xref: /linux/drivers/misc/mei/gsc-me.c (revision 7e6739b9336e61fe23ca4e2c8d1fda8f19f979bf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright(c) 2019-2022, Intel Corporation. All rights reserved.
4  *
5  * Intel Management Engine Interface (Intel MEI) Linux driver
6  */
7 
8 #include <linux/module.h>
9 #include <linux/mei_aux.h>
10 #include <linux/device.h>
11 #include <linux/irqreturn.h>
12 #include <linux/jiffies.h>
13 #include <linux/ktime.h>
14 #include <linux/delay.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/kthread.h>
17 
18 #include "mei_dev.h"
19 #include "hw-me.h"
20 #include "hw-me-regs.h"
21 
22 #include "mei-trace.h"
23 
24 #define MEI_GSC_RPM_TIMEOUT 500
25 
26 static int mei_gsc_read_hfs(const struct mei_device *dev, int where, u32 *val)
27 {
28 	struct mei_me_hw *hw = to_me_hw(dev);
29 
30 	*val = ioread32(hw->mem_addr + where + 0xC00);
31 
32 	return 0;
33 }
34 
35 static void mei_gsc_set_ext_op_mem(const struct mei_me_hw *hw, struct resource *mem)
36 {
37 	u32 low = lower_32_bits(mem->start);
38 	u32 hi  = upper_32_bits(mem->start);
39 	u32 limit = (resource_size(mem) / SZ_4K) | GSC_EXT_OP_MEM_VALID;
40 
41 	iowrite32(low, hw->mem_addr + H_GSC_EXT_OP_MEM_BASE_ADDR_LO_REG);
42 	iowrite32(hi, hw->mem_addr + H_GSC_EXT_OP_MEM_BASE_ADDR_HI_REG);
43 	iowrite32(limit, hw->mem_addr + H_GSC_EXT_OP_MEM_LIMIT_REG);
44 }
45 
46 static int mei_gsc_probe(struct auxiliary_device *aux_dev,
47 			 const struct auxiliary_device_id *aux_dev_id)
48 {
49 	struct mei_aux_device *adev = auxiliary_dev_to_mei_aux_dev(aux_dev);
50 	struct mei_device *dev;
51 	struct mei_me_hw *hw;
52 	struct device *device;
53 	const struct mei_cfg *cfg;
54 	int ret;
55 
56 	cfg = mei_me_get_cfg(aux_dev_id->driver_data);
57 	if (!cfg)
58 		return -ENODEV;
59 
60 	device = &aux_dev->dev;
61 
62 	dev = mei_me_dev_init(device, cfg, adev->slow_firmware);
63 	if (!dev) {
64 		ret = -ENOMEM;
65 		goto err;
66 	}
67 
68 	hw = to_me_hw(dev);
69 	hw->mem_addr = devm_ioremap_resource(device, &adev->bar);
70 	if (IS_ERR(hw->mem_addr)) {
71 		dev_err(device, "mmio not mapped\n");
72 		ret = PTR_ERR(hw->mem_addr);
73 		goto err;
74 	}
75 
76 	hw->irq = adev->irq;
77 	hw->read_fws = mei_gsc_read_hfs;
78 
79 	dev_set_drvdata(device, dev);
80 
81 	if (adev->ext_op_mem.start) {
82 		mei_gsc_set_ext_op_mem(hw, &adev->ext_op_mem);
83 		dev->pxp_mode = MEI_DEV_PXP_INIT;
84 	}
85 
86 	/* use polling */
87 	if (mei_me_hw_use_polling(hw)) {
88 		mei_disable_interrupts(dev);
89 		mei_clear_interrupts(dev);
90 		init_waitqueue_head(&hw->wait_active);
91 		hw->is_active = true; /* start in active mode for initialization */
92 		hw->polling_thread = kthread_run(mei_me_polling_thread, dev,
93 						 "kmegscirqd/%s", dev_name(device));
94 		if (IS_ERR(hw->polling_thread)) {
95 			ret = PTR_ERR(hw->polling_thread);
96 			dev_err(device, "unable to create kernel thread: %d\n", ret);
97 			goto err;
98 		}
99 	} else {
100 		ret = devm_request_threaded_irq(device, hw->irq,
101 						mei_me_irq_quick_handler,
102 						mei_me_irq_thread_handler,
103 						IRQF_ONESHOT, KBUILD_MODNAME, dev);
104 		if (ret) {
105 			dev_err(device, "irq register failed %d\n", ret);
106 			goto err;
107 		}
108 	}
109 
110 	pm_runtime_get_noresume(device);
111 	pm_runtime_set_active(device);
112 	pm_runtime_enable(device);
113 
114 	/* Continue to char device setup in spite of firmware handshake failure.
115 	 * In order to provide access to the firmware status registers to the user
116 	 * space via sysfs.
117 	 */
118 	if (mei_start(dev))
119 		dev_warn(device, "init hw failure.\n");
120 
121 	pm_runtime_set_autosuspend_delay(device, MEI_GSC_RPM_TIMEOUT);
122 	pm_runtime_use_autosuspend(device);
123 
124 	ret = mei_register(dev, device);
125 	if (ret)
126 		goto register_err;
127 
128 	pm_runtime_put_noidle(device);
129 	return 0;
130 
131 register_err:
132 	mei_stop(dev);
133 	if (!mei_me_hw_use_polling(hw))
134 		devm_free_irq(device, hw->irq, dev);
135 
136 err:
137 	dev_err(device, "probe failed: %d\n", ret);
138 	dev_set_drvdata(device, NULL);
139 	return ret;
140 }
141 
142 static void mei_gsc_remove(struct auxiliary_device *aux_dev)
143 {
144 	struct mei_device *dev;
145 	struct mei_me_hw *hw;
146 
147 	dev = dev_get_drvdata(&aux_dev->dev);
148 	if (!dev)
149 		return;
150 
151 	hw = to_me_hw(dev);
152 
153 	mei_stop(dev);
154 
155 	hw = to_me_hw(dev);
156 	if (mei_me_hw_use_polling(hw))
157 		kthread_stop(hw->polling_thread);
158 
159 	mei_deregister(dev);
160 
161 	pm_runtime_disable(&aux_dev->dev);
162 
163 	mei_disable_interrupts(dev);
164 	if (!mei_me_hw_use_polling(hw))
165 		devm_free_irq(&aux_dev->dev, hw->irq, dev);
166 }
167 
168 static int __maybe_unused mei_gsc_pm_suspend(struct device *device)
169 {
170 	struct mei_device *dev = dev_get_drvdata(device);
171 
172 	if (!dev)
173 		return -ENODEV;
174 
175 	mei_stop(dev);
176 
177 	mei_disable_interrupts(dev);
178 
179 	return 0;
180 }
181 
182 static int __maybe_unused mei_gsc_pm_resume(struct device *device)
183 {
184 	struct mei_device *dev = dev_get_drvdata(device);
185 	struct auxiliary_device *aux_dev;
186 	struct mei_aux_device *adev;
187 	int err;
188 	struct mei_me_hw *hw;
189 
190 	if (!dev)
191 		return -ENODEV;
192 
193 	hw = to_me_hw(dev);
194 	aux_dev = to_auxiliary_dev(device);
195 	adev = auxiliary_dev_to_mei_aux_dev(aux_dev);
196 	if (adev->ext_op_mem.start) {
197 		mei_gsc_set_ext_op_mem(hw, &adev->ext_op_mem);
198 		dev->pxp_mode = MEI_DEV_PXP_INIT;
199 	}
200 
201 	err = mei_restart(dev);
202 	if (err)
203 		return err;
204 
205 	/* Start timer if stopped in suspend */
206 	schedule_delayed_work(&dev->timer_work, HZ);
207 
208 	return 0;
209 }
210 
211 static int __maybe_unused mei_gsc_pm_runtime_idle(struct device *device)
212 {
213 	struct mei_device *dev = dev_get_drvdata(device);
214 
215 	if (!dev)
216 		return -ENODEV;
217 	if (mei_write_is_idle(dev))
218 		pm_runtime_autosuspend(device);
219 
220 	return -EBUSY;
221 }
222 
223 static int  __maybe_unused mei_gsc_pm_runtime_suspend(struct device *device)
224 {
225 	struct mei_device *dev = dev_get_drvdata(device);
226 	struct mei_me_hw *hw;
227 	int ret;
228 
229 	if (!dev)
230 		return -ENODEV;
231 
232 	mutex_lock(&dev->device_lock);
233 
234 	if (mei_write_is_idle(dev)) {
235 		hw = to_me_hw(dev);
236 		hw->pg_state = MEI_PG_ON;
237 
238 		if (mei_me_hw_use_polling(hw))
239 			hw->is_active = false;
240 		ret = 0;
241 	} else {
242 		ret = -EAGAIN;
243 	}
244 
245 	mutex_unlock(&dev->device_lock);
246 
247 	return ret;
248 }
249 
250 static int __maybe_unused mei_gsc_pm_runtime_resume(struct device *device)
251 {
252 	struct mei_device *dev = dev_get_drvdata(device);
253 	struct mei_me_hw *hw;
254 	irqreturn_t irq_ret;
255 
256 	if (!dev)
257 		return -ENODEV;
258 
259 	mutex_lock(&dev->device_lock);
260 
261 	hw = to_me_hw(dev);
262 	hw->pg_state = MEI_PG_OFF;
263 
264 	if (mei_me_hw_use_polling(hw)) {
265 		hw->is_active = true;
266 		wake_up(&hw->wait_active);
267 	}
268 
269 	mutex_unlock(&dev->device_lock);
270 
271 	irq_ret = mei_me_irq_thread_handler(1, dev);
272 	if (irq_ret != IRQ_HANDLED)
273 		dev_err(dev->dev, "thread handler fail %d\n", irq_ret);
274 
275 	return 0;
276 }
277 
278 static const struct dev_pm_ops mei_gsc_pm_ops = {
279 	SET_SYSTEM_SLEEP_PM_OPS(mei_gsc_pm_suspend,
280 				mei_gsc_pm_resume)
281 	SET_RUNTIME_PM_OPS(mei_gsc_pm_runtime_suspend,
282 			   mei_gsc_pm_runtime_resume,
283 			   mei_gsc_pm_runtime_idle)
284 };
285 
286 static const struct auxiliary_device_id mei_gsc_id_table[] = {
287 	{
288 		.name = "i915.mei-gsc",
289 		.driver_data = MEI_ME_GSC_CFG,
290 
291 	},
292 	{
293 		.name = "i915.mei-gscfi",
294 		.driver_data = MEI_ME_GSCFI_CFG,
295 	},
296 	{
297 		/* sentinel */
298 	}
299 };
300 MODULE_DEVICE_TABLE(auxiliary, mei_gsc_id_table);
301 
302 static struct auxiliary_driver mei_gsc_driver = {
303 	.probe	= mei_gsc_probe,
304 	.remove = mei_gsc_remove,
305 	.driver = {
306 		/* auxiliary_driver_register() sets .name to be the modname */
307 		.pm = &mei_gsc_pm_ops,
308 	},
309 	.id_table = mei_gsc_id_table
310 };
311 module_auxiliary_driver(mei_gsc_driver);
312 
313 MODULE_AUTHOR("Intel Corporation");
314 MODULE_ALIAS("auxiliary:i915.mei-gsc");
315 MODULE_ALIAS("auxiliary:i915.mei-gscfi");
316 MODULE_LICENSE("GPL");
317