252 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2018, Nuvoton Corporation.4 * Copyright (c) 2018, Intel Corporation.5 */6 7#define pr_fmt(fmt) "nuvoton-kcs-bmc: " fmt8 9#include <linux/atomic.h>10#include <linux/errno.h>11#include <linux/interrupt.h>12#include <linux/io.h>13#include <linux/mfd/syscon.h>14#include <linux/module.h>15#include <linux/of.h>16#include <linux/platform_device.h>17#include <linux/regmap.h>18#include <linux/slab.h>19 20#include "kcs_bmc_device.h"21 22#define DEVICE_NAME "npcm-kcs-bmc"23#define KCS_CHANNEL_MAX 324 25#define KCS1ST 0x0C26#define KCS2ST 0x1E27#define KCS3ST 0x3028 29#define KCS1DO 0x0E30#define KCS2DO 0x2031#define KCS3DO 0x3232 33#define KCS1DI 0x1034#define KCS2DI 0x2235#define KCS3DI 0x3436 37#define KCS1CTL 0x1838#define KCS2CTL 0x2A39#define KCS3CTL 0x3C40#define KCS_CTL_IBFIE BIT(0)41#define KCS_CTL_OBEIE BIT(1)42 43#define KCS1IE 0x1C44#define KCS2IE 0x2E45#define KCS3IE 0x4046#define KCS_IE_IRQE BIT(0)47#define KCS_IE_HIRQE BIT(3)48 49/*50 * 7.2.4 Core KCS Registers51 * Registers in this module are 8 bits. An 8-bit register must be accessed52 * by an 8-bit read or write.53 *54 * sts: KCS Channel n Status Register (KCSnST).55 * dob: KCS Channel n Data Out Buffer Register (KCSnDO).56 * dib: KCS Channel n Data In Buffer Register (KCSnDI).57 * ctl: KCS Channel n Control Register (KCSnCTL).58 * ie : KCS Channel n Interrupt Enable Register (KCSnIE).59 */60struct npcm7xx_kcs_reg {61 u32 sts;62 u32 dob;63 u32 dib;64 u32 ctl;65 u32 ie;66};67 68struct npcm7xx_kcs_bmc {69 struct kcs_bmc_device kcs_bmc;70 71 struct regmap *map;72 73 const struct npcm7xx_kcs_reg *reg;74};75 76static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = {77 { .sts = KCS1ST, .dob = KCS1DO, .dib = KCS1DI, .ctl = KCS1CTL, .ie = KCS1IE },78 { .sts = KCS2ST, .dob = KCS2DO, .dib = KCS2DI, .ctl = KCS2CTL, .ie = KCS2IE },79 { .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE },80};81 82static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc_device *kcs_bmc)83{84 return container_of(kcs_bmc, struct npcm7xx_kcs_bmc, kcs_bmc);85}86 87static u8 npcm7xx_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)88{89 struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);90 u32 val = 0;91 int rc;92 93 rc = regmap_read(priv->map, reg, &val);94 WARN(rc != 0, "regmap_read() failed: %d\n", rc);95 96 return rc == 0 ? (u8)val : 0;97}98 99static void npcm7xx_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)100{101 struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);102 int rc;103 104 rc = regmap_write(priv->map, reg, data);105 WARN(rc != 0, "regmap_write() failed: %d\n", rc);106}107 108static void npcm7xx_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 data)109{110 struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);111 int rc;112 113 rc = regmap_update_bits(priv->map, reg, mask, data);114 WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);115}116 117static void npcm7xx_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)118{119 struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);120 121 regmap_update_bits(priv->map, priv->reg->ie, KCS_IE_IRQE | KCS_IE_HIRQE,122 enable ? KCS_IE_IRQE | KCS_IE_HIRQE : 0);123}124 125static void npcm7xx_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)126{127 struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);128 129 if (mask & KCS_BMC_EVENT_TYPE_OBE)130 regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_OBEIE,131 !!(state & KCS_BMC_EVENT_TYPE_OBE) * KCS_CTL_OBEIE);132 133 if (mask & KCS_BMC_EVENT_TYPE_IBF)134 regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,135 !!(state & KCS_BMC_EVENT_TYPE_IBF) * KCS_CTL_IBFIE);136}137 138static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)139{140 struct kcs_bmc_device *kcs_bmc = arg;141 142 return kcs_bmc_handle_event(kcs_bmc);143}144 145static int npcm7xx_kcs_config_irq(struct kcs_bmc_device *kcs_bmc,146 struct platform_device *pdev)147{148 struct device *dev = &pdev->dev;149 int irq;150 151 irq = platform_get_irq(pdev, 0);152 if (irq < 0)153 return irq;154 155 return devm_request_irq(dev, irq, npcm7xx_kcs_irq, IRQF_SHARED,156 dev_name(dev), kcs_bmc);157}158 159static const struct kcs_bmc_device_ops npcm7xx_kcs_ops = {160 .irq_mask_update = npcm7xx_kcs_irq_mask_update,161 .io_inputb = npcm7xx_kcs_inb,162 .io_outputb = npcm7xx_kcs_outb,163 .io_updateb = npcm7xx_kcs_updateb,164};165 166static int npcm7xx_kcs_probe(struct platform_device *pdev)167{168 struct device *dev = &pdev->dev;169 struct npcm7xx_kcs_bmc *priv;170 struct kcs_bmc_device *kcs_bmc;171 u32 chan;172 int rc;173 174 rc = of_property_read_u32(dev->of_node, "kcs_chan", &chan);175 if (rc != 0 || chan == 0 || chan > KCS_CHANNEL_MAX) {176 dev_err(dev, "no valid 'kcs_chan' configured\n");177 return -ENODEV;178 }179 180 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);181 if (!priv)182 return -ENOMEM;183 184 priv->map = syscon_node_to_regmap(dev->parent->of_node);185 if (IS_ERR(priv->map)) {186 dev_err(dev, "Couldn't get regmap\n");187 return -ENODEV;188 }189 priv->reg = &npcm7xx_kcs_reg_tbl[chan - 1];190 191 kcs_bmc = &priv->kcs_bmc;192 kcs_bmc->dev = &pdev->dev;193 kcs_bmc->channel = chan;194 kcs_bmc->ioreg.idr = priv->reg->dib;195 kcs_bmc->ioreg.odr = priv->reg->dob;196 kcs_bmc->ioreg.str = priv->reg->sts;197 kcs_bmc->ops = &npcm7xx_kcs_ops;198 199 platform_set_drvdata(pdev, priv);200 201 rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);202 if (rc)203 return rc;204 205 npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);206 npcm7xx_kcs_enable_channel(kcs_bmc, true);207 208 rc = kcs_bmc_add_device(kcs_bmc);209 if (rc) {210 dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);211 return rc;212 }213 214 pr_info("channel=%u idr=0x%x odr=0x%x str=0x%x\n",215 chan,216 kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr, kcs_bmc->ioreg.str);217 218 return 0;219}220 221static void npcm7xx_kcs_remove(struct platform_device *pdev)222{223 struct npcm7xx_kcs_bmc *priv = platform_get_drvdata(pdev);224 struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;225 226 kcs_bmc_remove_device(kcs_bmc);227 228 npcm7xx_kcs_enable_channel(kcs_bmc, false);229 npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);230}231 232static const struct of_device_id npcm_kcs_bmc_match[] = {233 { .compatible = "nuvoton,npcm750-kcs-bmc" },234 { }235};236MODULE_DEVICE_TABLE(of, npcm_kcs_bmc_match);237 238static struct platform_driver npcm_kcs_bmc_driver = {239 .driver = {240 .name = DEVICE_NAME,241 .of_match_table = npcm_kcs_bmc_match,242 },243 .probe = npcm7xx_kcs_probe,244 .remove_new = npcm7xx_kcs_remove,245};246module_platform_driver(npcm_kcs_bmc_driver);247 248MODULE_LICENSE("GPL v2");249MODULE_AUTHOR("Avi Fishman <avifishman70@gmail.com>");250MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");251MODULE_DESCRIPTION("NPCM7xx device interface to the KCS BMC device");252