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Commit a3496855 authored by Mika Westerberg's avatar Mika Westerberg Committed by Mark Brown
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spi/pxa2xx: add support for Lynxpoint SPI controllers 



Intel Lynxpoint PCH Low Power Subsystem has two general purpose SPI
controllers that are LPSS_SSP compatible. These controllers are enumerated
from ACPI namespace with ACPI IDs INT33C0 and INT33C1.

Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: default avatarLu Cao <lucao@marvell.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent a0d2642e

drivers/spi/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -310,7 +310,7 @@ config SPI_PXA2XX_DMA 


config SPI_PXA2XX

	tristate "PXA2xx SSP SPI master"

	depends on ARCH_PXA || PCI

	depends on ARCH_PXA || PCI || ACPI

	select PXA_SSP if ARCH_PXA

	help

	  This enables using a PXA2xx or Sodaville SSP port as a SPI master

drivers/spi/spi-pxa2xx.c

+108 −2
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <linux/slab.h>

#include <linux/clk.h>

#include <linux/pm_runtime.h>

#include <linux/acpi.h>



#include <asm/io.h>

#include <asm/irq.h>
@@ -933,6 +934,13 @@ static int setup(struct spi_device *spi) 
		chip->dma_threshold = 0;

		if (chip_info->enable_loopback)

			chip->cr1 = SSCR1_LBM;

	} else if (ACPI_HANDLE(&spi->dev)) {

		/*

		 * Slave devices enumerated from ACPI namespace don't

		 * usually have chip_info but we still might want to use

		 * DMA with them.

		 */

		chip->enable_dma = drv_data->master_info->enable_dma;

	}



	chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
@@ -1025,6 +1033,99 @@ static void cleanup(struct spi_device *spi) 
	kfree(chip);

}



#ifdef CONFIG_ACPI

static int pxa2xx_spi_acpi_add_dma(struct acpi_resource *res, void *data)

{

	struct pxa2xx_spi_master *pdata = data;



	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {

		const struct acpi_resource_fixed_dma *dma;



		dma = &res->data.fixed_dma;

		if (pdata->tx_slave_id < 0) {

			pdata->tx_slave_id = dma->request_lines;

			pdata->tx_chan_id = dma->channels;

		} else if (pdata->rx_slave_id < 0) {

			pdata->rx_slave_id = dma->request_lines;

			pdata->rx_chan_id = dma->channels;

		}

	}



	/* Tell the ACPI core to skip this resource */

	return 1;

}



static struct pxa2xx_spi_master *

pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)

{

	struct pxa2xx_spi_master *pdata;

	struct list_head resource_list;

	struct acpi_device *adev;

	struct ssp_device *ssp;

	struct resource *res;

	int devid;



	if (!ACPI_HANDLE(&pdev->dev) ||

	    acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))

		return NULL;



	pdata = devm_kzalloc(&pdev->dev, sizeof(*ssp), GFP_KERNEL);

	if (!pdata) {

		dev_err(&pdev->dev,

			"failed to allocate memory for platform data\n");

		return NULL;

	}



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res)

		return NULL;



	ssp = &pdata->ssp;



	ssp->phys_base = res->start;

	ssp->mmio_base = devm_request_and_ioremap(&pdev->dev, res);

	if (!ssp->mmio_base) {

		dev_err(&pdev->dev, "failed to ioremap mmio_base\n");

		return NULL;

	}



	ssp->clk = devm_clk_get(&pdev->dev, NULL);

	ssp->irq = platform_get_irq(pdev, 0);

	ssp->type = LPSS_SSP;

	ssp->pdev = pdev;



	ssp->port_id = -1;

	if (adev->pnp.unique_id && !kstrtoint(adev->pnp.unique_id, 0, &devid))

		ssp->port_id = devid;



	pdata->num_chipselect = 1;

	pdata->rx_slave_id = -1;

	pdata->tx_slave_id = -1;



	INIT_LIST_HEAD(&resource_list);

	acpi_dev_get_resources(adev, &resource_list, pxa2xx_spi_acpi_add_dma,

			       pdata);

	acpi_dev_free_resource_list(&resource_list);



	pdata->enable_dma = pdata->rx_slave_id >= 0 && pdata->tx_slave_id >= 0;



	return pdata;

}



static struct acpi_device_id pxa2xx_spi_acpi_match[] = {

	{ "INT33C0", 0 },

	{ "INT33C1", 0 },

	{ },

};

MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);

#else

static inline struct pxa2xx_spi_master *

pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)

{

	return NULL;

}

#endif



static int pxa2xx_spi_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -1035,10 +1136,13 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) 
	int status;



	platform_info = dev_get_platdata(dev);

	if (!platform_info) {

		platform_info = pxa2xx_spi_acpi_get_pdata(pdev);

		if (!platform_info) {

			dev_err(&pdev->dev, "missing platform data\n");

			return -ENODEV;

		}

	}



	ssp = pxa_ssp_request(pdev->id, pdev->name);

	if (!ssp)
@@ -1064,6 +1168,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) 


	master->dev.parent = &pdev->dev;

	master->dev.of_node = pdev->dev.of_node;

	ACPI_HANDLE_SET(&master->dev, ACPI_HANDLE(&pdev->dev));

	/* the spi->mode bits understood by this driver: */

	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
@@ -1272,6 +1377,7 @@ static struct platform_driver driver = { 
		.name	= "pxa2xx-spi",

		.owner	= THIS_MODULE,

		.pm	= &pxa2xx_spi_pm_ops,

		.acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),

	},

	.probe = pxa2xx_spi_probe,

	.remove = pxa2xx_spi_remove,