Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Mika Westerberg <> | Subject | [PATCH 2/4] spi: pxa2xx: Translate ACPI DeviceSelection to Linux chip select on Baytrail | Date | Tue, 26 Jan 2016 13:18:29 +0200 |
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The Windows Baytrail SPI host controller driver uses 1 as the first (and only) value for ACPI DeviceSelection like can be seen in DSDT taken from Lenovo Thinkpad 10:
Device (FPNT) { ... Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings { Name (UBUF, ResourceTemplate () { SpiSerialBus (0x0001, // DeviceSelection PolarityLow, FourWireMode, 0x08, ControllerInitiated, 0x007A1200, ClockPolarityLow, ClockPhaseFirst, "\\_SB.SPI1", 0x00, ResourceConsumer,,)
This will fail to enumerate in Linux with following error:
[ 0.241296] pxa2xx-spi 80860F0E:00: cs1 >= max 1 [ 0.241312] spi_master spi32766: failed to add SPI device VFSI6101:00 from ACPI
To make the Linux SPI core successfully enumerate the device we provide a custom version of ->fw_translate_cs() that translates DeviceSelection correctly.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- drivers/spi/spi-pxa2xx.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index ab9914ad8365..baa98365a490 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1328,11 +1328,30 @@ static int pxa2xx_spi_get_port_id(struct acpi_device *adev) port_id = devid; return port_id; } + +static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs) +{ + struct driver_data *drv_data = spi_master_get_devdata(master); + + switch (drv_data->ssp_type) { + /* + * For Atoms the Windows driver starts enumerating chip selects + * from 1 instead of 0 so translate it here to match what Linux + * expects. + */ + case LPSS_BYT_SSP: + return cs - 1; + + default: + return cs; + } +} #else /* !CONFIG_ACPI */ static int pxa2xx_spi_get_port_id(struct acpi_device *adev) { return -1; } +#define pxa2xx_spi_fw_translate_cs NULL #endif /* @@ -1490,6 +1509,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) master->setup = setup; master->transfer_one_message = pxa2xx_spi_transfer_one_message; master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer; + master->fw_translate_cs = pxa2xx_spi_fw_translate_cs; master->auto_runtime_pm = true; drv_data->ssp_type = ssp->type; -- 2.7.0.rc3
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