kcs_bmc_npcm7xx.c
// 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_device.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)
#define KCS_CTL_OBEIE BIT(1)
#define KCS1IE 0x1C
#define KCS2IE 0x2E
#define KCS3IE 0x40
#define KCS_IE_IRQE BIT(0)
#define KCS_IE_HIRQE BIT(3)
/*
* 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).
* ie : KCS Channel n Interrupt Enable Register (KCSnIE).
*/
struct npcm7xx_kcs_reg {
u32 sts;
u32 dob;
u32 dib;
u32 ctl;
u32 ie;
};
struct npcm7xx_kcs_bmc {
struct kcs_bmc_device 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, .ie = KCS1IE },
{ .sts = KCS2ST, .dob = KCS2DO, .dib = KCS2DI, .ctl = KCS2CTL, .ie = KCS2IE },
{ .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE },
};
static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
{
return container_of(kcs_bmc, struct npcm7xx_kcs_bmc, kcs_bmc);
}
static u8 npcm7xx_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
{
struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(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_device *kcs_bmc, u32 reg, u8 data)
{
struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
int rc;
rc = regmap_write(priv->map, reg, data);
WARN(rc != 0, "regmap_write() failed: %d\n", rc);
}
static void npcm7xx_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 data)
{
struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
int rc;
rc = regmap_update_bits(priv->map, reg, mask, data);
WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
}
static void npcm7xx_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
{
struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
regmap_update_bits(priv->map, priv->reg->ie, KCS_IE_IRQE | KCS_IE_HIRQE,
enable ? KCS_IE_IRQE | KCS_IE_HIRQE : 0);
}
static void npcm7xx_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
{
struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
if (mask & KCS_BMC_EVENT_TYPE_OBE)
regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_OBEIE,
!!(state & KCS_BMC_EVENT_TYPE_OBE) * KCS_CTL_OBEIE);
if (mask & KCS_BMC_EVENT_TYPE_IBF)
regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
!!(state & KCS_BMC_EVENT_TYPE_IBF) * KCS_CTL_IBFIE);
}
static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)
{
struct kcs_bmc_device *kcs_bmc = arg;
return kcs_bmc_handle_event(kcs_bmc);
}
static int npcm7xx_kcs_config_irq(struct kcs_bmc_device *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 const struct kcs_bmc_device_ops npcm7xx_kcs_ops = {
.irq_mask_update = npcm7xx_kcs_irq_mask_update,
.io_inputb = npcm7xx_kcs_inb,
.io_outputb = npcm7xx_kcs_outb,
.io_updateb = npcm7xx_kcs_updateb,
};
static int npcm7xx_kcs_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct npcm7xx_kcs_bmc *priv;
struct kcs_bmc_device *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;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
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 = &priv->kcs_bmc;
kcs_bmc->dev = &pdev->dev;
kcs_bmc->channel = chan;
kcs_bmc->ioreg.idr = priv->reg->dib;
kcs_bmc->ioreg.odr = priv->reg->dob;
kcs_bmc->ioreg.str = priv->reg->sts;
kcs_bmc->ops = &npcm7xx_kcs_ops;
platform_set_drvdata(pdev, priv);
rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);
if (rc)
return rc;
npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
npcm7xx_kcs_enable_channel(kcs_bmc, true);
rc = kcs_bmc_add_device(kcs_bmc);
if (rc) {
dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
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 npcm7xx_kcs_bmc *priv = platform_get_drvdata(pdev);
struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
kcs_bmc_remove_device(kcs_bmc);
npcm7xx_kcs_enable_channel(kcs_bmc, false);
npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
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");