1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for the Intel P-Unit Mailbox IPC mechanism
4 *
5 * (C) Copyright 2015 Intel Corporation
6 *
7 * The heart of the P-Unit is the Foxton microcontroller and its firmware,
8 * which provide mailbox interface for power management usage.
9 */
10
11 #include <linux/bitops.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19
20 #include <asm/intel_punit_ipc.h>
21
22 /* IPC Mailbox registers */
23 #define OFFSET_DATA_LOW 0x0
24 #define OFFSET_DATA_HIGH 0x4
25 /* bit field of interface register */
26 #define CMD_RUN BIT(31)
27 #define CMD_ERRCODE_MASK GENMASK(7, 0)
28 #define CMD_PARA1_SHIFT 8
29 #define CMD_PARA2_SHIFT 16
30
31 #define CMD_TIMEOUT_SECONDS 1
32
33 enum {
34 BASE_DATA = 0,
35 BASE_IFACE,
36 BASE_MAX,
37 };
38
39 typedef struct {
40 struct device *dev;
41 struct mutex lock;
42 int irq;
43 struct completion cmd_complete;
44 /* base of interface and data registers */
45 void __iomem *base[RESERVED_IPC][BASE_MAX];
46 IPC_TYPE type;
47 } IPC_DEV;
48
49 static IPC_DEV *punit_ipcdev;
50
ipc_read_status(IPC_DEV * ipcdev,IPC_TYPE type)51 static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
52 {
53 return readl(ipcdev->base[type][BASE_IFACE]);
54 }
55
ipc_write_cmd(IPC_DEV * ipcdev,IPC_TYPE type,u32 cmd)56 static inline void ipc_write_cmd(IPC_DEV *ipcdev, IPC_TYPE type, u32 cmd)
57 {
58 writel(cmd, ipcdev->base[type][BASE_IFACE]);
59 }
60
ipc_read_data_low(IPC_DEV * ipcdev,IPC_TYPE type)61 static inline u32 ipc_read_data_low(IPC_DEV *ipcdev, IPC_TYPE type)
62 {
63 return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
64 }
65
ipc_read_data_high(IPC_DEV * ipcdev,IPC_TYPE type)66 static inline u32 ipc_read_data_high(IPC_DEV *ipcdev, IPC_TYPE type)
67 {
68 return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
69 }
70
ipc_write_data_low(IPC_DEV * ipcdev,IPC_TYPE type,u32 data)71 static inline void ipc_write_data_low(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
72 {
73 writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
74 }
75
ipc_write_data_high(IPC_DEV * ipcdev,IPC_TYPE type,u32 data)76 static inline void ipc_write_data_high(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
77 {
78 writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
79 }
80
ipc_err_string(int error)81 static const char *ipc_err_string(int error)
82 {
83 if (error == IPC_PUNIT_ERR_SUCCESS)
84 return "no error";
85 else if (error == IPC_PUNIT_ERR_INVALID_CMD)
86 return "invalid command";
87 else if (error == IPC_PUNIT_ERR_INVALID_PARAMETER)
88 return "invalid parameter";
89 else if (error == IPC_PUNIT_ERR_CMD_TIMEOUT)
90 return "command timeout";
91 else if (error == IPC_PUNIT_ERR_CMD_LOCKED)
92 return "command locked";
93 else if (error == IPC_PUNIT_ERR_INVALID_VR_ID)
94 return "invalid vr id";
95 else if (error == IPC_PUNIT_ERR_VR_ERR)
96 return "vr error";
97 else
98 return "unknown error";
99 }
100
intel_punit_ipc_check_status(IPC_DEV * ipcdev,IPC_TYPE type)101 static int intel_punit_ipc_check_status(IPC_DEV *ipcdev, IPC_TYPE type)
102 {
103 int loops = CMD_TIMEOUT_SECONDS * USEC_PER_SEC;
104 int errcode;
105 int status;
106
107 if (ipcdev->irq) {
108 if (!wait_for_completion_timeout(&ipcdev->cmd_complete,
109 CMD_TIMEOUT_SECONDS * HZ)) {
110 dev_err(ipcdev->dev, "IPC timed out\n");
111 return -ETIMEDOUT;
112 }
113 } else {
114 while ((ipc_read_status(ipcdev, type) & CMD_RUN) && --loops)
115 udelay(1);
116 if (!loops) {
117 dev_err(ipcdev->dev, "IPC timed out\n");
118 return -ETIMEDOUT;
119 }
120 }
121
122 status = ipc_read_status(ipcdev, type);
123 errcode = status & CMD_ERRCODE_MASK;
124 if (errcode) {
125 dev_err(ipcdev->dev, "IPC failed: %s, IPC_STS=0x%x\n",
126 ipc_err_string(errcode), status);
127 return -EIO;
128 }
129
130 return 0;
131 }
132
133 /**
134 * intel_punit_ipc_command() - IPC command with data and pointers
135 * @cmd: IPC command code.
136 * @para1: First 8bit parameter, set 0 if not used.
137 * @para2: Second 8bit parameter, set 0 if not used.
138 * @in: Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
139 * @out: Output data.
140 *
141 * Send a IPC command to P-Unit with data transaction
142 *
143 * Return: IPC error code or 0 on success.
144 */
intel_punit_ipc_command(u32 cmd,u32 para1,u32 para2,u32 * in,u32 * out)145 int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
146 {
147 IPC_DEV *ipcdev = punit_ipcdev;
148 IPC_TYPE type;
149 u32 val;
150 int ret;
151
152 mutex_lock(&ipcdev->lock);
153
154 reinit_completion(&ipcdev->cmd_complete);
155 type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
156
157 if (in) {
158 ipc_write_data_low(ipcdev, type, *in);
159 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
160 ipc_write_data_high(ipcdev, type, *++in);
161 }
162
163 val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
164 val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
165 ipc_write_cmd(ipcdev, type, val);
166
167 ret = intel_punit_ipc_check_status(ipcdev, type);
168 if (ret)
169 goto out;
170
171 if (out) {
172 *out = ipc_read_data_low(ipcdev, type);
173 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
174 *++out = ipc_read_data_high(ipcdev, type);
175 }
176
177 out:
178 mutex_unlock(&ipcdev->lock);
179 return ret;
180 }
181 EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
182
intel_punit_ioc(int irq,void * dev_id)183 static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
184 {
185 IPC_DEV *ipcdev = dev_id;
186
187 complete(&ipcdev->cmd_complete);
188 return IRQ_HANDLED;
189 }
190
intel_punit_get_bars(struct platform_device * pdev)191 static int intel_punit_get_bars(struct platform_device *pdev)
192 {
193 void __iomem *addr;
194
195 /*
196 * The following resources are required
197 * - BIOS_IPC BASE_DATA
198 * - BIOS_IPC BASE_IFACE
199 */
200 addr = devm_platform_ioremap_resource(pdev, 0);
201 if (IS_ERR(addr))
202 return PTR_ERR(addr);
203 punit_ipcdev->base[BIOS_IPC][BASE_DATA] = addr;
204
205 addr = devm_platform_ioremap_resource(pdev, 1);
206 if (IS_ERR(addr))
207 return PTR_ERR(addr);
208 punit_ipcdev->base[BIOS_IPC][BASE_IFACE] = addr;
209
210 /*
211 * The following resources are optional
212 * - ISPDRIVER_IPC BASE_DATA
213 * - ISPDRIVER_IPC BASE_IFACE
214 * - GTDRIVER_IPC BASE_DATA
215 * - GTDRIVER_IPC BASE_IFACE
216 */
217 addr = devm_platform_ioremap_resource(pdev, 2);
218 if (!IS_ERR(addr))
219 punit_ipcdev->base[ISPDRIVER_IPC][BASE_DATA] = addr;
220
221 addr = devm_platform_ioremap_resource(pdev, 3);
222 if (!IS_ERR(addr))
223 punit_ipcdev->base[ISPDRIVER_IPC][BASE_IFACE] = addr;
224
225 addr = devm_platform_ioremap_resource(pdev, 4);
226 if (!IS_ERR(addr))
227 punit_ipcdev->base[GTDRIVER_IPC][BASE_DATA] = addr;
228
229 addr = devm_platform_ioremap_resource(pdev, 5);
230 if (!IS_ERR(addr))
231 punit_ipcdev->base[GTDRIVER_IPC][BASE_IFACE] = addr;
232
233 return 0;
234 }
235
intel_punit_ipc_probe(struct platform_device * pdev)236 static int intel_punit_ipc_probe(struct platform_device *pdev)
237 {
238 int irq, ret;
239
240 punit_ipcdev = devm_kzalloc(&pdev->dev,
241 sizeof(*punit_ipcdev), GFP_KERNEL);
242 if (!punit_ipcdev)
243 return -ENOMEM;
244
245 platform_set_drvdata(pdev, punit_ipcdev);
246
247 irq = platform_get_irq_optional(pdev, 0);
248 if (irq < 0) {
249 dev_warn(&pdev->dev, "Invalid IRQ, using polling mode\n");
250 } else {
251 ret = devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
252 IRQF_NO_SUSPEND, "intel_punit_ipc",
253 &punit_ipcdev);
254 if (ret) {
255 dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
256 return ret;
257 }
258 punit_ipcdev->irq = irq;
259 }
260
261 ret = intel_punit_get_bars(pdev);
262 if (ret)
263 return ret;
264
265 punit_ipcdev->dev = &pdev->dev;
266 mutex_init(&punit_ipcdev->lock);
267 init_completion(&punit_ipcdev->cmd_complete);
268
269 return 0;
270 }
271
272 static const struct acpi_device_id punit_ipc_acpi_ids[] = {
273 { "INT34D4", 0 },
274 { }
275 };
276 MODULE_DEVICE_TABLE(acpi, punit_ipc_acpi_ids);
277
278 static struct platform_driver intel_punit_ipc_driver = {
279 .probe = intel_punit_ipc_probe,
280 .driver = {
281 .name = "intel_punit_ipc",
282 .acpi_match_table = punit_ipc_acpi_ids,
283 },
284 };
285
intel_punit_ipc_init(void)286 static int __init intel_punit_ipc_init(void)
287 {
288 return platform_driver_register(&intel_punit_ipc_driver);
289 }
290
intel_punit_ipc_exit(void)291 static void __exit intel_punit_ipc_exit(void)
292 {
293 platform_driver_unregister(&intel_punit_ipc_driver);
294 }
295
296 MODULE_AUTHOR("Zha Qipeng <[email protected]>");
297 MODULE_DESCRIPTION("Intel P-Unit IPC driver");
298 MODULE_LICENSE("GPL v2");
299
300 /* Some modules are dependent on this, so init earlier */
301 fs_initcall(intel_punit_ipc_init);
302 module_exit(intel_punit_ipc_exit);
303