[PATCH 2/2] i2c: mux: pca954x: replace property i2c-mux-idle-disconnect

From: Biwen Li
Date: Mon Oct 14 2019 - 07:37:04 EST


This replaces property i2c-mux-idle-disconnect with idle-state

Signed-off-by: Biwen Li <biwen.li@xxxxxxx>
---
drivers/i2c/muxes/i2c-mux-pca954x.c | 44 ++++++++++++++++++++---------
1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 923aa3a5a3dc..a330929c4d67 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -86,7 +86,7 @@ struct pca954x {

u8 last_chan; /* last register value */
/* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
- s8 idle_state;
+ s32 idle_state;

struct i2c_client *client;

@@ -256,7 +256,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
{
struct pca954x *data = i2c_mux_priv(muxc);
struct i2c_client *client = data->client;
- s8 idle_state;
+ s32 idle_state;

idle_state = READ_ONCE(data->idle_state);
if (idle_state >= 0)
@@ -411,7 +411,6 @@ static int pca954x_probe(struct i2c_client *client,
struct i2c_adapter *adap = client->adapter;
struct device *dev = &client->dev;
struct device_node *np = dev->of_node;
- bool idle_disconnect_dt;
struct gpio_desc *gpio;
struct i2c_mux_core *muxc;
struct pca954x *data;
@@ -462,22 +461,31 @@ static int pca954x_probe(struct i2c_client *client,
}
}

+ if (of_property_read_u32(np, "idle-state", &data->idle_state))
+ data->idle_state = MUX_IDLE_AS_IS;
+
/* Write the mux register at addr to verify
* that the mux is in fact present. This also
* initializes the mux to disconnected state.
*/
- if (i2c_smbus_write_byte(client, 0) < 0) {
+ if (data->idle_state >= 0){
+ data->last_chan = data->idle_state;
+ /* Always enable multiplexer */
+ ret = i2c_smbus_write_byte(client, data->last_chan |
+ (data->chip->muxtype == pca954x_ismux ?
+ data->chip->enable : 0));
+ }
+ else{
+ data->last_chan = 0; /* force the first selection */
+ /* Disconnect multiplexer */
+ ret = i2c_smbus_write_byte(client, data->last_chan);
+ }
+
+ if (ret < 0) {
dev_warn(dev, "probe failed\n");
return -ENODEV;
}

- data->last_chan = 0; /* force the first selection */
- data->idle_state = MUX_IDLE_AS_IS;
-
- idle_disconnect_dt = np &&
- of_property_read_bool(np, "i2c-mux-idle-disconnect");
- if (idle_disconnect_dt)
- data->idle_state = MUX_IDLE_DISCONNECT;

ret = pca954x_irq_setup(muxc);
if (ret)
@@ -531,8 +539,18 @@ static int pca954x_resume(struct device *dev)
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
struct pca954x *data = i2c_mux_priv(muxc);

- data->last_chan = 0;
- return i2c_smbus_write_byte(client, 0);
+ if (data->idle_state >= 0){
+ data->last_chan = data->idle_state;
+ /* Always enable multiplexer */
+ return i2c_smbus_write_byte(client, data->last_chan |
+ (data->chip->muxtype == pca954x_ismux ?
+ data->chip->enable : 0));
+ }
+ else{
+ data->last_chan = 0;
+ /* Disconnect multiplexer */
+ return i2c_smbus_write_byte(client, data->last_chan);
+ }
}
#endif

--
2.17.1