xref: /linux/drivers/mfd/ls2k-bmc-core.c (revision 0d64f6d1ffe96f59145481f7413344b1fa3ad1ce)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Loongson-2K Board Management Controller (BMC) Core Driver.
4  *
5  * Copyright (C) 2024-2025 Loongson Technology Corporation Limited.
6  *
7  * Authors:
8  *	Chong Qiao <qiaochong@loongson.cn>
9  *	Binbin Zhou <zhoubinbin@loongson.cn>
10  */
11 
12 #include <linux/aperture.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/mfd/core.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/pci_ids.h>
20 #include <linux/platform_data/simplefb.h>
21 #include <linux/platform_device.h>
22 
23 /* LS2K BMC resources */
24 #define LS2K_DISPLAY_RES_START		(SZ_16M + SZ_2M)
25 #define LS2K_IPMI_RES_SIZE		0x1C
26 #define LS2K_IPMI0_RES_START		(SZ_16M + 0xF00000)
27 #define LS2K_IPMI1_RES_START		(LS2K_IPMI0_RES_START + LS2K_IPMI_RES_SIZE)
28 #define LS2K_IPMI2_RES_START		(LS2K_IPMI1_RES_START + LS2K_IPMI_RES_SIZE)
29 #define LS2K_IPMI3_RES_START		(LS2K_IPMI2_RES_START + LS2K_IPMI_RES_SIZE)
30 #define LS2K_IPMI4_RES_START		(LS2K_IPMI3_RES_START + LS2K_IPMI_RES_SIZE)
31 
32 enum {
33 	LS2K_BMC_DISPLAY,
34 	LS2K_BMC_IPMI0,
35 	LS2K_BMC_IPMI1,
36 	LS2K_BMC_IPMI2,
37 	LS2K_BMC_IPMI3,
38 	LS2K_BMC_IPMI4,
39 };
40 
41 static struct resource ls2k_display_resources[] = {
42 	DEFINE_RES_MEM_NAMED(LS2K_DISPLAY_RES_START, SZ_4M, "simpledrm-res"),
43 };
44 
45 static struct resource ls2k_ipmi0_resources[] = {
46 	DEFINE_RES_MEM_NAMED(LS2K_IPMI0_RES_START, LS2K_IPMI_RES_SIZE, "ipmi0-res"),
47 };
48 
49 static struct resource ls2k_ipmi1_resources[] = {
50 	DEFINE_RES_MEM_NAMED(LS2K_IPMI1_RES_START, LS2K_IPMI_RES_SIZE, "ipmi1-res"),
51 };
52 
53 static struct resource ls2k_ipmi2_resources[] = {
54 	DEFINE_RES_MEM_NAMED(LS2K_IPMI2_RES_START, LS2K_IPMI_RES_SIZE, "ipmi2-res"),
55 };
56 
57 static struct resource ls2k_ipmi3_resources[] = {
58 	DEFINE_RES_MEM_NAMED(LS2K_IPMI3_RES_START, LS2K_IPMI_RES_SIZE, "ipmi3-res"),
59 };
60 
61 static struct resource ls2k_ipmi4_resources[] = {
62 	DEFINE_RES_MEM_NAMED(LS2K_IPMI4_RES_START, LS2K_IPMI_RES_SIZE, "ipmi4-res"),
63 };
64 
65 static struct mfd_cell ls2k_bmc_cells[] = {
66 	[LS2K_BMC_DISPLAY] = {
67 		.name = "simple-framebuffer",
68 		.num_resources = ARRAY_SIZE(ls2k_display_resources),
69 		.resources = ls2k_display_resources
70 	},
71 	[LS2K_BMC_IPMI0] = {
72 		.name = "ls2k-ipmi-si",
73 		.num_resources = ARRAY_SIZE(ls2k_ipmi0_resources),
74 		.resources = ls2k_ipmi0_resources
75 	},
76 	[LS2K_BMC_IPMI1] = {
77 		.name = "ls2k-ipmi-si",
78 		.num_resources = ARRAY_SIZE(ls2k_ipmi1_resources),
79 		.resources = ls2k_ipmi1_resources
80 	},
81 	[LS2K_BMC_IPMI2] = {
82 		.name = "ls2k-ipmi-si",
83 		.num_resources = ARRAY_SIZE(ls2k_ipmi2_resources),
84 		.resources = ls2k_ipmi2_resources
85 	},
86 	[LS2K_BMC_IPMI3] = {
87 		.name = "ls2k-ipmi-si",
88 		.num_resources = ARRAY_SIZE(ls2k_ipmi3_resources),
89 		.resources = ls2k_ipmi3_resources
90 	},
91 	[LS2K_BMC_IPMI4] = {
92 		.name = "ls2k-ipmi-si",
93 		.num_resources = ARRAY_SIZE(ls2k_ipmi4_resources),
94 		.resources = ls2k_ipmi4_resources
95 	},
96 };
97 
98 /*
99  * Currently the Loongson-2K BMC hardware does not have an I2C interface to adapt to the
100  * resolution. We set the resolution by presetting "video=1280x1024-16@2M" to the BMC memory.
101  */
102 static int ls2k_bmc_parse_mode(struct pci_dev *pdev, struct simplefb_platform_data *pd)
103 {
104 	char *mode;
105 	int depth, ret;
106 
107 	/* The last 16M of PCI BAR0 is used to store the resolution string. */
108 	mode = devm_ioremap(&pdev->dev, pci_resource_start(pdev, 0) + SZ_16M, SZ_16M);
109 	if (!mode)
110 		return -ENOMEM;
111 
112 	/* The resolution field starts with the flag "video=". */
113 	if (!strncmp(mode, "video=", 6))
114 		mode = mode + 6;
115 
116 	ret = kstrtoint(strsep(&mode, "x"), 10, &pd->width);
117 	if (ret)
118 		return ret;
119 
120 	ret = kstrtoint(strsep(&mode, "-"), 10, &pd->height);
121 	if (ret)
122 		return ret;
123 
124 	ret = kstrtoint(strsep(&mode, "@"), 10, &depth);
125 	if (ret)
126 		return ret;
127 
128 	pd->stride = pd->width * depth / 8;
129 	pd->format = depth == 32 ? "a8r8g8b8" : "r5g6b5";
130 
131 	return 0;
132 }
133 
134 static int ls2k_bmc_probe(struct pci_dev *dev, const struct pci_device_id *id)
135 {
136 	struct simplefb_platform_data pd;
137 	resource_size_t base;
138 	int ret;
139 
140 	ret = pci_enable_device(dev);
141 	if (ret)
142 		return ret;
143 
144 	ret = ls2k_bmc_parse_mode(dev, &pd);
145 	if (ret)
146 		goto disable_pci;
147 
148 	ls2k_bmc_cells[LS2K_BMC_DISPLAY].platform_data = &pd;
149 	ls2k_bmc_cells[LS2K_BMC_DISPLAY].pdata_size = sizeof(pd);
150 	base = dev->resource[0].start + LS2K_DISPLAY_RES_START;
151 
152 	/* Remove conflicting efifb device */
153 	ret = aperture_remove_conflicting_devices(base, SZ_4M, "simple-framebuffer");
154 	if (ret) {
155 		dev_err(&dev->dev, "Failed to removed firmware framebuffers: %d\n", ret);
156 		goto disable_pci;
157 	}
158 
159 	return devm_mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
160 				    ls2k_bmc_cells, ARRAY_SIZE(ls2k_bmc_cells),
161 				    &dev->resource[0], 0, NULL);
162 
163 disable_pci:
164 	pci_disable_device(dev);
165 	return ret;
166 }
167 
168 static void ls2k_bmc_remove(struct pci_dev *dev)
169 {
170 	pci_disable_device(dev);
171 }
172 
173 static struct pci_device_id ls2k_bmc_devices[] = {
174 	{ PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x1a05) },
175 	{ }
176 };
177 MODULE_DEVICE_TABLE(pci, ls2k_bmc_devices);
178 
179 static struct pci_driver ls2k_bmc_driver = {
180 	.name = "ls2k-bmc",
181 	.id_table = ls2k_bmc_devices,
182 	.probe = ls2k_bmc_probe,
183 	.remove = ls2k_bmc_remove,
184 };
185 module_pci_driver(ls2k_bmc_driver);
186 
187 MODULE_DESCRIPTION("Loongson-2K Board Management Controller (BMC) Core driver");
188 MODULE_AUTHOR("Loongson Technology Corporation Limited");
189 MODULE_LICENSE("GPL");
190