1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * extcon driver for Basin Cove PMIC
4 *
5 * Copyright (c) 2019, Intel Corporation.
6 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
7 */
8
9 #include <linux/extcon-provider.h>
10 #include <linux/interrupt.h>
11 #include <linux/mfd/intel_soc_pmic.h>
12 #include <linux/mfd/intel_soc_pmic_mrfld.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17
18 #include "extcon-intel.h"
19
20 #define BCOVE_USBIDCTRL 0x19
21 #define BCOVE_USBIDCTRL_ID BIT(0)
22 #define BCOVE_USBIDCTRL_ACA BIT(1)
23 #define BCOVE_USBIDCTRL_ALL (BCOVE_USBIDCTRL_ID | BCOVE_USBIDCTRL_ACA)
24
25 #define BCOVE_USBIDSTS 0x1a
26 #define BCOVE_USBIDSTS_GND BIT(0)
27 #define BCOVE_USBIDSTS_RARBRC_MASK GENMASK(2, 1)
28 #define BCOVE_USBIDSTS_RARBRC_SHIFT 1
29 #define BCOVE_USBIDSTS_NO_ACA 0
30 #define BCOVE_USBIDSTS_R_ID_A 1
31 #define BCOVE_USBIDSTS_R_ID_B 2
32 #define BCOVE_USBIDSTS_R_ID_C 3
33 #define BCOVE_USBIDSTS_FLOAT BIT(3)
34 #define BCOVE_USBIDSTS_SHORT BIT(4)
35
36 #define BCOVE_CHGRIRQ_ALL (BCOVE_CHGRIRQ_VBUSDET | BCOVE_CHGRIRQ_DCDET | \
37 BCOVE_CHGRIRQ_BATTDET | BCOVE_CHGRIRQ_USBIDDET)
38
39 #define BCOVE_CHGRCTRL0 0x4b
40 #define BCOVE_CHGRCTRL0_CHGRRESET BIT(0)
41 #define BCOVE_CHGRCTRL0_EMRGCHREN BIT(1)
42 #define BCOVE_CHGRCTRL0_EXTCHRDIS BIT(2)
43 #define BCOVE_CHGRCTRL0_SWCONTROL BIT(3)
44 #define BCOVE_CHGRCTRL0_TTLCK BIT(4)
45 #define BCOVE_CHGRCTRL0_BIT_5 BIT(5)
46 #define BCOVE_CHGRCTRL0_BIT_6 BIT(6)
47 #define BCOVE_CHGRCTRL0_CHR_WDT_NOKICK BIT(7)
48
49 struct mrfld_extcon_data {
50 struct device *dev;
51 struct regmap *regmap;
52 struct extcon_dev *edev;
53 unsigned int status;
54 unsigned int id;
55 };
56
57 static const unsigned int mrfld_extcon_cable[] = {
58 EXTCON_USB,
59 EXTCON_USB_HOST,
60 EXTCON_CHG_USB_SDP,
61 EXTCON_CHG_USB_CDP,
62 EXTCON_CHG_USB_DCP,
63 EXTCON_CHG_USB_ACA,
64 EXTCON_NONE,
65 };
66
mrfld_extcon_clear(struct mrfld_extcon_data * data,unsigned int reg,unsigned int mask)67 static int mrfld_extcon_clear(struct mrfld_extcon_data *data, unsigned int reg,
68 unsigned int mask)
69 {
70 return regmap_update_bits(data->regmap, reg, mask, 0x00);
71 }
72
mrfld_extcon_set(struct mrfld_extcon_data * data,unsigned int reg,unsigned int mask)73 static int mrfld_extcon_set(struct mrfld_extcon_data *data, unsigned int reg,
74 unsigned int mask)
75 {
76 return regmap_update_bits(data->regmap, reg, mask, 0xff);
77 }
78
mrfld_extcon_sw_control(struct mrfld_extcon_data * data,bool enable)79 static int mrfld_extcon_sw_control(struct mrfld_extcon_data *data, bool enable)
80 {
81 unsigned int mask = BCOVE_CHGRCTRL0_SWCONTROL;
82 struct device *dev = data->dev;
83 int ret;
84
85 if (enable)
86 ret = mrfld_extcon_set(data, BCOVE_CHGRCTRL0, mask);
87 else
88 ret = mrfld_extcon_clear(data, BCOVE_CHGRCTRL0, mask);
89 if (ret)
90 dev_err(dev, "can't set SW control: %d\n", ret);
91 return ret;
92 }
93
mrfld_extcon_get_id(struct mrfld_extcon_data * data)94 static int mrfld_extcon_get_id(struct mrfld_extcon_data *data)
95 {
96 struct regmap *regmap = data->regmap;
97 unsigned int id;
98 bool ground;
99 int ret;
100
101 ret = regmap_read(regmap, BCOVE_USBIDSTS, &id);
102 if (ret)
103 return ret;
104
105 if (id & BCOVE_USBIDSTS_FLOAT)
106 return INTEL_USB_ID_FLOAT;
107
108 switch ((id & BCOVE_USBIDSTS_RARBRC_MASK) >> BCOVE_USBIDSTS_RARBRC_SHIFT) {
109 case BCOVE_USBIDSTS_R_ID_A:
110 return INTEL_USB_RID_A;
111 case BCOVE_USBIDSTS_R_ID_B:
112 return INTEL_USB_RID_B;
113 case BCOVE_USBIDSTS_R_ID_C:
114 return INTEL_USB_RID_C;
115 }
116
117 /*
118 * PMIC A0 reports USBIDSTS_GND = 1 for ID_GND,
119 * but PMIC B0 reports USBIDSTS_GND = 0 for ID_GND.
120 * Thus we must check this bit at last.
121 */
122 ground = id & BCOVE_USBIDSTS_GND;
123 switch ('A' + BCOVE_MAJOR(data->id)) {
124 case 'A':
125 return ground ? INTEL_USB_ID_GND : INTEL_USB_ID_FLOAT;
126 case 'B':
127 return ground ? INTEL_USB_ID_FLOAT : INTEL_USB_ID_GND;
128 }
129
130 /* Unknown or unsupported type */
131 return INTEL_USB_ID_FLOAT;
132 }
133
mrfld_extcon_role_detect(struct mrfld_extcon_data * data)134 static int mrfld_extcon_role_detect(struct mrfld_extcon_data *data)
135 {
136 unsigned int id;
137 bool usb_host;
138 int ret;
139
140 ret = mrfld_extcon_get_id(data);
141 if (ret < 0)
142 return ret;
143
144 id = ret;
145
146 usb_host = (id == INTEL_USB_ID_GND) || (id == INTEL_USB_RID_A);
147 extcon_set_state_sync(data->edev, EXTCON_USB_HOST, usb_host);
148
149 return 0;
150 }
151
mrfld_extcon_cable_detect(struct mrfld_extcon_data * data)152 static int mrfld_extcon_cable_detect(struct mrfld_extcon_data *data)
153 {
154 struct regmap *regmap = data->regmap;
155 unsigned int status, change;
156 int ret;
157
158 /*
159 * It seems SCU firmware clears the content of BCOVE_CHGRIRQ1
160 * and makes it useless for OS. Instead we compare a previously
161 * stored status to the current one, provided by BCOVE_SCHGRIRQ1.
162 */
163 ret = regmap_read(regmap, BCOVE_SCHGRIRQ1, &status);
164 if (ret)
165 return ret;
166
167 change = status ^ data->status;
168 if (!change)
169 return -ENODATA;
170
171 if (change & BCOVE_CHGRIRQ_USBIDDET) {
172 ret = mrfld_extcon_role_detect(data);
173 if (ret)
174 return ret;
175 }
176
177 data->status = status;
178
179 return 0;
180 }
181
mrfld_extcon_interrupt(int irq,void * dev_id)182 static irqreturn_t mrfld_extcon_interrupt(int irq, void *dev_id)
183 {
184 struct mrfld_extcon_data *data = dev_id;
185 int ret;
186
187 ret = mrfld_extcon_cable_detect(data);
188
189 mrfld_extcon_clear(data, BCOVE_MIRQLVL1, BCOVE_LVL1_CHGR);
190
191 return ret ? IRQ_NONE: IRQ_HANDLED;
192 }
193
mrfld_extcon_probe(struct platform_device * pdev)194 static int mrfld_extcon_probe(struct platform_device *pdev)
195 {
196 struct device *dev = &pdev->dev;
197 struct intel_soc_pmic *pmic = dev_get_drvdata(dev->parent);
198 struct regmap *regmap = pmic->regmap;
199 struct mrfld_extcon_data *data;
200 unsigned int status;
201 unsigned int id;
202 int irq, ret;
203
204 irq = platform_get_irq(pdev, 0);
205 if (irq < 0)
206 return irq;
207
208 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
209 if (!data)
210 return -ENOMEM;
211
212 data->dev = dev;
213 data->regmap = regmap;
214
215 data->edev = devm_extcon_dev_allocate(dev, mrfld_extcon_cable);
216 if (IS_ERR(data->edev))
217 return PTR_ERR(data->edev);
218
219 ret = devm_extcon_dev_register(dev, data->edev);
220 if (ret < 0)
221 return dev_err_probe(dev, ret, "can't register extcon device\n");
222
223 ret = devm_request_threaded_irq(dev, irq, NULL, mrfld_extcon_interrupt,
224 IRQF_ONESHOT | IRQF_SHARED, pdev->name,
225 data);
226 if (ret)
227 return dev_err_probe(dev, ret, "can't register IRQ handler\n");
228
229 ret = regmap_read(regmap, BCOVE_ID, &id);
230 if (ret)
231 return dev_err_probe(dev, ret, "can't read PMIC ID\n");
232
233 data->id = id;
234
235 ret = mrfld_extcon_sw_control(data, true);
236 if (ret)
237 return ret;
238
239 /* Get initial state */
240 mrfld_extcon_role_detect(data);
241
242 /*
243 * Cached status value is used for cable detection, see comments
244 * in mrfld_extcon_cable_detect(), we need to sync cached value
245 * with a real state of the hardware.
246 */
247 regmap_read(regmap, BCOVE_SCHGRIRQ1, &status);
248 data->status = status;
249
250 mrfld_extcon_clear(data, BCOVE_MIRQLVL1, BCOVE_LVL1_CHGR);
251 mrfld_extcon_clear(data, BCOVE_MCHGRIRQ1, BCOVE_CHGRIRQ_ALL);
252
253 mrfld_extcon_set(data, BCOVE_USBIDCTRL, BCOVE_USBIDCTRL_ALL);
254
255 platform_set_drvdata(pdev, data);
256
257 return 0;
258 }
259
mrfld_extcon_remove(struct platform_device * pdev)260 static void mrfld_extcon_remove(struct platform_device *pdev)
261 {
262 struct mrfld_extcon_data *data = platform_get_drvdata(pdev);
263
264 mrfld_extcon_sw_control(data, false);
265 }
266
267 static const struct platform_device_id mrfld_extcon_id_table[] = {
268 { .name = "mrfld_bcove_pwrsrc" },
269 {}
270 };
271 MODULE_DEVICE_TABLE(platform, mrfld_extcon_id_table);
272
273 static struct platform_driver mrfld_extcon_driver = {
274 .driver = {
275 .name = "mrfld_bcove_pwrsrc",
276 },
277 .probe = mrfld_extcon_probe,
278 .remove = mrfld_extcon_remove,
279 .id_table = mrfld_extcon_id_table,
280 };
281 module_platform_driver(mrfld_extcon_driver);
282
283 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
284 MODULE_DESCRIPTION("extcon driver for Intel Merrifield Basin Cove PMIC");
285 MODULE_LICENSE("GPL v2");
286