From eff9ec95efaaf6b12d230f0ea7d3c295d3bc9d57 Mon Sep 17 00:00:00 2001 From: Marco Aurelio da Costa Date: Sat, 28 Mar 2009 21:34:44 +0100 Subject: i2c-algo-pca: Add PCA9665 support Add support for the PCA9665 I2C controller. Signed-off-by: Wolfram Sang Signed-off-by: Jean Delvare --- drivers/i2c/algos/i2c-algo-pca.c | 180 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 166 insertions(+), 14 deletions(-) (limited to 'drivers/i2c/algos') diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c index 943d70ee5d59..a8e51bd1a4f5 100644 --- a/drivers/i2c/algos/i2c-algo-pca.c +++ b/drivers/i2c/algos/i2c-algo-pca.c @@ -46,6 +46,14 @@ static int i2c_debug; #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) +{ + 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); +} + /* * Generate a start condition on the i2c bus. * @@ -333,27 +341,171 @@ static const struct i2c_algorithm pca_algo = { .functionality = pca_func, }; -static int pca_init(struct i2c_adapter *adap) +static unsigned int pca_probe_chip(struct i2c_adapter *adap) { - static int freqs[] = {330,288,217,146,88,59,44,36}; - int clock; struct i2c_algo_pca_data *pca_data = adap->algo_data; - - if (pca_data->i2c_clock > 7) { - printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n", - adap->name); - pca_data->i2c_clock = I2C_PCA_CON_59kHz; + /* The trick here is to check if there is an indirect register + * available. If there is one, we will read the value we first + * wrote on I2C_PCA_IADR. Otherwise, we will read the last value + * we wrote on I2C_PCA_ADR + */ + pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR); + pca_outw(pca_data, I2C_PCA_IND, 0xAA); + pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO); + pca_outw(pca_data, I2C_PCA_IND, 0x00); + 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; + } else { + printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name); + return I2C_PCA_CHIP_9564; } +} + +static int pca_init(struct i2c_adapter *adap) +{ + struct i2c_algo_pca_data *pca_data = adap->algo_data; adap->algo = &pca_algo; - pca_reset(pca_data); + if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) { + static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36}; + int clock; + + if (pca_data->i2c_clock > 7) { + switch (pca_data->i2c_clock) { + case 330000: + pca_data->i2c_clock = I2C_PCA_CON_330kHz; + break; + case 288000: + pca_data->i2c_clock = I2C_PCA_CON_288kHz; + break; + case 217000: + pca_data->i2c_clock = I2C_PCA_CON_217kHz; + break; + case 146000: + pca_data->i2c_clock = I2C_PCA_CON_146kHz; + break; + case 88000: + pca_data->i2c_clock = I2C_PCA_CON_88kHz; + break; + case 59000: + pca_data->i2c_clock = I2C_PCA_CON_59kHz; + break; + case 44000: + pca_data->i2c_clock = I2C_PCA_CON_44kHz; + break; + case 36000: + pca_data->i2c_clock = I2C_PCA_CON_36kHz; + break; + default: + printk(KERN_WARNING + "%s: Invalid I2C clock speed selected." + " Using default 59kHz.\n", adap->name); + pca_data->i2c_clock = I2C_PCA_CON_59kHz; + } + } else { + printk(KERN_WARNING "%s: " + "Choosing the clock frequency based on " + "index is deprecated." + " 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); + } else { + int clock; + int mode; + int tlow, thi; + /* Values can be found on PCA9665 datasheet section 7.3.2.6 */ + int min_tlow, min_thi; + /* These values are the maximum raise and fall values allowed + * by the I2C operation mode (Standard, Fast or Fast+) + * They are used (added) below to calculate the clock dividers + * of PCA9665. Note that they are slightly different of the + * real maximum, to allow the change on mode exactly on the + * maximum clock rate for each mode + */ + int raise_fall_time; + + struct i2c_algo_pca_data *pca_data = adap->algo_data; + + /* 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); + pca_data->i2c_clock = 1265800; + } + + if (pca_data->i2c_clock < 60300) { + printk(KERN_WARNING "%s: I2C clock speed too low." + " Using 60.3kHz.\n", adap->name); + pca_data->i2c_clock = 60300; + } + + /* To avoid integer overflow, use clock/100 for calculations */ + clock = pca_clock(pca_data) / 100; + + if (pca_data->i2c_clock > 10000) { + mode = I2C_PCA_MODE_TURBO; + min_tlow = 14; + min_thi = 5; + raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */ + } else if (pca_data->i2c_clock > 4000) { + mode = I2C_PCA_MODE_FASTP; + min_tlow = 17; + min_thi = 9; + raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */ + } else if (pca_data->i2c_clock > 1000) { + mode = I2C_PCA_MODE_FAST; + min_tlow = 44; + min_thi = 20; + raise_fall_time = 58; /* Raise 29e-8s, Fall 29e-8s */ + } else { + mode = I2C_PCA_MODE_STD; + min_tlow = 157; + min_thi = 134; + raise_fall_time = 127; /* Raise 29e-8s, Fall 98e-8s */ + } + + /* The minimum clock that respects the thi/tlow = 134/157 is + * 64800 Hz. Below that, we have to fix the tlow to 255 and + * calculate the thi factor. + */ + if (clock < 648) { + tlow = 255; + thi = 1000000 - clock * raise_fall_time; + thi /= (I2C_PCA_OSC_PER * clock) - tlow; + } else { + tlow = (1000000 - clock * raise_fall_time) * min_tlow; + tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow); + thi = tlow * min_thi / min_tlow; + } + + pca_reset(pca_data); - clock = pca_clock(pca_data); - printk(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, - freqs[clock]); + printk(KERN_INFO + "%s: Clock frequency is %dHz\n", adap->name, clock * 100); - pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock); + 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 oscilator to stabilise */ return 0; @@ -388,7 +540,7 @@ EXPORT_SYMBOL(i2c_pca_add_numbered_bus); MODULE_AUTHOR("Ian Campbell , " "Wolfram Sang "); -MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm"); +MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm"); MODULE_LICENSE("GPL"); module_param(i2c_debug, int, 0); -- cgit v1.2.3