)
+{
+	struct gpio_line *line;
+	char *cstr, *lstr, *tmp, *b, *o;
+	int rc;
+	int cn = 0;
+	int ln = 0;
+
+	/*
+	 * -s <slot>,virtio-gpio,<gpio resources>
+	 * <gpio resources> format
+	 * <@chip_name0{offset|name[=vname]:offset|name[=vname]:...}
+	 * [@chip_name1{offset|name[=vname]:offset|name[=vname]:...}]
+	 * [@chip_name2{offset|name[=vname]:offset|name[=vname]:...}]
+	 * ...>
+	 */
+
+	b = o = strdup(opts);
+	while ((tmp = strsep(&o, "@")) != NULL) {
+
+		/* discard subsequent chips */
+		if (cn >= VIRTIO_GPIO_MAX_CHIPS ||
+				ln >= VIRTIO_GPIO_MAX_VLINES) {
+			DPRINTF("gpio chips or lines reach max, cn %d, ln %d\n",
+					cn, ln);
+			break;
+		}
+
+		/* ignore the null string */
+		if (tmp[0] == '\0')
+			continue;
+
+		/*
+		 * parse gpio chip name
+		 * if there is no gpiochip information, like "@{...}"
+		 * ignore all of the lines.
+		 */
+		cstr = strsep(&tmp, "{");
+		if (!tmp || !cstr || cstr[0] == '\0')
+			continue;
+
+		/* get chip information with its name */
+		rc = native_gpio_open_chip(&gpio->chips[cn], cstr);
+		if (rc < 0)
+			continue;
+
+		/* parse all gpio lines in one chip */
+		cstr = strsep(&tmp, "}");
+		while ((lstr = strsep(&cstr, ":")) != NULL) {
+
+			/* safety check, to avoid "@gpiochip0{::0:1...}" */
+			if (lstr[0] == '\0')
+				continue;
+
+			/* discard subsequent lines */
+			if (ln >= VIRTIO_GPIO_MAX_VLINES) {
+				DPRINTF("Virtual gpio lines reach max:%d\n",
+						ln);
+				break;
+			}
+
+			/*
+			 * If the line provided by gpio command line is found
+			 * assign one virtual gpio offset for it.
+			 */
+			line = native_gpio_find_line(&gpio->chips[cn], lstr);
+			if (line) {
+				gpio->vlines[ln] = line;
+				line->voffset = ln;
+				ln++;
+			}
+		}
+		cn++;
+	}
+	gpio->nchip = cn;
+	gpio->nvline = ln;
+	free(b);
+	return ln == 0 ? -1 : 0;
+}
+
 static int
 virtio_gpio_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 {
 	struct virtio_gpio *gpio;
 	pthread_mutexattr_t attr;
-	int rc;
+	int rc, i;
 
 	/* Just support one bdf */
 	if (virtio_gpio_is_active)
@@ -202,6 +499,12 @@ virtio_gpio_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 		goto init_fail;
 	}
 
+	rc = native_gpio_init(gpio, opts);
+	if (rc) {
+		DPRINTF("%s", "virtio gpio: failed to initialize gpio\n");
+		goto gpio_fail;
+	}
+
 	/* init mutex attribute properly to avoid deadlock */
 	rc = pthread_mutexattr_init(&attr);
 	if (rc) {
@@ -226,6 +529,9 @@ virtio_gpio_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 	/* gpio base for frontend gpio chip */
 	gpio->config.base = 0;
 
+	/* gpio numbers for frontend gpio chip */
+	gpio->config.ngpio = gpio->nvline;
+
 	gpio->base.device_caps = VIRTIO_GPIO_S_HOSTCAPS;
 	gpio->base.mtx = &gpio->mtx;
 	gpio->queues[0].qsize = 64;
@@ -254,6 +560,10 @@ fail:
 	pthread_mutex_destroy(&gpio->mtx);
 
 mtx_fail:
+	for (i = 0; i < gpio->nchip; i++)
+		native_gpio_close_chip(&gpio->chips[i]);
+
+gpio_fail:
 	free(gpio);
 	dev->arg = NULL;
 
@@ -266,12 +576,15 @@ static void
 virtio_gpio_deinit(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 {
 	struct virtio_gpio *gpio;
+	int i;
 
 	DPRINTF("%s", "virtio gpio: pci_gpio_deinit\r\n");
 	virtio_gpio_is_active = false;
 	gpio = (struct virtio_gpio *)dev->arg;
 	if (gpio) {
 		pthread_mutex_destroy(&gpio->mtx);
+		for (i = 0; i < gpio->nchip; i++)
+			native_gpio_close_chip(&gpio->chips[i]);
 		free(gpio);
 		dev->arg = NULL;
 	}