From a76e7c6821b5dddf69db9d76ec282819545f5b73 Mon Sep 17 00:00:00 2001 From: Thomas Kavanagh Date: Thu, 20 Sep 2012 20:20:46 -0700 Subject: [PATCH] i2c: algo: pca: Fix chip reset function for PCA9665 The parameter passed to pca9665_reset is adap->data (which is bus driver specific), not i2c_algp_pca_data *adap. pca9665_reset expects it to be i2c_algp_pca_data *adap. All other wrappers from the algo call back to the bus driver, which knows to handle its custom data. Only pca9665_reset resides inside the algorithm code and does not know how to handle a custom data structure. This can result in a kernel crash. Fix by re-factoring pca_reset() from a macro to a function handling chip specific code, and only call adap->reset_chip() if the chip is not PCA9665. Signed-off-by: Thomas Kavanagh Signed-off-by: Guenter Roeck Signed-off-by: Wolfram Sang --- drivers/i2c/algos/i2c-algo-pca.c | 27 ++++++++++++++------------- include/linux/i2c-algo-pca.h | 1 + 2 files changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c index 73133b1063f..07ccbef6cc1 100644 --- a/drivers/i2c/algos/i2c-algo-pca.c +++ b/drivers/i2c/algos/i2c-algo-pca.c @@ -46,14 +46,19 @@ static int i2c_debug; #define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val) #define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON) #define pca_wait(adap) adap->wait_for_completion(adap->data) -#define pca_reset(adap) adap->reset_chip(adap->data) -static void pca9665_reset(void *pd) +static void pca_reset(struct i2c_algo_pca_data *adap) { - struct i2c_algo_pca_data *adap = pd; - pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET); - pca_outw(adap, I2C_PCA_IND, 0xA5); - pca_outw(adap, I2C_PCA_IND, 0x5A); + if (adap->chip == I2C_PCA_CHIP_9665) { + /* Ignore the reset function from the module, + * we can use the parallel bus reset. + */ + pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET); + pca_outw(adap, I2C_PCA_IND, 0xA5); + pca_outw(adap, I2C_PCA_IND, 0x5A); + } else { + adap->reset_chip(adap->data); + } } /* @@ -378,11 +383,12 @@ static unsigned int pca_probe_chip(struct i2c_adapter *adap) pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR); if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) { printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name); - return I2C_PCA_CHIP_9665; + pca_data->chip = I2C_PCA_CHIP_9665; } else { printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name); - return I2C_PCA_CHIP_9564; + pca_data->chip = I2C_PCA_CHIP_9564; } + return pca_data->chip; } static int pca_init(struct i2c_adapter *adap) @@ -456,11 +462,6 @@ static int pca_init(struct i2c_adapter *adap) */ int raise_fall_time; - /* Ignore the reset function from the module, - * we can use the parallel bus reset - */ - pca_data->reset_chip = pca9665_reset; - if (pca_data->i2c_clock > 1265800) { printk(KERN_WARNING "%s: I2C clock speed too high." " Using 1265.8kHz.\n", adap->name); diff --git a/include/linux/i2c-algo-pca.h b/include/linux/i2c-algo-pca.h index 1364d62e2fb..a3c3ecd59f0 100644 --- a/include/linux/i2c-algo-pca.h +++ b/include/linux/i2c-algo-pca.h @@ -62,6 +62,7 @@ struct i2c_algo_pca_data { * 330000, 288000, 217000, 146000, 88000, 59000, 44000, 36000 * For PCA9665, use the frequency you want here. */ unsigned int i2c_clock; + unsigned int chip; }; int i2c_pca_add_bus(struct i2c_adapter *); -- 2.41.0