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/intel-family.h>
 27#include <asm/iosf_mbi.h>
 28
 29/* Subsystem config/status Video processor */
 30#define VED_SS_PM0		0x32
 31/* Subsystem config/status ISP (Image Signal Processor) */
 32#define ISP_SS_PM0		0x39
 33/* Subsystem config/status Input/output controller */
 34#define MIO_SS_PM		0x3B
 35/* Shift bits for getting status for video, isp and i/o */
 36#define SSS_SHIFT		24
 37
 38/* Power gate status reg */
 39#define PWRGT_STATUS		0x61
 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
 47/* Subsystem config/status display for Cherry Trail SOC */
 48#define CHT_DSP_SSS		0x36
 49/* Shift bits for getting status for display */
 50#define CHT_DSP_SSS_POS		16
 51
 52struct punit_device {
 53	char *name;
 54	int reg;
 55	int sss_pos;
 56};
 57
 58static const struct punit_device punit_device_tng[] = {
 59	{ "DISPLAY",	CHT_DSP_SSS,	SSS_SHIFT },
 60	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
 61	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
 62	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
 63	{ NULL }
 64};
 65
 66static const struct punit_device punit_device_byt[] = {
 67	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
 68	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
 69	{ "DISPLAY",	PWRGT_STATUS,	VLV_DISPLAY_POS },
 70	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
 71	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
 72	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
 73	{ NULL }
 74};
 75
 76static const struct punit_device punit_device_cht[] = {
 77	{ "GFX RENDER",	PWRGT_STATUS,	RENDER_POS },
 78	{ "GFX MEDIA",	PWRGT_STATUS,	MEDIA_POS },
 79	{ "DISPLAY",	CHT_DSP_SSS,	CHT_DSP_SSS_POS },
 80	{ "VED",	VED_SS_PM0,	SSS_SHIFT },
 81	{ "ISP",	ISP_SS_PM0,	SSS_SHIFT },
 82	{ "MIO",	MIO_SS_PM,	SSS_SHIFT },
 83	{ NULL }
 84};
 85
 86static const char * const dstates[] = {"D0", "D0i1", "D0i2", "D0i3"};
 87
 88static int punit_dev_state_show(struct seq_file *seq_file, void *unused)
 89{
 90	u32 punit_pwr_status;
 91	struct punit_device *punit_devp = seq_file->private;
 92	int index;
 93	int status;
 94
 95	seq_puts(seq_file, "\n\nPUNIT NORTH COMPLEX DEVICES :\n");
 96	while (punit_devp->name) {
 97		status = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
 98				       punit_devp->reg, &punit_pwr_status);
 99		if (status) {
100			seq_printf(seq_file, "%9s : Read Failed\n",
101				   punit_devp->name);
102		} else  {
103			index = (punit_pwr_status >> punit_devp->sss_pos) & 3;
104			seq_printf(seq_file, "%9s : %s\n", punit_devp->name,
105				   dstates[index]);
106		}
107		punit_devp++;
108	}
109
110	return 0;
111}
112
113static int punit_dev_state_open(struct inode *inode, struct file *file)
114{
115	return single_open(file, punit_dev_state_show, inode->i_private);
116}
117
118static const struct file_operations punit_dev_state_ops = {
119	.open		= punit_dev_state_open,
120	.read		= seq_read,
121	.llseek		= seq_lseek,
122	.release	= single_release,
123};
124
125static struct dentry *punit_dbg_file;
126
127static int punit_dbgfs_register(struct punit_device *punit_device)
128{
129	static struct dentry *dev_state;
130
131	punit_dbg_file = debugfs_create_dir("punit_atom", NULL);
132	if (!punit_dbg_file)
133		return -ENXIO;
134
135	dev_state = debugfs_create_file("dev_power_state", S_IFREG | S_IRUGO,
136					punit_dbg_file, punit_device,
137					&punit_dev_state_ops);
138	if (!dev_state) {
139		pr_err("punit_dev_state register failed\n");
140		debugfs_remove(punit_dbg_file);
141		return -ENXIO;
142	}
143
144	return 0;
145}
146
147static void punit_dbgfs_unregister(void)
148{
149	debugfs_remove_recursive(punit_dbg_file);
150}
151
152#define ICPU(model, drv_data) \
153	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT,\
154	  (kernel_ulong_t)&drv_data }
155
156static const struct x86_cpu_id intel_punit_cpu_ids[] = {
157	ICPU(INTEL_FAM6_ATOM_SILVERMONT1, punit_device_byt),
158	ICPU(INTEL_FAM6_ATOM_MERRIFIELD,  punit_device_tng),
159	ICPU(INTEL_FAM6_ATOM_AIRMONT,	  punit_device_cht),
160	{}
161};
162
163MODULE_DEVICE_TABLE(x86cpu, intel_punit_cpu_ids);
164
165static int __init punit_atom_debug_init(void)
166{
167	const struct x86_cpu_id *id;
168	int ret;
169
170	id = x86_match_cpu(intel_punit_cpu_ids);
171	if (!id)
172		return -ENODEV;
173
174	ret = punit_dbgfs_register((struct punit_device *)id->driver_data);
175	if (ret < 0)
176		return ret;
177
178	return 0;
179}
180
181static void __exit punit_atom_debug_exit(void)
182{
183	punit_dbgfs_unregister();
184}
185
186module_init(punit_atom_debug_init);
187module_exit(punit_atom_debug_exit);
188
189MODULE_AUTHOR("Kumar P, Mahesh <mahesh.kumar.p@intel.com>");
190MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
191MODULE_DESCRIPTION("Driver for Punit devices states debugging");
192MODULE_LICENSE("GPL v2");