diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-isch.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-isch.c | 56 |
1 files changed, 29 insertions, 27 deletions
diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c index ddc258edb34..cf99dbf21fd 100644 --- a/drivers/i2c/busses/i2c-isch.c +++ b/drivers/i2c/busses/i2c-isch.c @@ -33,13 +33,13 @@ #include <linux/stddef.h> #include <linux/ioport.h> #include <linux/i2c.h> -#include <linux/init.h> #include <linux/io.h> #include <linux/acpi.h> /* SCH SMBus address offsets */ #define SMBHSTCNT (0 + sch_smba) #define SMBHSTSTS (1 + sch_smba) +#define SMBHSTCLK (2 + sch_smba) #define SMBHSTADD (4 + sch_smba) /* TSA */ #define SMBHSTCMD (5 + sch_smba) #define SMBHSTDAT0 (6 + sch_smba) @@ -47,7 +47,7 @@ #define SMBBLKDAT (0x20 + sch_smba) /* Other settings */ -#define MAX_TIMEOUT 500 +#define MAX_RETRIES 5000 /* I2C constants */ #define SCH_QUICK 0x00 @@ -58,6 +58,9 @@ static unsigned short sch_smba; static struct i2c_adapter sch_adapter; +static int backbone_speed = 33000; /* backbone speed in kHz */ +module_param(backbone_speed, int, S_IRUSR | S_IWUSR); +MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)"); /* * Start the i2c transaction -- the i2c_access will prepare the transaction @@ -68,7 +71,7 @@ static int sch_transaction(void) { int temp; int result = 0; - int timeout = 0; + int retries = 0; dev_dbg(&sch_adapter.dev, "Transaction (pre): CNT=%02x, CMD=%02x, " "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb(SMBHSTCNT), @@ -100,12 +103,12 @@ static int sch_transaction(void) outb(inb(SMBHSTCNT) | 0x10, SMBHSTCNT); do { - msleep(1); + usleep_range(100, 200); temp = inb(SMBHSTSTS) & 0x0f; - } while ((temp & 0x08) && (timeout++ < MAX_TIMEOUT)); + } while ((temp & 0x08) && (retries++ < MAX_RETRIES)); /* If the SMBus is still busy, we give up */ - if (timeout > MAX_TIMEOUT) { + if (retries > MAX_RETRIES) { dev_err(&sch_adapter.dev, "SMBus Timeout!\n"); result = -ETIMEDOUT; } @@ -141,7 +144,7 @@ static int sch_transaction(void) * This is the main access entry for i2c-sch access * adap is i2c_adapter pointer, addr is the i2c device bus address, read_write * (0 for read and 1 for write), size is i2c transaction type and data is the - * union of transaction for data to be transfered or data read from bus. + * union of transaction for data to be transferred or data read from bus. * return 0 for success and others for failure. */ static s32 sch_access(struct i2c_adapter *adap, u16 addr, @@ -156,6 +159,19 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr, dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp); return -EAGAIN; } + temp = inw(SMBHSTCLK); + if (!temp) { + /* + * We can't determine if we have 33 or 25 MHz clock for + * SMBus, so expect 33 MHz and calculate a bus clock of + * 100 kHz. If we actually run at 25 MHz the bus will be + * run ~75 kHz instead which should do no harm. + */ + dev_notice(&sch_adapter.dev, + "Clock divider unitialized. Setting defaults\n"); + outw(backbone_speed / (4 * 100), SMBHSTCLK); + } + dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size, (read_write)?"READ":"WRITE"); switch (size) { @@ -249,7 +265,7 @@ static struct i2c_adapter sch_adapter = { .algo = &smbus_algorithm, }; -static int __devinit smbus_sch_probe(struct platform_device *dev) +static int smbus_sch_probe(struct platform_device *dev) { struct resource *res; int retval; @@ -258,7 +274,8 @@ static int __devinit smbus_sch_probe(struct platform_device *dev) if (!res) return -EBUSY; - if (!request_region(res->start, resource_size(res), dev->name)) { + if (!devm_request_region(&dev->dev, res->start, resource_size(res), + dev->name)) { dev_err(&dev->dev, "SMBus region 0x%x already in use!\n", sch_smba); return -EBUSY; @@ -277,20 +294,16 @@ static int __devinit smbus_sch_probe(struct platform_device *dev) retval = i2c_add_adapter(&sch_adapter); if (retval) { dev_err(&dev->dev, "Couldn't register adapter!\n"); - release_region(res->start, resource_size(res)); sch_smba = 0; } return retval; } -static int __devexit smbus_sch_remove(struct platform_device *pdev) +static int smbus_sch_remove(struct platform_device *pdev) { - struct resource *res; if (sch_smba) { i2c_del_adapter(&sch_adapter); - res = platform_get_resource(pdev, IORESOURCE_IO, 0); - release_region(res->start, resource_size(res)); sch_smba = 0; } @@ -303,23 +316,12 @@ static struct platform_driver smbus_sch_driver = { .owner = THIS_MODULE, }, .probe = smbus_sch_probe, - .remove = __devexit_p(smbus_sch_remove), + .remove = smbus_sch_remove, }; -static int __init i2c_sch_init(void) -{ - return platform_driver_register(&smbus_sch_driver); -} - -static void __exit i2c_sch_exit(void) -{ - platform_driver_unregister(&smbus_sch_driver); -} +module_platform_driver(smbus_sch_driver); MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com>"); MODULE_DESCRIPTION("Intel SCH SMBus driver"); MODULE_LICENSE("GPL"); - -module_init(i2c_sch_init); -module_exit(i2c_sch_exit); MODULE_ALIAS("platform:isch_smbus"); |