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