kcs_bmc_npcm7xx.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2018, Nuvoton Corporation.
  4 * Copyright (c) 2018, Intel Corporation.
  5 */
  6
  7#define pr_fmt(fmt) "nuvoton-kcs-bmc: " fmt
  8
  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	3
 24
 25#define KCS1ST		0x0C
 26#define KCS2ST		0x1E
 27#define KCS3ST		0x30
 28
 29#define KCS1DO		0x0E
 30#define KCS2DO		0x20
 31#define KCS3DO		0x32
 32
 33#define KCS1DI		0x10
 34#define KCS2DI		0x22
 35#define KCS3DI		0x34
 36
 37#define KCS1CTL		0x18
 38#define KCS2CTL		0x2A
 39#define KCS3CTL		0x3C
 40#define    KCS_CTL_IBFIE	BIT(0)
 41#define    KCS_CTL_OBEIE	BIT(1)
 42
 43#define KCS1IE		0x1C
 44#define KCS2IE		0x2E
 45#define KCS3IE		0x40
 46#define    KCS_IE_IRQE          BIT(0)
 47#define    KCS_IE_HIRQE         BIT(3)
 48
 49/*
 50 * 7.2.4 Core KCS Registers
 51 * Registers in this module are 8 bits. An 8-bit register must be accessed
 52 * 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 = 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");