xref: /openbmc/linux/drivers/mfd/da9052-i2c.c (revision f7018c21)
1 /*
2  * I2C access for DA9052 PMICs.
3  *
4  * Copyright(c) 2011 Dialog Semiconductor Ltd.
5  *
6  * Author: David Dajun Chen <dchen@diasemi.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  */
14 
15 #include <linux/device.h>
16 #include <linux/module.h>
17 #include <linux/input.h>
18 #include <linux/mfd/core.h>
19 #include <linux/i2c.h>
20 #include <linux/err.h>
21 
22 #include <linux/mfd/da9052/da9052.h>
23 #include <linux/mfd/da9052/reg.h>
24 
25 #ifdef CONFIG_OF
26 #include <linux/of.h>
27 #include <linux/of_device.h>
28 #endif
29 
30 /* I2C safe register check */
31 static inline bool i2c_safe_reg(unsigned char reg)
32 {
33 	switch (reg) {
34 	case DA9052_STATUS_A_REG:
35 	case DA9052_STATUS_B_REG:
36 	case DA9052_STATUS_C_REG:
37 	case DA9052_STATUS_D_REG:
38 	case DA9052_ADC_RES_L_REG:
39 	case DA9052_ADC_RES_H_REG:
40 	case DA9052_VDD_RES_REG:
41 	case DA9052_ICHG_AV_REG:
42 	case DA9052_TBAT_RES_REG:
43 	case DA9052_ADCIN4_RES_REG:
44 	case DA9052_ADCIN5_RES_REG:
45 	case DA9052_ADCIN6_RES_REG:
46 	case DA9052_TJUNC_RES_REG:
47 	case DA9052_TSI_X_MSB_REG:
48 	case DA9052_TSI_Y_MSB_REG:
49 	case DA9052_TSI_LSB_REG:
50 	case DA9052_TSI_Z_MSB_REG:
51 		return true;
52 	default:
53 		return false;
54 	}
55 }
56 
57 /*
58  * There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
59  * gets lockup up or fails to respond following a system reset.
60  * This fix is to follow any read or write with a dummy read to a safe
61  * register.
62  */
63 static int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
64 {
65 	int val;
66 
67 	switch (da9052->chip_id) {
68 	case DA9052:
69 	case DA9053_AA:
70 	case DA9053_BA:
71 	case DA9053_BB:
72 		/* A dummy read to a safe register address. */
73 	if (!i2c_safe_reg(reg))
74 			return regmap_read(da9052->regmap,
75 					   DA9052_PARK_REGISTER,
76 					   &val);
77 		break;
78 	case DA9053_BC:
79 	default:
80 		/*
81 		 * For other chips parking of I2C register
82 		 * to a safe place is not required.
83 		 */
84 		break;
85 	}
86 
87 	return 0;
88 }
89 
90 /*
91  * According to errata item 24, multiwrite mode should be avoided
92  * in order to prevent register data corruption after power-down.
93  */
94 static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
95 {
96 	int reg_val, ret;
97 
98 	ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
99 	if (ret < 0)
100 		return ret;
101 
102 	if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
103 		reg_val |= DA9052_CONTROL_B_WRITEMODE;
104 		ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
105 				   reg_val);
106 		if (ret < 0)
107 			return ret;
108 	}
109 
110 	return 0;
111 }
112 
113 static const struct i2c_device_id da9052_i2c_id[] = {
114 	{"da9052", DA9052},
115 	{"da9053-aa", DA9053_AA},
116 	{"da9053-ba", DA9053_BA},
117 	{"da9053-bb", DA9053_BB},
118 	{"da9053-bc", DA9053_BC},
119 	{}
120 };
121 
122 #ifdef CONFIG_OF
123 static const struct of_device_id dialog_dt_ids[] = {
124 	{ .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
125 	{ .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
126 	{ .compatible = "dlg,da9053-ba", .data = &da9052_i2c_id[2] },
127 	{ .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
128 	{ .compatible = "dlg,da9053-bc", .data = &da9052_i2c_id[4] },
129 	{ /* sentinel */ }
130 };
131 #endif
132 
133 static int da9052_i2c_probe(struct i2c_client *client,
134 				       const struct i2c_device_id *id)
135 {
136 	struct da9052 *da9052;
137 	int ret;
138 
139 	da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
140 	if (!da9052)
141 		return -ENOMEM;
142 
143 	if (!i2c_check_functionality(client->adapter,
144 				     I2C_FUNC_SMBUS_BYTE_DATA)) {
145 		dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
146 			 __func__);
147 		return  -ENODEV;
148 	}
149 
150 	da9052->dev = &client->dev;
151 	da9052->chip_irq = client->irq;
152 	da9052->fix_io = da9052_i2c_fix;
153 
154 	i2c_set_clientdata(client, da9052);
155 
156 	da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
157 	if (IS_ERR(da9052->regmap)) {
158 		ret = PTR_ERR(da9052->regmap);
159 		dev_err(&client->dev, "Failed to allocate register map: %d\n",
160 			ret);
161 		return ret;
162 	}
163 
164 	ret = da9052_i2c_disable_multiwrite(da9052);
165 	if (ret < 0)
166 		return ret;
167 
168 #ifdef CONFIG_OF
169 	if (!id) {
170 		struct device_node *np = client->dev.of_node;
171 		const struct of_device_id *deviceid;
172 
173 		deviceid = of_match_node(dialog_dt_ids, np);
174 		id = deviceid->data;
175 	}
176 #endif
177 
178 	if (!id) {
179 		ret = -ENODEV;
180 		dev_err(&client->dev, "id is null.\n");
181 		return ret;
182 	}
183 
184 	ret = da9052_device_init(da9052, id->driver_data);
185 	if (ret != 0)
186 		return ret;
187 
188 	return 0;
189 }
190 
191 static int da9052_i2c_remove(struct i2c_client *client)
192 {
193 	struct da9052 *da9052 = i2c_get_clientdata(client);
194 
195 	da9052_device_exit(da9052);
196 	return 0;
197 }
198 
199 static struct i2c_driver da9052_i2c_driver = {
200 	.probe = da9052_i2c_probe,
201 	.remove = da9052_i2c_remove,
202 	.id_table = da9052_i2c_id,
203 	.driver = {
204 		.name = "da9052",
205 		.owner = THIS_MODULE,
206 #ifdef CONFIG_OF
207 		.of_match_table = dialog_dt_ids,
208 #endif
209 	},
210 };
211 
212 static int __init da9052_i2c_init(void)
213 {
214 	int ret;
215 
216 	ret = i2c_add_driver(&da9052_i2c_driver);
217 	if (ret != 0) {
218 		pr_err("DA9052 I2C registration failed %d\n", ret);
219 		return ret;
220 	}
221 
222 	return 0;
223 }
224 subsys_initcall(da9052_i2c_init);
225 
226 static void __exit da9052_i2c_exit(void)
227 {
228 	i2c_del_driver(&da9052_i2c_driver);
229 }
230 module_exit(da9052_i2c_exit);
231 
232 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
233 MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
234 MODULE_LICENSE("GPL");
235