1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (c) 2023 Code Construct |
4 | * |
5 | * Author: Jeremy Kerr <jk@codeconstruct.com.au> |
6 | */ |
7 | |
8 | #include <linux/mfd/syscon.h> |
9 | #include <linux/module.h> |
10 | #include <linux/of.h> |
11 | #include <linux/platform_device.h> |
12 | #include <linux/regmap.h> |
13 | |
14 | #include "dw-i3c-master.h" |
15 | |
16 | /* AST2600-specific global register set */ |
17 | #define AST2600_I3CG_REG0(idx) (((idx) * 4 * 4) + 0x10) |
18 | #define AST2600_I3CG_REG1(idx) (((idx) * 4 * 4) + 0x14) |
19 | |
20 | #define AST2600_I3CG_REG0_SDA_PULLUP_EN_MASK GENMASK(29, 28) |
21 | #define AST2600_I3CG_REG0_SDA_PULLUP_EN_2K (0x0 << 28) |
22 | #define AST2600_I3CG_REG0_SDA_PULLUP_EN_750 (0x2 << 28) |
23 | #define AST2600_I3CG_REG0_SDA_PULLUP_EN_545 (0x3 << 28) |
24 | |
25 | #define AST2600_I3CG_REG1_I2C_MODE BIT(0) |
26 | #define AST2600_I3CG_REG1_TEST_MODE BIT(1) |
27 | #define AST2600_I3CG_REG1_ACT_MODE_MASK GENMASK(3, 2) |
28 | #define AST2600_I3CG_REG1_ACT_MODE(x) (((x) << 2) & AST2600_I3CG_REG1_ACT_MODE_MASK) |
29 | #define AST2600_I3CG_REG1_PENDING_INT_MASK GENMASK(7, 4) |
30 | #define AST2600_I3CG_REG1_PENDING_INT(x) (((x) << 4) & AST2600_I3CG_REG1_PENDING_INT_MASK) |
31 | #define AST2600_I3CG_REG1_SA_MASK GENMASK(14, 8) |
32 | #define AST2600_I3CG_REG1_SA(x) (((x) << 8) & AST2600_I3CG_REG1_SA_MASK) |
33 | #define AST2600_I3CG_REG1_SA_EN BIT(15) |
34 | #define AST2600_I3CG_REG1_INST_ID_MASK GENMASK(19, 16) |
35 | #define AST2600_I3CG_REG1_INST_ID(x) (((x) << 16) & AST2600_I3CG_REG1_INST_ID_MASK) |
36 | |
37 | #define AST2600_DEFAULT_SDA_PULLUP_OHMS 2000 |
38 | |
39 | #define DEV_ADDR_TABLE_IBI_PEC BIT(11) |
40 | |
41 | struct ast2600_i3c { |
42 | struct dw_i3c_master dw; |
43 | struct regmap *global_regs; |
44 | unsigned int global_idx; |
45 | unsigned int sda_pullup; |
46 | }; |
47 | |
48 | static struct ast2600_i3c *to_ast2600_i3c(struct dw_i3c_master *dw) |
49 | { |
50 | return container_of(dw, struct ast2600_i3c, dw); |
51 | } |
52 | |
53 | static int ast2600_i3c_pullup_to_reg(unsigned int ohms, u32 *regp) |
54 | { |
55 | u32 reg; |
56 | |
57 | switch (ohms) { |
58 | case 2000: |
59 | reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K; |
60 | break; |
61 | case 750: |
62 | reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_750; |
63 | break; |
64 | case 545: |
65 | reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_545; |
66 | break; |
67 | default: |
68 | return -EINVAL; |
69 | } |
70 | |
71 | if (regp) |
72 | *regp = reg; |
73 | |
74 | return 0; |
75 | } |
76 | |
77 | static int ast2600_i3c_init(struct dw_i3c_master *dw) |
78 | { |
79 | struct ast2600_i3c *i3c = to_ast2600_i3c(dw); |
80 | u32 reg = 0; |
81 | int rc; |
82 | |
83 | /* reg0: set SDA pullup values */ |
84 | rc = ast2600_i3c_pullup_to_reg(ohms: i3c->sda_pullup, regp: ®); |
85 | if (rc) |
86 | return rc; |
87 | |
88 | rc = regmap_write(map: i3c->global_regs, |
89 | AST2600_I3CG_REG0(i3c->global_idx), val: reg); |
90 | if (rc) |
91 | return rc; |
92 | |
93 | /* reg1: set up the instance id, but leave everything else disabled, |
94 | * as it's all for client mode |
95 | */ |
96 | reg = AST2600_I3CG_REG1_INST_ID(i3c->global_idx); |
97 | rc = regmap_write(map: i3c->global_regs, |
98 | AST2600_I3CG_REG1(i3c->global_idx), val: reg); |
99 | |
100 | return rc; |
101 | } |
102 | |
103 | static void ast2600_i3c_set_dat_ibi(struct dw_i3c_master *i3c, |
104 | struct i3c_dev_desc *dev, |
105 | bool enable, u32 *dat) |
106 | { |
107 | /* |
108 | * The ast2600 i3c controller will lock up on receiving 4n+1-byte IBIs |
109 | * if the PEC is disabled. We have no way to restrict the length of |
110 | * IBIs sent to the controller, so we need to unconditionally enable |
111 | * PEC checking, which means we drop a byte of payload data |
112 | */ |
113 | if (enable && dev->info.bcr & I3C_BCR_IBI_PAYLOAD) { |
114 | dev_warn_once(&i3c->base.dev, |
115 | "Enabling PEC workaround. IBI payloads will be truncated\n" ); |
116 | *dat |= DEV_ADDR_TABLE_IBI_PEC; |
117 | } |
118 | } |
119 | |
120 | static const struct dw_i3c_platform_ops ast2600_i3c_ops = { |
121 | .init = ast2600_i3c_init, |
122 | .set_dat_ibi = ast2600_i3c_set_dat_ibi, |
123 | }; |
124 | |
125 | static int ast2600_i3c_probe(struct platform_device *pdev) |
126 | { |
127 | struct device_node *np = pdev->dev.of_node; |
128 | struct of_phandle_args gspec; |
129 | struct ast2600_i3c *i3c; |
130 | int rc; |
131 | |
132 | i3c = devm_kzalloc(dev: &pdev->dev, size: sizeof(*i3c), GFP_KERNEL); |
133 | if (!i3c) |
134 | return -ENOMEM; |
135 | |
136 | rc = of_parse_phandle_with_fixed_args(np, list_name: "aspeed,global-regs" , cell_count: 1, index: 0, |
137 | out_args: &gspec); |
138 | if (rc) |
139 | return -ENODEV; |
140 | |
141 | i3c->global_regs = syscon_node_to_regmap(np: gspec.np); |
142 | of_node_put(node: gspec.np); |
143 | |
144 | if (IS_ERR(ptr: i3c->global_regs)) |
145 | return PTR_ERR(ptr: i3c->global_regs); |
146 | |
147 | i3c->global_idx = gspec.args[0]; |
148 | |
149 | rc = of_property_read_u32(np, propname: "sda-pullup-ohms" , out_value: &i3c->sda_pullup); |
150 | if (rc) |
151 | i3c->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS; |
152 | |
153 | rc = ast2600_i3c_pullup_to_reg(ohms: i3c->sda_pullup, NULL); |
154 | if (rc) |
155 | dev_err(&pdev->dev, "invalid sda-pullup value %d\n" , |
156 | i3c->sda_pullup); |
157 | |
158 | i3c->dw.platform_ops = &ast2600_i3c_ops; |
159 | i3c->dw.ibi_capable = true; |
160 | return dw_i3c_common_probe(master: &i3c->dw, pdev); |
161 | } |
162 | |
163 | static void ast2600_i3c_remove(struct platform_device *pdev) |
164 | { |
165 | struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev); |
166 | |
167 | dw_i3c_common_remove(master: dw_i3c); |
168 | } |
169 | |
170 | static const struct of_device_id ast2600_i3c_master_of_match[] = { |
171 | { .compatible = "aspeed,ast2600-i3c" , }, |
172 | {}, |
173 | }; |
174 | MODULE_DEVICE_TABLE(of, ast2600_i3c_master_of_match); |
175 | |
176 | static struct platform_driver ast2600_i3c_driver = { |
177 | .probe = ast2600_i3c_probe, |
178 | .remove_new = ast2600_i3c_remove, |
179 | .driver = { |
180 | .name = "ast2600-i3c-master" , |
181 | .of_match_table = ast2600_i3c_master_of_match, |
182 | }, |
183 | }; |
184 | module_platform_driver(ast2600_i3c_driver); |
185 | |
186 | MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>" ); |
187 | MODULE_DESCRIPTION("ASPEED AST2600 I3C driver" ); |
188 | MODULE_LICENSE("GPL" ); |
189 | |