diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-isch.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-isch.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c index 4099f79c228..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) @@ -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 @@ -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) { @@ -258,7 +274,8 @@ static int 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; @@ -277,7 +294,6 @@ static int 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; } @@ -286,11 +302,8 @@ static int smbus_sch_probe(struct platform_device *dev) 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; } |