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.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 42 #define KCS1IE 0x1C 43 #define KCS2IE 0x2E 44 #define KCS3IE 0x40 45 #define KCS_IE_IRQE BIT(0) 46 #define KCS_IE_HIRQE BIT(3) 47 48 /* 49 * 7.2.4 Core KCS Registers 50 * Registers in this module are 8 bits. An 8-bit register must be accessed 51 * by an 8-bit read or write. 52 * 53 * sts: KCS Channel n Status Register (KCSnST). 54 * dob: KCS Channel n Data Out Buffer Register (KCSnDO). 55 * dib: KCS Channel n Data In Buffer Register (KCSnDI). 56 * ctl: KCS Channel n Control Register (KCSnCTL). 57 * ie : KCS Channel n Interrupt Enable Register (KCSnIE). 58 */ 59 struct npcm7xx_kcs_reg { 60 u32 sts; 61 u32 dob; 62 u32 dib; 63 u32 ctl; 64 u32 ie; 65 }; 66 67 struct npcm7xx_kcs_bmc { 68 struct regmap *map; 69 70 const struct npcm7xx_kcs_reg *reg; 71 }; 72 73 static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = { 74 { .sts = KCS1ST, .dob = KCS1DO, .dib = KCS1DI, .ctl = KCS1CTL, .ie = KCS1IE }, 75 { .sts = KCS2ST, .dob = KCS2DO, .dib = KCS2DI, .ctl = KCS2CTL, .ie = KCS2IE }, 76 { .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE }, 77 }; 78 79 static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg) 80 { 81 struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc); 82 u32 val = 0; 83 int rc; 84 85 rc = regmap_read(priv->map, reg, &val); 86 WARN(rc != 0, "regmap_read() failed: %d\n", rc); 87 88 return rc == 0 ? (u8)val : 0; 89 } 90 91 static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data) 92 { 93 struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc); 94 int rc; 95 96 rc = regmap_write(priv->map, reg, data); 97 WARN(rc != 0, "regmap_write() failed: %d\n", rc); 98 } 99 100 static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable) 101 { 102 struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc); 103 104 regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE, 105 enable ? KCS_CTL_IBFIE : 0); 106 107 regmap_update_bits(priv->map, priv->reg->ie, KCS_IE_IRQE | KCS_IE_HIRQE, 108 enable ? KCS_IE_IRQE | KCS_IE_HIRQE : 0); 109 } 110 111 static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg) 112 { 113 struct kcs_bmc *kcs_bmc = arg; 114 115 if (!kcs_bmc_handle_event(kcs_bmc)) 116 return IRQ_HANDLED; 117 118 return IRQ_NONE; 119 } 120 121 static int npcm7xx_kcs_config_irq(struct kcs_bmc *kcs_bmc, 122 struct platform_device *pdev) 123 { 124 struct device *dev = &pdev->dev; 125 int irq; 126 127 irq = platform_get_irq(pdev, 0); 128 if (irq < 0) 129 return irq; 130 131 return devm_request_irq(dev, irq, npcm7xx_kcs_irq, IRQF_SHARED, 132 dev_name(dev), kcs_bmc); 133 } 134 135 static int npcm7xx_kcs_probe(struct platform_device *pdev) 136 { 137 struct device *dev = &pdev->dev; 138 struct npcm7xx_kcs_bmc *priv; 139 struct kcs_bmc *kcs_bmc; 140 u32 chan; 141 int rc; 142 143 rc = of_property_read_u32(dev->of_node, "kcs_chan", &chan); 144 if (rc != 0 || chan == 0 || chan > KCS_CHANNEL_MAX) { 145 dev_err(dev, "no valid 'kcs_chan' configured\n"); 146 return -ENODEV; 147 } 148 149 kcs_bmc = kcs_bmc_alloc(dev, sizeof(*priv), chan); 150 if (!kcs_bmc) 151 return -ENOMEM; 152 153 priv = kcs_bmc_priv(kcs_bmc); 154 priv->map = syscon_node_to_regmap(dev->parent->of_node); 155 if (IS_ERR(priv->map)) { 156 dev_err(dev, "Couldn't get regmap\n"); 157 return -ENODEV; 158 } 159 priv->reg = &npcm7xx_kcs_reg_tbl[chan - 1]; 160 161 kcs_bmc->ioreg.idr = priv->reg->dib; 162 kcs_bmc->ioreg.odr = priv->reg->dob; 163 kcs_bmc->ioreg.str = priv->reg->sts; 164 kcs_bmc->io_inputb = npcm7xx_kcs_inb; 165 kcs_bmc->io_outputb = npcm7xx_kcs_outb; 166 167 dev_set_drvdata(dev, kcs_bmc); 168 169 npcm7xx_kcs_enable_channel(kcs_bmc, true); 170 rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev); 171 if (rc) 172 return rc; 173 174 rc = misc_register(&kcs_bmc->miscdev); 175 if (rc) { 176 dev_err(dev, "Unable to register device\n"); 177 return rc; 178 } 179 180 pr_info("channel=%u idr=0x%x odr=0x%x str=0x%x\n", 181 chan, 182 kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr, kcs_bmc->ioreg.str); 183 184 return 0; 185 } 186 187 static int npcm7xx_kcs_remove(struct platform_device *pdev) 188 { 189 struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev); 190 191 misc_deregister(&kcs_bmc->miscdev); 192 193 return 0; 194 } 195 196 static const struct of_device_id npcm_kcs_bmc_match[] = { 197 { .compatible = "nuvoton,npcm750-kcs-bmc" }, 198 { } 199 }; 200 MODULE_DEVICE_TABLE(of, npcm_kcs_bmc_match); 201 202 static struct platform_driver npcm_kcs_bmc_driver = { 203 .driver = { 204 .name = DEVICE_NAME, 205 .of_match_table = npcm_kcs_bmc_match, 206 }, 207 .probe = npcm7xx_kcs_probe, 208 .remove = npcm7xx_kcs_remove, 209 }; 210 module_platform_driver(npcm_kcs_bmc_driver); 211 212 MODULE_LICENSE("GPL v2"); 213 MODULE_AUTHOR("Avi Fishman <avifishman70@gmail.com>"); 214 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>"); 215 MODULE_DESCRIPTION("NPCM7xx device interface to the KCS BMC device"); 216