diff options
| -rw-r--r-- | drivers/i2c/muxes/pca954x.c | 101 |
1 files changed, 100 insertions, 1 deletions
diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c index 6f8953664636..90fd47b54df5 100644 --- a/drivers/i2c/muxes/pca954x.c +++ b/drivers/i2c/muxes/pca954x.c @@ -41,6 +41,9 @@ #include <linux/device.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/delay.h> #include <linux/i2c/pca954x.h> @@ -62,6 +65,8 @@ struct pca954x { struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS]; u8 last_chan; /* last register value */ + struct regulator *vcc_reg; + struct regulator *i2c_reg; }; struct chip_desc { @@ -123,6 +128,26 @@ static int pca954x_reg_write(struct i2c_adapter *adap, struct i2c_client *client, u8 val) { int ret = -ENODEV; + struct pca954x *data = i2c_get_clientdata(client); + + /* Increase ref count for pca954x vcc */ + if (data->vcc_reg) { + ret = regulator_enable(data->vcc_reg); + if (ret) { + dev_err(&client->dev, "%s: failed to enable vcc\n", + __func__); + goto vcc_regulator_failed; + } + } + /* Increase ref count for pca954x vcc_i2c */ + if (data->i2c_reg) { + ret = regulator_enable(data->i2c_reg); + if (ret) { + dev_err(&client->dev, "%s: failed to enable vcc_i2c\n", + __func__); + goto i2c_regulator_failed; + } + } if (adap->algo->master_xfer) { struct i2c_msg msg; @@ -142,6 +167,15 @@ static int pca954x_reg_write(struct i2c_adapter *adap, val, I2C_SMBUS_BYTE, &data); } + /* Decrease ref count for pca954x vcc_i2c */ + if (data->i2c_reg) + regulator_disable(data->i2c_reg); + +i2c_regulator_failed: + /* Decrease ref count for pca954x vcc */ + if (data->vcc_reg) + regulator_disable(data->vcc_reg); +vcc_regulator_failed: return ret; } @@ -201,15 +235,74 @@ static int pca954x_probe(struct i2c_client *client, i2c_set_clientdata(client, data); + /* Get regulator pointer for pca954x vcc */ + data->vcc_reg = regulator_get(&client->dev, "vcc"); + if (PTR_ERR(data->vcc_reg) == -ENODEV) + data->vcc_reg = NULL; + else if (IS_ERR(data->vcc_reg)) { + dev_err(&client->dev, "%s: failed to get vcc\n", + __func__); + ret = PTR_ERR(data->vcc_reg); + goto exit_free; + } + /* Get regulator pointer for pca954x vcc_i2c */ + data->i2c_reg = regulator_get(&client->dev, "vcc_i2c"); + if (PTR_ERR(data->i2c_reg) == -ENODEV) + data->i2c_reg = NULL; + else if (IS_ERR(data->i2c_reg)) { + dev_err(&client->dev, "%s: failed to get vcc_i2c\n", + __func__); + ret = PTR_ERR(data->i2c_reg); + regulator_put(data->vcc_reg); + goto exit_free; + } + + /* Increase ref count for pca954x vcc */ + if (data->vcc_reg) { + pr_info("%s: enable vcc\n", __func__); + ret = regulator_enable(data->vcc_reg); + if (ret) { + dev_err(&client->dev, "%s: failed to enable vcc\n", + __func__); + goto exit_regulator_put; + } + } + /* Increase ref count for pca954x vcc_i2c */ + if (data->i2c_reg) { + pr_info("%s: enable vcc_i2c\n", __func__); + ret = regulator_enable(data->i2c_reg); + if (ret) { + dev_err(&client->dev, "%s: failed to enable vcc_i2c\n", + __func__); + regulator_disable(data->vcc_reg); + goto exit_regulator_put; + } + } + + /* + * Power-On Reset takes time. + * I2C is ready after Power-On Reset. + */ + msleep(1); + /* 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) { dev_warn(&client->dev, "probe failed\n"); - goto exit_free; + regulator_disable(data->vcc_reg); + regulator_disable(data->i2c_reg); + goto exit_regulator_put; } + /* Decrease ref count for pca954x vcc */ + if (data->vcc_reg) + regulator_disable(data->vcc_reg); + /* Decrease ref count for pca954x vcc_i2c */ + if (data->i2c_reg) + regulator_disable(data->i2c_reg); + data->type = id->driver_data; data->last_chan = 0; /* force the first selection */ @@ -250,6 +343,9 @@ static int pca954x_probe(struct i2c_client *client, virt_reg_failed: for (num--; num >= 0; num--) i2c_del_mux_adapter(data->virt_adaps[num]); +exit_regulator_put: + regulator_put(data->vcc_reg); + regulator_put(data->i2c_reg); exit_free: kfree(data); err: @@ -270,6 +366,9 @@ static int pca954x_remove(struct i2c_client *client) data->virt_adaps[i] = NULL; } + regulator_put(data->i2c_reg); + regulator_put(data->vcc_reg); + kfree(data); return 0; } |