diff options
author | Marco Aurelio da Costa <costa@gamic.com> | 2009-03-28 21:34:44 +0100 |
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committer | Jean Delvare <khali@linux-fr.org> | 2009-03-28 21:34:44 +0100 |
commit | eff9ec95efaaf6b12d230f0ea7d3c295d3bc9d57 (patch) | |
tree | 741c1ec65283018583bc2a8d5577e3ce8c201994 /drivers/i2c | |
parent | bac3e7c2aa2575a1c71f6fa643499676ca7c12c3 (diff) | |
download | lwn-eff9ec95efaaf6b12d230f0ea7d3c295d3bc9d57.tar.gz lwn-eff9ec95efaaf6b12d230f0ea7d3c295d3bc9d57.zip |
i2c-algo-pca: Add PCA9665 support
Add support for the PCA9665 I2C controller.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/algos/i2c-algo-pca.c | 180 | ||||
-rw-r--r-- | drivers/i2c/busses/Kconfig | 8 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-pca-isa.c | 14 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-pca-platform.c | 9 |
4 files changed, 185 insertions, 26 deletions
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 <icampbell@arcom.com>, " "Wolfram Sang <w.sang@pengutronix.de>"); -MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm"); +MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm"); MODULE_LICENSE("GPL"); module_param(i2c_debug, int, 0); diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 7f95905bbb9d..68650643d116 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -617,12 +617,12 @@ config I2C_ELEKTOR will be called i2c-elektor. config I2C_PCA_ISA - tristate "PCA9564 on an ISA bus" + tristate "PCA9564/PCA9665 on an ISA bus" depends on ISA select I2C_ALGOPCA default n help - This driver supports ISA boards using the Philips PCA9564 + This driver supports ISA boards using the Philips PCA9564/PCA9665 parallel bus to I2C bus controller. This driver can also be built as a module. If so, the module @@ -634,11 +634,11 @@ config I2C_PCA_ISA time). If unsure, say N. config I2C_PCA_PLATFORM - tristate "PCA9564 as platform device" + tristate "PCA9564/PCA9665 as platform device" select I2C_ALGOPCA default n help - This driver supports a memory mapped Philips PCA9564 + This driver supports a memory mapped Philips PCA9564/PCA9665 parallel bus to I2C bus controller. This driver can also be built as a module. If so, the module diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c index c420a7c0f3e4..0cc8017b3f64 100644 --- a/drivers/i2c/busses/i2c-pca-isa.c +++ b/drivers/i2c/busses/i2c-pca-isa.c @@ -41,7 +41,7 @@ static int irq = -1; /* Data sheet recommends 59kHz for 100kHz operation due to variation * in the actual clock rate */ -static int clock = I2C_PCA_CON_59kHz; +static int clock = 59000; static wait_queue_head_t pca_wait; @@ -103,7 +103,7 @@ static struct i2c_algo_pca_data pca_isa_data = { static struct i2c_adapter pca_isa_ops = { .owner = THIS_MODULE, .algo_data = &pca_isa_data, - .name = "PCA9564 ISA Adapter", + .name = "PCA9564/PCA9665 ISA Adapter", .timeout = 100, }; @@ -196,7 +196,7 @@ static void __exit pca_isa_exit(void) } MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>"); -MODULE_DESCRIPTION("ISA base PCA9564 driver"); +MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver"); MODULE_LICENSE("GPL"); module_param(base, ulong, 0); @@ -205,7 +205,13 @@ MODULE_PARM_DESC(base, "I/O base address"); module_param(irq, int, 0); MODULE_PARM_DESC(irq, "IRQ"); module_param(clock, int, 0); -MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet"); +MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t" + "For PCA9564: 330000,288000,217000,146000," + "88000,59000,44000,36000\n" + "\t\tFor PCA9665:\tStandard: 60300 - 100099\n" + "\t\t\t\tFast: 100100 - 400099\n" + "\t\t\t\tFast+: 400100 - 10000099\n" + "\t\t\t\tTurbo: Up to 1265800"); module_init(pca_isa_init); module_exit(pca_isa_exit); diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c index 6bb15ad0a6b6..51d179bbddf9 100644 --- a/drivers/i2c/busses/i2c-pca-platform.c +++ b/drivers/i2c/busses/i2c-pca-platform.c @@ -172,8 +172,9 @@ static int __devinit i2c_pca_pf_probe(struct platform_device *pdev) i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0; i2c->adap.owner = THIS_MODULE; - snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx", - (unsigned long) res->start); + snprintf(i2c->adap.name, sizeof(i2c->adap.name), + "PCA9564/PCA9665 at 0x%08lx", + (unsigned long) res->start); i2c->adap.algo_data = &i2c->algo_data; i2c->adap.dev.parent = &pdev->dev; i2c->adap.timeout = platform_data->timeout; @@ -246,7 +247,7 @@ e_remap: e_alloc: release_mem_region(res->start, res_len(res)); e_print: - printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret); + printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); return ret; } @@ -290,7 +291,7 @@ static void __exit i2c_pca_pf_exit(void) } MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); -MODULE_DESCRIPTION("I2C-PCA9564 platform driver"); +MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); MODULE_LICENSE("GPL"); module_init(i2c_pca_pf_init); |