[PATCH ipmi/kcs_bmc v1] ipmi: add an NPCM7xx KCS BMC driver
Haiyue Wang
haiyue.wang at linux.intel.com
Thu Mar 22 23:50:15 AEDT 2018
This driver exposes the Keyboard Controller Style (KCS) interface on
Novoton NPCM7xx SoCs as a character device. Such SOCs are commonly used
as a BaseBoard Management Controller (BMC) on a server board, and KCS
interface is commonly used to perform the in-band IPMI communication
between the server and its BMC.
Signed-off-by: Avi Fishman <avifishman70 at gmail.com>
Signed-off-by: Haiyue Wang <haiyue.wang at linux.intel.com>
---
.../devicetree/bindings/ipmi/npcm7xx-kcs-bmc.txt | 39 ++++
drivers/char/ipmi/Kconfig | 15 ++
drivers/char/ipmi/Makefile | 1 +
drivers/char/ipmi/kcs_bmc_npcm7xx.c | 204 +++++++++++++++++++++
4 files changed, 259 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ipmi/npcm7xx-kcs-bmc.txt
create mode 100644 drivers/char/ipmi/kcs_bmc_npcm7xx.c
diff --git a/Documentation/devicetree/bindings/ipmi/npcm7xx-kcs-bmc.txt b/Documentation/devicetree/bindings/ipmi/npcm7xx-kcs-bmc.txt
new file mode 100644
index 0000000..3538a21
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/npcm7xx-kcs-bmc.txt
@@ -0,0 +1,39 @@
+* Nuvoton NPCM7xx KCS (Keyboard Controller Style) IPMI interface
+
+The Nuvoton SOCs (NPCM7xx) are commonly used as BMCs
+(Baseboard Management Controllers) and the KCS interface can be
+used to perform in-band IPMI communication with their host.
+
+Required properties:
+- compatible : should be one of
+ "nuvoton,npcm750-kcs-bmc"
+- interrupts : interrupt generated by the controller
+- kcs_chan : The KCS channel number in the controller
+
+Example:
+
+ lpc_kcs: lpc_kcs at f0007000 {
+ compatible = "nuvoton,npcm750-lpc-kcs", "simple-mfd", "syscon";
+ reg = <0xf0007000 0x40>;
+ reg-io-width = <1>;
+
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0xf0007000 0x40>;
+
+ kcs1: kcs1 at 0 {
+ compatible = "nuvoton,npcm750-kcs-bmc";
+ reg = <0x0 0x40>;
+ interrupts = <0 9 4>;
+ kcs_chan = <1>;
+ status = "disabled";
+ };
+
+ kcs2: kcs2 at 0 {
+ compatible = "nuvoton,npcm750-kcs-bmc";
+ reg = <0x0 0x40>;
+ interrupts = <0 9 4>;
+ kcs_chan = <2>;
+ status = "disabled";
+ };
+ };
\ No newline at end of file
diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 3bda116..470f976 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -111,6 +111,21 @@ config ASPEED_KCS_IPMI_BMC
The driver implements the BMC side of the KCS contorller, it
provides the access of KCS IO space for BMC side.
+config NPCM7XX_KCS_IPMI_BMC
+ depends on ARCH_NPCM7XX || COMPILE_TEST
+ select IPMI_KCS_BMC
+ select REGMAP_MMIO
+ tristate "NPCM7xx KCS IPMI BMC driver"
+ help
+ Provides a driver for the KCS (Keyboard Controller Style) IPMI
+ interface found on Nuvoton NPCM7xx SOCs.
+
+ The driver implements the BMC side of the KCS contorller, it
+ provides the access of KCS IO space for BMC side.
+
+ This support is also available as a module. If so, the module
+ will be called kcs_bmc_npcm7xx.
+
config ASPEED_BT_IPMI_BMC
depends on ARCH_ASPEED || COMPILE_TEST
depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index 21e9e87..7a3baf3 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
+obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
new file mode 100644
index 0000000..7bc898c
--- /dev/null
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, Nuvoton Corporation.
+ * Copyright (c) 2018, Intel Corporation.
+ */
+
+#define pr_fmt(fmt) "nuvoton-kcs-bmc: " fmt
+
+#include <linux/atomic.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "kcs_bmc.h"
+
+#define DEVICE_NAME "npcm-kcs-bmc"
+#define KCS_CHANNEL_MAX 3
+
+#define KCS1ST 0x0C
+#define KCS2ST 0x1E
+#define KCS3ST 0x30
+
+#define KCS1DO 0x0E
+#define KCS2DO 0x20
+#define KCS3DO 0x32
+
+#define KCS1DI 0x10
+#define KCS2DI 0x22
+#define KCS3DI 0x34
+
+#define KCS1CTL 0x18
+#define KCS2CTL 0x2A
+#define KCS3CTL 0x3C
+#define KCS_CTL_IBFIE BIT(0)
+
+/*
+ * 7.2.4 Core KCS Registers
+ * Registers in this module are 8 bits. An 8-bit register must be accessed
+ * by an 8-bit read or write.
+ *
+ * sts: KCS Channel n Status Register (KCSnST).
+ * dob: KCS Channel n Data Out Buffer Register (KCSnDO).
+ * dib: KCS Channel n Data In Buffer Register (KCSnDI).
+ * ctl: KCS Channel n Control Register (KCSnCTL).
+ */
+struct npcm7xx_kcs_reg {
+ u32 sts;
+ u32 dob;
+ u32 dib;
+ u32 ctl;
+};
+
+struct npcm7xx_kcs_bmc {
+ struct regmap *map;
+
+ const struct npcm7xx_kcs_reg *reg;
+};
+
+static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = {
+ { .sts = KCS1ST, .dob = KCS1DO, .dib = KCS1DI, .ctl = KCS1CTL },
+ { .sts = KCS2ST, .dob = KCS2DO, .dib = KCS2DI, .ctl = KCS2CTL },
+ { .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL },
+};
+
+static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
+{
+ struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+ u32 val = 0;
+ int rc;
+
+ rc = regmap_read(priv->map, reg, &val);
+ WARN(rc != 0, "regmap_read() failed: %d\n", rc);
+
+ return rc == 0 ? (u8)val : 0;
+}
+
+static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
+{
+ struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+ int rc;
+
+ rc = regmap_write(priv->map, reg, data);
+ WARN(rc != 0, "regmap_write() failed: %d\n", rc);
+}
+
+static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
+{
+ struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+
+ regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
+ enable ? KCS_CTL_IBFIE : 0);
+}
+
+static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)
+{
+ struct kcs_bmc *kcs_bmc = arg;
+
+ if (!kcs_bmc_handle_event(kcs_bmc))
+ return IRQ_HANDLED;
+
+ return IRQ_NONE;
+}
+
+static int npcm7xx_kcs_config_irq(struct kcs_bmc *kcs_bmc,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ return devm_request_irq(dev, irq, npcm7xx_kcs_irq, IRQF_SHARED,
+ dev_name(dev), kcs_bmc);
+}
+
+static int npcm7xx_kcs_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct npcm7xx_kcs_bmc *priv;
+ struct kcs_bmc *kcs_bmc;
+ u32 chan;
+ int rc;
+
+ rc = of_property_read_u32(dev->of_node, "kcs_chan", &chan);
+ if (rc != 0 || chan == 0 || chan > KCS_CHANNEL_MAX) {
+ dev_err(dev, "no valid 'kcs_chan' configured\n");
+ return -ENODEV;
+ }
+
+ kcs_bmc = kcs_bmc_alloc(dev, sizeof(*priv), chan);
+ if (!kcs_bmc)
+ return -ENOMEM;
+
+ priv = kcs_bmc_priv(kcs_bmc);
+ priv->map = syscon_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(priv->map)) {
+ dev_err(dev, "Couldn't get regmap\n");
+ return -ENODEV;
+ }
+ priv->reg = &npcm7xx_kcs_reg_tbl[chan - 1];
+
+ kcs_bmc->ioreg.idr = priv->reg->dib;
+ kcs_bmc->ioreg.odr = priv->reg->dob;
+ kcs_bmc->ioreg.str = priv->reg->sts;
+ kcs_bmc->io_inputb = npcm7xx_kcs_inb;
+ kcs_bmc->io_outputb = npcm7xx_kcs_outb;
+
+ dev_set_drvdata(dev, kcs_bmc);
+
+ npcm7xx_kcs_enable_channel(kcs_bmc, true);
+ rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);
+ if (rc)
+ return rc;
+
+ rc = misc_register(&kcs_bmc->miscdev);
+ if (rc) {
+ dev_err(dev, "Unable to register device\n");
+ return rc;
+ }
+
+ pr_info("channel=%u idr=0x%x odr=0x%x str=0x%x\n",
+ chan,
+ kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr, kcs_bmc->ioreg.str);
+
+ return 0;
+}
+
+static int npcm7xx_kcs_remove(struct platform_device *pdev)
+{
+ struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+
+ misc_deregister(&kcs_bmc->miscdev);
+
+ return 0;
+}
+
+static const struct of_device_id npcm_kcs_bmc_match[] = {
+ { .compatible = "nuvoton,npcm750-kcs-bmc" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, npcm_kcs_bmc_match);
+
+static struct platform_driver npcm_kcs_bmc_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = npcm_kcs_bmc_match,
+ },
+ .probe = npcm7xx_kcs_probe,
+ .remove = npcm7xx_kcs_remove,
+};
+module_platform_driver(npcm_kcs_bmc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Avi Fishman <avifishman70 at gmail.com>");
+MODULE_AUTHOR("Haiyue Wang <haiyue.wang at linux.intel.com>");
+MODULE_DESCRIPTION("NPCM7xx device interface to the KCS BMC device");
--
2.7.4
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