Commit 0c27d9cf authored Feb 08, 2016 by Mika Westerberg Committed by Mark Brown Feb 09, 2016

spi: pxa2xx: Translate ACPI DeviceSelection to Linux chip select on Baytrail



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>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent fcdcc796

drivers/spi/spi-pxa2xx.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -1445,6 +1445,28 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev)
		}
		#endif

		static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs)
		{
		struct driver_data *drv_data = spi_master_get_devdata(master);

		if (has_acpi_companion(&drv_data->pdev->dev)) {
		switch (drv_data->ssp_type) {
		/*
		* For Atoms the ACPI DeviceSelection used by the Windows
		* driver starts from 1 instead of 0 so translate it here
		* to match what Linux expects.
		*/
		case LPSS_BYT_SSP:
		return cs - 1;

		default:
		break;
		}
		}

		return cs;
		}

		static int pxa2xx_spi_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		@@ -1497,6 +1519,7 @@ 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;

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