xref: /openbmc/u-boot/arch/x86/cpu/tangier/pinmux.c (revision 4e710ebb)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2018 Emlid Limited
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <dm/pinctrl.h>
9 #include <dm/read.h>
10 #include <regmap.h>
11 #include <syscon.h>
12 #include <asm/cpu.h>
13 #include <asm/scu.h>
14 #include <linux/io.h>
15 
16 #define BUFCFG_OFFSET				0x100
17 
18 #define MRFLD_FAMILY_LEN			0x400
19 
20 /* These are taken from Linux kernel */
21 #define MRFLD_PINMODE_MASK			0x07
22 
23 #define pin_to_bufno(f, p)			((p) - (f)->pin_base)
24 
25 struct mrfld_family {
26 	unsigned int family_number;
27 	unsigned int pin_base;
28 	size_t npins;
29 	void __iomem *regs;
30 };
31 
32 #define MRFLD_FAMILY(b, s, e)				\
33 	{						\
34 		.family_number = (b),			\
35 		.pin_base = (s),			\
36 		.npins = (e) - (s) + 1,			\
37 	}
38 
39 /* Now we only support I2C family of pins */
40 static struct mrfld_family mrfld_families[] = {
41 	MRFLD_FAMILY(7, 101, 114),
42 };
43 
44 struct mrfld_pinctrl {
45 	const struct mrfld_family *families;
46 	size_t nfamilies;
47 };
48 
49 static const struct mrfld_family *
mrfld_get_family(struct mrfld_pinctrl * mp,unsigned int pin)50 mrfld_get_family(struct mrfld_pinctrl *mp, unsigned int pin)
51 {
52 	const struct mrfld_family *family;
53 	unsigned int i;
54 
55 	for (i = 0; i < mp->nfamilies; i++) {
56 		family = &mp->families[i];
57 		if (pin >= family->pin_base &&
58 		    pin < family->pin_base + family->npins)
59 			return family;
60 	}
61 
62 	pr_err("failed to find family for pin %u\n", pin);
63 	return NULL;
64 }
65 
66 static void __iomem *
mrfld_get_bufcfg(struct mrfld_pinctrl * pinctrl,unsigned int pin)67 mrfld_get_bufcfg(struct mrfld_pinctrl *pinctrl, unsigned int pin)
68 {
69 	const struct mrfld_family *family;
70 	unsigned int bufno;
71 
72 	family =  mrfld_get_family(pinctrl, pin);
73 	if (!family)
74 		return NULL;
75 
76 	bufno = pin_to_bufno(family, pin);
77 
78 	return family->regs + BUFCFG_OFFSET + bufno * 4;
79 }
80 
81 static void
mrfld_setup_families(void * base_addr,struct mrfld_family * families,unsigned int nfam)82 mrfld_setup_families(void *base_addr,
83 		     struct mrfld_family *families, unsigned int nfam)
84 {
85 	for (int i = 0; i < nfam; i++) {
86 		struct mrfld_family *family = &families[i];
87 
88 		family->regs = base_addr +
89 			       family->family_number * MRFLD_FAMILY_LEN;
90 	}
91 }
92 
mrfld_pinconfig_protected(unsigned int pin,u32 mask,u32 bits)93 static int mrfld_pinconfig_protected(unsigned int pin, u32 mask, u32 bits)
94 {
95 	struct mrfld_pinctrl *pinctrl;
96 	struct udevice *dev;
97 	void __iomem *bufcfg;
98 	u32 v, value;
99 	int ret;
100 
101 	ret = syscon_get_by_driver_data(X86_SYSCON_PINCONF, &dev);
102 	if (ret)
103 		return ret;
104 
105 	pinctrl = dev_get_priv(dev);
106 
107 	bufcfg = mrfld_get_bufcfg(pinctrl, pin);
108 	if (!bufcfg)
109 		return -EINVAL;
110 
111 	value = readl(bufcfg);
112 
113 	v = (value & ~mask) | (bits & mask);
114 
115 	debug("scu: v: 0x%x p: 0x%x bits: %d, mask: %d bufcfg: 0x%p\n",
116 	      v, (u32)bufcfg, bits, mask, bufcfg);
117 
118 	ret = scu_ipc_raw_command(IPCMSG_INDIRECT_WRITE, 0, &v, 4,
119 				  NULL, 0, (u32)bufcfg, 0);
120 	if (ret)
121 		pr_err("Failed to set mode via SCU for pin %u (%d)\n",
122 		       pin, ret);
123 
124 	return ret;
125 }
126 
mrfld_pinctrl_cfg_pin(ofnode pin_node)127 static int mrfld_pinctrl_cfg_pin(ofnode pin_node)
128 {
129 	bool is_protected;
130 	int pad_offset;
131 	int mode;
132 	u32 mask;
133 	int ret;
134 
135 	/* For now we only support just protected Family of pins */
136 	is_protected = ofnode_read_bool(pin_node, "protected");
137 	if (!is_protected)
138 		return -ENOTSUPP;
139 
140 	pad_offset = ofnode_read_s32_default(pin_node, "pad-offset", -1);
141 	if (pad_offset == -1)
142 		return -EINVAL;
143 
144 	mode = ofnode_read_s32_default(pin_node, "mode-func", -1);
145 	if (mode == -1)
146 		return -EINVAL;
147 
148 	mask = MRFLD_PINMODE_MASK;
149 
150 	/* We don't support modes not in range 0..7 */
151 	if (mode & ~mask)
152 		return -ENOTSUPP;
153 
154 	ret = mrfld_pinconfig_protected(pad_offset, mask, mode);
155 
156 	return ret;
157 }
158 
tangier_pinctrl_probe(struct udevice * dev)159 static int tangier_pinctrl_probe(struct udevice *dev)
160 {
161 	void *base_addr = syscon_get_first_range(X86_SYSCON_PINCONF);
162 	struct mrfld_pinctrl *pinctrl = dev_get_priv(dev);
163 	ofnode pin_node;
164 	int ret;
165 
166 	mrfld_setup_families(base_addr, mrfld_families,
167 			     ARRAY_SIZE(mrfld_families));
168 
169 	pinctrl->families = mrfld_families;
170 	pinctrl->nfamilies = ARRAY_SIZE(mrfld_families);
171 
172 	ofnode_for_each_subnode(pin_node, dev_ofnode(dev)) {
173 		ret = mrfld_pinctrl_cfg_pin(pin_node);
174 		if (ret) {
175 			pr_err("%s: invalid configuration for the pin %ld\n",
176 			       __func__, pin_node.of_offset);
177 		}
178 	}
179 
180 	return 0;
181 }
182 
183 static const struct udevice_id tangier_pinctrl_match[] = {
184 	{ .compatible = "intel,pinctrl-tangier", .data = X86_SYSCON_PINCONF },
185 	{ /* sentinel */ }
186 };
187 
188 U_BOOT_DRIVER(tangier_pinctrl) = {
189 	.name = "tangier_pinctrl",
190 	.id = UCLASS_SYSCON,
191 	.of_match = tangier_pinctrl_match,
192 	.probe = tangier_pinctrl_probe,
193 	.priv_auto_alloc_size = sizeof(struct mrfld_pinctrl),
194 };
195