mfd: intel-m10-bmc: Add PMCI driver

Add the mfd driver for the Platform Management Component Interface
(PMCI) based interface of Intel MAX10 BMC controller.

PMCI is a software-visible interface, connected to card BMC which
provided the basic functionality of read/write BMC register. The access
to the register is done indirectly via a hardware controller/bridge
that handles read/write/clear commands and acknowledgments for the
commands.

Previously, intel-m10-bmc provided sysfs under
/sys/bus/spi/devices/... which is generalized in this change because
not all MAX10 BMC appear under SPI anymore.

Co-developed-by: Tianfei zhang <tianfei.zhang@intel.com>
Signed-off-by: Tianfei zhang <tianfei.zhang@intel.com>
Co-developed-by: Russ Weight <russell.h.weight@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Co-developed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230116100845.6153-11-ilpo.jarvinen@linux.intel.com

3 files changed, 232 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b6ab85831cde..2632ca2162de 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2243,6 +2243,18 @@ config MFD_INTEL_M10_BMC_SPI
           additional drivers must be enabled in order to use the functionality
           of the device.
 
+config MFD_INTEL_M10_BMC_PMCI
+	tristate "Intel MAX 10 Board Management Controller with PMCI"
+	depends on FPGA_DFL
+	select MFD_INTEL_M10_BMC_CORE
+	select REGMAP
+	help
+	  Support for the Intel MAX 10 board management controller via PMCI.
+
+	  This driver provides common support for accessing the device,
+	  additional drivers must be enabled in order to use the functionality
+	  of the device.
+
 config MFD_RSMU_I2C
 	tristate "Renesas Synchronization Management Unit with I2C"
 	depends on I2C && OF
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index b360b29150b5..81c30d7cf5d4 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -272,6 +272,7 @@ obj-$(CONFIG_MFD_SMPRO)		+= smpro-core.o
 
 obj-$(CONFIG_MFD_INTEL_M10_BMC_CORE)   += intel-m10-bmc-core.o
 obj-$(CONFIG_MFD_INTEL_M10_BMC_SPI)    += intel-m10-bmc-spi.o
+obj-$(CONFIG_MFD_INTEL_M10_BMC_PMCI)   += intel-m10-bmc-pmci.o
 
 obj-$(CONFIG_MFD_ATC260X)	+= atc260x-core.o
 obj-$(CONFIG_MFD_ATC260X_I2C)	+= atc260x-i2c.o
diff --git a/drivers/mfd/intel-m10-bmc-pmci.c b/drivers/mfd/intel-m10-bmc-pmci.c
new file mode 100644
index 000000000000..975019f644b5
--- /dev/null
+++ b/drivers/mfd/intel-m10-bmc-pmci.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MAX10 BMC Platform Management Component Interface (PMCI) based
+ * interface.
+ *
+ * Copyright (C) 2020-2023 Intel Corporation.
+ */
+
+#include <linux/device.h>
+#include <linux/dfl.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/intel-m10-bmc.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+struct m10bmc_pmci_device {
+	void __iomem *base;
+	struct intel_m10bmc m10bmc;
+};
+
+/*
+ * Intel FGPA indirect register access via hardware controller/bridge.
+ */
+#define INDIRECT_CMD_OFF	0
+#define INDIRECT_CMD_CLR	0
+#define INDIRECT_CMD_RD		BIT(0)
+#define INDIRECT_CMD_WR		BIT(1)
+#define INDIRECT_CMD_ACK	BIT(2)
+
+#define INDIRECT_ADDR_OFF	0x4
+#define INDIRECT_RD_OFF		0x8
+#define INDIRECT_WR_OFF		0xc
+
+#define INDIRECT_INT_US		1
+#define INDIRECT_TIMEOUT_US	10000
+
+struct indirect_ctx {
+	void __iomem *base;
+	struct device *dev;
+};
+
+static int indirect_clear_cmd(struct indirect_ctx *ctx)
+{
+	unsigned int cmd;
+	int ret;
+
+	writel(INDIRECT_CMD_CLR, ctx->base + INDIRECT_CMD_OFF);
+
+	ret = readl_poll_timeout(ctx->base + INDIRECT_CMD_OFF, cmd,
+				 cmd == INDIRECT_CMD_CLR,
+				 INDIRECT_INT_US, INDIRECT_TIMEOUT_US);
+	if (ret)
+		dev_err(ctx->dev, "timed out waiting clear cmd (residual cmd=0x%x)\n", cmd);
+
+	return ret;
+}
+
+static int indirect_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct indirect_ctx *ctx = context;
+	unsigned int cmd, ack, tmpval;
+	int ret, ret2;
+
+	cmd = readl(ctx->base + INDIRECT_CMD_OFF);
+	if (cmd != INDIRECT_CMD_CLR)
+		dev_warn(ctx->dev, "residual cmd 0x%x on read entry\n", cmd);
+
+	writel(reg, ctx->base + INDIRECT_ADDR_OFF);
+	writel(INDIRECT_CMD_RD, ctx->base + INDIRECT_CMD_OFF);
+
+	ret = readl_poll_timeout(ctx->base + INDIRECT_CMD_OFF, ack,
+				 (ack & INDIRECT_CMD_ACK) == INDIRECT_CMD_ACK,
+				 INDIRECT_INT_US, INDIRECT_TIMEOUT_US);
+	if (ret)
+		dev_err(ctx->dev, "read timed out on reg 0x%x ack 0x%x\n", reg, ack);
+	else
+		tmpval = readl(ctx->base + INDIRECT_RD_OFF);
+
+	ret2 = indirect_clear_cmd(ctx);
+
+	if (ret)
+		return ret;
+	if (ret2)
+		return ret2;
+
+	*val = tmpval;
+	return 0;
+}
+
+static int indirect_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct indirect_ctx *ctx = context;
+	unsigned int cmd, ack;
+	int ret, ret2;
+
+	cmd = readl(ctx->base + INDIRECT_CMD_OFF);
+	if (cmd != INDIRECT_CMD_CLR)
+		dev_warn(ctx->dev, "residual cmd 0x%x on write entry\n", cmd);
+
+	writel(val, ctx->base + INDIRECT_WR_OFF);
+	writel(reg, ctx->base + INDIRECT_ADDR_OFF);
+	writel(INDIRECT_CMD_WR, ctx->base + INDIRECT_CMD_OFF);
+
+	ret = readl_poll_timeout(ctx->base + INDIRECT_CMD_OFF, ack,
+				 (ack & INDIRECT_CMD_ACK) == INDIRECT_CMD_ACK,
+				 INDIRECT_INT_US, INDIRECT_TIMEOUT_US);
+	if (ret)
+		dev_err(ctx->dev, "write timed out on reg 0x%x ack 0x%x\n", reg, ack);
+
+	ret2 = indirect_clear_cmd(ctx);
+
+	if (ret)
+		return ret;
+	return ret2;
+}
+
+static const struct regmap_range m10bmc_pmci_regmap_range[] = {
+	regmap_reg_range(M10BMC_N6000_SYS_BASE, M10BMC_N6000_SYS_END),
+};
+
+static const struct regmap_access_table m10bmc_pmci_access_table = {
+	.yes_ranges	= m10bmc_pmci_regmap_range,
+	.n_yes_ranges	= ARRAY_SIZE(m10bmc_pmci_regmap_range),
+};
+
+static struct regmap_config m10bmc_pmci_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.wr_table = &m10bmc_pmci_access_table,
+	.rd_table = &m10bmc_pmci_access_table,
+	.reg_read = &indirect_reg_read,
+	.reg_write = &indirect_reg_write,
+	.max_register = M10BMC_N6000_SYS_END,
+};
+
+static struct mfd_cell m10bmc_pmci_n6000_bmc_subdevs[] = {
+	{ .name = "n6000bmc-hwmon" },
+};
+
+static const struct m10bmc_csr_map m10bmc_n6000_csr_map = {
+	.base = M10BMC_N6000_SYS_BASE,
+	.build_version = M10BMC_N6000_BUILD_VER,
+	.fw_version = NIOS2_N6000_FW_VERSION,
+	.mac_low = M10BMC_N6000_MAC_LOW,
+	.mac_high = M10BMC_N6000_MAC_HIGH,
+	.doorbell = M10BMC_N6000_DOORBELL,
+	.auth_result = M10BMC_N6000_AUTH_RESULT,
+	.bmc_prog_addr = M10BMC_N6000_BMC_PROG_ADDR,
+	.bmc_reh_addr = M10BMC_N6000_BMC_REH_ADDR,
+	.bmc_magic = M10BMC_N6000_BMC_PROG_MAGIC,
+	.sr_prog_addr = M10BMC_N6000_SR_PROG_ADDR,
+	.sr_reh_addr = M10BMC_N6000_SR_REH_ADDR,
+	.sr_magic = M10BMC_N6000_SR_PROG_MAGIC,
+	.pr_prog_addr = M10BMC_N6000_PR_PROG_ADDR,
+	.pr_reh_addr = M10BMC_N6000_PR_REH_ADDR,
+	.pr_magic = M10BMC_N6000_PR_PROG_MAGIC,
+	.rsu_update_counter = M10BMC_N6000_STAGING_FLASH_COUNT,
+};
+
+static const struct intel_m10bmc_platform_info m10bmc_pmci_n6000 = {
+	.cells = m10bmc_pmci_n6000_bmc_subdevs,
+	.n_cells = ARRAY_SIZE(m10bmc_pmci_n6000_bmc_subdevs),
+	.csr_map = &m10bmc_n6000_csr_map,
+};
+
+static int m10bmc_pmci_probe(struct dfl_device *ddev)
+{
+	struct device *dev = &ddev->dev;
+	struct m10bmc_pmci_device *pmci;
+	struct indirect_ctx *ctx;
+
+	pmci = devm_kzalloc(dev, sizeof(*pmci), GFP_KERNEL);
+	if (!pmci)
+		return -ENOMEM;
+
+	pmci->m10bmc.dev = dev;
+
+	pmci->base = devm_ioremap_resource(dev, &ddev->mmio_res);
+	if (IS_ERR(pmci->base))
+		return PTR_ERR(pmci->base);
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->base = pmci->base + M10BMC_N6000_INDIRECT_BASE;
+	ctx->dev = dev;
+	indirect_clear_cmd(ctx);
+	pmci->m10bmc.regmap = devm_regmap_init(dev, NULL, ctx, &m10bmc_pmci_regmap_config);
+
+	if (IS_ERR(pmci->m10bmc.regmap))
+		return PTR_ERR(pmci->m10bmc.regmap);
+
+	return m10bmc_dev_init(&pmci->m10bmc, &m10bmc_pmci_n6000);
+}
+
+#define FME_FEATURE_ID_M10BMC_PMCI	0x12
+
+static const struct dfl_device_id m10bmc_pmci_ids[] = {
+	{ FME_ID, FME_FEATURE_ID_M10BMC_PMCI },
+	{ }
+};
+MODULE_DEVICE_TABLE(dfl, m10bmc_pmci_ids);
+
+static struct dfl_driver m10bmc_pmci_driver = {
+	.drv	= {
+		.name       = "intel-m10-bmc",
+		.dev_groups = m10bmc_dev_groups,
+	},
+	.id_table = m10bmc_pmci_ids,
+	.probe    = m10bmc_pmci_probe,
+};
+
+module_dfl_driver(m10bmc_pmci_driver);
+
+MODULE_DESCRIPTION("MAX10 BMC PMCI-based interface");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");