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 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 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 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 } 107 108 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 } 116 117 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 } 124 125 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 } 137 138 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 } 144 145 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 }; 165 166 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 } 220 221 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