[PATCH v7 06/24] i2c: i2c-mux-pca954x: convert to use an explicit i2c mux core

Peter Rosin
2016-04-20T15:19:40Z

Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.

Add a mask to handle the case where not all child adapters should
cause a mux deselect to happen, now that there is a common deselect op
for all child adapters.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/muxes/i2c-mux-pca954x.c | 61 ++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 31 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index acfcef3d4068..528e755c468f 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -60,9 +60,10 @@ enum pca_type {

struct pca954x {
enum pca_type type;
- struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS];

u8 last_chan; /* last register value */
+ u8 deselect;
+ struct i2c_client *client;
};

struct chip_desc {
@@ -146,10 +147,10 @@ static int pca954x_reg_write(struct i2c_adapter *adap,
return ret;
}

-static int pca954x_select_chan(struct i2c_adapter *adap,
- void *client, u32 chan)
+static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
- struct pca954x *data = i2c_get_clientdata(client);
+ struct pca954x *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
const struct chip_desc *chip = &chips[data->type];
u8 regval;
int ret = 0;
@@ -162,21 +163,24 @@ static int pca954x_select_chan(struct i2c_adapter *adap,

/* Only select the channel if its different from the last channel */
if (data->last_chan != regval) {
- ret = pca954x_reg_write(adap, client, regval);
+ ret = pca954x_reg_write(muxc->parent, client, regval);
data->last_chan = regval;
}

return ret;
}

-static int pca954x_deselect_mux(struct i2c_adapter *adap,
- void *client, u32 chan)
+static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
{
- struct pca954x *data = i2c_get_clientdata(client);
+ struct pca954x *data = i2c_mux_priv(muxc);
+ struct i2c_client *client = data->client;
+
+ if (!(data->deselect & (1 << chan)))
+ return 0;

/* Deselect active channel */
data->last_chan = 0;
- return pca954x_reg_write(adap, client, data->last_chan);
+ return pca954x_reg_write(muxc->parent, client, data->last_chan);
}

/*
@@ -191,17 +195,22 @@ static int pca954x_probe(struct i2c_client *client,
bool idle_disconnect_dt;
struct gpio_desc *gpio;
int num, force, class;
+ struct i2c_mux_core *muxc;
struct pca954x *data;
int ret;

if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
return -ENODEV;

- data = devm_kzalloc(&client->dev, sizeof(struct pca954x), GFP_KERNEL);
- if (!data)
+ muxc = i2c_mux_alloc(adap, &client->dev,
+ PCA954X_MAX_NCHANS, sizeof(*data), 0,
+ pca954x_select_chan, pca954x_deselect_mux);
+ if (!muxc)
return -ENOMEM;
+ data = i2c_mux_priv(muxc);

- i2c_set_clientdata(client, data);
+ i2c_set_clientdata(client, muxc);
+ data->client = client;

/* Get the mux out of reset if a reset GPIO is specified. */
gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
@@ -238,16 +247,13 @@ static int pca954x_probe(struct i2c_client *client,
/* discard unconfigured channels */
break;
idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
+ data->deselect |= (idle_disconnect_pd
+ || idle_disconnect_dt) << num;
}

- data->virt_adaps[num] =
- i2c_add_mux_adapter(adap, &client->dev, client,
- force, num, class, pca954x_select_chan,
- (idle_disconnect_pd || idle_disconnect_dt)
- ? pca954x_deselect_mux : NULL);
+ ret = i2c_mux_add_adapter(muxc, force, num, class);

- if (data->virt_adaps[num] == NULL) {
- ret = -ENODEV;
+ if (ret) {
dev_err(&client->dev,
"failed to register multiplexed adapter"
" %d as bus %d\n", num, force);
@@ -263,23 +269,15 @@ static int pca954x_probe(struct i2c_client *client,
return 0;

virt_reg_failed:
- for (num--; num >= 0; num--)
- i2c_del_mux_adapter(data->virt_adaps[num]);
+ i2c_mux_del_adapters(muxc);
return ret;
}

static int pca954x_remove(struct i2c_client *client)
{
- struct pca954x *data = i2c_get_clientdata(client);
- const struct chip_desc *chip = &chips[data->type];
- int i;
-
- for (i = 0; i < chip->nchans; ++i)
- if (data->virt_adaps[i]) {
- i2c_del_mux_adapter(data->virt_adaps[i]);
- data->virt_adaps[i] = NULL;
- }
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);

+ i2c_mux_del_adapters(muxc);
return 0;
}

@@ -287,7 +285,8 @@ static int pca954x_remove(struct i2c_client *client)
static int pca954x_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
- struct pca954x *data = i2c_get_clientdata(client);
+ 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);
--
2.1.4