xref: /linux/arch/x86/platform/atom/punit_atom_debug.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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 /* Power gate status reg */
29 #define PWRGT_STATUS		0x61
30 /* Subsystem config/status Video processor */
31 #define VED_SS_PM0		0x32
32 /* Subsystem config/status ISP (Image Signal Processor) */
33 #define ISP_SS_PM0		0x39
34 /* Subsystem config/status Input/output controller */
35 #define MIO_SS_PM		0x3B
36 /* Shift bits for getting status for video, isp and i/o */
37 #define SSS_SHIFT		24
38 /* Shift bits for getting status for graphics rendering */
39 #define RENDER_POS		0
40 /* Shift bits for getting status for media control */
41 #define MEDIA_POS		2
42 /* Shift bits for getting status for Valley View/Baytrail display */
43 #define VLV_DISPLAY_POS		6
44 /* Subsystem config/status display for Cherry Trail SOC */
45 #define CHT_DSP_SSS		0x36
46 /* Shift bits for getting status for display */
47 #define CHT_DSP_SSS_POS		16
48 
49 struct punit_device {
50 	char *name;
51 	int reg;
52 	int sss_pos;
53 };
54 
55 static const struct punit_device punit_device_byt[] = {
56 	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
57 	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
58 	{ "DISPLAY",	PWRGT_STATUS,	VLV_DISPLAY_POS },
59 	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
60 	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
61 	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
62 	{ NULL }
63 };
64 
65 static const struct punit_device punit_device_cht[] = {
66 	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
67 	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
68 	{ "DISPLAY",	CHT_DSP_SSS,	CHT_DSP_SSS_POS },
69 	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
70 	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
71 	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
72 	{ NULL }
73 };
74 
75 static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
76 
77 static int punit_dev_state_show(struct seq_file *seq_file, void *unused)
78 {
79 	u32 punit_pwr_status;
80 	struct punit_device *punit_devp = seq_file->private;
81 	int index;
82 	int status;
83 
84 	seq_puts(seq_file, "\n\nPUNIT NORTH COMPLEX DEVICES :\n");
85 	while (punit_devp->name) {
86 		status = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
87 				       punit_devp->reg, &punit_pwr_status);
88 		if (status) {
89 			seq_printf(seq_file, "%9s : Read Failed\n",
90 				   punit_devp->name);
91 		} else  {
92 			index = (punit_pwr_status >> punit_devp->sss_pos) & 3;
93 			seq_printf(seq_file, "%9s : %s\n", punit_devp->name,
94 				   dstates[index]);
95 		}
96 		punit_devp++;
97 	}
98 
99 	return 0;
100 }
101 
102 static int punit_dev_state_open(struct inode *inode, struct file *file)
103 {
104 	return single_open(file, punit_dev_state_show, inode->i_private);
105 }
106 
107 static const struct file_operations punit_dev_state_ops = {
108 	.open		= punit_dev_state_open,
109 	.read		= seq_read,
110 	.llseek		= seq_lseek,
111 	.release	= single_release,
112 };
113 
114 static struct dentry *punit_dbg_file;
115 
116 static int punit_dbgfs_register(struct punit_device *punit_device)
117 {
118 	static struct dentry *dev_state;
119 
120 	punit_dbg_file = debugfs_create_dir("punit_atom", NULL);
121 	if (!punit_dbg_file)
122 		return -ENXIO;
123 
124 	dev_state = debugfs_create_file("dev_power_state", S_IFREG | S_IRUGO,
125 					punit_dbg_file, punit_device,
126 					&punit_dev_state_ops);
127 	if (!dev_state) {
128 		pr_err("punit_dev_state register failed\n");
129 		debugfs_remove(punit_dbg_file);
130 		return -ENXIO;
131 	}
132 
133 	return 0;
134 }
135 
136 static void punit_dbgfs_unregister(void)
137 {
138 	debugfs_remove_recursive(punit_dbg_file);
139 }
140 
141 #define ICPU(model, drv_data) \
142 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT,\
143 	  (kernel_ulong_t)&drv_data }
144 
145 static const struct x86_cpu_id intel_punit_cpu_ids[] = {
146 	ICPU(55, punit_device_byt), /* Valleyview, Bay Trail */
147 	ICPU(76, punit_device_cht), /* Braswell, Cherry Trail */
148 	{}
149 };
150 
151 MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
152 
153 static int __init punit_atom_debug_init(void)
154 {
155 	const struct x86_cpu_id *id;
156 	int ret;
157 
158 	id = x86_match_cpu(intel_punit_cpu_ids);
159 	if (!id)
160 		return -ENODEV;
161 
162 	ret = punit_dbgfs_register((struct punit_device *)id->driver_data);
163 	if (ret < 0)
164 		return ret;
165 
166 	return 0;
167 }
168 
169 static void __exit punit_atom_debug_exit(void)
170 {
171 	punit_dbgfs_unregister();
172 }
173 
174 module_init(punit_atom_debug_init);
175 module_exit(punit_atom_debug_exit);
176 
177 MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
178 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
179 MODULE_DESCRIPTION("Driver for Punit devices states debugging");
180 MODULE_LICENSE("GPL v2");
181