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: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Lu Cao <lucao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 8913d3d..e79884e 100644 (file)
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -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

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 4bd6b72..90b27a3 100644 (file)
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -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;
@@ -1036,8 +1137,11 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 
        platform_info = dev_get_platdata(dev);
        if (!platform_info) {
-               dev_err(&pdev->dev, "missing platform data\n");
-               return -ENODEV;
+               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);
@@ -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,