On Mon, Jul 08, 2013 at 02:45:27PM +0300, Mika Westerberg wrote: > Some Intel LPSS I2C devices make the *CNT values available from ACPI > namespace in similar way than the SDA hold value. These values allow > platform/BIOS to specify the most accurate *CNT values for the device > driver to use. > > So change the ACPI part of the driver to use these values if they exists > and otherwise use the default method based solely on the input clock speed. > > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > --- > This applies on top of following patch which is not yet in i2c tree: > > http://permalink.gmane.org/gmane.linux.drivers.i2c/15754 > > drivers/i2c/busses/i2c-designware-platdrv.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index c7cfdac..a1488df 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -59,7 +59,6 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) > struct dw_i2c_dev *dev = platform_get_drvdata(pdev); > struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; > acpi_handle handle = ACPI_HANDLE(&pdev->dev); > - acpi_string name; > > if (!handle) > return -ENODEV; > @@ -68,14 +67,32 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) > dev->tx_fifo_depth = 32; > dev->rx_fifo_depth = 32; > > - name = dev->master_cfg & DW_IC_CON_SPEED_FAST ? "FMCN" : "SSCN"; > - if (ACPI_SUCCESS(acpi_evaluate_object(handle, name, NULL, &buf))) { > + /* Standard speed configuration */ > + if (ACPI_SUCCESS(acpi_evaluate_object(handle, "SSCN", NULL, &buf))) { > union acpi_object *obj = (union acpi_object *)buf.pointer; > > if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { > const union acpi_object *objs = obj->package.elements; > > - dev->sda_hold_time = (u32)objs[2].integer.value; > + dev->ss_hcnt = (u16)objs[0].integer.value; > + dev->ss_lcnt = (u16)objs[1].integer.value; > + if (!(dev->master_cfg & DW_IC_CON_SPEED_FAST)) > + dev->sda_hold_time = (u32)objs[2].integer.value; > + } > + > + kfree(buf.pointer); > + } > + /* Fast speed configuration */ > + if (ACPI_SUCCESS(acpi_evaluate_object(handle, "FMCN", NULL, &buf))) { There is a problem with the above as it reuses buf from the previous call. I'll post a new revision of the patches with this fixed. > + union acpi_object *obj = (union acpi_object *)buf.pointer; > + > + if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { > + const union acpi_object *objs = obj->package.elements; > + > + dev->fs_hcnt = (u16)objs[0].integer.value; > + dev->fs_lcnt = (u16)objs[1].integer.value; > + if (dev->master_cfg & DW_IC_CON_SPEED_FAST) > + dev->sda_hold_time = (u32)objs[2].integer.value; > } > > kfree(buf.pointer); > -- > 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
