1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * Driver for the Intel Broxton PMC
4   *
5   * (C) Copyright 2014 - 2020 Intel Corporation
6   *
7   * This driver is based on Intel SCU IPC driver (intel_scu_ipc.c) by
8   * Sreedhara DS <sreedhara.ds@intel.com>
9   *
10   * The PMC (Power Management Controller) running on the ARC processor
11   * communicates with another entity running in the IA (Intel Architecture)
12   * core through an IPC (Intel Processor Communications) mechanism which in
13   * turn sends messages between the IA and the PMC.
14   */
15  
16  #include <linux/acpi.h>
17  #include <linux/delay.h>
18  #include <linux/errno.h>
19  #include <linux/interrupt.h>
20  #include <linux/io-64-nonatomic-lo-hi.h>
21  #include <linux/mfd/core.h>
22  #include <linux/mfd/intel_pmc_bxt.h>
23  #include <linux/module.h>
24  #include <linux/platform_device.h>
25  #include <linux/platform_data/itco_wdt.h>
26  #include <linux/platform_data/x86/intel_scu_ipc.h>
27  
28  /* Residency with clock rate at 19.2MHz to usecs */
29  #define S0IX_RESIDENCY_IN_USECS(d, s)		\
30  ({						\
31  	u64 result = 10ull * ((d) + (s));	\
32  	do_div(result, 192);			\
33  	result;					\
34  })
35  
36  /* Resources exported from IFWI */
37  #define PLAT_RESOURCE_IPC_INDEX		0
38  #define PLAT_RESOURCE_IPC_SIZE		0x1000
39  #define PLAT_RESOURCE_GCR_OFFSET	0x1000
40  #define PLAT_RESOURCE_GCR_SIZE		0x1000
41  #define PLAT_RESOURCE_BIOS_DATA_INDEX	1
42  #define PLAT_RESOURCE_BIOS_IFACE_INDEX	2
43  #define PLAT_RESOURCE_TELEM_SSRAM_INDEX	3
44  #define PLAT_RESOURCE_ISP_DATA_INDEX	4
45  #define PLAT_RESOURCE_ISP_IFACE_INDEX	5
46  #define PLAT_RESOURCE_GTD_DATA_INDEX	6
47  #define PLAT_RESOURCE_GTD_IFACE_INDEX	7
48  #define PLAT_RESOURCE_ACPI_IO_INDEX	0
49  
50  /*
51   * BIOS does not create an ACPI device for each PMC function, but
52   * exports multiple resources from one ACPI device (IPC) for multiple
53   * functions. This driver is responsible for creating a child device and
54   * to export resources for those functions.
55   */
56  #define SMI_EN_OFFSET			0x0040
57  #define SMI_EN_SIZE			4
58  #define TCO_BASE_OFFSET			0x0060
59  #define TCO_REGS_SIZE			16
60  #define TELEM_SSRAM_SIZE		240
61  #define TELEM_PMC_SSRAM_OFFSET		0x1b00
62  #define TELEM_PUNIT_SSRAM_OFFSET	0x1a00
63  
64  /* Commands */
65  #define PMC_NORTHPEAK_CTRL		0xed
66  
is_gcr_valid(u32 offset)67  static inline bool is_gcr_valid(u32 offset)
68  {
69  	return offset < PLAT_RESOURCE_GCR_SIZE - 8;
70  }
71  
72  /**
73   * intel_pmc_gcr_read64() - Read a 64-bit PMC GCR register
74   * @pmc: PMC device pointer
75   * @offset: offset of GCR register from GCR address base
76   * @data: data pointer for storing the register output
77   *
78   * Reads the 64-bit PMC GCR register at given offset.
79   *
80   * Return: Negative value on error or 0 on success.
81   */
intel_pmc_gcr_read64(struct intel_pmc_dev * pmc,u32 offset,u64 * data)82  int intel_pmc_gcr_read64(struct intel_pmc_dev *pmc, u32 offset, u64 *data)
83  {
84  	if (!is_gcr_valid(offset))
85  		return -EINVAL;
86  
87  	spin_lock(&pmc->gcr_lock);
88  	*data = readq(pmc->gcr_mem_base + offset);
89  	spin_unlock(&pmc->gcr_lock);
90  
91  	return 0;
92  }
93  EXPORT_SYMBOL_GPL(intel_pmc_gcr_read64);
94  
95  /**
96   * intel_pmc_gcr_update() - Update PMC GCR register bits
97   * @pmc: PMC device pointer
98   * @offset: offset of GCR register from GCR address base
99   * @mask: bit mask for update operation
100   * @val: update value
101   *
102   * Updates the bits of given GCR register as specified by
103   * @mask and @val.
104   *
105   * Return: Negative value on error or 0 on success.
106   */
intel_pmc_gcr_update(struct intel_pmc_dev * pmc,u32 offset,u32 mask,u32 val)107  int intel_pmc_gcr_update(struct intel_pmc_dev *pmc, u32 offset, u32 mask, u32 val)
108  {
109  	u32 new_val;
110  
111  	if (!is_gcr_valid(offset))
112  		return -EINVAL;
113  
114  	spin_lock(&pmc->gcr_lock);
115  	new_val = readl(pmc->gcr_mem_base + offset);
116  
117  	new_val = (new_val & ~mask) | (val & mask);
118  	writel(new_val, pmc->gcr_mem_base + offset);
119  
120  	new_val = readl(pmc->gcr_mem_base + offset);
121  	spin_unlock(&pmc->gcr_lock);
122  
123  	/* Check whether the bit update is successful */
124  	return (new_val & mask) != (val & mask) ? -EIO : 0;
125  }
126  EXPORT_SYMBOL_GPL(intel_pmc_gcr_update);
127  
128  /**
129   * intel_pmc_s0ix_counter_read() - Read S0ix residency
130   * @pmc: PMC device pointer
131   * @data: Out param that contains current S0ix residency count.
132   *
133   * Writes to @data how many usecs the system has been in low-power S0ix
134   * state.
135   *
136   * Return: An error code or 0 on success.
137   */
intel_pmc_s0ix_counter_read(struct intel_pmc_dev * pmc,u64 * data)138  int intel_pmc_s0ix_counter_read(struct intel_pmc_dev *pmc, u64 *data)
139  {
140  	u64 deep, shlw;
141  
142  	spin_lock(&pmc->gcr_lock);
143  	deep = readq(pmc->gcr_mem_base + PMC_GCR_TELEM_DEEP_S0IX_REG);
144  	shlw = readq(pmc->gcr_mem_base + PMC_GCR_TELEM_SHLW_S0IX_REG);
145  	spin_unlock(&pmc->gcr_lock);
146  
147  	*data = S0IX_RESIDENCY_IN_USECS(deep, shlw);
148  	return 0;
149  }
150  EXPORT_SYMBOL_GPL(intel_pmc_s0ix_counter_read);
151  
152  /**
153   * simplecmd_store() - Send a simple IPC command
154   * @dev: Device under the attribute is
155   * @attr: Attribute in question
156   * @buf: Buffer holding data to be stored to the attribute
157   * @count: Number of bytes in @buf
158   *
159   * Expects a string with two integers separated with space. These two
160   * values hold command and subcommand that is send to PMC.
161   *
162   * Return: Number number of bytes written (@count) or negative errno in
163   *	   case of error.
164   */
simplecmd_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)165  static ssize_t simplecmd_store(struct device *dev, struct device_attribute *attr,
166  			       const char *buf, size_t count)
167  {
168  	struct intel_pmc_dev *pmc = dev_get_drvdata(dev);
169  	struct intel_scu_ipc_dev *scu = pmc->scu;
170  	int subcmd;
171  	int cmd;
172  	int ret;
173  
174  	ret = sscanf(buf, "%d %d", &cmd, &subcmd);
175  	if (ret != 2) {
176  		dev_err(dev, "Invalid values, expected: cmd subcmd\n");
177  		return -EINVAL;
178  	}
179  
180  	ret = intel_scu_ipc_dev_simple_command(scu, cmd, subcmd);
181  	if (ret)
182  		return ret;
183  
184  	return count;
185  }
186  static DEVICE_ATTR_WO(simplecmd);
187  
188  /**
189   * northpeak_store() - Enable or disable Northpeak
190   * @dev: Device under the attribute is
191   * @attr: Attribute in question
192   * @buf: Buffer holding data to be stored to the attribute
193   * @count: Number of bytes in @buf
194   *
195   * Expects an unsigned integer. Non-zero enables Northpeak and zero
196   * disables it.
197   *
198   * Return: Number number of bytes written (@count) or negative errno in
199   *	   case of error.
200   */
northpeak_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)201  static ssize_t northpeak_store(struct device *dev, struct device_attribute *attr,
202  			       const char *buf, size_t count)
203  {
204  	struct intel_pmc_dev *pmc = dev_get_drvdata(dev);
205  	struct intel_scu_ipc_dev *scu = pmc->scu;
206  	unsigned long val;
207  	int subcmd;
208  	int ret;
209  
210  	ret = kstrtoul(buf, 0, &val);
211  	if (ret)
212  		return ret;
213  
214  	/* Northpeak is enabled if subcmd == 1 and disabled if it is 0 */
215  	if (val)
216  		subcmd = 1;
217  	else
218  		subcmd = 0;
219  
220  	ret = intel_scu_ipc_dev_simple_command(scu, PMC_NORTHPEAK_CTRL, subcmd);
221  	if (ret)
222  		return ret;
223  
224  	return count;
225  }
226  static DEVICE_ATTR_WO(northpeak);
227  
228  static struct attribute *intel_pmc_attrs[] = {
229  	&dev_attr_northpeak.attr,
230  	&dev_attr_simplecmd.attr,
231  	NULL
232  };
233  
234  static const struct attribute_group intel_pmc_group = {
235  	.attrs = intel_pmc_attrs,
236  };
237  
238  static const struct attribute_group *intel_pmc_groups[] = {
239  	&intel_pmc_group,
240  	NULL
241  };
242  
243  static struct resource punit_res[6];
244  
245  static struct mfd_cell punit = {
246  	.name = "intel_punit_ipc",
247  	.resources = punit_res,
248  };
249  
250  static struct itco_wdt_platform_data tco_pdata = {
251  	.name = "Apollo Lake SoC",
252  	.version = 5,
253  	.no_reboot_use_pmc = true,
254  };
255  
256  static struct resource tco_res[2];
257  
258  static const struct mfd_cell tco = {
259  	.name = "iTCO_wdt",
260  	.ignore_resource_conflicts = true,
261  	.resources = tco_res,
262  	.num_resources = ARRAY_SIZE(tco_res),
263  	.platform_data = &tco_pdata,
264  	.pdata_size = sizeof(tco_pdata),
265  };
266  
267  static const struct resource telem_res[] = {
268  	DEFINE_RES_MEM(TELEM_PUNIT_SSRAM_OFFSET, TELEM_SSRAM_SIZE),
269  	DEFINE_RES_MEM(TELEM_PMC_SSRAM_OFFSET, TELEM_SSRAM_SIZE),
270  };
271  
272  static const struct mfd_cell telem = {
273  	.name = "intel_telemetry",
274  	.resources = telem_res,
275  	.num_resources = ARRAY_SIZE(telem_res),
276  };
277  
intel_pmc_get_tco_resources(struct platform_device * pdev)278  static int intel_pmc_get_tco_resources(struct platform_device *pdev)
279  {
280  	struct resource *res;
281  
282  	if (acpi_has_watchdog())
283  		return 0;
284  
285  	res = platform_get_resource(pdev, IORESOURCE_IO,
286  				    PLAT_RESOURCE_ACPI_IO_INDEX);
287  	if (!res) {
288  		dev_err(&pdev->dev, "Failed to get IO resource\n");
289  		return -EINVAL;
290  	}
291  
292  	tco_res[0].flags = IORESOURCE_IO;
293  	tco_res[0].start = res->start + TCO_BASE_OFFSET;
294  	tco_res[0].end = tco_res[0].start + TCO_REGS_SIZE - 1;
295  	tco_res[1].flags = IORESOURCE_IO;
296  	tco_res[1].start = res->start + SMI_EN_OFFSET;
297  	tco_res[1].end = tco_res[1].start + SMI_EN_SIZE - 1;
298  
299  	return 0;
300  }
301  
intel_pmc_get_resources(struct platform_device * pdev,struct intel_pmc_dev * pmc,struct intel_scu_ipc_data * scu_data)302  static int intel_pmc_get_resources(struct platform_device *pdev,
303  				   struct intel_pmc_dev *pmc,
304  				   struct intel_scu_ipc_data *scu_data)
305  {
306  	struct resource gcr_res;
307  	size_t npunit_res = 0;
308  	struct resource *res;
309  	int ret;
310  
311  	scu_data->irq = platform_get_irq_optional(pdev, 0);
312  
313  	res = platform_get_resource(pdev, IORESOURCE_MEM,
314  				    PLAT_RESOURCE_IPC_INDEX);
315  	if (!res) {
316  		dev_err(&pdev->dev, "Failed to get IPC resource\n");
317  		return -EINVAL;
318  	}
319  
320  	/* IPC registers */
321  	scu_data->mem.flags = res->flags;
322  	scu_data->mem.start = res->start;
323  	scu_data->mem.end = res->start + PLAT_RESOURCE_IPC_SIZE - 1;
324  
325  	/* GCR registers */
326  	gcr_res.flags = res->flags;
327  	gcr_res.start = res->start + PLAT_RESOURCE_GCR_OFFSET;
328  	gcr_res.end = gcr_res.start + PLAT_RESOURCE_GCR_SIZE - 1;
329  
330  	pmc->gcr_mem_base = devm_ioremap_resource(&pdev->dev, &gcr_res);
331  	if (IS_ERR(pmc->gcr_mem_base))
332  		return PTR_ERR(pmc->gcr_mem_base);
333  
334  	/* Only register iTCO watchdog if there is no WDAT ACPI table */
335  	ret = intel_pmc_get_tco_resources(pdev);
336  	if (ret)
337  		return ret;
338  
339  	/* BIOS data register */
340  	res = platform_get_resource(pdev, IORESOURCE_MEM,
341  				    PLAT_RESOURCE_BIOS_DATA_INDEX);
342  	if (!res) {
343  		dev_err(&pdev->dev, "Failed to get resource of P-unit BIOS data\n");
344  		return -EINVAL;
345  	}
346  	punit_res[npunit_res++] = *res;
347  
348  	/* BIOS interface register */
349  	res = platform_get_resource(pdev, IORESOURCE_MEM,
350  				    PLAT_RESOURCE_BIOS_IFACE_INDEX);
351  	if (!res) {
352  		dev_err(&pdev->dev, "Failed to get resource of P-unit BIOS interface\n");
353  		return -EINVAL;
354  	}
355  	punit_res[npunit_res++] = *res;
356  
357  	/* ISP data register, optional */
358  	res = platform_get_resource(pdev, IORESOURCE_MEM,
359  				    PLAT_RESOURCE_ISP_DATA_INDEX);
360  	if (res)
361  		punit_res[npunit_res++] = *res;
362  
363  	/* ISP interface register, optional */
364  	res = platform_get_resource(pdev, IORESOURCE_MEM,
365  				    PLAT_RESOURCE_ISP_IFACE_INDEX);
366  	if (res)
367  		punit_res[npunit_res++] = *res;
368  
369  	/* GTD data register, optional */
370  	res = platform_get_resource(pdev, IORESOURCE_MEM,
371  				    PLAT_RESOURCE_GTD_DATA_INDEX);
372  	if (res)
373  		punit_res[npunit_res++] = *res;
374  
375  	/* GTD interface register, optional */
376  	res = platform_get_resource(pdev, IORESOURCE_MEM,
377  				    PLAT_RESOURCE_GTD_IFACE_INDEX);
378  	if (res)
379  		punit_res[npunit_res++] = *res;
380  
381  	punit.num_resources = npunit_res;
382  
383  	/* Telemetry SSRAM is optional */
384  	res = platform_get_resource(pdev, IORESOURCE_MEM,
385  				    PLAT_RESOURCE_TELEM_SSRAM_INDEX);
386  	if (res)
387  		pmc->telem_base = res;
388  
389  	return 0;
390  }
391  
intel_pmc_create_devices(struct intel_pmc_dev * pmc)392  static int intel_pmc_create_devices(struct intel_pmc_dev *pmc)
393  {
394  	int ret;
395  
396  	if (!acpi_has_watchdog()) {
397  		ret = devm_mfd_add_devices(pmc->dev, PLATFORM_DEVID_AUTO, &tco,
398  					   1, NULL, 0, NULL);
399  		if (ret)
400  			return ret;
401  	}
402  
403  	ret = devm_mfd_add_devices(pmc->dev, PLATFORM_DEVID_AUTO, &punit, 1,
404  				   NULL, 0, NULL);
405  	if (ret)
406  		return ret;
407  
408  	if (pmc->telem_base) {
409  		ret = devm_mfd_add_devices(pmc->dev, PLATFORM_DEVID_AUTO,
410  					   &telem, 1, pmc->telem_base, 0, NULL);
411  	}
412  
413  	return ret;
414  }
415  
416  static const struct acpi_device_id intel_pmc_acpi_ids[] = {
417  	{ "INT34D2" },
418  	{ }
419  };
420  MODULE_DEVICE_TABLE(acpi, intel_pmc_acpi_ids);
421  
intel_pmc_probe(struct platform_device * pdev)422  static int intel_pmc_probe(struct platform_device *pdev)
423  {
424  	struct intel_scu_ipc_data scu_data = {};
425  	struct intel_pmc_dev *pmc;
426  	int ret;
427  
428  	pmc = devm_kzalloc(&pdev->dev, sizeof(*pmc), GFP_KERNEL);
429  	if (!pmc)
430  		return -ENOMEM;
431  
432  	pmc->dev = &pdev->dev;
433  	spin_lock_init(&pmc->gcr_lock);
434  
435  	ret = intel_pmc_get_resources(pdev, pmc, &scu_data);
436  	if (ret) {
437  		dev_err(&pdev->dev, "Failed to request resources\n");
438  		return ret;
439  	}
440  
441  	pmc->scu = devm_intel_scu_ipc_register(&pdev->dev, &scu_data);
442  	if (IS_ERR(pmc->scu))
443  		return PTR_ERR(pmc->scu);
444  
445  	platform_set_drvdata(pdev, pmc);
446  
447  	ret = intel_pmc_create_devices(pmc);
448  	if (ret)
449  		dev_err(&pdev->dev, "Failed to create PMC devices\n");
450  
451  	return ret;
452  }
453  
454  static struct platform_driver intel_pmc_driver = {
455  	.probe = intel_pmc_probe,
456  	.driver = {
457  		.name = "intel_pmc_bxt",
458  		.acpi_match_table = intel_pmc_acpi_ids,
459  		.dev_groups = intel_pmc_groups,
460  	},
461  };
462  module_platform_driver(intel_pmc_driver);
463  
464  MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
465  MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
466  MODULE_DESCRIPTION("Intel Broxton PMC driver");
467  MODULE_LICENSE("GPL v2");
468