Re: [PATCH v7 3/3] fpga: dfl: add support for N3000 Nios private feature

Moritz Fischer
2020-09-05T00:46:10Z

Hi Xu,

On Wed, Aug 19, 2020 at 03:45:21PM +0800, Xu Yilun wrote:
> This patch adds support for the Nios handshake private feature on Intel
> PAC (Programmable Acceleration Card) N3000.
>
> The Nios is the embedded processor on the FPGA card. This private feature
> provides a handshake interface to FPGA Nois firmware, which receives
FPGA *NIOS* or *Nios* I think ;-)
> retimer configuration command from host and executes via an internal SPI
> master (spi-altera). When Nios finishes the configuration, host takes over
> the ownership of the SPI master to control an Intel MAX10 BMC (Board
> Management Controller) Chip on the SPI bus.
>
> For Nios firmware handshake part, this driver requests the retimer
> configuration for Nios with parameters from module param, and adds some
> sysfs nodes for user to query the onboard retimer's working mode and
> Nios firmware version.
>
> For SPI part, this driver adds a spi-altera platform device as well as
> the MAX10 BMC spi slave info. A spi-altera driver will be matched to
> handle the following SPI work.
>
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@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>
> Acked-by: Wu Hao <hao.wu@intel.com>
> ---
> v3: Add the doc for this driver
> Minor fixes for comments from Tom
> v4: Move the err log in regmap implementation, and delete
> n3000_nios_writel/readl(), they have nothing to wrapper now.
> Some minor fixes and comments improvement.
> v5: Fix the output of fec_mode sysfs inf to "no" on 10G configuration,
> cause no FEC mode could be configured for 10G.
> Rename the dfl_n3000_nios_* to n3000_nios_*
> Improves comments.
> v6: Fix the output of fec_mode sysfs inf to "not supported" if in 10G,
> or the firmware version major < 3.
> Minor fixes and improves comments.
> v7: Improves comments.
> ---
> .../ABI/testing/sysfs-bus-dfl-devices-n3000-nios | 21 +
> Documentation/fpga/dfl-n3000-nios.rst | 80 +++
> Documentation/fpga/index.rst | 1 +
> drivers/fpga/Kconfig | 11 +
> drivers/fpga/Makefile | 2 +
> drivers/fpga/dfl-n3000-nios.c | 542 +++++++++++++++++++++
> 6 files changed, 657 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> create mode 100644 Documentation/fpga/dfl-n3000-nios.rst
> create mode 100644 drivers/fpga/dfl-n3000-nios.c
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> new file mode 100644
> index 0000000..ce5b474
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-dfl-devices-n3000-nios
> @@ -0,0 +1,21 @@
> +What: /sys/bus/dfl/devices/dfl_dev.X/fec_mode
> +Date: Aug 2020
> +KernelVersion: 5.10
> +Contact: Xu Yilun <yilun.xu@intel.com>
> +Description: Read-only. It returns the FEC mode of the 25G links of the
> + ethernet retimers configured by NIOS firmware. "rs" for Reed
> + Solomon FEC, "kr" for Fire Code FEC, "no" for NO FEC.
> + "not supported" if the FEC mode setting is not supported, this
> + happens when the Nios firmware version major < 3, or no link is
> + configured to 25G. The FEC mode could be set by module
> + parameters, but it could only be set once after the board
> + powers up.
> + Format: string
> +
> +What: /sys/bus/dfl/devices/dfl_dev.X/nios_fw_version
> +Date: Aug 2020
> +KernelVersion: 5.10
> +Contact: Xu Yilun <yilun.xu@intel.com>
> +Description: Read-only. It returns the version of the NIOS firmware in FPGA.
> + Its format is "major.minor.patch".
> + Format: %x.%x.%x
> diff --git a/Documentation/fpga/dfl-n3000-nios.rst b/Documentation/fpga/dfl-n3000-nios.rst
> new file mode 100644
> index 0000000..72dd600
> --- /dev/null
> +++ b/Documentation/fpga/dfl-n3000-nios.rst
> @@ -0,0 +1,80 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=================================
> +N3000 Nios Private Feature Driver
> +=================================
> +
> +The N3000 Nios driver supports for the Nios handshake private feature on Intel
> +PAC (Programmable Acceleration Card) N3000.
> +
> +The Nios is the embedded processor in the FPGA, it will configure the 2 onboard
> +ethernet retimers on power up. This private feature provides a handshake
> +interface to FPGA Nios firmware, which receives the ethernet retimer
> +configuration command from host and does the configuration via an internal SPI
> +master (spi-altera). When Nios finishes the configuration, host takes over the
> +ownership of the SPI master to control an Intel MAX10 BMC (Board Management
> +Controller) Chip on the SPI bus.
> +
> +So the driver does 2 major tasks on probe, uses the Nios firmware to configure
> +the ethernet retimer, and then creates a spi master platform device with the
> +MAX10 device info in spi_board_info.
> +
> +
> +Configuring the ethernet retimer
> +================================
> +
> +The Intel PAC N3000 is a FPGA based SmartNIC platform which could be programmed
> +to various configurations (with different link numbers and speeds, e.g. 8x10G,
> +4x25G ...). And the retimer chips should also be configured correspondingly by
> +Nios firmware. There are 2 retimer chips on the board, each of them supports 4
> +links. For example, in 8x10G configuration, the 2 retimer chips are both set to
> +4x10G mode, while in 4x25G configuration, retimer A is set to 4x25G and retimer
> +B is in reset. For now, the Nios firmware only supports 10G and 25G mode
> +setting for the retimer chips.
Make sure your API above exposes all of that.
> +
> +For all 25G links, their FEC (Forward Error Correction) mode could be further
> +configured by Nios firmware for user's requirement. For 10G links, they don't
> +have the FEC mode at all, the firmware ignores the FEC mode setting for them.
> +The FEC setting is not supported if the firmware version major < 3.
> +
> +The retimer configuration can only be done once after the board powers up, the
> +Nios firmware will not accept second configuration afterward. So it is not
> +proper for the driver to create a RW sysfs node for the FEC mode. A better way
> +is that the driver accepts a module parameter for the FEC mode, and does the
> +retimer configuration on driver probe, it also creates a RO sysfs node for the
> +FEC mode query.
> +
> +Module Parameters
> +=================
> +
> +The N3000 Nios driver supports the following module parameters:
> +
> +* fec_mode: string
> + Require the Nios firmware to set the FEC mode for all 25G links of the
> + ethernet retimers. The Nios firmware configures all these links with the same
> + FEC mode. The possible values of fec_mode could be:
> +
> + - "rs": Reed Solomon FEC (default)
> + - "kr": Fire Code FEC
> + - "no": No FEC
> +
> + Since the firmware doesn't accept second configuration, The FEC mode will not
> + be changed if the module is reloaded with a different parameter value.
> +
> + The parameter has no effect for 10G links. It has no effect to all the links
> + if firmware version major < 3.
> +
> +
> +Sysfs Attributes
> +================
> +
> +The driver creates the sysfs file in /sys/bus/dfl/devices/dfl_dev.X/
> +
> +* fec_mode:
> + Read-only. It shows the FEC mode of the 25G links of the ethernet retimers.
> + The possible values are the same as the fec_mode module parameter. An extra
> + value "not supported" is returned if firmware version major < 3, or no link
> + is configured to 25G.

This seems somewhat duplicate, runs the risk to get out of sync with the
ABI doc?

> +
> +* nios_fw_version:
> + Read-only. It shows the version of the Nios firmware in FPGA.
> diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
> index f80f956..5fd3c37 100644
> --- a/Documentation/fpga/index.rst
> +++ b/Documentation/fpga/index.rst
> @@ -8,6 +8,7 @@ fpga
> :maxdepth: 1
>
> dfl
> + dfl-n3000-nios
>
> .. only:: subproject and html
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 7cd5a29..38c7130 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -191,6 +191,17 @@ config FPGA_DFL_AFU
> to the FPGA infrastructure via a Port. There may be more than one
> Port/AFU per DFL based FPGA device.
>
> +config FPGA_DFL_NIOS_INTEL_PAC_N3000
> + tristate "FPGA DFL NIOS Driver for Intel PAC N3000"
> + depends on FPGA_DFL
> + select REGMAP
> + help
> + This is the driver for the N3000 Nios private feature on Intel
> + PAC (Programmable Acceleration Card) N3000. It communicates
> + with the embedded Nios processor to configure the retimers on
> + the card. It also instantiates the SPI master (spi-altera) for
> + the card's BMC (Board Management Controller) control.
> +
> config FPGA_DFL_PCI
> tristate "FPGA DFL PCIe Device Driver"
> depends on PCI && FPGA_DFL
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index d8e21df..18dc9885 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -44,5 +44,7 @@ dfl-fme-objs += dfl-fme-perf.o
> dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
> dfl-afu-objs += dfl-afu-error.o
>
> +obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000) += dfl-n3000-nios.o
> +
> # Drivers for FPGAs which implement DFL
> obj-$(CONFIG_FPGA_DFL_PCI) += dfl-pci.o
> diff --git a/drivers/fpga/dfl-n3000-nios.c b/drivers/fpga/dfl-n3000-nios.c
> new file mode 100644
> index 0000000..c73ce38
> --- /dev/null
> +++ b/drivers/fpga/dfl-n3000-nios.c
> @@ -0,0 +1,542 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DFL device driver for Nios private feature on Intel PAC (Programmable
> + * Acceleration Card) N3000
> + *
> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
> + *
> + * Authors:
> + * Wu Hao <hao.wu@intel.com>
> + * Xu Yilun <yilun.xu@intel.com>
> + */
> +#include <linux/bitfield.h>
> +#include <linux/errno.h>
> +#include <linux/io.h>
> +#include <linux/io-64-nonatomic-lo-hi.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/stddef.h>
> +#include <linux/spi/altera.h>
> +#include <linux/spi/spi.h>
> +#include <linux/types.h>
> +
> +#include "dfl.h"
> +
> +static char *fec_mode = "rs";
> +module_param(fec_mode, charp, 0444);
> +MODULE_PARM_DESC(fec_mode, "FEC mode of the ethernet retimer on Intel PAC N3000");
> +
> +/* N3000 Nios private feature registers */
> +#define NIOS_SPI_PARAM 0x8
> +#define PARAM_SHIFT_MODE_MSK BIT_ULL(1)
> +#define PARAM_SHIFT_MODE_MSB 0
> +#define PARAM_SHIFT_MODE_LSB 1
> +#define PARAM_DATA_WIDTH GENMASK_ULL(7, 2)
> +#define PARAM_NUM_CS GENMASK_ULL(13, 8)
> +#define PARAM_CLK_POL BIT_ULL(14)
> +#define PARAM_CLK_PHASE BIT_ULL(15)
> +#define PARAM_PERIPHERAL_ID GENMASK_ULL(47, 32)
> +
> +#define NIOS_SPI_CTRL 0x10
> +#define CTRL_WR_DATA GENMASK_ULL(31, 0)
> +#define CTRL_ADDR GENMASK_ULL(44, 32)
> +#define CTRL_CMD_MSK GENMASK_ULL(63, 62)
> +#define CTRL_CMD_NOP 0
> +#define CTRL_CMD_RD 1
> +#define CTRL_CMD_WR 2
> +
> +#define NIOS_SPI_STAT 0x18
> +#define STAT_RD_DATA GENMASK_ULL(31, 0)
> +#define STAT_RW_VAL BIT_ULL(32)
> +
> +/* Nios handshake registers, indirect access */
> +#define NIOS_INIT 0x1000
> +#define NIOS_INIT_DONE BIT(0)
> +#define NIOS_INIT_START BIT(1)
> +/* Mode for retimer A, link 0, the same below */
> +#define REQ_FEC_MODE_A0_MSK GENMASK(9, 8)
> +#define REQ_FEC_MODE_A1_MSK GENMASK(11, 10)
> +#define REQ_FEC_MODE_A2_MSK GENMASK(13, 12)
> +#define REQ_FEC_MODE_A3_MSK GENMASK(15, 14)
> +#define REQ_FEC_MODE_B0_MSK GENMASK(17, 16)
> +#define REQ_FEC_MODE_B1_MSK GENMASK(19, 18)
> +#define REQ_FEC_MODE_B2_MSK GENMASK(21, 20)
> +#define REQ_FEC_MODE_B3_MSK GENMASK(23, 22)
> +#define REQ_FEC_MODE_NO 0x0
> +#define REQ_FEC_MODE_KR 0x1
> +#define REQ_FEC_MODE_RS 0x2
> +
> +#define NIOS_FW_VERSION 0x1004
> +#define NIOS_FW_VERSION_PATCH GENMASK(23, 20)
> +#define NIOS_FW_VERSION_MINOR GENMASK(27, 24)
> +#define NIOS_FW_VERSION_MAJOR GENMASK(31, 28)
> +
> +/* The retimers we use on Intel PAC N3000 is Parkvale, abbreviated to PKVL */
> +#define PKVL_A_MODE_STS 0x1020
> +#define PKVL_B_MODE_STS 0x1024
> +#define PKVL_MODE_STS_GROUP_MSK GENMASK(15, 8)
> +#define PKVL_MODE_STS_GROUP_OK 0x0
> +#define PKVL_MODE_STS_ID_MSK GENMASK(7, 0)
> +/* When GROUP MASK field == GROUP_OK */
> +#define PKVL_MODE_ID_RESET 0x0
> +#define PKVL_MODE_ID_4X10G 0x1
> +#define PKVL_MODE_ID_4X25G 0x2
> +#define PKVL_MODE_ID_2X25G 0x3
> +#define PKVL_MODE_ID_2X25G_2X10G 0x4
> +#define PKVL_MODE_ID_1X25G 0x5
> +
> +#define NS_REGBUS_WAIT_TIMEOUT 10000 /* loop count */
> +#define NIOS_INIT_TIMEOUT 10000000 /* usec */
> +#define NIOS_INIT_TIME_INTV 100000 /* usec */
> +
> +struct n3000_nios {
> + void __iomem *base;
> + struct regmap *regmap;
> + struct device *dev;
> + struct platform_device *altera_spi;
> +};
> +
> +static ssize_t nios_fw_version_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct n3000_nios *ns = dev_get_drvdata(dev);
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> + if (ret)
> + return ret;
> +
> + return sprintf(buf, "%x.%x.%x\n",
> + (u8)FIELD_GET(NIOS_FW_VERSION_MAJOR, val),
> + (u8)FIELD_GET(NIOS_FW_VERSION_MINOR, val),
> + (u8)FIELD_GET(NIOS_FW_VERSION_PATCH, val));
> +}
> +static DEVICE_ATTR_RO(nios_fw_version);
> +
> +#define IS_MODE_STATUS_OK(mode_stat) \
> + (FIELD_GET(PKVL_MODE_STS_GROUP_MSK, (mode_stat)) == \
> + PKVL_MODE_STS_GROUP_OK)
> +
> +#define IS_RETIMER_FEC_SUPPORTED(retimer_mode) \
> + ((retimer_mode) != PKVL_MODE_ID_RESET && \
> + (retimer_mode) != PKVL_MODE_ID_4X10G)
> +
> +static int get_retimer_mode(struct n3000_nios *ns, unsigned int mode_stat_reg,
> + unsigned int *retimer_mode)
> +{
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_read(ns->regmap, mode_stat_reg, &val);
> + if (ret)
> + return ret;
> +
> + if (!IS_MODE_STATUS_OK(val))
> + return -EFAULT;
> +
> + *retimer_mode = FIELD_GET(PKVL_MODE_STS_ID_MSK, val);
> +
> + return 0;
> +}
> +
> +static ssize_t fec_mode_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct n3000_nios *ns = dev_get_drvdata(dev);
> + unsigned int val, retimer_a_mode, retimer_b_mode, fec_mode;
Can you make this reverse x-mas tree if possible?
> + int ret;
> +
> + /* FEC mode setting is not supported in early FW versions */
> + ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> + if (ret)
> + return ret;
> +
> + if (FIELD_GET(NIOS_FW_VERSION_MAJOR, val) < 3)
> + return sprintf(buf, "not supported\n");
> +
> + /* If no 25G links, FEC mode setting is not supported either */
> + ret = get_retimer_mode(ns, PKVL_A_MODE_STS, &retimer_a_mode);
> + if (ret)
> + return ret;
> +
> + ret = get_retimer_mode(ns, PKVL_B_MODE_STS, &retimer_b_mode);
> + if (ret)
> + return ret;
> +
> + if (!IS_RETIMER_FEC_SUPPORTED(retimer_a_mode) &&
> + !IS_RETIMER_FEC_SUPPORTED(retimer_b_mode))
> + return sprintf(buf, "not supported\n");
> +
> + /* get the valid FEC mode for 25G links */
> + ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> + if (ret)
> + return ret;
> +
> + /*
> + * FEC mode should always be the same for all links, as we set them
> + * in this way.
> + */
> + fec_mode = FIELD_GET(REQ_FEC_MODE_A0_MSK, val);
> + if (fec_mode != FIELD_GET(REQ_FEC_MODE_A1_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_A2_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_A3_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_B0_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_B1_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_B2_MSK, val) ||
> + fec_mode != FIELD_GET(REQ_FEC_MODE_B3_MSK, val))
> + return -EFAULT;
> +
> + switch (fec_mode) {
> + case REQ_FEC_MODE_NO:
> + return sprintf(buf, "no\n");
> + case REQ_FEC_MODE_KR:
> + return sprintf(buf, "kr\n");
> + case REQ_FEC_MODE_RS:
> + return sprintf(buf, "rs\n");
> + }
> +
> + return -EFAULT;
> +}
> +static DEVICE_ATTR_RO(fec_mode);
> +
> +static struct attribute *n3000_nios_attrs[] = {
> + &dev_attr_nios_fw_version.attr,
> + &dev_attr_fec_mode.attr,
> + NULL,
> +};
> +ATTRIBUTE_GROUPS(n3000_nios);
> +
> +static int init_error_detected(struct n3000_nios *ns)
Do you want to make the function either bool, or the return values ints?
> +{
> + unsigned int val;
> +
> + if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> + return true;
> +
> + if (!IS_MODE_STATUS_OK(val))
> + return true;
> +
> + if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> + return true;
> +
> + if (!IS_MODE_STATUS_OK(val))
> + return true;
> +
> + return false;
> +}
> +
> +static void dump_error_stat(struct n3000_nios *ns)
> +{
> + unsigned int val;
> +
> + if (regmap_read(ns->regmap, PKVL_A_MODE_STS, &val))
> + return;
> +
> + dev_err(ns->dev, "PKVL_A_MODE_STS 0x%x\n", val);
> +
> + if (regmap_read(ns->regmap, PKVL_B_MODE_STS, &val))
> + return;
> +
> + dev_err(ns->dev, "PKVL_B_MODE_STS 0x%x\n", val);
> +}
> +
> +static int n3000_nios_init_done_check(struct n3000_nios *ns)
> +{
> + struct device *dev = ns->dev;
> + unsigned int val, mode;
> + int ret;
> +
> + /*
> + * this SPI is shared by Nios core inside FPGA, Nios will use this SPI
> + * master to do some one time initialization after power up, and then
> + * release the control to OS. driver needs to poll on INIT_DONE to
> + * see when driver could take the control.
> + *
> + * Please note that after Nios firmware version 3.0.0, INIT_START is
> + * introduced, so driver needs to trigger START firstly and then check
> + * INIT_DONE.
> + */
> +
> + ret = regmap_read(ns->regmap, NIOS_FW_VERSION, &val);
> + if (ret)
> + return ret;
> +
> + /*
> + * If Nios version register is totally uninitialized(== 0x0), then the
> + * Nios firmware is missing. So host could take control of SPI master
> + * safely, but initialization work for Nios is not done. To restore the
> + * card, we need to reprogram a new Nios firmware via the BMC chip on
> + * SPI bus. So the driver doesn't error out, it continues to create the
> + * spi controller device and spi_board_info for BMC.
> + */
> + if (val == 0) {
> + dev_err(dev, "Nios version reg = 0x%x, skip INIT_DONE check, but the retimer may be uninitialized\n",
This looks long, any chance you can linebreak this?
> + val);
> + return 0;
> + }
> +
> + if (FIELD_GET(NIOS_FW_VERSION_MAJOR, val) >= 3) {
> + /* read NIOS_INIT to check if retimer initialization is done */
> + ret = regmap_read(ns->regmap, NIOS_INIT, &val);
> + if (ret)
> + return ret;
> +
> + /* check if retimers are initialized already */
> + if (val & NIOS_INIT_DONE || val & NIOS_INIT_START)
> + goto nios_init_done;
> +
> + /* configure FEC mode per module param */
> + val = NIOS_INIT_START;
> +
> + /*
> + * When the retimer is to be set to 10G mode, there is no FEC
> + * mode setting, so the REQ_FEC_MODE field will be ignored by
> + * Nios firmware in this case. But we should still fill the FEC
> + * mode field cause host could not get the retimer working mode
> + * until the Nios init is done.
> + */
> + if (!strcmp(fec_mode, "no"))
> + mode = REQ_FEC_MODE_NO;
> + else if (!strcmp(fec_mode, "kr"))
> + mode = REQ_FEC_MODE_KR;
> + else if (!strcmp(fec_mode, "rs"))
> + mode = REQ_FEC_MODE_RS;
> + else
> + return -EINVAL;
> +
> + /* set the same FEC mode for all links */
> + val |= FIELD_PREP(REQ_FEC_MODE_A0_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_A1_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_A2_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_A3_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_B0_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_B1_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_B2_MSK, mode) |
> + FIELD_PREP(REQ_FEC_MODE_B3_MSK, mode);
> +
> + ret = regmap_write(ns->regmap, NIOS_INIT, val);
> + if (ret)
> + return ret;
> + }
> +
> +nios_init_done:
> + /* polls on NIOS_INIT_DONE */
> + ret = regmap_read_poll_timeout(ns->regmap, NIOS_INIT, val,
> + val & NIOS_INIT_DONE,
> + NIOS_INIT_TIME_INTV,
> + NIOS_INIT_TIMEOUT);
> + if (ret) {
> + dev_err(dev, "NIOS_INIT_DONE %s\n",
> + (ret == -ETIMEDOUT) ? "timed out" : "check error");
> + goto dump_sts;
> + }
> +
> + /*
> + * After INIT_DONE is detected, it still needs to check if any error
> + * detected.
> + */
> + if (init_error_detected(ns)) {
> + /*
> + * If the retimer configuration is failed, the Nios firmware
> + * will still release the spi controller for host to
> + * communicate with the BMC. It makes possible for people to
> + * reprogram a new Nios firmware and restore the card. So the
> + * driver doesn't error out, it continues to create the spi
> + * controller device and spi_board_info for BMC.
> + */
> + dev_err(dev, "NIOS_INIT_DONE OK, but err found during init\n");
> + goto dump_sts;
> + }
> + return 0;
> +
> +dump_sts:
> + dump_error_stat(ns);
> +
> + return ret;
> +}
> +
> +struct spi_board_info m10_n3000_info = {
> + .modalias = "m10-n3000",
Did I miss the patch for this, or did this only go to the SPI folks?
> + .max_speed_hz = 12500000,
> + .bus_num = 0,
> + .chip_select = 0,
> +};

> +
> +static int create_altera_spi_controller(struct n3000_nios *ns)
> +{
> + struct altera_spi_platform_data pdata = { 0 };
> + struct platform_device_info pdevinfo = { 0 };
> + void __iomem *base = ns->base;
> + u64 v;
> +
> + v = readq(base + NIOS_SPI_PARAM);
> +
> + pdata.mode_bits = SPI_CS_HIGH;
> + if (FIELD_GET(PARAM_CLK_POL, v))
> + pdata.mode_bits |= SPI_CPOL;
> + if (FIELD_GET(PARAM_CLK_PHASE, v))
> + pdata.mode_bits |= SPI_CPHA;
> +
> + pdata.num_chipselect = FIELD_GET(PARAM_NUM_CS, v);
> + pdata.bits_per_word_mask =
> + SPI_BPW_RANGE_MASK(1, FIELD_GET(PARAM_DATA_WIDTH, v));
> +
> + pdata.num_devices = 1;
> + pdata.devices = &m10_n3000_info;
> +
> + dev_dbg(ns->dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
> + pdata.num_chipselect, pdata.bits_per_word_mask,
> + pdata.mode_bits);
> +
> + pdevinfo.name = "subdev_spi_altera";
> + pdevinfo.id = PLATFORM_DEVID_AUTO;
> + pdevinfo.parent = ns->dev;
> + pdevinfo.data = &pdata;
> + pdevinfo.size_data = sizeof(pdata);
> +
> + ns->altera_spi = platform_device_register_full(&pdevinfo);
> + return PTR_ERR_OR_ZERO(ns->altera_spi);
> +}
> +
> +static void destroy_altera_spi_controller(struct n3000_nios *ns)
> +{
> + platform_device_unregister(ns->altera_spi);
> +}
> +
> +/* ns is the abbreviation of nios_spi */
> +static int ns_poll_stat_timeout(void __iomem *base, u64 *v)
> +{
> + int loops = NS_REGBUS_WAIT_TIMEOUT;
> +
> + /*
> + * We don't use the time based timeout here for performance.
> + *
> + * The regbus read/write is on the critical path of Intel PAC N3000
> + * image programing. The time based timeout checking will add too much
> + * overhead on it. Usually the state changes in 1 or 2 loops on the
> + * test server, and we set 10000 times loop here for safety.
> + */
> + do {
> + *v = readq(base + NIOS_SPI_STAT);
> + if (*v & STAT_RW_VAL)
> + break;
> + cpu_relax();
> + } while (--loops);
> +
> + return loops ? 0 : -ETIMEDOUT;
> +}
> +
> +static int ns_reg_write(void *context, unsigned int reg, unsigned int val)
> +{
> + struct n3000_nios *ns = context;
> + u64 v = 0;
> + int ret;
> +
> + v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_WR);
> + v |= FIELD_PREP(CTRL_ADDR, reg);
> + v |= FIELD_PREP(CTRL_WR_DATA, val);
> + writeq(v, ns->base + NIOS_SPI_CTRL);
> +
> + ret = ns_poll_stat_timeout(ns->base, &v);
> + if (ret)
> + dev_err(ns->dev, "fail to write reg 0x%x val 0x%x: %d\n",
> + reg, val, ret);
> +
> + return ret;
> +}
> +
> +static int ns_reg_read(void *context, unsigned int reg, unsigned int *val)
> +{
> + struct n3000_nios *ns = context;
> + u64 v = 0;
> + int ret;
> +
> + v |= FIELD_PREP(CTRL_CMD_MSK, CTRL_CMD_RD);
> + v |= FIELD_PREP(CTRL_ADDR, reg);
> + writeq(v, ns->base + NIOS_SPI_CTRL);
> +
> + ret = ns_poll_stat_timeout(ns->base, &v);
> + if (ret)
> + dev_err(ns->dev, "fail to read reg 0x%x: %d\n", reg, ret);
> + else
> + *val = FIELD_GET(STAT_RD_DATA, v);
> +
> + return ret;
> +}
> +
> +static const struct regmap_config ns_regbus_cfg = {
> + .reg_bits = 32,
> + .reg_stride = 4,
> + .val_bits = 32,
> + .fast_io = true,
> +
> + .reg_write = ns_reg_write,
> + .reg_read = ns_reg_read,
> +};
> +
> +static int n3000_nios_probe(struct dfl_device *dfl_dev)
> +{
> + struct device *dev = &dfl_dev->dev;
> + struct n3000_nios *ns;
> + int ret;
> +
> + ns = devm_kzalloc(dev, sizeof(*ns), GFP_KERNEL);
> + if (!ns)
> + return -ENOMEM;
> +
> + dev_set_drvdata(&dfl_dev->dev, ns);
> +
> + ns->dev = dev;
> +
> + ns->base = devm_ioremap_resource(&dfl_dev->dev, &dfl_dev->mmio_res);
> + if (IS_ERR(ns->base))
> + return PTR_ERR(ns->base);
> +
> + ns->regmap = devm_regmap_init(dev, NULL, ns, &ns_regbus_cfg);
> + if (IS_ERR(ns->regmap))
> + return PTR_ERR(ns->regmap);
> +
> + ret = n3000_nios_init_done_check(ns);
> + if (ret)
> + return ret;
> +
> + ret = create_altera_spi_controller(ns);
> + if (ret)
> + dev_err(dev, "altera spi controller create failed: %d\n", ret);
> +
> + return ret;
> +}
> +
> +static void n3000_nios_remove(struct dfl_device *dfl_dev)
> +{
> + struct n3000_nios *ns = dev_get_drvdata(&dfl_dev->dev);
> +
> + destroy_altera_spi_controller(ns);
> +}
> +
> +#define FME_FEATURE_ID_N3000_NIOS 0xd
> +
> +static const struct dfl_device_id n3000_nios_ids[] = {
> + { FME_ID, FME_FEATURE_ID_N3000_NIOS },
> + { }
> +};
> +
> +static struct dfl_driver n3000_nios_driver = {
> + .drv = {
> + .name = "n3000-nios",
> + .dev_groups = n3000_nios_groups,
> + },
> + .id_table = n3000_nios_ids,
> + .probe = n3000_nios_probe,
> + .remove = n3000_nios_remove,
> +};
> +
> +module_dfl_driver(n3000_nios_driver);
> +
> +MODULE_DEVICE_TABLE(dfl, n3000_nios_ids);
> +MODULE_DESCRIPTION("Driver for Nios private feature on Intel PAC N3000");
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>
Thanks,
Moritz