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path: root/drivers/spi/spi-dw-mmio.c
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Diffstat (limited to 'drivers/spi/spi-dw-mmio.c')
-rw-r--r--drivers/spi/spi-dw-mmio.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index d25cc4037e23..e80f60ed6fdf 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -15,11 +15,13 @@
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/scatterlist.h>
+#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/property.h>
+#include <linux/regmap.h>
#include "spi-dw.h"
@@ -28,10 +30,90 @@
struct dw_spi_mmio {
struct dw_spi dws;
struct clk *clk;
+ void *priv;
};
+#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
+#define OCELOT_IF_SI_OWNER_MASK GENMASK(5, 4)
+#define OCELOT_IF_SI_OWNER_OFFSET 4
+#define MSCC_IF_SI_OWNER_SISL 0
+#define MSCC_IF_SI_OWNER_SIBM 1
+#define MSCC_IF_SI_OWNER_SIMC 2
+
+#define MSCC_SPI_MST_SW_MODE 0x14
+#define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13)
+#define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5)
+
+struct dw_spi_mscc {
+ struct regmap *syscon;
+ void __iomem *spi_mst;
+};
+
+/*
+ * The Designware SPI controller (referred to as master in the documentation)
+ * automatically deasserts chip select when the tx fifo is empty. The chip
+ * selects then needs to be either driven as GPIOs or, for the first 4 using the
+ * the SPI boot controller registers. the final chip select is an OR gate
+ * between the Designware SPI controller and the SPI boot controller.
+ */
+static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
+{
+ struct dw_spi *dws = spi_master_get_devdata(spi->master);
+ struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
+ struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
+ u32 cs = spi->chip_select;
+
+ if (cs < 4) {
+ u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;
+
+ if (!enable)
+ sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));
+
+ writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
+ }
+
+ dw_spi_set_cs(spi, enable);
+}
+
+static int dw_spi_mscc_init(struct platform_device *pdev,
+ struct dw_spi_mmio *dwsmmio)
+{
+ struct dw_spi_mscc *dwsmscc;
+ struct resource *res;
+
+ dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
+ if (!dwsmscc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ dwsmscc->spi_mst = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(dwsmscc->spi_mst)) {
+ dev_err(&pdev->dev, "SPI_MST region map failed\n");
+ return PTR_ERR(dwsmscc->spi_mst);
+ }
+
+ dwsmscc->syscon = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon");
+ if (IS_ERR(dwsmscc->syscon))
+ return PTR_ERR(dwsmscc->syscon);
+
+ /* Deassert all CS */
+ writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
+
+ /* Select the owner of the SI interface */
+ regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
+ OCELOT_IF_SI_OWNER_MASK,
+ MSCC_IF_SI_OWNER_SIMC << OCELOT_IF_SI_OWNER_OFFSET);
+
+ dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
+ dwsmmio->priv = dwsmscc;
+
+ return 0;
+}
+
static int dw_spi_mmio_probe(struct platform_device *pdev)
{
+ int (*init_func)(struct platform_device *pdev,
+ struct dw_spi_mmio *dwsmmio);
struct dw_spi_mmio *dwsmmio;
struct dw_spi *dws;
struct resource *mem;
@@ -99,6 +181,13 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
}
}
+ init_func = device_get_match_data(&pdev->dev);
+ if (init_func) {
+ ret = init_func(pdev, dwsmmio);
+ if (ret)
+ goto out;
+ }
+
ret = dw_spi_add_host(&pdev->dev, dws);
if (ret)
goto out;
@@ -123,6 +212,7 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
static const struct of_device_id dw_spi_mmio_of_match[] = {
{ .compatible = "snps,dw-apb-ssi", },
+ { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_init},
{ /* end of table */}
};
MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);