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Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-5.6

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The main feature is the idle-state rework of the pca954x driver from Biwen Li.
This commit is contained in:
Wolfram Sang
2020-01-29 21:59:20 +01:00
parent 6810df46c4 e65e228eb0
commit 4a890148df
3 changed files with 62 additions and 36 deletions
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27
drivers/i2c/muxes/i2c-mux-pca9541.c
View File

@@ -16,6 +16,7 @@
* warranty of any kind, whether express or implied.
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/i2c.h>
@@ -42,20 +43,20 @@
#define PCA9541_CONTROL 0x01
#define PCA9541_ISTAT 0x02
#define PCA9541_CTL_MYBUS (1 << 0)
#define PCA9541_CTL_NMYBUS (1 << 1)
#define PCA9541_CTL_BUSON (1 << 2)
#define PCA9541_CTL_NBUSON (1 << 3)
#define PCA9541_CTL_BUSINIT (1 << 4)
#define PCA9541_CTL_TESTON (1 << 6)
#define PCA9541_CTL_NTESTON (1 << 7)
#define PCA9541_CTL_MYBUS BIT(0)
#define PCA9541_CTL_NMYBUS BIT(1)
#define PCA9541_CTL_BUSON BIT(2)
#define PCA9541_CTL_NBUSON BIT(3)
#define PCA9541_CTL_BUSINIT BIT(4)
#define PCA9541_CTL_TESTON BIT(6)
#define PCA9541_CTL_NTESTON BIT(7)
#define PCA9541_ISTAT_INTIN (1 << 0)
#define PCA9541_ISTAT_BUSINIT (1 << 1)
#define PCA9541_ISTAT_BUSOK (1 << 2)
#define PCA9541_ISTAT_BUSLOST (1 << 3)
#define PCA9541_ISTAT_MYTEST (1 << 6)
#define PCA9541_ISTAT_NMYTEST (1 << 7)
#define PCA9541_ISTAT_INTIN BIT(0)
#define PCA9541_ISTAT_BUSINIT BIT(1)
#define PCA9541_ISTAT_BUSOK BIT(2)
#define PCA9541_ISTAT_BUSLOST BIT(3)
#define PCA9541_ISTAT_MYTEST BIT(6)
#define PCA9541_ISTAT_NMYTEST BIT(7)
#define BUSON (PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
#define MYBUS (PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)

69
drivers/i2c/muxes/i2c-mux-pca954x.c
View File

@@ -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;
@@ -229,20 +229,23 @@ static int pca954x_reg_write(struct i2c_adapter *adap,
I2C_SMBUS_BYTE, &dummy);
}
static u8 pca954x_regval(struct pca954x *data, u8 chan)
{
/* We make switches look like muxes, not sure how to be smarter. */
if (data->chip->muxtype == pca954x_ismux)
return chan | data->chip->enable;
else
return 1 << chan;
}
static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
struct pca954x *data = i2c_mux_priv(muxc);
struct i2c_client *client = data->client;
const struct chip_desc *chip = data->chip;
u8 regval;
int ret = 0;
/* we make switches look like muxes, not sure how to be smarter */
if (chip->muxtype == pca954x_ismux)
regval = chan | chip->enable;
else
regval = 1 << chan;
regval = pca954x_regval(data, chan);
/* Only select the channel if its different from the last channel */
if (data->last_chan != regval) {
ret = pca954x_reg_write(muxc->parent, client, regval);
@@ -256,7 +259,7 @@ 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)
@@ -402,6 +405,22 @@ static void pca954x_cleanup(struct i2c_mux_core *muxc)
i2c_mux_del_adapters(muxc);
}
static int pca954x_init(struct i2c_client *client, struct pca954x *data)
{
int ret;
if (data->idle_state >= 0)
data->last_chan = pca954x_regval(data, data->idle_state);
else
data->last_chan = 0; /* Disconnect multiplexer */
ret = i2c_smbus_write_byte(client, data->last_chan);
if (ret < 0)
data->last_chan = 0;
return ret;
}
/*
* I2C init/probing/exit functions
*/
@@ -411,7 +430,6 @@ 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;
@@ -462,23 +480,24 @@ static int pca954x_probe(struct i2c_client *client,
}
}
/* Write the mux register at addr to verify
data->idle_state = MUX_IDLE_AS_IS;
if (of_property_read_u32(np, "idle-state", &data->idle_state)) {
if (np && of_property_read_bool(np, "i2c-mux-idle-disconnect"))
data->idle_state = MUX_IDLE_DISCONNECT;
}
/*
* Write the mux register at addr to verify
* that the mux is in fact present. This also
* initializes the mux to disconnected state.
* initializes the mux to a channel
* or disconnected state.
*/
if (i2c_smbus_write_byte(client, 0) < 0) {
ret = pca954x_init(client, data);
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)
goto fail_cleanup;
@@ -530,9 +549,13 @@ static int pca954x_resume(struct device *dev)
struct i2c_client *client = to_i2c_client(dev);
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
struct pca954x *data = i2c_mux_priv(muxc);
int ret;
data->last_chan = 0;
return i2c_smbus_write_byte(client, 0);
ret = pca954x_init(client, data);
if (ret < 0)
dev_err(&client->dev, "failed to verify mux presence\n");
return ret;
}
#endif