diff options
Diffstat (limited to 'drivers/char/ipmi/kcs_bmc_npcm7xx.c')
| -rw-r--r-- | drivers/char/ipmi/kcs_bmc_npcm7xx.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c new file mode 100644 index 000000000000..722f7391fe1f --- /dev/null +++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c @@ -0,0 +1,215 @@ +// 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) + +#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 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 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); + + regmap_update_bits(priv->map, priv->reg->ie, KCS_IE_IRQE | KCS_IE_HIRQE, + enable ? KCS_IE_IRQE | KCS_IE_HIRQE : 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"); |