Before this commit the i2c-designware-platdrv assumes that if the pdev has an apci-companion it should use a dynamic adapter-nr and otherwise it will use pdev->id as adapter-nr.
On some devices e.g. the Apollo Lake using Acer TravelMate Spin B118, some of the LPSS i2c-adapters are enumerated through PCI and do not have an ACPI fwnode. These devices are handled as mfd devices so they end up using the i2c-designware-platdrv driver. This results in the i2c-adapter being registered with the mfd generated pdev->id as adapter-nr, which conflicts with existing adapters, triggering a WARN(id < 0, "couldn't get idr") in i2c-core-base.c and causing the adapter registration to fail. This commit adds support for setting a "linux,use-dynamic-adapter-nr" device property on the device to make i2c-designware-platdrv use dynamic adapter-nrs on devices without an ACPI fwnode, together with changes to drivers/mfd/intel-lpss-pci.c to set this, this fixes the WARN. Before this commit the setting of the adapter.nr was somewhat convoluted, in the acpi_companion case it was set from dw_i2c_acpi_configure, in the non acpi_companion case it was set from dw_i2c_set_fifo_size() based on tx_fifo_depth not being set yet. This commit also cleans this up. Note the "linux,use-dynamic-adapter-nr" is meant for kernel internal use only, therefor it is NOT documented under Documents/devicetree/bindings. BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1687065 Signed-off-by: Hans de Goede <hdego...@redhat.com> --- drivers/i2c/busses/i2c-designware-platdrv.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index ead5e7de3e4d..9f28159efdb2 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -86,7 +86,6 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) struct i2c_timings *t = &dev->timings; u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; - dev->adapter.nr = -1; dev->tx_fifo_depth = 32; dev->rx_fifo_depth = 32; @@ -219,7 +218,7 @@ static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) dev->mode = DW_IC_SLAVE; } -static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) +static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev) { u32 param, tx_fifo_depth, rx_fifo_depth; @@ -233,7 +232,6 @@ static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) if (!dev->tx_fifo_depth) { dev->tx_fifo_depth = tx_fifo_depth; dev->rx_fifo_depth = rx_fifo_depth; - dev->adapter.nr = id; } else if (tx_fifo_depth >= 2) { dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, tx_fifo_depth); @@ -324,6 +322,13 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) if (has_acpi_companion(&pdev->dev)) dw_i2c_acpi_configure(pdev); + if (has_acpi_companion(&pdev->dev) || + device_property_read_bool(&pdev->dev, + "linux,use-dynamic-adapter-nr")) + dev->adapter.nr = -1; + else + dev->adapter.nr = pdev->id; + /* * Only standard mode at 100kHz, fast mode at 400kHz, * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. @@ -358,7 +363,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000); } - dw_i2c_set_fifo_size(dev, pdev->id); + dw_i2c_set_fifo_size(dev); adap = &dev->adapter; adap->owner = THIS_MODULE; -- 2.20.1
