1 // SPDX-License-Identifier: GPL-2.0+
3 * Host interface (LPC or eSPI) configuration on Nuvoton BMC
4 * Copyright (c) 2022 Nuvoton Technology Corp.
12 #include <dm/device_compat.h>
13 #include <linux/bitfield.h>
15 #define SMC_CTL_REG_ADDR 0xc0001001
16 #define SMC_CTL_HOSTWAIT 0x80
18 /* GCR Register Offsets */
23 /* ESPI Register offsets */
25 #define ESPIHINDP 0x80
27 /* MFSEL bit fileds */
28 #define MFSEL1_LPCSEL BIT(26)
29 #define MFSEL4_ESPISEL BIT(8)
31 /* ESPICFG bit fileds */
32 #define CHSUPP_MASK GENMASK(27, 24)
33 #define IOMODE_MASK GENMASK(9, 8)
34 #define IOMODE_SDQ FIELD_PREP(IOMODE_MASK, 3)
35 #define MAXFREQ_MASK GENMASK(12, 10)
36 #define MAXFREQ_33MHZ FIELD_PREP(MAXFREQ_MASK, 2)
38 /* ESPIHINDP bit fileds */
39 #define AUTO_SBLD BIT(4)
40 #define AUTO_HS1 BIT(8)
41 #define AUTO_HS2 BIT(12)
42 #define AUTO_HS3 BIT(16)
44 static int npcm_host_intf_bind(struct udevice *dev)
46 struct regmap *syscon;
53 /* Release host wait */
54 setbits_8(SMC_CTL_REG_ADDR, SMC_CTL_HOSTWAIT);
56 syscon = syscon_regmap_lookup_by_phandle(dev, "syscon");
58 dev_err(dev, "%s: unable to get syscon, dev %s\n", __func__, dev->name);
59 return PTR_ERR(syscon);
62 ioaddr = dev_read_u32_default(dev, "ioaddr", 0);
64 regmap_write(syscon, HIFCR, ioaddr);
66 type = dev_read_string(dev, "type");
70 if (!strcmp(type, "espi")) {
71 base = dev_read_addr_ptr(dev);
75 ret = dev_read_u32(dev, "channel-support", &ch_supp);
79 /* Select eSPI pins function */
80 regmap_update_bits(syscon, MFSEL1, MFSEL1_LPCSEL, 0);
81 regmap_update_bits(syscon, MFSEL4, MFSEL4_ESPISEL, MFSEL4_ESPISEL);
83 val = AUTO_SBLD | AUTO_HS1 | AUTO_HS2 | AUTO_HS3 | ch_supp;
84 writel(val, base + ESPIHINDP);
86 val = readl(base + ESPICFG);
87 val &= ~(CHSUPP_MASK | IOMODE_MASK | MAXFREQ_MASK);
88 val |= IOMODE_SDQ | MAXFREQ_33MHZ | FIELD_PREP(CHSUPP_MASK, ch_supp);
89 writel(val, base + ESPICFG);
90 } else if (!strcmp(type, "lpc")) {
91 /* Select LPC pin function */
92 regmap_update_bits(syscon, MFSEL4, MFSEL4_ESPISEL, 0);
93 regmap_update_bits(syscon, MFSEL1, MFSEL1_LPCSEL, MFSEL1_LPCSEL);
99 static const struct udevice_id npcm_hostintf_ids[] = {
100 { .compatible = "nuvoton,npcm750-host-intf" },
101 { .compatible = "nuvoton,npcm845-host-intf" },
105 U_BOOT_DRIVER(npcm_host_intf) = {
106 .name = "npcm_host_intf",
108 .of_match = npcm_hostintf_ids,
109 .bind = npcm_host_intf_bind,