MCP2221_ALT_F_NOT_GPIOD = 0xEF,
};
+/* MCP GPIO direction encoding */
+enum {
+ MCP2221_DIR_OUT = 0x00,
+ MCP2221_DIR_IN = 0x01,
+};
+
+#define MCP_NGPIO 4
+
+/* MCP GPIO set command layout */
+struct mcp_set_gpio {
+ u8 cmd;
+ u8 dummy;
+ struct {
+ u8 change_value;
+ u8 value;
+ u8 change_direction;
+ u8 direction;
+ } gpio[MCP_NGPIO];
+} __packed;
+
+/* MCP GPIO get command layout */
+struct mcp_get_gpio {
+ u8 cmd;
+ u8 dummy;
+ struct {
+ u8 direction;
+ u8 value;
+ } gpio[MCP_NGPIO];
+} __packed;
+
/*
* There is no way to distinguish responses. Therefore next command
* is sent only after response to previous has been received. Mutex
mcp->txbuf[0] = MCP2221_GPIO_GET;
- mcp->gp_idx = (offset + 1) * 2;
+ mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].value);
mutex_lock(&mcp->lock);
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
memset(mcp->txbuf, 0, 18);
mcp->txbuf[0] = MCP2221_GPIO_SET;
- mcp->gp_idx = ((offset + 1) * 4) - 1;
+ mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].value);
mcp->txbuf[mcp->gp_idx - 1] = 1;
mcp->txbuf[mcp->gp_idx] = !!value;
memset(mcp->txbuf, 0, 18);
mcp->txbuf[0] = MCP2221_GPIO_SET;
- mcp->gp_idx = (offset + 1) * 5;
+ mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].direction);
mcp->txbuf[mcp->gp_idx - 1] = 1;
mcp->txbuf[mcp->gp_idx] = val;
struct mcp2221 *mcp = gpiochip_get_data(gc);
mutex_lock(&mcp->lock);
- ret = mcp_gpio_dir_set(mcp, offset, 0);
+ ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_IN);
mutex_unlock(&mcp->lock);
return ret;
struct mcp2221 *mcp = gpiochip_get_data(gc);
mutex_lock(&mcp->lock);
- ret = mcp_gpio_dir_set(mcp, offset, 1);
+ ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_OUT);
mutex_unlock(&mcp->lock);
/* Can't configure as output, bailout early */
mcp->txbuf[0] = MCP2221_GPIO_GET;
- mcp->gp_idx = (offset + 1) * 2;
+ mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].direction);
mutex_lock(&mcp->lock);
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
if (ret)
return ret;
- if (mcp->gpio_dir)
+ if (mcp->gpio_dir == MCP2221_DIR_IN)
return GPIO_LINE_DIRECTION_IN;
return GPIO_LINE_DIRECTION_OUT;
mcp->status = -ENOENT;
} else {
mcp->status = !!data[mcp->gp_idx];
- mcp->gpio_dir = !!data[mcp->gp_idx + 1];
+ mcp->gpio_dir = data[mcp->gp_idx + 1];
}
break;
default:
mcp->gc->get_direction = mcp_gpio_get_direction;
mcp->gc->set = mcp_gpio_set;
mcp->gc->get = mcp_gpio_get;
- mcp->gc->ngpio = 4;
+ mcp->gc->ngpio = MCP_NGPIO;
mcp->gc->base = -1;
mcp->gc->can_sleep = 1;
mcp->gc->parent = &hdev->dev;