On 4/13/21 3:58 PM, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
This patch adds a Device Feature List (DFL) bus driver for the
Altera SPI Master controller. The SPI master is connected to an
Intel SPI Slave to Avalon Master Bridge inside an Intel MAX10
BMC Chip.
Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
---
v2: moved drivers/fpga/dfl-spi-altera.c to drivers/spi/spi-altera-dfl.c
---
drivers/spi/Kconfig | 9 ++
drivers/spi/Makefile | 1 +
drivers/spi/spi-altera-dfl.c | 222 +++++++++++++++++++++++++++++++++++++++++++
does this need a MAINTAINER's entry ?
3 files changed, 232 insertions(+)
create mode 100644 drivers/spi/spi-altera-dfl.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 853cf4c..6c6798e 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -63,6 +63,15 @@ config SPI_ALTERA
help
This is the driver for the Altera SPI Controller.
+config SPI_ALTERA_DFL
+ tristate "DFL driver for Altera SPI Controller"
+ depends on FPGA_DFL
+ select SPI_ALTERA
+ help
+ This is a Device Feature List (DFL) bus driver for the
+ Altera SPI master controller. The SPI master is connected
+ to a SPI slave to Avalon Master bridge in a Intel MAX BMC.
Last sentence is a little confusing with two 'masters', could this be
The SPI master is connected to the Avalon SPI bridge in the Intel Max10 BMC.
?
+
config SPI_AR934X
tristate "Qualcomm Atheros AR934X/QCA95XX SPI controller driver"
depends on ATH79 || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 29fee71..2e348ea 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_SPI_LOOPBACK_TEST) += spi-loopback-test.o
# SPI master controller drivers (bus)
obj-$(CONFIG_SPI_ALTERA) += spi-altera.o
+obj-$(CONFIG_SPI_ALTERA_DFL) += spi-altera-dfl.o
obj-$(CONFIG_SPI_AR934X) += spi-ar934x.o
obj-$(CONFIG_SPI_ARMADA_3700) += spi-armada-3700.o
obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o
diff --git a/drivers/spi/spi-altera-dfl.c b/drivers/spi/spi-altera-dfl.c
new file mode 100644
index 0000000..8ddfc5d
--- /dev/null
+++ b/drivers/spi/spi-altera-dfl.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DFL bus driver for Altera SPI Master
+ *
+ * Copyright (C) 2020 Intel Corporation, Inc.
+ *
+ * Authors:
+ * Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
+ */
+
+#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>
+
+struct dfl_altera_spi {
+ void __iomem *base;
+ struct regmap *regmap;
+ struct device *dev;
+ struct platform_device *altr_spi;
the read/write can take a while, is a lock needed ?
+};
+
+#define SPI_CORE_PARAMETER 0x8
a prefix would like 'DFL_' would make this less likely to have namespace
issues.
+#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)
checkpatch --strict complains here and similar, preferring spaces around
the '+'
+#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
this does not have units of time, maybe rename to INDIRECT_RETRY_COUNT
+
+static int indirect_bus_reg_read(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ struct dfl_altera_spi *aspi = context;
+ void __iomem *base = aspi->base;
+ int loops;
could initialize loop here
+ u64 v;
+
+ writeq((reg >> 2) | INDIRECT_RD, base + INDIRECT_ADDR);
is input 'reg' checked elsewhere ?
+
+ 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;
maybe -EBUSY ?
+ }
+
+ 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)
+{
+ struct dfl_altera_spi *aspi = context;
+ void __iomem *base = aspi->base;
+ 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 struct platform_device *create_cntrl(struct device *dev,
+ void __iomem *base,
+ struct spi_board_info *m10_info)
+{
could this function be inlined to probe ?
+ struct altera_spi_platform_data pdata;
+ struct platform_device_info pdevinfo;
+ u64 v;
+
+ v = readq(base + SPI_CORE_PARAMETER);
move down two lines to before the if-checks that use it
+
+ memset(&pdata, 0, sizeof(pdata));
+ pdata.mode_bits = SPI_CS_HIGH;
+ if (FIELD_GET(CLK_POLARITY, v))
+ pdata.mode_bits |= SPI_CPOL;
+ if (FIELD_GET(CLK_PHASE, v))
+ pdata.mode_bits |= SPI_CPHA;
+
+ pdata.num_chipselect = FIELD_GET(NUM_CHIPSELECT, v);
+ pdata.bits_per_word_mask =
+ SPI_BPW_RANGE_MASK(1, FIELD_GET(DATA_WIDTH, v));
+
+ pdata.num_devices = 1;
+ pdata.devices = m10_info;
+
+ dev_dbg(dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
+ pdata.num_chipselect, pdata.bits_per_word_mask,
+ pdata.mode_bits);
+
+ memset(&pdevinfo, 0, sizeof(pdevinfo));
+
+ pdevinfo.name = "subdev_spi_altera";
+ pdevinfo.id = PLATFORM_DEVID_AUTO;
+ pdevinfo.parent = dev;
+ pdevinfo.data = &pdata;
+ pdevinfo.size_data = sizeof(pdata);
+
+ return platform_device_register_full(&pdevinfo);
+}
+static int dfl_spi_altera_probe(struct dfl_device *dfl_dev)
+{
+ struct device *dev = &dfl_dev->dev;
+ struct dfl_altera_spi *aspi;
+
+ aspi = devm_kzalloc(dev, sizeof(*aspi), GFP_KERNEL);
+
+ if (!aspi)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, aspi);
+
+ aspi->dev = dev;
+
+ aspi->base = devm_ioremap_resource(dev, &dfl_dev->mmio_res);
+
+ if (IS_ERR(aspi->base)) {
+ dev_err(dev, "%s get mem resource fail!\n", __func__);
+ return PTR_ERR(aspi->base);
+ }
+
+ aspi->regmap = devm_regmap_init(dev, NULL, aspi, &indirect_regbus_cfg);
+ if (IS_ERR(aspi->regmap))
+ return PTR_ERR(aspi->regmap);
+
+ aspi->altr_spi = create_cntrl(dev, aspi->base, &m10_bmc_info);
it does not seem like this can fail for device reasons. is there a
sanity check on the reg values that could be done ?
Tom
+
+ if (IS_ERR(aspi->altr_spi)) {
+ dev_err(dev, "%s failed to create spi platform driver\n",
+ __func__);
+ return PTR_ERR(aspi->base);
+ }
+
+ return 0;
+}
+
+static void dfl_spi_altera_remove(struct dfl_device *dfl_dev)
+{
+ struct dfl_altera_spi *aspi = dev_get_drvdata(&dfl_dev->dev);
+
+ platform_device_unregister(aspi->altr_spi);
+}
+
+#define FME_FEATURE_ID_MAX10_SPI 0xe
+
+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,
+ .remove = dfl_spi_altera_remove,
+};
+
+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");
