punit_ipc.c

  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
 33enum {
 34	BASE_DATA = 0,
 35	BASE_IFACE,
 36	BASE_MAX,
 37};
 38
 39typedef 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
 49static IPC_DEV *punit_ipcdev;
 50
 51static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
 52{
 53	return readl(ipcdev->base[type][BASE_IFACE]);
 54}
 55
 56static inline void ipc_write_cmd(IPC_DEV *ipcdev, IPC_TYPE type, u32 cmd)
 57{
 58	writel(cmd, ipcdev->base[type][BASE_IFACE]);
 59}
 60
 61static 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
 66static 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
 71static 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
 76static 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
 81static 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
101static 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 */
145int 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
177out:
178	mutex_unlock(&ipcdev->lock);
179	return ret;
180}
181EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
182
183static 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
191static 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
236static 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
272static const struct acpi_device_id punit_ipc_acpi_ids[] = {
273	{ "INT34D4", 0 },
274	{ }
275};
276MODULE_DEVICE_TABLE(acpi, punit_ipc_acpi_ids);
277
278static 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
286static int __init intel_punit_ipc_init(void)
287{
288	return platform_driver_register(&intel_punit_ipc_driver);
289}
290
291static void __exit intel_punit_ipc_exit(void)
292{
293	platform_driver_unregister(&intel_punit_ipc_driver);
294}
295
296MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
297MODULE_DESCRIPTION("Intel P-Unit IPC driver");
298MODULE_LICENSE("GPL v2");
299
300/* Some modules are dependent on this, so init earlier */
301fs_initcall(intel_punit_ipc_init);
302module_exit(intel_punit_ipc_exit);