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path: root/drivers/i2c/algos/i2c-algo-pca.c
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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pca.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-pca.c35
1 files changed, 23 insertions, 12 deletions
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 */