diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c index 710fbef9a9c2..384af88e58ad 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 75f07138a6fa..dfcf04e1967f 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 2591c21b2b5d..26a23abc053d 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 d03071732db4..7c522fdd9ea7 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 *);