spi: altera: add SPI core parameters support via platform data.

This patch introduced SPI core parameters in platform data, it
allows passing these SPI core parameters via platform data.

Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/1591845911-10197-3-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index d5fa0c5..e6e6708 100644 (file)
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -14,6 +14,7 @@
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/spi/altera.h>
 #include <linux/spi/spi.h>
 #include <linux/io.h>
 #include <linux/of.h>
@@ -40,6 +41,8 @@
 #define ALTERA_SPI_CONTROL_IE_MSK      0x100
 #define ALTERA_SPI_CONTROL_SSO_MSK     0x400
 
+#define ALTERA_SPI_MAX_CS              32
+
 struct altera_spi {
        void __iomem *base;
        int irq;
@@ -182,6 +185,7 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 
 static int altera_spi_probe(struct platform_device *pdev)
 {
+       struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
        struct altera_spi *hw;
        struct spi_master *master;
        int err = -ENODEV;
@@ -192,9 +196,24 @@ static int altera_spi_probe(struct platform_device *pdev)
 
        /* setup the master state. */
        master->bus_num = pdev->id;
-       master->num_chipselect = 16;
-       master->mode_bits = SPI_CS_HIGH;
-       master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
+
+       if (pdata) {
+               if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
+                       dev_err(&pdev->dev,
+                               "Invalid number of chipselect: %hu\n",
+                               pdata->num_chipselect);
+                       return -EINVAL;
+               }
+
+               master->num_chipselect = pdata->num_chipselect;
+               master->mode_bits = pdata->mode_bits;
+               master->bits_per_word_mask = pdata->bits_per_word_mask;
+       } else {
+               master->num_chipselect = 16;
+               master->mode_bits = SPI_CS_HIGH;
+               master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
+       }
+
        master->dev.of_node = pdev->dev.of_node;
        master->transfer_one = altera_spi_txrx;
        master->set_cs = altera_spi_set_cs;

diff --git a/include/linux/spi/altera.h b/include/linux/spi/altera.h
new file mode 100644 (file)
index 0000000..344a3fc
--- /dev/null
+++ b/include/linux/spi/altera.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header File for Altera SPI Driver.
+ */
+#ifndef __LINUX_SPI_ALTERA_H
+#define __LINUX_SPI_ALTERA_H
+
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+
+/**
+ * struct altera_spi_platform_data - Platform data of the Altera SPI driver
+ * @mode_bits:         Mode bits of SPI master.
+ * @num_chipselect:    Number of chipselects.
+ * @bits_per_word_mask:        bitmask of supported bits_per_word for transfers.
+ */
+struct altera_spi_platform_data {
+       u16                             mode_bits;
+       u16                             num_chipselect;
+       u32                             bits_per_word_mask;
+};
+
+#endif /* __LINUX_SPI_ALTERA_H */