diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index 710fbef9a9c2099f50a6d44a6ff583f4ae10cf43..384af88e58adaeb99cce13cb7f21cef812607280 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -41,8 +41,22 @@ static void pca_reset(struct i2c_algo_pca_data *adap)
pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
pca_outw(adap, I2C_PCA_IND, 0xA5);
pca_outw(adap, I2C_PCA_IND, 0x5A);
+
+ /*
+ * After a reset we need to re-apply any configuration
+ * (calculated in pca_init) to get the bus in a working state.
+ */
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IMODE);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.mode);
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.tlow);
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.thi);
+
+ pca_set_con(adap, I2C_PCA_CON_ENSIO);
} else {
adap->reset_chip(adap->data);
+ pca_set_con(adap, I2C_PCA_CON_ENSIO | adap->bus_settings.clock_freq);
}
}
@@ -423,13 +437,14 @@ static int pca_init(struct i2c_adapter *adap)
" Use the nominal frequency.\n", adap->name);
}
- pca_reset(pca_data);
-
clock = pca_clock(pca_data);
printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
adap->name, freqs[clock]);
- pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+ /* Store settings as these will be needed when the PCA chip is reset */
+ pca_data->bus_settings.clock_freq = clock;
+
+ pca_reset(pca_data);
} else {
int clock;
int mode;
@@ -496,19 +511,15 @@ static int pca_init(struct i2c_adapter *adap)
thi = tlow * min_thi / min_tlow;
}
+ /* Store settings as these will be needed when the PCA chip is reset */
+ pca_data->bus_settings.mode = mode;
+ pca_data->bus_settings.tlow = tlow;
+ pca_data->bus_settings.thi = thi;
+
pca_reset(pca_data);
printk(KERN_INFO
"%s: Clock frequency is %dHz\n", adap->name, clock * 100);
-
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
- pca_outw(pca_data, I2C_PCA_IND, mode);
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
- pca_outw(pca_data, I2C_PCA_IND, tlow);
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
- pca_outw(pca_data, I2C_PCA_IND, thi);
-
- pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
}
udelay(500); /* 500 us for oscillator to stabilise */
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 75f07138a6fa25d19463c659dc3c7e886daf4dee..dfcf04e1967f1743db35b82a7c62532a1d57ac36 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2093,8 +2093,12 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
}
}
- /* Adaptive TimeOut: astimated time in usec + 100% margin */
- timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite);
+ /*
+ * Adaptive TimeOut: estimated time in usec + 100% margin:
+ * 2: double the timeout for clock stretching case
+ * 9: bits per transaction (including the ack/nack)
+ */
+ timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec));
if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 2591c21b2b5d84667a8e8a6a03bee4c109721ace..26a23abc053d2cc6ec761b6c37f74a4999ff9cdf 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -692,10 +692,6 @@ static int at24_probe(struct i2c_client *client)
nvmem_config.word_size = 1;
nvmem_config.size = byte_len;
- at24->nvmem = devm_nvmem_register(dev, &nvmem_config);
- if (IS_ERR(at24->nvmem))
- return PTR_ERR(at24->nvmem);
-
i2c_set_clientdata(client, at24);
err = regulator_enable(at24->vcc_reg);
@@ -708,6 +704,13 @@ static int at24_probe(struct i2c_client *client)
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
+ at24->nvmem = devm_nvmem_register(dev, &nvmem_config);
+ if (IS_ERR(at24->nvmem)) {
+ pm_runtime_disable(dev);
+ regulator_disable(at24->vcc_reg);
+ return PTR_ERR(at24->nvmem);
+ }
+
/*
* Perform a one-byte test read to verify that the
* chip is functional.
diff --git a/include/linux/i2c-algo-pca.h b/include/linux/i2c-algo-pca.h
index d03071732db4add88eadef01988c6585b23b5955..7c522fdd9ea735280a2cd04ada1507e766967ff6 100644
--- a/include/linux/i2c-algo-pca.h
+++ b/include/linux/i2c-algo-pca.h
@@ -53,6 +53,20 @@
#define I2C_PCA_CON_SI 0x08 /* Serial Interrupt */
#define I2C_PCA_CON_CR 0x07 /* Clock Rate (MASK) */
+/**
+ * struct pca_i2c_bus_settings - The configured PCA i2c bus settings
+ * @mode: Configured i2c bus mode
+ * @tlow: Configured SCL LOW period
+ * @thi: Configured SCL HIGH period
+ * @clock_freq: The configured clock frequency
+ */
+struct pca_i2c_bus_settings {
+ int mode;
+ int tlow;
+ int thi;
+ int clock_freq;
+};
+
struct i2c_algo_pca_data {
void *data; /* private low level data */
void (*write_byte) (void *data, int reg, int val);
@@ -64,6 +78,7 @@ struct i2c_algo_pca_data {
* For PCA9665, use the frequency you want here. */
unsigned int i2c_clock;
unsigned int chip;
+ struct pca_i2c_bus_settings bus_settings;
};
int i2c_pca_add_bus(struct i2c_adapter *);