> +#define GPIOS_PER_PORT 32
Maybe this should be from DT, using "ngpios". The Documentation says:
Optionally, a GPIO controller may have a "ngpios" property. This
property indicates the number of in-use slots of available slots for
GPIOs. The typical example is something like this: the hardware
register is 32 bits wide, but only 18 of the bits have a physical
counterpart. The driver is generally written so that all 32 bits can
be used, but the IP block is reused in a lot of designs, some using
all 32 bits, some using 18 and some using 12. In this case, setting
"ngpios = <18>;" informs the driver that only the first 18 GPIOs, at
local offset 0 .. 17, are in use.
Just because your hardware has 32 does not mean every vendor does.
> +struct gpio_rpmsg_head {
> + u8 id; /* Message ID Code */
> + u8 vendor; /* Vendor ID number */
> + u8 version; /* Vendor-specific version number */
> + u8 type; /* Message type */
> + u8 cmd; /* Command code */
> + u8 reserved[5];
> +} __packed;
I still think this should be a clean design from scratch, and you
modify your firmware.
This data structure is 10 bytes. Are these all needed for a generic
GPIO controller? version, type, command and one reserved byte seems
like enough, and it is then 4 bytes, so there is no need for __packed.
> +struct gpio_rpmsg_packet {
> + struct gpio_rpmsg_head header;
> + u8 pin_idx;
> + u8 port_idx;
> + union {
> + u8 event;
> + u8 retcode;
> + u8 value;
> + } out;
> + union {
> + u8 wakeup;
> + u8 value;
> + } in;
> +} __packed __aligned(8);
This then becomes 8 bytes, so there is no need for __packed or
__aligned(8).
I don't want to force this, it is something i think which should be
discussed. Do we adopt your design, which is not so nice, but at least
has one working implementation, or do we do a clean design?
> +static int gpio_send_message(struct rpmsg_gpio_port *port,
> + struct gpio_rpmsg_packet *msg,
> + bool sync)
> +{
> + struct gpio_rpmsg_info *info = &port->info;
> + int err;
> +
> + reinit_completion(&info->cmd_complete);
> + err = rpmsg_send(info->rpdev->ept, msg, sizeof(struct
> gpio_rpmsg_packet));
> + if (err) {
> + dev_err(&info->rpdev->dev, "rpmsg_send failed: %d\n", err);
> + return err;
> + }
> +
> + if (sync) {
> + err = wait_for_completion_timeout(&info->cmd_complete,
> +
> msecs_to_jiffies(RPMSG_TIMEOUT));
> + if (!err) {
> + dev_err(&info->rpdev->dev, "rpmsg_send timeout!\n");
> + return -ETIMEDOUT;
> + }
I _think_ you need to handle negative values of err. It looks like
do_wait_for_common() can return -ERESTARTSYS;
> +static struct gpio_rpmsg_packet *gpio_setup_msg_header(struct
> rpmsg_gpio_port *port,
> + unsigned int offset,
> + u8 cmd)
> +{
> + struct gpio_rpmsg_packet *msg = &port->gpio_pins[offset].msg;
> +
> + memset(msg, 0, sizeof(struct gpio_rpmsg_packet));
> + msg->header.id = RPMSG_GPIO_ID;
> + msg->header.vendor = RPMSG_VENDOR;
> + msg->header.version = RPMSG_VERSION;
> + msg->header.type = GPIO_RPMSG_SETUP;
> + msg->header.cmd = cmd;
> + msg->pin_idx = offset;
> + msg->port_idx = port->idx;
Why is a function called gpio_setup_msg_header() setting things
outside of the header?
> +static int rpmsg_gpio_get(struct gpio_chip *gc, unsigned int gpio)
> +{
> + struct rpmsg_gpio_port *port = gpiochip_get_data(gc);
> + struct gpio_rpmsg_packet *msg;
> + int ret;
> +
> + guard(mutex)(&port->info.lock);
> +
> + msg = gpio_setup_msg_header(port, gpio, GPIO_RPMSG_INPUT_GET);
> +
> + ret = gpio_send_message(port, msg, true);
If gpio_setup_msg_header() does what it sounds like it should do, what
is setting up the message body before you send the message?
Andrew
