xref: /linux/drivers/i3c/master/mipi-i3c-hci/dat_v1.c (revision 576d7fed09c7edbae7600f29a8a3ed6c1ead904f)
1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Copyright (c) 2020, MIPI Alliance, Inc.
4  *
5  * Author: Nicolas Pitre <npitre@baylibre.com>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bitmap.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/i3c/master.h>
13 #include <linux/io.h>
14 
15 #include "hci.h"
16 #include "dat.h"
17 
18 
19 /*
20  * Device Address Table Structure
21  */
22 
23 #define DAT_1_AUTOCMD_HDR_CODE		W1_MASK(58, 51)
24 #define DAT_1_AUTOCMD_MODE		W1_MASK(50, 48)
25 #define DAT_1_AUTOCMD_VALUE		W1_MASK(47, 40)
26 #define DAT_1_AUTOCMD_MASK		W1_MASK(39, 32)
27 /*	DAT_0_I2C_DEVICE		W0_BIT_(31) */
28 #define DAT_0_DEV_NACK_RETRY_CNT	W0_MASK(30, 29)
29 #define DAT_0_RING_ID			W0_MASK(28, 26)
30 #define DAT_0_DYNADDR_PARITY		W0_BIT_(23)
31 #define DAT_0_DYNAMIC_ADDRESS		W0_MASK(22, 16)
32 #define DAT_0_TS			W0_BIT_(15)
33 #define DAT_0_MR_REJECT			W0_BIT_(14)
34 /*	DAT_0_SIR_REJECT		W0_BIT_(13) */
35 /*	DAT_0_IBI_PAYLOAD		W0_BIT_(12) */
36 #define DAT_0_STATIC_ADDRESS		W0_MASK(6, 0)
37 
38 #define dat_w0_read(i)		readl(hci->DAT_regs + (i) * 8)
39 #define dat_w1_read(i)		readl(hci->DAT_regs + (i) * 8 + 4)
40 #define dat_w0_write(i, v)	writel(v, hci->DAT_regs + (i) * 8)
41 #define dat_w1_write(i, v)	writel(v, hci->DAT_regs + (i) * 8 + 4)
42 
43 static inline bool dynaddr_parity(unsigned int addr)
44 {
45 	addr |= 1 << 7;
46 	addr += addr >> 4;
47 	addr += addr >> 2;
48 	addr += addr >> 1;
49 	return (addr & 1);
50 }
51 
52 static int hci_dat_v1_init(struct i3c_hci *hci)
53 {
54 	unsigned int dat_idx;
55 
56 	if (!hci->DAT_regs) {
57 		dev_err(&hci->master.dev,
58 			"only DAT in register space is supported at the moment\n");
59 		return -EOPNOTSUPP;
60 	}
61 	if (hci->DAT_entry_size != 8) {
62 		dev_err(&hci->master.dev,
63 			"only 8-bytes DAT entries are supported at the moment\n");
64 		return -EOPNOTSUPP;
65 	}
66 
67 	if (!hci->DAT_data) {
68 		/* use a bitmap for faster free slot search */
69 		hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL);
70 		if (!hci->DAT_data)
71 			return -ENOMEM;
72 
73 		/* clear them */
74 		for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) {
75 			dat_w0_write(dat_idx, 0);
76 			dat_w1_write(dat_idx, 0);
77 		}
78 	}
79 
80 	return 0;
81 }
82 
83 static void hci_dat_v1_cleanup(struct i3c_hci *hci)
84 {
85 	bitmap_free(hci->DAT_data);
86 	hci->DAT_data = NULL;
87 }
88 
89 static int hci_dat_v1_alloc_entry(struct i3c_hci *hci)
90 {
91 	unsigned int dat_idx;
92 	int ret;
93 
94 	if (!hci->DAT_data) {
95 		ret = hci_dat_v1_init(hci);
96 		if (ret)
97 			return ret;
98 	}
99 	dat_idx = find_first_zero_bit(hci->DAT_data, hci->DAT_entries);
100 	if (dat_idx >= hci->DAT_entries)
101 		return -ENOENT;
102 	__set_bit(dat_idx, hci->DAT_data);
103 
104 	/* default flags */
105 	dat_w0_write(dat_idx, DAT_0_SIR_REJECT | DAT_0_MR_REJECT);
106 
107 	return dat_idx;
108 }
109 
110 static void hci_dat_v1_free_entry(struct i3c_hci *hci, unsigned int dat_idx)
111 {
112 	dat_w0_write(dat_idx, 0);
113 	dat_w1_write(dat_idx, 0);
114 	if (hci->DAT_data)
115 		__clear_bit(dat_idx, hci->DAT_data);
116 }
117 
118 static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci,
119 					unsigned int dat_idx, u8 address)
120 {
121 	u32 dat_w0;
122 
123 	dat_w0 = dat_w0_read(dat_idx);
124 	dat_w0 &= ~(DAT_0_DYNAMIC_ADDRESS | DAT_0_DYNADDR_PARITY);
125 	dat_w0 |= FIELD_PREP(DAT_0_DYNAMIC_ADDRESS, address) |
126 		  (dynaddr_parity(address) ? DAT_0_DYNADDR_PARITY : 0);
127 	dat_w0_write(dat_idx, dat_w0);
128 }
129 
130 static void hci_dat_v1_set_static_addr(struct i3c_hci *hci,
131 				       unsigned int dat_idx, u8 address)
132 {
133 	u32 dat_w0;
134 
135 	dat_w0 = dat_w0_read(dat_idx);
136 	dat_w0 &= ~DAT_0_STATIC_ADDRESS;
137 	dat_w0 |= FIELD_PREP(DAT_0_STATIC_ADDRESS, address);
138 	dat_w0_write(dat_idx, dat_w0);
139 }
140 
141 static void hci_dat_v1_set_flags(struct i3c_hci *hci, unsigned int dat_idx,
142 				 u32 w0_flags, u32 w1_flags)
143 {
144 	u32 dat_w0, dat_w1;
145 
146 	dat_w0 = dat_w0_read(dat_idx);
147 	dat_w1 = dat_w1_read(dat_idx);
148 	dat_w0 |= w0_flags;
149 	dat_w1 |= w1_flags;
150 	dat_w0_write(dat_idx, dat_w0);
151 	dat_w1_write(dat_idx, dat_w1);
152 }
153 
154 static void hci_dat_v1_clear_flags(struct i3c_hci *hci, unsigned int dat_idx,
155 				   u32 w0_flags, u32 w1_flags)
156 {
157 	u32 dat_w0, dat_w1;
158 
159 	dat_w0 = dat_w0_read(dat_idx);
160 	dat_w1 = dat_w1_read(dat_idx);
161 	dat_w0 &= ~w0_flags;
162 	dat_w1 &= ~w1_flags;
163 	dat_w0_write(dat_idx, dat_w0);
164 	dat_w1_write(dat_idx, dat_w1);
165 }
166 
167 static int hci_dat_v1_get_index(struct i3c_hci *hci, u8 dev_addr)
168 {
169 	unsigned int dat_idx;
170 	u32 dat_w0;
171 
172 	for_each_set_bit(dat_idx, hci->DAT_data, hci->DAT_entries) {
173 		dat_w0 = dat_w0_read(dat_idx);
174 		if (FIELD_GET(DAT_0_DYNAMIC_ADDRESS, dat_w0) == dev_addr)
175 			return dat_idx;
176 	}
177 
178 	return -ENODEV;
179 }
180 
181 const struct hci_dat_ops mipi_i3c_hci_dat_v1 = {
182 	.init			= hci_dat_v1_init,
183 	.cleanup		= hci_dat_v1_cleanup,
184 	.alloc_entry		= hci_dat_v1_alloc_entry,
185 	.free_entry		= hci_dat_v1_free_entry,
186 	.set_dynamic_addr	= hci_dat_v1_set_dynamic_addr,
187 	.set_static_addr	= hci_dat_v1_set_static_addr,
188 	.set_flags		= hci_dat_v1_set_flags,
189 	.clear_flags		= hci_dat_v1_clear_flags,
190 	.get_index		= hci_dat_v1_get_index,
191 };
192