diff options
Diffstat (limited to 'drivers/spi/spi-altera-dfl.c')
| -rw-r--r-- | drivers/spi/spi-altera-dfl.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/spi/spi-altera-dfl.c b/drivers/spi/spi-altera-dfl.c new file mode 100644 index 0000000000..5d6e08c12d --- /dev/null +++ b/drivers/spi/spi-altera-dfl.c @@ -0,0 +1,201 @@ +// 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 void config_spi_host(void __iomem *base, struct spi_controller *host) +{ + u64 v; + + v = readq(base + SPI_CORE_PARAMETER); + + host->mode_bits = SPI_CS_HIGH; + if (FIELD_GET(CLK_POLARITY, v)) + host->mode_bits |= SPI_CPOL; + if (FIELD_GET(CLK_PHASE, v)) + host->mode_bits |= SPI_CPHA; + + host->num_chipselect = FIELD_GET(NUM_CHIPSELECT, v); + host->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 spi_board_info board_info = { 0 }; + struct device *dev = &dfl_dev->dev; + struct spi_controller *host; + struct altera_spi *hw; + void __iomem *base; + int err; + + host = devm_spi_alloc_host(dev, sizeof(struct altera_spi)); + if (!host) + return -ENOMEM; + + host->bus_num = -1; + + hw = spi_controller_get_devdata(host); + + hw->dev = dev; + + base = devm_ioremap_resource(dev, &dfl_dev->mmio_res); + + if (IS_ERR(base)) + return PTR_ERR(base); + + config_spi_host(base, host); + dev_dbg(dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__, + host->num_chipselect, host->bits_per_word_mask, + host->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_host(host); + + err = devm_spi_register_controller(dev, host); + if (err) + return dev_err_probe(dev, err, "%s failed to register spi host\n", + __func__); + + if (dfl_dev->revision == FME_FEATURE_REV_MAX10_SPI_N5010) + strscpy(board_info.modalias, "m10-n5010", SPI_NAME_SIZE); + else + strscpy(board_info.modalias, "m10-d5005", SPI_NAME_SIZE); + + board_info.max_speed_hz = 12500000; + board_info.bus_num = 0; + board_info.chip_select = 0; + + if (!spi_new_device(host, &board_info)) { + dev_err(dev, "%s failed to create SPI device: %s\n", + __func__, board_info.modalias); + } + + return 0; +} + +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"); |