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 
51 static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
52 {
53 	return readl(ipcdev->base[type][BASE_IFACE]);
54 }
55 
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 
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 
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 
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 
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 
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 
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_simple_command() - Simple IPC command
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  *
139  * Send a IPC command to P-Unit when there is no data transaction
140  *
141  * Return:	IPC error code or 0 on success.
142  */
143 int intel_punit_ipc_simple_command(int cmd, int para1, int para2)
144 {
145 	IPC_DEV *ipcdev = punit_ipcdev;
146 	IPC_TYPE type;
147 	u32 val;
148 	int ret;
149 
150 	mutex_lock(&ipcdev->lock);
151 
152 	reinit_completion(&ipcdev->cmd_complete);
153 	type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
154 
155 	val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
156 	val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
157 	ipc_write_cmd(ipcdev, type, val);
158 	ret = intel_punit_ipc_check_status(ipcdev, type);
159 
160 	mutex_unlock(&ipcdev->lock);
161 
162 	return ret;
163 }
164 EXPORT_SYMBOL(intel_punit_ipc_simple_command);
165 
166 /**
167  * intel_punit_ipc_command() - IPC command with data and pointers
168  * @cmd:	IPC command code.
169  * @para1:	First 8bit parameter, set 0 if not used.
170  * @para2:	Second 8bit parameter, set 0 if not used.
171  * @in:		Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
172  * @out:	Output data.
173  *
174  * Send a IPC command to P-Unit with data transaction
175  *
176  * Return:	IPC error code or 0 on success.
177  */
178 int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
179 {
180 	IPC_DEV *ipcdev = punit_ipcdev;
181 	IPC_TYPE type;
182 	u32 val;
183 	int ret;
184 
185 	mutex_lock(&ipcdev->lock);
186 
187 	reinit_completion(&ipcdev->cmd_complete);
188 	type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
189 
190 	if (in) {
191 		ipc_write_data_low(ipcdev, type, *in);
192 		if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
193 			ipc_write_data_high(ipcdev, type, *++in);
194 	}
195 
196 	val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
197 	val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
198 	ipc_write_cmd(ipcdev, type, val);
199 
200 	ret = intel_punit_ipc_check_status(ipcdev, type);
201 	if (ret)
202 		goto out;
203 
204 	if (out) {
205 		*out = ipc_read_data_low(ipcdev, type);
206 		if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
207 			*++out = ipc_read_data_high(ipcdev, type);
208 	}
209 
210 out:
211 	mutex_unlock(&ipcdev->lock);
212 	return ret;
213 }
214 EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
215 
216 static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
217 {
218 	IPC_DEV *ipcdev = dev_id;
219 
220 	complete(&ipcdev->cmd_complete);
221 	return IRQ_HANDLED;
222 }
223 
224 static int intel_punit_get_bars(struct platform_device *pdev)
225 {
226 	void __iomem *addr;
227 
228 	/*
229 	 * The following resources are required
230 	 * - BIOS_IPC BASE_DATA
231 	 * - BIOS_IPC BASE_IFACE
232 	 */
233 	addr = devm_platform_ioremap_resource(pdev, 0);
234 	if (IS_ERR(addr))
235 		return PTR_ERR(addr);
236 	punit_ipcdev->base[BIOS_IPC][BASE_DATA] = addr;
237 
238 	addr = devm_platform_ioremap_resource(pdev, 1);
239 	if (IS_ERR(addr))
240 		return PTR_ERR(addr);
241 	punit_ipcdev->base[BIOS_IPC][BASE_IFACE] = addr;
242 
243 	/*
244 	 * The following resources are optional
245 	 * - ISPDRIVER_IPC BASE_DATA
246 	 * - ISPDRIVER_IPC BASE_IFACE
247 	 * - GTDRIVER_IPC BASE_DATA
248 	 * - GTDRIVER_IPC BASE_IFACE
249 	 */
250 	addr = devm_platform_ioremap_resource(pdev, 2);
251 	if (!IS_ERR(addr))
252 		punit_ipcdev->base[ISPDRIVER_IPC][BASE_DATA] = addr;
253 
254 	addr = devm_platform_ioremap_resource(pdev, 3);
255 	if (!IS_ERR(addr))
256 		punit_ipcdev->base[ISPDRIVER_IPC][BASE_IFACE] = addr;
257 
258 	addr = devm_platform_ioremap_resource(pdev, 4);
259 	if (!IS_ERR(addr))
260 		punit_ipcdev->base[GTDRIVER_IPC][BASE_DATA] = addr;
261 
262 	addr = devm_platform_ioremap_resource(pdev, 5);
263 	if (!IS_ERR(addr))
264 		punit_ipcdev->base[GTDRIVER_IPC][BASE_IFACE] = addr;
265 
266 	return 0;
267 }
268 
269 static int intel_punit_ipc_probe(struct platform_device *pdev)
270 {
271 	int irq, ret;
272 
273 	punit_ipcdev = devm_kzalloc(&pdev->dev,
274 				    sizeof(*punit_ipcdev), GFP_KERNEL);
275 	if (!punit_ipcdev)
276 		return -ENOMEM;
277 
278 	platform_set_drvdata(pdev, punit_ipcdev);
279 
280 	irq = platform_get_irq_optional(pdev, 0);
281 	if (irq < 0) {
282 		dev_warn(&pdev->dev, "Invalid IRQ, using polling mode\n");
283 	} else {
284 		ret = devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
285 				       IRQF_NO_SUSPEND, "intel_punit_ipc",
286 				       &punit_ipcdev);
287 		if (ret) {
288 			dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
289 			return ret;
290 		}
291 		punit_ipcdev->irq = irq;
292 	}
293 
294 	ret = intel_punit_get_bars(pdev);
295 	if (ret)
296 		return ret;
297 
298 	punit_ipcdev->dev = &pdev->dev;
299 	mutex_init(&punit_ipcdev->lock);
300 	init_completion(&punit_ipcdev->cmd_complete);
301 
302 	return 0;
303 }
304 
305 static const struct acpi_device_id punit_ipc_acpi_ids[] = {
306 	{ "INT34D4", 0 },
307 	{ }
308 };
309 MODULE_DEVICE_TABLE(acpi, punit_ipc_acpi_ids);
310 
311 static struct platform_driver intel_punit_ipc_driver = {
312 	.probe = intel_punit_ipc_probe,
313 	.driver = {
314 		.name = "intel_punit_ipc",
315 		.acpi_match_table = punit_ipc_acpi_ids,
316 	},
317 };
318 
319 static int __init intel_punit_ipc_init(void)
320 {
321 	return platform_driver_register(&intel_punit_ipc_driver);
322 }
323 
324 static void __exit intel_punit_ipc_exit(void)
325 {
326 	platform_driver_unregister(&intel_punit_ipc_driver);
327 }
328 
329 MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
330 MODULE_DESCRIPTION("Intel P-Unit IPC driver");
331 MODULE_LICENSE("GPL v2");
332 
333 /* Some modules are dependent on this, so init earlier */
334 fs_initcall(intel_punit_ipc_init);
335 module_exit(intel_punit_ipc_exit);
336