ipmi: add an NPCM7xx KCS BMC driver

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@gmail.com>
Signed-off-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
This commit is contained in:
Haiyue Wang 2018-03-22 20:50:15 +08:00 committed by Corey Minyard
parent 93c303d204
commit 6b2e54f7ba
4 changed files with 259 additions and 0 deletions

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@ -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@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@0 {
compatible = "nuvoton,npcm750-kcs-bmc";
reg = <0x0 0x40>;
interrupts = <0 9 4>;
kcs_chan = <1>;
status = "disabled";
};
kcs2: kcs2@0 {
compatible = "nuvoton,npcm750-kcs-bmc";
reg = <0x0 0x40>;
interrupts = <0 9 4>;
kcs_chan = <2>;
status = "disabled";
};
};

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@ -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

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@ -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

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@ -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@gmail.com>");
MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
MODULE_DESCRIPTION("NPCM7xx device interface to the KCS BMC device");