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path: root/drivers/spi/spi-altera-dfl.c
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Diffstat (limited to 'drivers/spi/spi-altera-dfl.c')
-rw-r--r--drivers/spi/spi-altera-dfl.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/spi/spi-altera-dfl.c b/drivers/spi/spi-altera-dfl.c
new file mode 100644
index 000000000000..3e32e4fe5895
--- /dev/null
+++ b/drivers/spi/spi-altera-dfl.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// DFL bus driver for Altera SPI Master
+//
+// Copyright (C) 2020 Intel Corporation, Inc.
+//
+// Authors:
+// Matthew Gerlach <matthew.gerlach@linux.intel.com>
+//
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/bitfield.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/altera.h>
+#include <linux/dfl.h>
+
+#define FME_FEATURE_ID_MAX10_SPI 0xe
+#define FME_FEATURE_REV_MAX10_SPI_N5010 0x1
+
+#define SPI_CORE_PARAMETER 0x8
+#define SHIFT_MODE BIT_ULL(1)
+#define SHIFT_MODE_MSB 0
+#define SHIFT_MODE_LSB 1
+#define DATA_WIDTH GENMASK_ULL(7, 2)
+#define NUM_CHIPSELECT GENMASK_ULL(13, 8)
+#define CLK_POLARITY BIT_ULL(14)
+#define CLK_PHASE BIT_ULL(15)
+#define PERIPHERAL_ID GENMASK_ULL(47, 32)
+#define SPI_CLK GENMASK_ULL(31, 22)
+#define SPI_INDIRECT_ACC_OFST 0x10
+
+#define INDIRECT_ADDR (SPI_INDIRECT_ACC_OFST+0x0)
+#define INDIRECT_WR BIT_ULL(8)
+#define INDIRECT_RD BIT_ULL(9)
+#define INDIRECT_RD_DATA (SPI_INDIRECT_ACC_OFST+0x8)
+#define INDIRECT_DATA_MASK GENMASK_ULL(31, 0)
+#define INDIRECT_DEBUG BIT_ULL(32)
+#define INDIRECT_WR_DATA (SPI_INDIRECT_ACC_OFST+0x10)
+#define INDIRECT_TIMEOUT 10000
+
+static int indirect_bus_reg_read(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ void __iomem *base = context;
+ int loops;
+ u64 v;
+
+ writeq((reg >> 2) | INDIRECT_RD, base + INDIRECT_ADDR);
+
+ loops = 0;
+ while ((readq(base + INDIRECT_ADDR) & INDIRECT_RD) &&
+ (loops++ < INDIRECT_TIMEOUT))
+ cpu_relax();
+
+ if (loops >= INDIRECT_TIMEOUT) {
+ pr_err("%s timed out %d\n", __func__, loops);
+ return -ETIME;
+ }
+
+ v = readq(base + INDIRECT_RD_DATA);
+
+ *val = v & INDIRECT_DATA_MASK;
+
+ return 0;
+}
+
+static int indirect_bus_reg_write(void *context, unsigned int reg,
+ unsigned int val)
+{
+ void __iomem *base = context;
+ int loops;
+
+ writeq(val, base + INDIRECT_WR_DATA);
+ writeq((reg >> 2) | INDIRECT_WR, base + INDIRECT_ADDR);
+
+ loops = 0;
+ while ((readq(base + INDIRECT_ADDR) & INDIRECT_WR) &&
+ (loops++ < INDIRECT_TIMEOUT))
+ cpu_relax();
+
+ if (loops >= INDIRECT_TIMEOUT) {
+ pr_err("%s timed out %d\n", __func__, loops);
+ return -ETIME;
+ }
+ return 0;
+}
+
+static const struct regmap_config indirect_regbus_cfg = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .fast_io = true,
+ .max_register = 24,
+
+ .reg_write = indirect_bus_reg_write,
+ .reg_read = indirect_bus_reg_read,
+};
+
+static struct spi_board_info m10_bmc_info = {
+ .modalias = "m10-d5005",
+ .max_speed_hz = 12500000,
+ .bus_num = 0,
+ .chip_select = 0,
+};
+
+static void config_spi_master(void __iomem *base, struct spi_master *master)
+{
+ u64 v;
+
+ v = readq(base + SPI_CORE_PARAMETER);
+
+ master->mode_bits = SPI_CS_HIGH;
+ if (FIELD_GET(CLK_POLARITY, v))
+ master->mode_bits |= SPI_CPOL;
+ if (FIELD_GET(CLK_PHASE, v))
+ master->mode_bits |= SPI_CPHA;
+
+ master->num_chipselect = FIELD_GET(NUM_CHIPSELECT, v);
+ master->bits_per_word_mask =
+ SPI_BPW_RANGE_MASK(1, FIELD_GET(DATA_WIDTH, v));
+}
+
+static int dfl_spi_altera_probe(struct dfl_device *dfl_dev)
+{
+ struct device *dev = &dfl_dev->dev;
+ struct spi_master *master;
+ struct altera_spi *hw;
+ void __iomem *base;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(dev, sizeof(struct altera_spi));
+ if (!master)
+ return -ENOMEM;
+
+ master->bus_num = dfl_dev->id;
+
+ hw = spi_master_get_devdata(master);
+
+ hw->dev = dev;
+
+ base = devm_ioremap_resource(dev, &dfl_dev->mmio_res);
+
+ if (IS_ERR(base)) {
+ dev_err(dev, "%s get mem resource fail!\n", __func__);
+ return PTR_ERR(base);
+ }
+
+ config_spi_master(base, master);
+ dev_dbg(dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
+ master->num_chipselect, master->bits_per_word_mask,
+ master->mode_bits);
+
+ hw->regmap = devm_regmap_init(dev, NULL, base, &indirect_regbus_cfg);
+ if (IS_ERR(hw->regmap))
+ return PTR_ERR(hw->regmap);
+
+ hw->irq = -EINVAL;
+
+ altera_spi_init_master(master);
+
+ err = devm_spi_register_master(dev, master);
+ if (err) {
+ dev_err(dev, "%s failed to register spi master %d\n", __func__, err);
+ goto exit;
+ }
+
+ if (!spi_new_device(master, &m10_bmc_info)) {
+ dev_err(dev, "%s failed to create SPI device: %s\n",
+ __func__, m10_bmc_info.modalias);
+ }
+
+ return 0;
+exit:
+ spi_master_put(master);
+ return err;
+}
+
+static const struct dfl_device_id dfl_spi_altera_ids[] = {
+ { FME_ID, FME_FEATURE_ID_MAX10_SPI },
+ { }
+};
+
+static struct dfl_driver dfl_spi_altera_driver = {
+ .drv = {
+ .name = "dfl-spi-altera",
+ },
+ .id_table = dfl_spi_altera_ids,
+ .probe = dfl_spi_altera_probe,
+};
+
+module_dfl_driver(dfl_spi_altera_driver);
+
+MODULE_DEVICE_TABLE(dfl, dfl_spi_altera_ids);
+MODULE_DESCRIPTION("DFL spi altera driver");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");