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 */
60 struct npcm7xx_kcs_reg {
61 u32 sts;
62 u32 dob;
63 u32 dib;
64 u32 ctl;
65 u32 ie;
66 };
67
68 struct 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
76 static 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
to_npcm7xx_kcs_bmc(struct kcs_bmc_device * kcs_bmc)82 static 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
npcm7xx_kcs_inb(struct kcs_bmc_device * kcs_bmc,u32 reg)87 static 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
npcm7xx_kcs_outb(struct kcs_bmc_device * kcs_bmc,u32 reg,u8 data)99 static 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
npcm7xx_kcs_updateb(struct kcs_bmc_device * kcs_bmc,u32 reg,u8 mask,u8 data)108 static 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
npcm7xx_kcs_enable_channel(struct kcs_bmc_device * kcs_bmc,bool enable)117 static 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
npcm7xx_kcs_irq_mask_update(struct kcs_bmc_device * kcs_bmc,u8 mask,u8 state)125 static 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
npcm7xx_kcs_irq(int irq,void * arg)138 static 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
npcm7xx_kcs_config_irq(struct kcs_bmc_device * kcs_bmc,struct platform_device * pdev)145 static 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
159 static 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
npcm7xx_kcs_probe(struct platform_device * pdev)166 static 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
npcm7xx_kcs_remove(struct platform_device * pdev)221 static int 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 return 0;
232 }
233
234 static const struct of_device_id npcm_kcs_bmc_match[] = {
235 { .compatible = "nuvoton,npcm750-kcs-bmc" },
236 { }
237 };
238 MODULE_DEVICE_TABLE(of, npcm_kcs_bmc_match);
239
240 static struct platform_driver npcm_kcs_bmc_driver = {
241 .driver = {
242 .name = DEVICE_NAME,
243 .of_match_table = npcm_kcs_bmc_match,
244 },
245 .probe = npcm7xx_kcs_probe,
246 .remove = npcm7xx_kcs_remove,
247 };
248 module_platform_driver(npcm_kcs_bmc_driver);
249
250 MODULE_LICENSE("GPL v2");
251 MODULE_AUTHOR("Avi Fishman <avifishman70@gmail.com>");
252 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
253 MODULE_DESCRIPTION("NPCM7xx device interface to the KCS BMC device");
254