Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
49struct punit_device {
50 char *name;
51 int reg;
52 int sss_pos;
53};
54
55static 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
65static 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
75static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
76
77static 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
102static 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
107static 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
114static struct dentry *punit_dbg_file;
115
116static 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
136static 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
145static 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
151MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
152
153static 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
169static void __exit punit_atom_debug_exit(void)
170{
171 punit_dbgfs_unregister();
172}
173
174module_init(punit_atom_debug_init);
175module_exit(punit_atom_debug_exit);
176
177MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
178MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
179MODULE_DESCRIPTION("Driver for Punit devices states debugging");
180MODULE_LICENSE("GPL v2");