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path: root/drivers/hid/hid-mcp2221.c
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Diffstat (limited to 'drivers/hid/hid-mcp2221.c')
-rw-r--r--drivers/hid/hid-mcp2221.c48
1 files changed, 39 insertions, 9 deletions
diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
index 0d27ccb55dd9..4211b9839209 100644
--- a/drivers/hid/hid-mcp2221.c
+++ b/drivers/hid/hid-mcp2221.c
@@ -49,6 +49,36 @@ enum {
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
@@ -542,7 +572,7 @@ static int mcp_gpio_get(struct gpio_chip *gc,
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);
@@ -559,7 +589,7 @@ static void mcp_gpio_set(struct gpio_chip *gc,
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;
@@ -575,7 +605,7 @@ static int mcp_gpio_dir_set(struct mcp2221 *mcp,
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;
@@ -590,7 +620,7 @@ static int mcp_gpio_direction_input(struct gpio_chip *gc,
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;
@@ -603,7 +633,7 @@ static int mcp_gpio_direction_output(struct gpio_chip *gc,
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 */
@@ -623,7 +653,7 @@ static int mcp_gpio_get_direction(struct gpio_chip *gc,
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);
@@ -632,7 +662,7 @@ static int mcp_gpio_get_direction(struct gpio_chip *gc,
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;
@@ -758,7 +788,7 @@ static int mcp2221_raw_event(struct hid_device *hdev,
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:
@@ -860,7 +890,7 @@ static int mcp2221_probe(struct hid_device *hdev,
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;