xref: /linux/arch/x86/platform/atom/punit_atom_debug.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * Intel SOC Punit device state debug driver
3  * Punit controls power management for North Complex devices (Graphics
4  * blocks, Image Signal Processing, video processing, display, DSP etc.)
5  *
6  * Copyright (c) 2015, Intel Corporation.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/device.h>
22 #include <linux/debugfs.h>
23 #include <linux/seq_file.h>
24 #include <linux/io.h>
25 #include <asm/cpu_device_id.h>
26 #include <asm/iosf_mbi.h>
27 
28 /* Side band Interface port */
29 #define PUNIT_PORT		0x04
30 /* Power gate status reg */
31 #define PWRGT_STATUS		0x61
32 /* Subsystem config/status Video processor */
33 #define VED_SS_PM0		0x32
34 /* Subsystem config/status ISP (Image Signal Processor) */
35 #define ISP_SS_PM0		0x39
36 /* Subsystem config/status Input/output controller */
37 #define MIO_SS_PM		0x3B
38 /* Shift bits for getting status for video, isp and i/o */
39 #define SSS_SHIFT		24
40 /* Shift bits for getting status for graphics rendering */
41 #define RENDER_POS		0
42 /* Shift bits for getting status for media control */
43 #define MEDIA_POS		2
44 /* Shift bits for getting status for Valley View/Baytrail display */
45 #define VLV_DISPLAY_POS		6
46 /* Subsystem config/status display for Cherry Trail SOC */
47 #define CHT_DSP_SSS		0x36
48 /* Shift bits for getting status for display */
49 #define CHT_DSP_SSS_POS		16
50 
51 struct punit_device {
52 	char *name;
53 	int reg;
54 	int sss_pos;
55 };
56 
57 static const struct punit_device punit_device_byt[] = {
58 	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
59 	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
60 	{ "DISPLAY",	PWRGT_STATUS,	VLV_DISPLAY_POS },
61 	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
62 	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
63 	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
64 	{ NULL }
65 };
66 
67 static const struct punit_device punit_device_cht[] = {
68 	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
69 	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
70 	{ "DISPLAY",	CHT_DSP_SSS,	CHT_DSP_SSS_POS },
71 	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
72 	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
73 	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
74 	{ NULL }
75 };
76 
77 static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
78 
79 static int punit_dev_state_show(struct seq_file *seq_file, void *unused)
80 {
81 	u32 punit_pwr_status;
82 	struct punit_device *punit_devp = seq_file->private;
83 	int index;
84 	int status;
85 
86 	seq_puts(seq_file, "\n\nPUNIT NORTH COMPLEX DEVICES :\n");
87 	while (punit_devp->name) {
88 		status = iosf_mbi_read(PUNIT_PORT, BT_MBI_PMC_READ,
89 				       punit_devp->reg,
90 				       &punit_pwr_status);
91 		if (status) {
92 			seq_printf(seq_file, "%9s : Read Failed\n",
93 				   punit_devp->name);
94 		} else  {
95 			index = (punit_pwr_status >> punit_devp->sss_pos) & 3;
96 			seq_printf(seq_file, "%9s : %s\n", punit_devp->name,
97 				   dstates[index]);
98 		}
99 		punit_devp++;
100 	}
101 
102 	return 0;
103 }
104 
105 static int punit_dev_state_open(struct inode *inode, struct file *file)
106 {
107 	return single_open(file, punit_dev_state_show, inode->i_private);
108 }
109 
110 static const struct file_operations punit_dev_state_ops = {
111 	.open		= punit_dev_state_open,
112 	.read		= seq_read,
113 	.llseek		= seq_lseek,
114 	.release	= single_release,
115 };
116 
117 static struct dentry *punit_dbg_file;
118 
119 static int punit_dbgfs_register(struct punit_device *punit_device)
120 {
121 	static struct dentry *dev_state;
122 
123 	punit_dbg_file = debugfs_create_dir("punit_atom", NULL);
124 	if (!punit_dbg_file)
125 		return -ENXIO;
126 
127 	dev_state = debugfs_create_file("dev_power_state", S_IFREG | S_IRUGO,
128 					punit_dbg_file, punit_device,
129 					&punit_dev_state_ops);
130 	if (!dev_state) {
131 		pr_err("punit_dev_state register failed\n");
132 		debugfs_remove(punit_dbg_file);
133 		return -ENXIO;
134 	}
135 
136 	return 0;
137 }
138 
139 static void punit_dbgfs_unregister(void)
140 {
141 	debugfs_remove_recursive(punit_dbg_file);
142 }
143 
144 #define ICPU(model, drv_data) \
145 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT,\
146 	  (kernel_ulong_t)&drv_data }
147 
148 static const struct x86_cpu_id intel_punit_cpu_ids[] = {
149 	ICPU(55, punit_device_byt), /* Valleyview, Bay Trail */
150 	ICPU(76, punit_device_cht), /* Braswell, Cherry Trail */
151 	{}
152 };
153 
154 MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
155 
156 static int __init punit_atom_debug_init(void)
157 {
158 	const struct x86_cpu_id *id;
159 	int ret;
160 
161 	id = x86_match_cpu(intel_punit_cpu_ids);
162 	if (!id)
163 		return -ENODEV;
164 
165 	ret = punit_dbgfs_register((struct punit_device *)id->driver_data);
166 	if (ret < 0)
167 		return ret;
168 
169 	return 0;
170 }
171 
172 static void __exit punit_atom_debug_exit(void)
173 {
174 	punit_dbgfs_unregister();
175 }
176 
177 module_init(punit_atom_debug_init);
178 module_exit(punit_atom_debug_exit);
179 
180 MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
181 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
182 MODULE_DESCRIPTION("Driver for Punit devices states debugging");
183 MODULE_LICENSE("GPL v2");
184