1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel SOC Punit device state debug driver
4 * Punit controls power management for North Complex devices (Graphics
5 * blocks, Image Signal Processing, video processing, display, DSP etc.)
6 *
7 * Copyright (c) 2015, Intel Corporation.
8 */
9
10#define pr_fmt(fmt) "punit_atom: " fmt
11
12#include <linux/acpi.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/device.h>
16#include <linux/debugfs.h>
17#include <linux/seq_file.h>
18#include <linux/io.h>
19#include <asm/cpu_device_id.h>
20#include <asm/intel-family.h>
21#include <asm/iosf_mbi.h>
22
23/* Subsystem config/status Video processor */
24#define VED_SS_PM0		0x32
25/* Subsystem config/status ISP (Image Signal Processor) */
26#define ISP_SS_PM0		0x39
27/* Subsystem config/status Input/output controller */
28#define MIO_SS_PM		0x3B
29/* Shift bits for getting status for video, isp and i/o */
30#define SSS_SHIFT		24
31
32/* Power gate status reg */
33#define PWRGT_STATUS		0x61
34/* Shift bits for getting status for graphics rendering */
35#define RENDER_POS		0
36/* Shift bits for getting status for media control */
37#define MEDIA_POS		2
38/* Shift bits for getting status for Valley View/Baytrail display */
39#define VLV_DISPLAY_POS		6
40
41/* Subsystem config/status display for Cherry Trail SOC */
42#define CHT_DSP_SSS		0x36
43/* Shift bits for getting status for display */
44#define CHT_DSP_SSS_POS		16
45
46struct punit_device {
47	char *name;
48	int reg;
49	int sss_pos;
50};
51
52static const struct punit_device punit_device_tng[] = {
53	{ "DISPLAY",	CHT_DSP_SSS,	SSS_SHIFT },
54	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
55	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
56	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
57	{ NULL }
58};
59
60static const struct punit_device punit_device_byt[] = {
61	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
62	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
63	{ "DISPLAY",	PWRGT_STATUS,	VLV_DISPLAY_POS },
64	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
65	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
66	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
67	{ NULL }
68};
69
70static const struct punit_device punit_device_cht[] = {
71	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
72	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
73	{ "DISPLAY",	CHT_DSP_SSS,	CHT_DSP_SSS_POS },
74	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
75	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
76	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
77	{ NULL }
78};
79
80static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
81
82static int punit_dev_state_show(struct seq_file *seq_file, void *unused)
83{
84	u32 punit_pwr_status;
85	struct punit_device *punit_devp = seq_file->private;
86	int index;
87	int status;
88
89	seq_puts(seq_file, "\n\nPUNIT NORTH COMPLEX DEVICES :\n");
90	while (punit_devp->name) {
91		status = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
92				       punit_devp->reg, &punit_pwr_status);
93		if (status) {
94			seq_printf(seq_file, "%9s : Read Failed\n",
95				   punit_devp->name);
96		} else  {
97			index = (punit_pwr_status >> punit_devp->sss_pos) & 3;
98			seq_printf(seq_file, "%9s : %s\n", punit_devp->name,
99				   dstates[index]);
100		}
101		punit_devp++;
102	}
103
104	return 0;
105}
106DEFINE_SHOW_ATTRIBUTE(punit_dev_state);
107
108static struct dentry *punit_dbg_file;
109
110static void punit_dbgfs_register(struct punit_device *punit_device)
111{
112	punit_dbg_file = debugfs_create_dir("punit_atom", NULL);
113
114	debugfs_create_file("dev_power_state", 0444, punit_dbg_file,
115			    punit_device, &punit_dev_state_fops);
116}
117
118static void punit_dbgfs_unregister(void)
119{
120	debugfs_remove_recursive(punit_dbg_file);
121}
122
123#if defined(CONFIG_ACPI) && defined(CONFIG_SUSPEND)
124static const struct punit_device *punit_dev;
125
126static void punit_s2idle_check(void)
127{
128	const struct punit_device *punit_devp;
129	u32 punit_pwr_status, dstate;
130	int status;
131
132	for (punit_devp = punit_dev; punit_devp->name; punit_devp++) {
133		/* Skip MIO, it is on till the very last moment */
134		if (punit_devp->reg == MIO_SS_PM)
135			continue;
136
137		status = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
138				       punit_devp->reg, &punit_pwr_status);
139		if (status) {
140			pr_err("%s read failed\n", punit_devp->name);
141		} else  {
142			dstate = (punit_pwr_status >> punit_devp->sss_pos) & 3;
143			if (!dstate)
144				pr_err("%s is in D0 prior to s2idle\n", punit_devp->name);
145		}
146	}
147}
148
149static struct acpi_s2idle_dev_ops punit_s2idle_ops = {
150	.check = punit_s2idle_check,
151};
152
153static void punit_s2idle_check_register(struct punit_device *punit_device)
154{
155	punit_dev = punit_device;
156	acpi_register_lps0_dev(&punit_s2idle_ops);
157}
158
159static void punit_s2idle_check_unregister(void)
160{
161	acpi_unregister_lps0_dev(&punit_s2idle_ops);
162}
163#else
164static void punit_s2idle_check_register(struct punit_device *punit_device) {}
165static void punit_s2idle_check_unregister(void) {}
166#endif
167
168#define X86_MATCH(model, data)						 \
169	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, INTEL_FAM6_##model, \
170					   X86_FEATURE_MWAIT, data)
171
172static const struct x86_cpu_id intel_punit_cpu_ids[] = {
173	X86_MATCH(ATOM_SILVERMONT,		&punit_device_byt),
174	X86_MATCH(ATOM_SILVERMONT_MID,		&punit_device_tng),
175	X86_MATCH(ATOM_AIRMONT,			&punit_device_cht),
176	{}
177};
178MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
179
180static int __init punit_atom_debug_init(void)
181{
182	struct punit_device *punit_device;
183	const struct x86_cpu_id *id;
184
185	id = x86_match_cpu(intel_punit_cpu_ids);
186	if (!id)
187		return -ENODEV;
188
189	punit_device = (struct punit_device *)id->driver_data;
190	punit_dbgfs_register(punit_device);
191	punit_s2idle_check_register(punit_device);
192
193	return 0;
194}
195
196static void __exit punit_atom_debug_exit(void)
197{
198	punit_s2idle_check_unregister();
199	punit_dbgfs_unregister();
200}
201
202module_init(punit_atom_debug_init);
203module_exit(punit_atom_debug_exit);
204
205MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
206MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
207MODULE_DESCRIPTION("Driver for Punit devices states debugging");
208MODULE_LICENSE("GPL v2");
209